Innovation use of computer tools in teaching structural engineering applications

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Institution of Engineers Australia, 2010 Australasian Journal of Engineering Education, Vol 16 No 1

* Paper D09-077 submitted 23/09/09; accepted forpublication after review and revision 13/04/10.

Corresponding author Dr Khaled El-Sawy can becontacted at [email protected].

1 INTRODUCTION

Matrix Structural Analysis and Finite ElementMethod: Theory and Applications are technicalelective courses offered by the Department of Civiland Environmental Engineering in United ArabEmirates University (UAEU) at the undergraduate andgraduate levels, respectively. The Matrix StructuralAnalysis course covers the analysis of different two-dimensional (2D) structures using the stiffness matrixmethod; namely 2D spring systems, trusses, beamsand frames. It also covers some special topics in thestructural analysis, including inclined supports, fastreduced analysis of rectangular frames, the solution

of stiffness equations using banded matrices and themodelling of temperature loads on structures. As aresult of the nature of the covered subjects, studentsare requested to pass two main courses before beingeligible for registering in the Matrix StructuralAnalysis course. These prerequisites are StructuralAnalysis I and Introduction to Programming. Theformer prerequisite covers traditional techniquesfor solving simple statically determinate structuresusing manual calculations. It also includes influencelines of moving loads, deflection analysis using

geometric and energy approach, and introductionto indeterminate structures using slope deflection

and moment distribution methods. Meanwhile, thelatter aims at providing the concepts of programmingwith Visual Basic language using VB 6.0 compiler.The Matrix Structural Analysis course subjects arecovered in about 15-16 weeks with two sessions perweek. Each session is about 110 minutes composedof 20- to 30-minute mini-lectures followed by studentproblem-solving activities on the learned concepts.

At the graduate level, the Finite Element Method:Theory and Applications course is considered as acontinuation of the basic concepts of stiffness methodoffered in the Matrix Structural Analysis course. Inother words, no specific prerequisites exist for thatcourse given that all basic concepts of structuralanalysis and programming have been offered at theundergraduate level. The course covers the principlesof theory of elasticity along with the compatibilityequations and constitutive relations. It also introducesthe virtual work approach and its application toconduct finite element formulation of various basicand advanced elements such as: bar, beam, frameand isoparametric solid elements, in addition to plateand shell elements. Most of the graduate students ofthe Civil & Environmental Engineering Department

are full-time practitioner engineers and therefore thegraduate course topics are covered in weekly single-sessions for about 15-16 weeks. The typical sessionis about 180 minutes composed of 50- to 60-minute

Innovative use of computer tools in

teaching structural engineering applications*

KM El-Sawy and AMI SweedanCivil and Environmental Engineering Department, Faculty of Engineering, United Arab Emirates

University, Abu Dhabi, United Arab Emirates

SUMMARY: This paper reports on using Microsoft Excel coupled with Visual Basic forApplication (VBA) in teaching two courses for the students in the Civil & EnvironmentalEngineering Department in United Arab Emirates University. The first course covers the use ofthe stiffness matrix method for the analysis of 2D trusses, beams and frames. The latter has a moreadvanced content by focusing on 2D solid elements, plates and shells. Throughout the offering ofboth courses, the authors, with the aid of hands-on sessions and multimedia, guide their studentsto develop different user-defined VBA functions in Excel, which are used to derive the solution ofdifferent structural and stress analysis problems. The paper also proposes a new method in Excelthat may be used to eliminate possible cheating (e-cheating) when students exchange files usingemail, Bluetooth or any other means. The proposed method has been utilised by the authors tominimise potential e-cheating and copying among students.


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36 Innovative use of computer tools in teaching structural engineering applications El-Sawy & Sweedan

Australasian Journal of Engineering Education Vol 16 No 1

mini-lectures, followed by student problem-solvingactivities and applications on the covered material.

The teaching and learning environment andinfrastructure in the Faculty of Engineering at UAEUplayed a significant role in the teaching approachimplemented in this study. Since every studentin the Faculty of Engineering is required to buy a

laptop (an admission requirement), there is no needto reserve PC labs for such courses. A classroomequipped with wireless network, an LCD projector,a projection screen and tables is typical. Blackboard(Electronic Course Management System) is usedby the instructors to publish the course material, toreceive students solutions for the assignments andexams, and to communicate with the students.

It should be noted that the main learning aims ofthe two courses are to help the students to learn anduse the matrix structural analysis and/or the finiteelement approaches to perform the structural andstress analysis of structures. To employ Excel andVisual Basic for Application (VBA) tools to analyserealistic large-scale problems in contrast to abstractones used mainly for teaching. Nonetheless, anytools that may be used by the instructor or by thestudents to aid the students learning process are tobe used without losing the focus on the main targetoutcome and mistakenly concentrating on the aidingtools themselves.

Generally, and as implied by the two courses titles,matrix operations (multiplications, transpose andinversion) are the basic operations that are usedextensively throughout the courses to perform theinvolved matrix structural analyses, which are,by nature, numerically demanding. In this typeof courses, two approaches may be followed. Thefirst limits the complexity of the course practiceproblems and requests the students to solve selectedabstract problems manually using handheldcalculators. With this approach it may be difficultfor the students to develop the link between theabstract problems they practised and the analysis ofstructures in the real world. The second approachrequires the implementation of any available user-

friendly tools to facilitate the matrix operations.That, accordingly, enables the students to solvemore complex and realistic practical problemswithout losing the focus on the target outcome inthe understanding of the structural analysis andfinite element procedures. This paper considers thesecond approach since it provides the students withthe required computational skills and engineeringexperience in solving real-life structural and stressanalysis problems.

Several commercial software products (eg. SAP2000,STAAD Pro, Robot Millennium, ANSYS, ADENA,

etc.) are available to analyse stresses in structuresand solids using the stiffness matrix method but,unfortunately, they provide the final answer andcannot replace the need of students to visualise

the different analysis steps that will build theircomprehension and understanding of the subject.Therefore, they are not suitable for teaching basicconcepts to the students. This software may still helptrain the students to enter the job market. Differentcommercial software products (SAP2000, RobotMillennium, ANSYS and ADENA) are currently

licensed for the UAEU, and are used interchangeablyto train the students on using commercial structuraland stress analysis software. Other free andcommercial tools that may help to show theintermediate calculations have been reported inliterature and have been used by many instructors.Examples of such instructional tools are CAL-91(Wilson, 1991), Excel (Chandrupatla & Belegundu,2002; Malasri & Syed-Mohammad-Ridzuan, 1987),MathCAD (Nirmal, 2002; Parametric TechnologyCorporation, 2010), MATLAB (Chandrupatla &Belegundu, 2002; Arfiadi & Hadi, 2002; Shahnam& Nirmal, 2002; The MathWorks, 2010), MAPLE(Waterloo Maple Inc., 2010) and MATHEMATICA(Wolfram Research, Inc., 2010), in addition to C,FORTRAN, QBASIC and others (Chandrupatla &Belegundu, 2002; Martini, 2001; 2006).

The current study proposes an innovative methodto aid the teaching/learning of the matrix structuralanalysis and finite element method courses usingExcel and VBA. The paper also reports on anew procedure that may be used to eliminatepossible cheating (e-cheating) cases where studentsexchange/copy solution files for assignments or

exams by direct copying, e-mail, Bluetooth or anyother means. Finally, the paper presents the results ofa survey that was conducted to explore the studentsfeedback on the proposed teaching/learning method.

One sample of the VBA functions used in the analysisof trusses is listed in the Appendix. Illustrativeexamples of the Excel template files with their VBAfunctions are provided in this work to demonstratetheir use in the analysis of 2D truss problems. Theseexamples of the Excel template files are available athttp://beam.to/amr_sawy_edupaper (El-Sawy &Sweedan, n. d.).

In addition to face-to-face hands-on teachingsessions, digital multimedia is provided to helpstudents understand the development process ofthe VBA functions used throughout the two courses.Illustrative multimedia is available at http://beam.to/amr_sawy_edupaper (El-Sawy & Sweedan, n. d.).

2 LITERATURE SURVEY

A literature review is conducted to provide someinformation about tools used (or may be used) to

improve the teaching and learning of a typical matrixstructural analysis and finite element method courses.

Prior to the evolution in computer technology andthe advancement in the computational capabilities


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37Innovative use of computer tools in teaching structural engineering applications El-Sawy & Sweedan


of newer generations of personal computers alongwith noticeable reduction in their prices, traditionalteaching techniques of these type of courses used tobe the only feasible teaching method for a fairly longtime. Traditional techniques depend mainly on usingcalculators to calculate the structural stiffness matricesand imposed load vectors. Furthermore, and once the

governing equilibrium equations are assembled in amatrix form, calculators are needed again to conductthe matrix manipulation operations that yield theunknown nodal degrees of freedom and/or supportreactions. It is worth mentioning that the involvedmatrix operations constitute the basic operationsthat are employed extensively to achieve the majorobjective of performing structural analysis. Given thefact that these operations are numerically demanding,this imposes stringent limitations on the size andcomplexity of problems that can be handled in thecourse. As a result of the aforementioned calculationscomplexity and execution time constraints, especiallyduring exams, students will be able to handle simpleproblems that tackle basic concepts only. Suchlimitations motivated instructors to incorporatemore computer tools and capabilities in teaching thisspecial type of courses to enable students to handlemore complicated and realistic practice problems.A recent textbook by Chandrupatla & Belegundu(2002) provided different computer tools, in differentprogramming languages, to facilitate the calculationsinvolved in the structural analysis.

2.1 Special purpose structuralanalysis software CAL

CAL-91 (Wilson, 1991) is a relatively old educationalcomputer program that is written in FORTRANby Ed Wilson (Wilson, 2010) at the University ofCalifornia, Berkeley, in 1978 specifically to teachmatrix structural analysis. The program and otherversions, built on its original structure, are usedby several teaching institutions. CAL is used tointroduce the students to the stiffness matrix methodand solve several analysis problems in the subject.CAL is free, has a small size and can be acquired by

all students. It needs an instruction file written usingspecial pseudo-code. The pseudo-code is composedof a number of keywords or commands used todescribe the geometrical and physical properties ofthe structure, to process the solution and to post-process the results.

Later, several general-purpose mathematicalsoftware programs started to appear providingpossibilities for more suitable tools. Some of thesemathematical software packages may be better thanothers depending on the way they handle variables,matrices and their operations. Examples of such

software are MathCAD, MATLAB, MAPLE andMATHEMATICA. The students usually have accessto the software through computer laboratories intheir educational institutions (which is the case in

most of the educational institutions). On the otherhand, students may hardly get access to the softwareat home or after graduation.

2.2 General-purpose spreadsheets

Historically, VisiCalc (Bricklin, 2010) was the first

spreadsheet program ever available for PCs. Soon,more powerful clones of VisiCalc were released,including SuperCalc, Microsofts MultiPlan, Lotus1-2-3 and the spreadsheet module in AppleWorks.With Microsoft Excel for Windows 2.0 in 1987, a newgeneration of spreadsheets was born. Since 1993,Excel included VBA, a programming language basedon Visual Basic, which adds the ability to automatetasks in Excel and to provide user-defined functions(UDFs) for use in worksheets. These capabilities,in addition to others, make Excel an attractive andaffordable tool to solve a number of engineering

problems, including ones in civil engineeringapplications and in particular structural analysisproblems (Chandrupatla & Belegundu, 2002; Casas& Oppenheim, 1987; Cooke & Balakrishnan, 1985;Hadi, 1996; Malasri, 1987; Smith & Warner, 1992;Wenzel, 1987).

Based on the previous discussion and due to thesignificant popularity and availability of Excel relativeto other software, a decision is made by the authors touse Excel, and empower it with VBA in the teachingand learning of structural engineering courses.

3 BASIC CAPABILITIES OF EXCEL

Before discussing the various computationalcapabilities of Excel, it is essential to present a basicfeature that is relevant to the development discussedin this study. This feature is related to assigninga reference name for a range of cells that is usedextensively in this study (figure 1).

The assigned name can be used later in all theExcel formulae, which significantly enhances thereadability and tracking of the formulae.

3.1 Built-in matrix manipulationfunctions in Excel

The current version of Excel (version 2003 or 2007)provides a number of built-in matrix manipulationfunctions. It is important to note that these functionsare range-functions, where the function returns arange and not a single value. To execute this type ofrange-functions in Excel, the user should type theformula and then press Ctrl+Shift+Enter, rather thanpressing the Enter key as in regular single-valued

functions.Using the previously described range functioncapabilities, addition and subtraction of matricescan be performed simply by adding or subtracting


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returns a 44 range (ie. stiffness matrix). It is importantto note that names _E1, _A1 and _L1 are used to referto the cells containing E

1,A

1and L

1, respectively.

The other basic functions used in the analysis, at theelement level, are Truss_T_Mat, which is used tocalculate the transformation matrix for any inclinedtruss element, and Truss_Kxy, which is used tocalculate the stiffness matrix of an element definedin the global coordinates. These functions are used

to calculate two matrices denoted as [T] and [Kxy],respectively. Such matrices are defined by:

cos( ) sin( ) 0 0

sin( ) cos( ) 0 0

0 0 cos( ) sin( )

0 0 sin( ) cos( )

T

(2)

[Kxy

] = [T]T[ke][T] (3)

where q represents the rotation angle of the trusselement measured counter clockwise from thepositive global x-axis to the element.

For completeness, another UDF, Kxy2S, is developedto build the global stiffness matrix [S] of the entirestructure from its constituents (ie. matrices [K

xy] for

the different elements). The entries of each of theelement stiffness matrices [K

xy] are arranged in the

global stiffness matrix [S] based on the degrees offreedom at the nodes of the considered element. Foreach element, the degrees of freedom are definedby an element location vector {LV}, which stores thedegrees of freedom at the start node followed by theones at the end node. The function Kxy2S takes anelement stiffness matrix [K

xy] and returns a square

range of size (S_Size S_Size) with the contentsof the entries of [K

xy] arranged in the proper places

based on a predefined element location vector {LV}.The size, S_Size, of the [S] matrix corresponds to the

maximum degree of freedom of the structure. Thesuperposition of the different elements is performedin Excel by writing a formula in the range allocatedfor [S] as:

= Kxy2S(Kxy1, LV1, S_Size)+ Kxy2S(Kxy2, LV2, S_Size) +

Figure 4 shows the [S] matrix after arranging twoelement stiffness matrices [K

xy]

1and [K

xy]

2, for element

1 and 2, respectively, into it. The location vectors ofthe two elements {LV}

1 and {LV}

2 are given in the

table, and are shown on the top and side of each ofthe [K

xy] matrices. To help in visualising the process, it

may worth mentioning that names _Kxy1 and _Kxy2are used to refer to the matrices [K

xy]

1and [K

xy]

2, while

names _LV1 and _LV2 are used to refer to the locationvectors {LV}

1and {LV}

2.

4.2 User-defined functions for the analysis of2D constant-stress triangular element

Application of the proposed teaching methodologyto solid elements is introduced in this section, whichpertains to the particular case of the 2D constant-stresstriangular (CST) element with constant thickness. Asdiscussed in the previous section, a key parameterthat is needed to be evaluated is the stiffness matrix ofthe considered element. To overcome the complexityin the calculations of the stiffness matrix of suchhigher order element, the element stiffness matrixin the global coordinates, [K

xy] may be expressed in

terms of the strain matrix [B] and the constitutivematrix [C] as follows (Malasri, 1987):

[Kxy

] = Ve[B]T[C][B] (4)

In which, Verepresents the volume of the constant

thickness triangular element.

Figure 3: Using Truss_Ke user-defined function to calculate [ke] for truss element 1.


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The strain matrix [B] is evaluated in terms of theelement geometry as (Cook, 1995):

1 2 3

1 2 3

1 1 2 2 3 3

0 0 0

0 0 0

b b b

B c c c

c b c b c b

(5)

where the elements biand c

iare related to the nodal

coordinates through the relations:

1 1

and2 2

i j k i k j

e e

b y y c x xA A

(6)

whereAeis the area of the triangular element and i,

j, k= 1, 2, 3.

A UDF B_Mat is introduced for the calculation ofthe [B] matrix. The B_Mat function varies with theelement nodal coordinates and the element type (2DCST in this case) as shown in figure 5.

Meanwhile, the constitutive relationship defined by

the element matrix [C] depends on the classificationof the element as being plane stress or plane strain(Cook, 1995). This matrix is evaluated by using theUDF C_Mat. As such, the element stiffness matrix

Figure 4: Building the structure global stiffness matrix [S].

Figure 5: Building the element strain matrix [B_Mat] where XY_Range refers tothe XY-coordinates of the element nodes.


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[Kxy

] is obtained by employing the UDF Kxy_Matas presented in figure 6. Once the elements stiffnessmatrices are determined, the global stiffness matrix [S]is assembled based on the degrees of freedom at theelement nodes and the corresponding element locationvector {LV} as explained in the previous section.

Finally, the stresses developed in each element {se}

are readily obtained as:

{se} = [C][B]{d

e} (7)

where {de} is the vector of nodal degrees of freedom

resulting from the finite element solution.

One of the many benefits of the developedspreadsheet is to explain the implementation of thesymmetry boundary conditions and the associatedtime saving as a result of the significant reduction inthe number of active nodal degrees of freedom to besolved for. For the plane structure shown in figure

5, as a result of its symmetry about the vertical (Y)axis, only half the structure needs to be modelled.This reduces the number of elements into two ratherthan four elements. In addition, the symmetryboundary conditions allow for the elimination ofall the horizontal degrees of freedom along theY-axis. In order to verify this concept to the students,the problem is solved twice. First by ignoring thesymmetry and modelling the four-element structure,and once more by considering the symmetry andmodelling half the structure only. By comparing theoutcomes of both models, students can observe thatthe full model results in zero values for all the verticaldisplacements along the Y-axis, which is in agreementwith the symmetry boundary conditions. In addition,all other degrees of freedom are found to be identicalbased on both models. This simple case illustratesthe advantage of using the analysis spreadsheet inproducing various models for the same problem

which allows for cross-checking the various sets ofnumerical results to gain better understanding of thephysical problem and the symmetry concept.

A sample Excel template file that is developed andused by the students in the solution of the 2D CSTproblems is given at http://beam.to/amr_sawy_edupaper (El-Sawy & Sweedan, n. d.).

5 INSTRUCTIONAL STRATEGY

The instructional strategy adopted in the currentstudy is primarily based on the eight-step ExCEEDmodel instructional strategy outlined by Welchet al (2005) to facilitate students learning of majorconcepts. Such eight-step strategy is based on thelearning process methodology developed by Appleet al (1995), which aims at enhancing self-learningskills of students. In general, the main framework of

this model instructional strategy aims at increasingthe possibility of learning through encouraging theengagement of students to allow for faster learningand achieving better levels of understanding. Theapplication of the adopted eight-step ExCEED modelinstructional strategy in the current study can besummarised as follows:

1. Provide an orientation the instructor communicateswhy the topic is important and how it relates toother topics that students already understand inthe course or other previous relevant courses

2. Provide learning objectives to increase the

effectiveness of the learning process, the instructordefines what students will be able to do uponsuccessful completion of the learning process.In addition, students should be aware of thestandards by which their achievement of theobjectives will be evaluated.

Figure 6: Calculation of the element stiffness matrix [Kxy_Mat].


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3. Provide information for the two courses,information is provided by the instructor in aseries of mini-lectures followed by discussionsand/or short quizzes to ensure that studentshave acquired the necessary information beforethe learning process is continued.

4. Stimulate critical thinking the instructors

stimulate critical thinking by asking conceptually-challenging questions that may be solved throughstudent-instructor discussions, collaborative in-class work or homework problems.

5. Provide models the instructor model theproblem-solving process by guiding the studentsto solve representative example problems inclass. This task should involve training studentsto think in a logical manner, make reasonableassumptions and make key decisions as theywork through the problem.

6. Provide opportunities to apply knowledge applying

knowledge that takes the form of problem-solvingof in-class exercises, homework assignmentsand projects, since successful application of theconcept is the best way to ensure understandingit (Chickering & Gamson, 1991).

7. Assess performance and provide feedback theinstructor assesses the students solution ofboth the in-class and out-of-class assignments toidentify possible shortcomings in the studentslearning. Feedback is provided regularly to helpimprove their learning.

8. Provide opportunities for self-assessment to foster

the development of students assessment skills,in the presentations of the term-project, theinstructor requests students to critique oralpresentations of other students before receivingfeedback from the instructor.

5.1 Details of the instructional method

The proposed teaching/learning method is basedon mini-lectures describing the important conceptsfollowed by brainstorming discussions, problem-solving exercises or development of Excel template/

UDFs. In the latter, students are requested to designan Excel template file to enter the data for anygiven problem and show the calculated results (eg.deformations, element forces, element strains andstresses). This process continues for a couple ofweeks until the final template design is completed,verified against textbook solved examples and readyto be used to solve assignment problems. As thestudents progress through this process, the instructorthrough face-to-face hands-on sessions helps themto write the previously discussed user-defined VBAfunctions in Excel; namely Truss_ke, Truss_Kxy,Truss_T and Kxy2S for the Matrix Structural Analysis

course, and B_Mat, C_Mat and Kxy_Mat for thefinite element method course. Multimedia describingthe development of the VBA UDFs are also used toprovided to aid the students self learning process.

The students may struggle and encounter someproblems while writing their first VBA function. But,gradually they overcome such difficulties, and theirlogic and programming skills improve. Once thestudents complete the development of the templatefiles, they submit them for grading and receive asimilar error-free version of the template that has

been designed and checked by the instructor. TheVBA code, in the error-free version, is passwordprotected so that students cannot tamper with it bymistake. It also includes some special VBA securitycodes that will be discussed later in the plagiarismdetection section. The typical procedure outlinedabove is employed while covering other topicsincluded in the two courses.

In-class and out-of-class assignments with varyinglevels of difficulty are used to check the level ofunderstanding of the students. The difficulty mayrange from problems with two or three members/

elements, which the students are asked to solveusing both manual calculations and Excel, to realisticproblems with higher number of members/elements.The main objective of offering simple questions is toallow students to practise manual calculations anduse their results to verify the developed computer-based tools. Besides, simple manual calculationchecks that can be performed to verify the resultsof complicated problems are taught to the students,as discussed in the following paragraph. Theassignments questions vary in difficulty and transferthe students smoothly from one level to another untilthey reach the maximum difficulty where studentsare required to solve complex practical problems andreport on their results.

Based on the authors experience with the proposedteaching/learning method, it is found that most ofthe students go smoothly through the Excel solutionsteps but struggle in interpretation of results andproducing graphical presentation of the obtainednumbers into meaningful engineering results (eg.deformed shape, bending moment, shearing forceand thrust diagrams, and strain and stress contours).This typically requires special attention from the

instructor. Simple checks are discussed with thestudents to make sure that the results they obtainare correct and reliable. This is important sincestudents tend to accept any results obtained from thecomputers under the impression that these resultsare undoubtfully 100% correct. Such simple checksmay be performed using engineering inspection andhandheld calculators. For example, the deformedshape of the structure under consideration should becompatible with the applied external loads. Anothertype of quick check that can be conducted is to ensurethat bending moments in a multi-span beam donot exceed the bending moment for the same beam

when simply supported. Combining manual andcomputer-based calculations is intended to satisfy anessential objective of the courses that aim to help thestudents to analyse both abstract models and realistic


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large-scale structures without losing the focus on themain target outcome and mistakenly concentratingon the aiding tools only.

To add a practical aspect to the courses, twocommercial software packages available in the Civil& Environmental Engineering Department areintroduced, one for each course, and the students are

requested to resolve some of the previously-assignedcomplex problems using the relevant software.Comparison between the two sets of results is held toverify the numerical procedure previously developedand employed by the students to tackle the sameproblems. This, in addition to the simple checks usinghandheld calculators, adds more confidence in theobtained solution.

Submission of the assigned problems includes twobasic parts. The first part provides the figures thatshow the degrees of freedom (free and restrainednodes), elements and nodes numbering, element

directions, and diagrams showing deformed shapes,bending moments, shearing and thrust forces, andstrain and stress distributions. Meanwhile, thesecond part of the submission is the digital Excel filesthat hold the input data and corresponding results.The students digital files are submitted throughany learning management system (Blackboard inthis case).

6 PLAGIARISM CONTROL

Plagiarism and cheating, in general, have a verylong history. Some instructors and researchersprefer not to tackle the issue since it may not reflecta good image of their institutes. On the contrary,others acknowledge the need to clearly identifycopied assignments, proctor exams, and to adoptstrict policies to prohibit students misconductand cheating. As a result of the recent significanttechnological advancement that has affected highereducation, instructors may also prefer to use anyavailable online plagiarism control means (eg.SafeAssign in the Blackboard Learning ManagementSystem) or design their own plagiarism control tools.

In the traditional teaching style and before applyingthe proposed method presented herein, few casesof possible plagiarism were noticed by the authors(mainly in the undergraduate course, MatrixStructural Analysis) through direct comparisonbetw ee n assi gn ment s submit ted by di fferen tstudents. In these few cases, the same mistakes(eg. using wrong equations, inadequate solutionprocedure, spelling mistakes, missing/wrong units,etc.) were observed. In such incidences, the instructorof the course held private meetings with concernedstudents, on an individual basis, to discuss the

details of the technical procedure that the studentadopted in solving the assignments. In the majorityof the suspected cases, the student could not showa reasonable level of understanding of parts of

the submitted solution of the assignment(s). Thismotivated the authors to develop a new techniqueas an attempt to control plagiarism and to ensurea reasonable level of fairness when evaluatingstudents work.

The development of new communication toolsand digital nature of the students work has given

the plagiarism and cheating another dimension. Ithas made copying the work of others much easier,simply by cutting and pasting parts of a file or even,in some cases, copying the whole file. The Faculty ofEngineering at UAEU expects intellectual honestyfrom its students. Intellectual honesty demandsthat the contribution of others be acknowledged.Intellectual dishonesty undermines the quality ofacademic activity and, accordingly, the Facultyof Engineering has adopted severe penalties forstudent misconduct with respect to plagiarism andcheating. The charge of plagiarism and cheating may

have severe consequences, including suspensionor expulsion from the program, not to mention astudents loss of credibility.

In the same line of using cheating control aids, amethod was developed for potential control ofelectronic copying (e-cheating) between students.To the best of the authors knowledge, no evidenceof e-cheating incidences was observed after theplagiarism control method was adopted. Thisobservation has been verified based on directcomparison between submitted assignments andafter holding one-on-one technical discussions with

random sample of students where the studentsshowed very good understanding of their submittedsolutions. Moreover a good match is observed

between the students marks in the assignments andtheir marks in the exams.

The proposed e-cheating control method dependsmainly on three tricks that can be achieved usingVBA in Excel, which, as discussed earlier, is theselected software to be used by the students insolving assignments, quizzes and exams. Thefollowing subsections describe these tricks in details.The security code is available as part of the sample

Excel template file provided at http://beam.to/amr_sawy_edupaper (El-Sawy & Sweedan, n. d.).

6.1 Hiding a sheet in Excel

A user can hide a sheet in Excel simply by goingto the VBA Editor screen and adjusting the visiblesheet property to xlSheetVeryHidden. Figure 7 showsthe process of hiding Sheet1 by changing its visibleproperty, and it is clear that it does not show in Excelafter this property is changed.

If the VBA code is protected by a password, the user

will not have access to such sheet properties and,therefore, any information written in this sheet willbe hidden in a safe place from the Excel user. Figure8 shows this scenario.


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Using this method, a sheet named Security Datais created in the Excel template file and is used tohide the student name and ID in two cells named_Student_Name and _Student_ID, respectively.

6.2 Disabling simultaneousaccess to two workbooks

It is intended, as part of the plagiarism prevention,that students cannot open any other workbookssimultaneously with the template file. This is toprevent copying and pasting between the differentfiles. This can be achieved by adding VBA codes forthe Workbook in the events WindowActivate andWindowDeactivate. This code is triggered when theuser tries to activate the workbook (ie. opens the

template file) or deactivate the workbook (ie. opensanother file besides the template). Figure 9 shows thecode for the two workbook events WindowActivateand WindowDeactivate.

6.3 Collecting student information at start-up

The Excel template file includes a VBA code thatcollects the students information once the file isopened. This is usually written in a subroutine with aspecial name Auto_Open. The code in that subroutine(refer to figure 10) simply checks the content of thecell _Student_Name in the hidden sheet SecurityData. If the cell contains data, this implies that thestudent has already entered his name and ID, andthe code displays this information to the student.Otherwise, the code requests the student to entera name and ID, and stores them in the proper cells(ie. _Student_name and _Student_ID) in the hiddensheet Security Data. In both cases, the code unhides

the sheet Detailed Calculations that contains all ofthe template design.

If a student fails to provide name and ID (eg. didnot enter any value and clicked OK for the blank

Figure 7: Hiding Sheet1 in Excel.

Figure 8: Protecting Sheet1 and its content from being visible.


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Public Quiet_Close As Boolean'==========================================================================Private Sub Workbook_WindowActivate(ByVal Wn As Window)Dim WB As Workbook, Answer As IntegerOn Error GoTo Err_Handler' Get the name of the current Excel workbookIf Current_WB_Name = Empty Then' Get the current workbook nameCurrent_WB_Name = Application.ActiveWorkbook.Name

End If' Check for another active Excel workbook

For Each WB In Application.WorkbooksIf WB.Name Current_WB_Name Then' Case of opening another Excel workbookAnswer = MsgBox("Activating " & Current_WB_Name & _

" would close all other" & _" Excel workbooks. Accept?", vbYesNo)

If Answer = vbNo Then' User decided to close the Excel TemplateQuiet_Close = TrueApplication.Workbooks Current_WB_Name).Close SaveChanges:=FalseQuiet_Close = False

End If' User decided not to open any other fileWB.Close SaveChanges:=False

End IfNext WB

Err_Handler:On Error GoTo 0

End Sub'=========================================================================

Private Sub Workbook_WindowDeactivate(ByVal Wn As Window)

Dim WB As Workbook

If Quiet_Close Then Exit Sub

On Error GoTo Err_Handler

' Check for another active Excel workbookFor Each WB In Application.WorkbooksIf WB.Name Current_WB_Name And Current_WB_Name "" ThenMsgBox "No workbook is allowed to be opened with " & Current_WB_NameWB.Close SaveChanges:=False

End IfNext WB

Err_Handler:On Error GoTo 0

End Sub

Figure 9: Plagiarism prevention VBA code.

Public Current_WB_Name As String'=========================================================================Public Sub Auto_Open()Dim Student_Name As String, Student_ID As String' Check for the Student_Name and the Student_ID in the security sheetIf Range("_Student_Name") = Empty Then' Student name has not been entered. Ask user to input his/her' name and IDStudent_Name = InputBox("Enter your name)Student_ID = InputBox("Enter ID:")

' Check that user entered some stringsIf Student_Name = "" Or Student_ID = "" ThenMsgBox "Enter both your name and ID - Application will close"Application.ActiveWorkbook.Close SaveChanges:=False

End If' Place name and ID in the security sheetRange("_Student_Name") = Student_NameRange("_Student_ID") = Student_ID' Unhide the "Detailed Calculation" sheetSheets("Detailed Calculations").Visible=TrueSheets("Detailed Calculations").SelectElse' Student name has been entered already. Display this information' to the studentStudent_Name = Range("_Student_Name")Student_ID = Range("_Student_ID")MsgBox "Welcome " & Student_Name & ":" & Student_ID' Unhide the "Detailed Calculation" sheetSheets("Detailed Calculations").Visible=TrueSheets("Detailed Calculations").Select

End IfEnd Sub

Figure 10: Plagiarism detection VBA code.


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cells), the sheet provides an error message andcloses automatically. Some students may think thatthey can bypass the VBA code by disabling macros,and bypassing the plagiarism detection process. Toovercome this possibility, the Excel template fileis designed to contain 3 sheets: Sheet1, DetailedCalculations and Security Data. Initially, the blank

sheet Sheet1 is set to be visible while the other twosheets are hidden. If the student disables macros,he/she can see the empty Sheet1 but neither getsaccess to the Detailed Calculations sheet nor to theVBA functions. If the student follows the instructionsand enables macros, the macros will request his/hername and ID, and inserts them in the hidden SecurityData sheet.

7 ASSESSMENT OF STUDENTPERFORMANCE

The assessment covers both individual and teamwork. Individual work assessment is simply carriedout through grades assigned to class participationand assignments in addition to progress, midtermand final exams. The design of the exams is a difficulttask since both the manual calculation skills andpracticality of the problems should be reflected in theexamination questions. Therefore, the exams containsimple questions that require manual calculationsand even sometimes no calculations but theunderstanding of the basic concepts. Figure 11 showsa sample of the exam questions that requires simple

calculations in addition to a thorough understandingof the analysis procedure.

The major part of a typical exam (about 60% to70%) consists of practical questions that requiresignificant involvement of using Excel and the

provided course template. Figure 12 gives anexample of such practical questions.

In the last two to three weeks of the course, studentsare divided into teams (groups). Each team isassigned one of the advanced topics to conductresearch and present the major outcomes to therest of the class. To stimulate participation in the

discussions and brainstorming after each grouppresentation, grades are assigned to the appropriatestudents participation. Following each presentation,the instructor usually reviews the main conceptsand adds any missing information. The groupassessment is evaluated based on a group projectand its accompanied presentation and discussion.The distribution of the total grades is shown in table2. Weighting the assignments grade, relative to thecourse overall grade, is still an unresolved issue. Ifthe weight is to be increased, more effort should bedevoted to observe and minimise possible e-cheating.

Although e-cheating is prohibited, discussion amongstudents is encouraged and allowed even duringclass activities. To verify individual contributionof the students in solving the assignments, theinstructor may selectively discuss with students theirsubmitted answers. In few cases, a student who failsto explain his/her answers reported that they havebeen working in groups. After such incidents, it hasbeen made clear to all students that collaborationis something and reporting the answer blindly issomething else.

8 SURVEY FOR STUDENT SATISFACTION

In the past, the course Matrix Structural Analysishad been offered and taught using the traditionalmanual calculation method. Over the last four years,

The shown truss has been analyzed and the following results have been obtained:

3

1 2 4

3

1 2

45

20 ft 20 ft

18 ft

,kips

0

167.4

0

167.4

,kips

0

167.4

0

167.4

21

FF

kips

5.17

167.19

25.17

167.19

,kips

0.6

0

0.6

0

,kips

75.3

167.4

75.3

167.4

543

FFF

a)Calculate and show magnitudes and directions of the reactions at the supports

b)Check the equilibrium of member 3

Figure 11: Sample of the exam questions that requires manual hand calculations.


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the course has been offered several times using thereported teaching method; three of them have beenanonymously surveyed for students feedback.The course Finite Element Method: Theory andApplications has been offered and anonymouslysurveyed for two times over the past two years. Theaverage results of surveys that are conducted arereported herein. Each survey is conducted to collectthe students opinion about the new teaching/learning method. Unfortunately, the results ofthese surveys cannot be compared to any othersurveys conducted on other student population whohave been taught using the conventional manualcalculation method. This is due to the significantlydifferent instruction styles, and different complexityof the example, assignment and exam problemsin the two cases. In the conventional teachingtechnique, all examples and problems had to be inthe form of simplified abstract models with reducedlevel of complexity. With the implementation of theproposed teaching technique, more realistic modelswith significantly higher level of complexity could betackled. With regard to the enhancement in students

understanding and capabilities when implementingthe proposed technique, the achievements outlinedbelow are considered as evidence of the usefulnessof the proposed methodology:

For the shown truss:

a)calculate the deformation vector {d} and draw the deformed shape

b)calculate the member forces in the truss members

c)calculate the support reactions, and

d)calculate the elongation/shortening in member 5.

1 4

2 3

1

52

3

4

Figure 12: Sample of the exam questions that requires the use of Excel.

Table 2: Distribution of the grades betweencourse activities.

Activity Percentage of total grade

Class participation 5%

Assignments 25%

Quizzes 10%

Group presentation 10%

Midterm exam 20%

Final exam 30%

Significant change in nature and complexity ofexamples and problems.

Ability to attain better physical understating ofthe structural behaviour through conductingdetailed parametric analysis to assess theinfluence of various design parameters on theoverall structural behaviour and response.

Being exposed to large-scale practical problemsthat are similar to real-world situationsencountered by engineering graduates. Thisassists in familiarising students with samplepractical situations that are vastly different fromthe abstract models that could be studied usingthe conventional teaching approach.

Attainment of such skills and capabilities isconfirmed by the outcomes of questionnaire surveythat was tailored to enable measuring them. Thesurvey includes 12 questions. The response foreach question ranges from 1 to 5 with 1 assigned toTotally Disagree and 5 assigned to Highly Agree.The questions and their average response, among astudents sample of 37 students (26 students for thecourse Matrix Structural Analysis and 11 students

for the course Finite Element Method: Theory andApplications), is presented in table 3.

In addition to the questionnaire presented in table 3,the surveys allowed for written feedback from thestudents. Usually few interested students providetheir written feedback. The following lists the mostcommon positive and negative feedback received:

Many students reported their satisfaction withthe course contents and presentation.

Few students reported that the course topicswere difficult, especially that the interpretation ofnumerical results needed deep understanding of

the subject. Based on the students comments, theinstructors revised their instruction, and devotedmore time and put more emphasis on tackling thisissue in the example problems solved in class.


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Table 3: Survey questions, students responses and authors comments.

Please provide a response to the following statements:

(Totally Disagree = 1, Disagree = 2, Agree = 3, Moderately Agree = 4, Highly Agree = 5)

Averageresponse

Q1:Using laptops (not PC labs) is essential for the success of this course.

Authors comments:The students response does not give a clear cut answer. The authors believe that using laptopsdoes not essentially have advantages over using PC labs. However, It may add extra flexibility and conveniencefor the students.

2.7

Q2:Using Excel capabilities in designing the course template is simple and is clearly introduced.

Authors comments:During offering the courses, the authors noticed that the students were very receptive to usingadvanced features of Excel to design their course templates, which is reflected in the high score of this question.In addition, few students informed the instructor that they have used their newly learned skills in other courses,especially senior students in their graduation project.

4.5

Q3:Programming using VBA (in Excel) is introduced gradually until the concepts become straight forward.

Authors comments:It is clear that the students feedback reflect some inconvenience in programming using VBA.Although all the students have passed the course Introduction to Programming using Visual Basic, they showed someinconvenience when starting to use VBA in Excel. By the help of the instructor, this barrier is overcome gradually. Atthe end of the course, the students succeeded to add their own VBA user-defined functions to handle the advancedtopics they were requested to research.

3.9

Q4:Using Excel did not distract you form understanding the basic concepts

Authors comments:Based on the high score shown by the students response, it is clear that they feel that Exceldid not distract them from understanding the main concepts. This is also validated by the authors after lookingat the good grades achieved in specific assignments and exams questions that are designed to measure studentsunderstanding of main engineering concepts through either manual calculations or interpretation of Excel results.

4.6

Q5:Manual calculations represent an essential component of the course exercises.

Authors comments:The relatively low student response reflects the difficulty associated with performing tediousmanual calculations of small problems and/or interpretation of the Excel output of large problems. After using Excelto get the numeric output, many students struggled to relate the problems numerical output to their correspondingphysical values (eg. draw the deformed shape, shearing force and bending moment diagrams). In the authorsopinion, this represents a basic difficulty that requires a special attention from the instructor.

3.1

Q6: Some questions in the assignments and exams are practical and, mostly, cannot be solved using manualcalculations

Authors comments:The high student response to this question reveals that the students, after solving some small-scale simplified problems manually, realised that many other problems in the assignments and exams are practical,

but complicated, and required significant amount of calculations that is made possible by using the Excel template.

4.6

Q7:Using programming to automate the calculations is an efficient time-saving approach.

Authors comments:Although the students response to Q3 shows that the students were not fully receptive to writingprograms using VBA, their high response to Q7 indicates their high appreciation to the significant time saving achievedwhen using the developed programs in solving complicated applications that reflect real life engineering problems.

4.5

Q8:Automation of involved calculations helps in achieving higher levels of physical understanding by allowing forquick and efficient parametric analyses.

Authors comments:The high agreement shown by the students feedback confirms the achievement of a majorobjective intended from utilisation of the Excel/VBA tools in teaching the course. The authors believe thatimplementing the Excel/VBA tools allows the instructor to provide better explanation of physical structural behaviourthrough conducting in-depth parametric analyses of complex real life models.

4.5

Q9:Using commercial software adds an extra skill that is highly required by the job market.

Authors comments:The authors believe that any course, if possible, should add practical experience to the students.

This is achieved in the considered courses by training the students on using one of the commercial software, whichis highly appreciated by the students, especially those who have used the software later in their graduation projects.

4.6

Q10:Team research of a new subject improves your team-work skills and self confidence.

Authors comments:The high agreement between the students reflects their appreciation to being exposed to theteamwork environment. In addition, the authors believe that the team projects and their accompanied research ontopics, which have not been discussed in class, add other aspects to the teamwork skills and students self confidence.

4.3

Q11:Using the security option in the Excel template provides good grounds for fair evaluations of the students work.

Authors comments:The student response reflects high agreement. Although few students may illegally benefit frome-cheating, many others would like to receive fair evaluations for their work. Most probably, those students votedpositively for the security option in the Excel template. The authors believe that the security option has controlledthe e-cheating since no cases have been observed after using the plagiarism control method.

4.0

Q12:Distribution of grades among course activities is reasonable and appropriate.

Authors comments:The relatively low student response reveals that some students may disagree with the adoptedmarks breakdown. As previously mentioned, some students may expect assignments to have higher weight sincethey consume most of their time. On the contrary, the authors believe that although e-cheating was controlled, it isstill possible that a student gets help from others without understanding the basic concepts. This has been observedin very few cases through discussion of technical contents of assignments with students.

3.5


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Many students reported that their skills in usingExcel have been improved significantly. Theyalso reported that without Excel they may havenot been able to solve the complex realisticproblems that reflect real-life situations they mayface in practice.

Very few students who were not competent

in using Excel, and computer software ingeneral, preferred to solve simple problemsusing a handheld calculator, although theyacknowledged that making a simple mistake inmanual calculations requires significant time andeffort to fix the generated errors in all subsequentsteps, which is not the case for the Excel solution.

Although commercial software was onlyintroduced with no emphasis on its design aspect,most of the students liked using it in solvingin-class problems, and for verification of theirmanual and Excel solutions.

None of the students provided any writtencomments on the security measures taken inExcel VBA to minimise cheating, although fewstudents were anxious to know how this has beenprogrammed in VBA.

It should be noted that some senior students, whohave successfully passed the courses one or twosemesters earlier, have showed gratefulness tothe instructors for helping them acquire usefulknowledge at both conceptual and applicationlevels that helped them later in their graduationprojects. Based on this and in addition to theabove comments, the authors believe that themajority of the students have grasped the mainconcepts of the courses and were able to applythem in realistic graduation project problems.

9 EVALUATION OF THE EFFECTIVENESSOF THE PROPOSED METHOD

Since a good match was observed between thestudents marks in the assignments and their marksin the exams, the exam grades are considereda reasonable measure of the students overall

performance. A comparison between the examgrades, based on both the traditional and newlyproposed teaching/learning methods, is utilised toevaluate the effectiveness of the new technique (table4). It should be noted, however, that the proposedmethod has new features that have no counterpartin the traditional method and therefore are denotedas N/A in the comparison table. Since the FiniteElement Method course was introduced very recentlyin the Masters Program and was not taught earlierusing the traditional teaching style, the comparison ofgrades is performed for the course Matrix StructuralAnalysis only and is summarised in table 4.

In general, the comparison presented in table 4indicates a slight improvement in the studentscomprehension of the subject relative to whatwas achieved based on the traditional teachingstyle. However, this cannot be considered a realsignificant improvement as a result of the smallstudent sample size, which may increase the noisein the analysed data. Comparison item 1 reveals aslight improvement in the level of understandingof basic engineering concepts. This confirms thatthe proposed teaching/learning technique does notoverlook this essential engineering component byfocusing only on programming and applications.Meanwhile, students performance in manualcalculations of abstract structures remained almostunchanged as shown by comparison item 2 in table 4.

Table 4: Comparison between traditional and newly proposed methods of teaching/learning.

# Field of comparisonAverage grade

traditional method (based ongrades of 3 years)

Average grade proposed method (based

on grades of 4 years)

1Solving questions targetingunderstanding of main concepts

(sometimes with no calculations)

75% 77%

2Analysing abstract structures requiringmanual calculations

73% 72%

3Analysis of structures requiringmoderately long manual calculations

74%N/A

(Excel is used instead, seecomparison item #4)

4Analysis of realistic structural systemsrequiring long computer calculations

N/A(not valid due to the associated

high level of complexity)

76%(Calculations are

conducted using Excel)

5Effect of changing geometricalparameters on load transfer mechanisms

of realistic structural models

N/A(not valid due to the associated

difficulties and time constrains)

75%(Calculations are

conducted using Excel)

6Analysing realistic complicatedstructures using commercial software(eg. SAP2000)

74% 76%


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Comparison items 3 through 5 imply that a majoradvantage is achieved by implementing the proposedtechnique to handle problems with high level ofcomplexity. In addition, the technique allows forassessing the influence of various geometricalparameters on the load transfer mechanisms andtheir associated load paths. It should be noted

that questions targeted by comparison item 5 alsomeasure the comprehension level by requesting thestudents to discuss and comment on the results andfindings of their conducted parametric analyses.The students are also required to provide theirengineering recommendations related to structuralsystem efficiency. Finally, the comparison in item6 shows slight improvement in using commercialsoftware in structural analysis.

In general, comparison items 1, 2 and 6 indicatethat the new approach did not degrade the originaloutcomes of the traditional teaching method. In

addition, the new approach certainly adds newlearning outcomes for the students as depicted bycomparison items 4 and 5. Despite the general slightimprovement shown by the comparison provided intable 4, it should be emphasised that this comparisonis not intended to prove the superiority of theproposed technique over the traditional style. It justhighlights the fact that the new method introducesnew learning outcomes represented by computerusage as an integral part of the course (either in usingExcel or the commercial structural analysis software).This is in addition to the improved students ability to

solve large-size realistic problems that are impossibleto handle using the traditional manual calculations.It is also important to notice that learning Excel as acomputational tool is considered a positive additionto the students skills, not only in the structuralanalysis field, but also in many other computationalareas in engineering.

10 CONCLUSIONS

The study reported herein provides some insightsthat may help other instructors and researchers to

improve their teaching of similar courses. In viewof the learning technique presented, and its relateddiscussions and evaluations, authors observations,students feedback provided and evaluation of thestudents grades throughout the paper, the followingconclusions may be highlighted:

Comparison between the students performancebefore and after implementing the proposedteaching method reveals that the originaloutcomes of the traditional teaching method havenot been degraded.

The introduction of computer-based tools to be an

integral part of the structural and stress analysiscourses adds a new learning outcome. This helpedthe students in solving realistic engineeringproblems with higher complexity level than

the simple abstract models that are typicallyconsidered in similar courses when taughtusing traditional manual solution methods. Thisexperience is expected to help the students aftergraduation when they need to analyse realisticcomplex structures. This has been supported bythe good students grades in analysing complex

structures after the implementation of the newlyproposed method.

The students feedback and authors observationsreveal that many students are very receptive tousing advanced features of Excel to assist themin solving complicated structural engineeringproblems in a quick and efficient manner.

Monitoring of students performance and thelevel of complexity in solved problems reveal thatusing computer tools to automate the solutionassists in achieving better levels of physicalunderstanding by allowing the students to

conduct detailed parametric analysis (eg. differentsolution scenarios of the same problem).

Based on the authors experience, instructorsshould give special attention to the fact that usingcomputer tools should not result in losing thefocus on the essential objective of understandingthe basic concepts of structural analysis and finiteelement technique.

From the experience gained by the authorsthrough implementing the proposed methodologyover several semesters, it can be concluded thatimproving the students skills in programming is

not a real barrier and may be overcome graduallywith instructors effort and patience.

This study reports on an attempt that maybe applied to control electronic plagiarism(e-cheating) if Excel/VBA is decided to be usedfor calculations purposes.

REFERENCES

Apple, D. K., et al. 1995, Foundations of Learning,Pacific Crest Software, Corvallis, Ore.

Arfiadi, Y. & Hadi, M. N. S. 2002, Development ofmatrix method based structural analysis toolbox inMatlab, Proceedings of International Conference onComputational Structures Technology, pp. 13-14.

Bricklin, D. 2010, Dan Bricklin: The personal website of the co-creator of VisiCalc, www.bricklin.com.

Casas, A. & Oppenheim, I. J. 1987, Spreadsheetprogramming for structural design, ComputerApplications in Concrete Technology, ACI SP-98, pp.233-247.

Chandrupatla, T. R. & Belegundu, A. D. 2002,Introduction to Finite Elements in Engineering , 3rdedition, Prentice Hall, Upper Saddle River, NJ, USA.


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Chickering, A. W. & Gamson, Z. F. 1991, Applying theSeven Principles for Good Practice in UndergraduateEducation: New Directions for Teaching andLearning, No. 47, Fall, Jossey-Bass, San Francisco.

Cook, R. D. 1995, Finite Element Modeling for StressAnalysis, John Wiley and Sons, Inc., New York, NY,

USA.

Cooke, B. & Balakrishnan, S. V. 1985, ComputerSpreadsheet Applications in building and surveying ,Macmillan, UK.

El-Sawy, K. M. & Sweedan, A. M. I. (n. d.), InnovativeUse of Computer Tools in Teaching StructuralEngineering Applications, http://beam.to/amr_sawy_edupaper.

Hadi, M. N. S. 1996, Utilising the Capabilitiesof Spreadsheets for Designing Structures, TheInternational Journal of Construction InformationTechnology, Vol. 4, No. 2, pp. 15-28.

Kassimali, A. 1999, Matrix Analysis of Structures,Brooks/Cole, Thomson Learning, Florence, KY.

Malasri, S. 1987, Spreadsheet RC Beam DesignAid, Structural Engineering Practice, Vol. 4, No. 1 &2, pp. 67-77.

Malasri, S. & Syed-Mohammad-Ridzuan, S. R.1987, Educational software development using

spreadsheet program, Int. J. of App. Engrg. Educ.,Vol. 3, No. 1, pp. 55-58.

Martini, K. 2001, Non-linear Structural Analysis asReal-Time Animation: Borrowing from the Arcade,Proceedings of the Computer-Aided Architectural DesignFutures 2001 Conference, Kluwer Academic Publishers,Dordrecht, Netherlands, pp. 643-656.

Martini, K. 2006, A New Kind of Software forTeaching Structural Behavior and Design, Proceedingsof the 2006 Building Technology Educators Conference,

College Park, Maryland, 3-5 August.

Nirmal, K. D., 2002, Teaching and LearningStructural Analysis Using Mathcad, Proceedingsof the 2002 ASEE/SEFI/TUB Colloquium, AmericanSociety for Engineering Education.

Parametric Technology Corporation, 2010,Mathcad, www.ptc.com/products/mathcad.

Shahnam, N. & Nirmal, K. D. 2002, Utilization ofMATLAB in Structural Analysis, Proceedings of the2002 ASEE/SEFI/TUB Colloquium, American Societyfor Engineering Education.

Smith, C. A. S. & Warner, R. F. 1992, Design ofcircular concrete columns using spreadsheets,Australian Civil Engineering Transactions, Vol. CE34,No. 4, pp. 337-342.

The MathWorks, 2010, MATLAB and Simulink forTechnical Computing, www.mathworks.com.

Waterloo Maple Inc., 2010, Math Software forEngineers, Educations & Students, www.maplesoft.com.

Welch, R. W., Ressler, S. J. & Estes, A. C. 2005, AModel for Instructional Design,Journal of ProfessionalIssues in Engineering Education and Practice, Vol. 131,No. 3, pp. 167-171.

Wenzel, T. H. 1987, Use of spreadsheet programsin teaching reinforced concrete design, Computer

Applications in Concrete Technology, ACI SP-98, Vol.149-158.

Wilson, E. L. 1991, CAL-91: Computer AssistedLearning of Static and Dynamic Analysis ofStructural Systems, UCB/SEMM-1991/01, Dept. ofCivil Engineering, University of California, Berkeley,1991-01 (500/C23/91/01/Ref.).

Wilson, E. L. 2010, Welcome to Ed Wilson, www.edwilson.org.

Wolfram Research, Inc., 2010, Mathematica, Technical

and Scientific Software, www.wolfram.com.


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APPENDIX: LISTING OF VBA UDFS USED IN THE ANALYSIS OF 2D TRUSSES

Function Truss_ke(E As Single, A As Single, L As Single) As Variant' This function calculates the element stiffness matrix [ke]' defined in the local axes and based on the element's Young's' modulus E, cross-sectional area A, and Length L.

' Define variablesDim arr(1 To 4, 1 To 4) As Single, Tmp As Single, _

I As Integer, J As Integer

' Check for correct lengthIf L = 0 ThenTruss_ke = "Member has zero length"Exit Function

End If

' Initialize the matrix [arr]For I = 1 To 4For J = 1 To 4arr(I, J) = 0#

Next JNext I

' Calculate the stiffness matrix [ke] defined in local axes

Tmp = E * A / Larr(1, 1) = Tmparr(1, 3) = -Tmparr(3, 1) = -Tmparr(3, 3) = Tmp

' Return the truss stiffness matrix [ke]Truss_ke = arr

End Function'========================================================================

Public Function Truss_T_Mat(Theta As Single)' This function calculates the transformation matrix of the truss' element based on the element inclination angle "Theta" measured' in Radians counter-clockwise from the global +ve horizontal x-axis

' Define variablesDim arr(1 To 4, 1 To 4) As Single, Pi As Single, Angle As Single, _I As Integer, J As Integer

' Initialize the matrix [arr]For I = 1 To 4For J = 1 To 4arr(I, J) = 0#

Next JNext I' Define Transformation matrix [T]arr(1, 1) = Cos(Theta)arr(1, 2) = Sin(Theta)arr(2, 1) = -Sin(Theta)arr(2, 2) = Cos(Theta)arr(3, 3) = Cos(Theta)arr(3, 4) = Sin(Theta)arr(4, 3) = -Sin(Theta)arr(4, 4) = Cos(Theta)

' Return the transformation matrix [T]Truss_T_Mat = arr

End Function


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'========================================================================

Function Truss_Kxy(E As Single, A As Single, L As Single, Theta As Single) _As Variant

' This function calculates the element global stiffness matrix [Kxy]' based on the element's Young's modulus E, cross-sectional area A,' Length L, and inclination angle "Theta" measured counter-clockwise' from the +ve horizontal x-axis.

' Define variables

Dim T As Variant, ke As Variant

' Check for correct lengthIf L = 0 Then

Truss_Kxy = "Member has zero length"Exit Function

End If

' Get the local stiffness matrix [ke]ke = Truss_ke(E, A, L)

' Get the transformation matrix [T]T = Truss_T_Mat(Theta)' T' Calculate [kxy] = [T] [k] [T]With Application.WorksheetFunction

Truss_Kxy=.MMult(.MMult(.Transpose(T),ke), T)End WithEnd Function

'=========================================================================

Public Function Kxy2S(Kxy As Range, LV As Range, S_Size As Integer) _As Variant

' This function fills the global structural stiffness matrix [S]' with values of the given element stiffness matrix [Kxy] based' on it location vector {LV}. The size of the global stiffness' matrix is S_Size.

' Define variables. Note that [S] is a dynamic arrayDim I As Integer, J As Integer, S() As Single

' Re-dimension [S] matrix with the right size

ReDim S(1 To S_Size, 1 To S_Size)

' Zero the [s] matrixFor I = 1 To S_Size

For J = 1 To S_SizeS(I, J) = 0#

Next JNext I

' Fill the [S] matrix with [Kxy] entriesFor I = 1 To Kxy.Rows.Count

For J = 1 To Kxy.Columns.CountIf LV.Cells(I)0 And LV.Cells(J)0 Then

S(LV(I), LV(J)) = S(LV(I), LV(J)) + Kxy.Cells(I, J)End If

Next JNext I

' Return [S]Kxy2S = S

End Function


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KHALED EL-SAWY

Dr Khaled M El-Sawy joined the Department of Civil and EnvironmentalEngineering at the United Arab Emirates University (UAEU) in August 1997 asan Assistant Professor in the area of Structural Engineering. He is currently anAssociate Professor in the Civil and Environmental Engineering Departmentand the Director, Unit of Research Support and Services. Khaled earned his

PhD in the area of soil-structure interaction from the Department of CivilEngineering, University of Western Ontario, Canada, in 1996. He receivedhis MSc from the same university in 1992 in the area of structural dynamics.Before joining UAEU, Khaled worked as a senior civil engineer in ENPPI, Cairo,Egypt. During the period of 1992 to present, Khaled has authored/co-authoredabout 40 technical research publications and technical reports in the areas oftrenchless rehabilitation, stability of steel members and plates, and education.He has taught many engineering and civil engineering courses. His teachinginterests include the teaching of Introduction to Programming, Computer AidedDrawing for Civil Engineering, Statics, Mechanics of Materials, ReinforcedConcrete Design, Design of Steel Structures, and Matrix Structural Analysis.

AMR SWEEDAN

Dr Amr MI Sweedan joined the Department of Civil and EnvironmentalEngineering at the United Arab Emirates University (UAEU) in August 2005 asan Assistant Professor of Structural Engineering. He earned his PhD in StructuralDynamics from the University of Western Ontario, Canada, in October 2003. Hereceived his MSc and BSc degrees in Structural Engineering from Ain ShamsUniversity, Cairo, Egypt in 1998 and 1992, respectively. Before joining UAEU,Amr held the position of a Senior Engineer at the head office of Rowan Williams

Davies & Irwin Inc., Consulting Engineers and Scientists, in Guelph, Ontario,Canada. Amr is an active member of several professional associations, includingthe Association of Professional Engineers of Ontario, the American Society ofCivil Engineers and the Structural Engineering Institute. He is a recipient ofseveral research awards from Natural Science and Engineering Research Councilin Canada, Ministry of Training in Canada, Colleges and Universities in Canada.He is also the recipient of several research grants from the Research AffairsSector at UAEU. Amr authored and co-authored over 30 technical publicationsin refereed journals, conference proceedings and project reports on structuraldynamics, fluid-structure interaction and finite element modelling of steel,masonry, and cardboard building and non-building structures.

Documents

Innovation use of computer tools in teaching structural engineering applications