01408744

8/2/2019 01408744

1/6

Session S2G

0-7803-8552-7/04/$20.00 2004 IEEE October 20 23, 2004, Savannah, GA

34th

ASEE/IEEE Frontiers in Education Conference

S2G-18

Early Introduction of CAE Tools Enhances Success

In Student Design CompetitionsCraig J. Hoff

1, Travis Slagle

2, Alan Lo

3, Paul Zang

4, William K. Waldron

5

1 Craig J. Hoff, Kettering University, Department of Mechanical Engineering, Flint, MI, 48504, [email protected] Travis Slagle, Kettering University, Department of Mechanical Engineering, Flint, MI, 48504, completed BSME December 2003.3 Alan Lo, Kettering University, Department of Mechanical Engineering, Flint, MI, 48504, completed BSME December 2003.4 Paul Zang, Kettering University, Department of Mechanical Engineering, Flint, MI, 48504, [email protected] William K. Waldron, Kettering University, Department of Mechanical Engineering, Flint, MI, 48504, [email protected]

Abstract The Society of Automotive Engineers (SAE)

Formula Car events are the premier competitions for

automotive engineering students worldwide. Student

teams from accredited engineering educational

institutions are asked to design and build small open-

wheel, Formula-One style vehicles. Younger members on

the teams (freshman and sophomores) are often asked to

design parts for the vehicle, long before they have

completed the necessary core engineering courses. At

Kettering University early introduction of CAE tools in

the curriculum has helped to enhance the students ability

to compete. With a high level of motivation, the team

members are able to leverage their basic understanding ofengineering and engineering tools to perform engineering

analysis and design at a much higher level than one would

expect. The early exposure to CAE tools has resulted in a

number of successes for the Kettering Formula Car team

including a 6th placed finish (out of 140 vehicles) in the

Formula SAE design event

Index Terms Computer Aided Engineering, Design

Competitions, Student Design Projects

BACKGROUND

The Society of Automotive Engineers (SAE) Formula Carevents are the premier competitions for automotive

engineering students worldwide. Student teams fromaccredited engineering educational institutions are asked to

design and build small open-wheel, Formula-One style

vehicles. Since its humble beginnings in Texas with four

teams in 1981, the competition has grown to over 200 teams,participating in events held in the United States (Formula

SAE), Europe (Formula Student), and Australia (FormulaAustralasia) each year. The worlds automakers have

embraced the competition supporting it financially and

providing judges, stewards, and event workers. They also use

the event as a major recruiting ground for their future

engineering talent.The competition rules place restrictions on the car frameand engine to ensure that the vehicles are safe and to ensure

that the students knowledge, creativity, and imagination are

tested. The vehicles are judged in both static and dynamic

events. The static events consist of: an engineering design

review (written and oral), a manufacturing and cost report

(written and oral), and a marketing presentation (oral only).

The dynamic events consist of: an acceleration test, a skid

pad test, an autocross (to test maneuverability and handling),

and a demanding fuel economy and endurance test. Thevehicles must also pass a comprehensive safety inspection,

noise inspection, and brake test.

The points possible for each event are given in Table I.

Quality engineering design work is crucial, both directly (theengineering design is worth 150 points) and indirectly (as a

good engineering design is the key to being successful in the

dynamic events).

TABLE IAVAILABLE POINTS IN EACH EVENT [1]

Event Available Points

StaticPresentationEngineering DesignCost Analysis

DynamicAccelerationSkid PadAutocrossFuel EconomyEndurance

Total Points

75150100

7550

15050

350

1000

There are many models used for creating the Formula

Car team. At many universities the vehicle is used as the

subject of the capstone project course(s), in which case the

team members consist of senior-level students. In other

universities the vehicle is setup as a club activity, whichmeans students of all educational levels can join the team.

Other universities have a hybrid structure of the two basic

approaches.

At Kettering University the Formula SAE (FSAE) team

is a club activity. Historically, most of the team members aremechanical engineering students, although it is highlydesirable to recruit students from electrical engineering,

manufacturing engineering and even the managementprogram. Students may join the race team as freshman and in

fact it is very important to recruit them as freshman.

Experience shows that if a student does not join the team as a

freshman, the student will get involved in other campus

8/2/2019 01408744

2/6

Session S2G


34th


S2G-19

activities and the chances of them joining the FSAE team are

small. To keep them on the team, it is important to get

students involved in club activities. This requires giving theteam members meaningful engineering projects.

The major disadvantage of this approach is that the

students are asked to design parts for the car long before they

take the core engineering courses which are essential to

designing a race car. For example the university offers

courses in Finite Element Analysis, Automotive Powertrains,Vehicle Dynamics and Chassis Systems, but those courses

are not available to the students until they have senior

standing. Other core courses such as Solid Mechanics,

Dynamics and Machine Design are not available to students

until they are sophomore or juniors. Still, even freshman team

members are able to contribute to the success of the projectdue to the early introduction of Computer Aided Engineering

(CAE) tools in the Kettering University mechanical

engineering curriculum.

Beginning with their first term at the university, studentslearn the essentials of Engineering Graphics and Solid

Modeling through the use of a series of software tools

obtained through the PACE Program Grant of GeneralMotors, EDS PLM Solutions and SUN Microsystems.

Initially, students use Solid Edge to produce solid models and

then progress to Unigraphics and I-DEAS as the models grow

in complexity and sophistication. A follow up course in thestudents sophomore year

6extends the students knowledge of

solid modeling and introduces the concepts of finite element

analysis (FEA) and mechanic system dynamics simulation

(MSD).

USAGE OF CAETOOLS

With the early introduction of basic CAE tools in the

students curriculum along with a high-level of motivationthe team members are able leverage their basic understanding

of engineering and engineering tools to perform engineering

analysis and design at a much higher level than one would

expect. A partial list of the CAE tools employed by theFormula Car team is given in Table II.

TABLE IIPARTIAL LIST OF ENGINEERING SOFTWARE USED BY TEAM

Software Name Use

EDS I-DEAS Solid Modeling, Mechanical andThermal Modeling

EDS Unigraphics Solid Modeling

MSC. Adams Mechanical System DynamicsGT Power Engine Simulation

Fluent Computational Fluid DynamicsPi Sim Racecar data acquisitionElectronics Workbench Electrical Design

6 Beginning in 2004 Solid Mechanics will be a prerequisite to the secondCAE course, to better prepare the students for the discussion of FEA. Thismeans that the second course will be pushed back to the first term of thestudents junior year.

For purposes of this discussion the software may be used

in two ways, either to do analytical work or to do non-

analyticalwork. Analytical work requires a greater level ofengineering knowledge on the part of the student than non-

analytical work. Analytical tasks include FEA and MSD

analysis. Non-analytical tasks, such as basic component

design and computer-aided manufacturing, can be assigned to

lower-level students than the analytical tasks.

One of the first tasks that younger students take on isbasic component design. Before the vehicle can be

manufactured the vehicle and its components need to be

visualized. Solid modeling allows the students to design their

components and to check on how their components will fit

into the vehicle. Exploded views (such as Figure 1) can be

used to look for interferences, assembly and packagingissues. The use of solid models allows the student to focus

on the overall product development rather than simply

drafting.

FIGURE 1EXPLODED VIEW OF FRONT UPRIGHT ASSEMBLY GENERATED USING

I-DEASSOFTWARE

The first use of analytical software by the team members

is usually conducting FEA analysis of their components. The

basic concepts of FEA (create part, mesh part, apply

boundary conditions, apply load, calculate stress, evaluatestress, redesign part as needed to minimize stress ordeflection) is quickly learned, although considerable

monitoring of their work is required. At this point the

students do not have the necessary experience to recognize agood mesh from a bad mesh, understand the appropriate size

for the mesh (they tend to use a much finer mesh than is

necessary), nor do they have a feel for knowing when it isappropriate to simplify a part (for example by taking out

9011234

(McMaster)

3/8-24 x 2

24 lb-ft

9152834

(McMaster)

5/16 shoulder

1/4 20 x 1/2

20 lb-ft

04-G2-120/5

Front UCA

block (L/R)

04-G2-100/5

Front upright

(L/R)

04-G2-150/5

Steer arm

block (L/R)

02-G2-251

Front brake

rotor

02-G2-227

Front brake

rotor hat

44610-HN2

(Honda)

Hub

5206BZZ/2A

(NTN)

Wheel bearing120-2498

(Wilwood)

Front brake

caliper

02-G2-202

Front brake

caliper bracket

9011234

(McMaster)

3/8-24 x 2

24 lb-ft

9152834

(McMaster)

5/16 shoulder

1/4 20 x 1/2

20 lb-ft

04-G2-120/5

Front UCA

block (L/R)

04-G2-100/5

Front upright

(L/R)

04-G2-150/5

Steer arm

block (L/R)

02-G2-251

Front brake

rotor

02-G2-227

Front brake

rotor hat

44610-HN2

(Honda)

Hub

5206BZZ/2A

(NTN)

Wheel bearing120-2498

(Wilwood)

Front brake

caliper

02-G2-202

Front brake

caliper bracket

8/2/2019 01408744

3/6

Session S2G


34th


S2G-20

fillets) before they mesh. Of most concern is the fact that

they are not always able to recognize bad results.

What they do understand that FEA is a powerful tool thatallows them to make endless iteration attempts without

spending a penny on materials. They also learn that even if a

FEA package does not provide exact results, the relative

increase/decrease in part stiffness or strength is a valid tool

for evaluating competing designs.

An example of this is the design of the vehicles frame.The students started out with a target for the frames torsional

stiffness of 2000 ft-lb/deg, which is a value that they arrived

at through their independent reading of books on the subject

and from discussions with the design judges at previous

competitions. To complicate the process this stiffness must

be achieved while keeping the weight of the frame under 45lb. After evaluating many frame topologies and considering

alternate tubing size, their FEA analysis (Figure 2) indicated

that the target was met. However, after building the frame

and physically testing the structure, they found the stiffness tobe much smaller than expected, around 1200 ft-lb/deg.

FIGURE 2FINITE ELEMENT ANALYSIS OF FORMULA CARFRAME

The reason for this discrepancy is that the joints are

infinitely rigid in the simple beam element FEA model.However, in building their frame manufacturing inaccuracies

mean that the frame tubes do not fit together perfectly. As

the students welded the frame together they filled the gaps

between the tubes with filler rod. The result being that the

joints were not anywhere near being perfectly rigid and therigidity of their frame was much lower than their FEA

predicted.This is an invaluable lesson. The FSAE team members

understand the limitations of their computer models. They

also understand that even though the absolute values of their

answers may not be correct, they can still use the relative

values of the results to identify designs that are superior toothers. This understanding helps the team to increase the

integrity of their future analyses.

The solid models then allow the students to quickly

move from the design environment to the manufacturing

environment. It is a relatively straight forward matter totransfer the solid models to CNC milling machines for

production. The CNC technique can significantly reduce the

time needed to produce a part, and as with any engineering

project time is precious commodity.

CNC manufacturing is not currently taught in the

Mechanical Engineering curriculum. Historically, the teamhas been able to identify one or two members who will

become the manufacturing expert(s). These students take the

CNC course offered in the Manufacturing Engineering

Department. Once they have been certified with the course

instructor, they are given access to the CNC machines.

Recently, a new approach has been tried with greatsuccess. The instructor of the CNC course has agreed to use

FSAE parts for projects in his course. This approach requires

that the design work be completed long before the start of the

term in which the CNC course is taught. This year one of thecourse projects was to manufacture the wheel hub assembly

(see Figure 3). In the future additional parts can be made this

way.

FIGURE 3WHEEL HUB ASSEMBLY MANUFACTURED USING CNCMACHINES

Another important application of analytical software is inevaluating the vehicles suspension. An MSC.ADAMS/Car

full-vehicle model is shown in Figure 4. The software gives

the user a wide variety of simulation tools both in kinematics

and dynamics. Suspension roll center locations and

movements, camber curves, damper motion ratios, bump

steer, roll steer, and many other parameters can bedetermined at the click of a mouse rather than laboriously

laying out the geometry by hand.

8/2/2019 01408744

4/6

Session S2G


34th


S2G-21

FIGURE 4FULL-VEHICLE SUSPENSION ANALYSIS IN MSC.ADAMS/CAR

The full-vehicle dynamics capabilities allow the studentto test their vehicle on a track before a single part is made.

This requires that suspension geometry be determined,

masses and inertias of components be input, and criticalcomponents be chosen and modeled. The output of this

model may also be used to determine loads, which become

inputs to FEA analysis of the frame and suspensioncomponents.

The quality of the chassis design can be assessed in

several ways. Ultimately, it is assessed by the performance

on the vehicle on the racetrack. Additionally, it is possible to

instrument the vehicle with a data acquisition system to look

at specific measures of vehicle performance such as lateral

acceleration, roll rates, etc. The Kettering FSAE teamarranged for the donation of a Pi Research data acquisitionsystem and has used it to evaluate their car (see Figure 5).

The FSAE team uses parametric engine models, as

shown in Figure 6, to gain insight into internal combustionengines. This approach is much more accessible than

building prototype engines and gives a better starting point

for developing the engine on the dynamometer.

As a final example, thermal finite element analysis

module in I-DEAS allowed the team to properly size the

components for the custom engine igniter shown in Figure 7.This analysis allowed the team to quickly perform thermal

analysis of the part that resulted in a five pound reduction in

overall vehicle weight.

FIGURE 5SUSPENSION EVALUATION USING PI RESEARCH DATA ACQUISITION SYSTEM

FIGURE 6PARAMETRIC ENGINE MODEL DEVELOPED WITH GTPOWER

FIGURE 7THERMAL MODEL OF AN ENGINE IGNITER

8/2/2019 01408744

5/6

Session S2G


34th


S2G-22

The use of these advanced CAE tools has paid off for the

Kettering Formula Car team. In 2000, the team won the

Formula Student Best Use of CAE Tools award and in2003 the team placed 6th (out of 140 vehicles) in the Formula

SAE design event. The early exposure to the CAE tools was

essential to making this possible.

PEDAGOGY

The SAE Formula Car events are unsurpassed as learning

opportunities for automotive engineering students. It has

been shown that the key to knowledge transfer is the amountof time devoted to acquiring skills within a domain [2]. The

main factor that influences the time that students will spend

working in a domain is motivation. Studies by NSF

Coalitions [3-7] and other math/science educational groupshave identified many methods which seem to motivate

students including problem-based learning, reality-basedlearning and service-learning.

According to Project Kaleidoscope, the ideal model for

learning science and mathematics in college has three

irreducible qualities:

The learner is enmeshed in a community of learners; The learning experience is personal; The learning established connections that place science

in context. [9]

The FSAE competitions more than meet each of thesecriteria. The FSAE team members are firmly enmeshed in a

community of learners. The team members spend countless

hours working together in order to determine how to make

the car faster, lighter, or more nimble. The more experienced

members of the team are constantly teaching and encouraging

the eager new team members.This community is not restricted to simply the members

of a single team, but it extends to the members of other teams

both nationally and internationally. A great amount of timeat the Formula Car events is spent talking with and learning

from the other teams that are present. Discussion boards,websites [8-11], and email exchanges are used by students to

share their ideas and to offer tips on how to successfully

overcome difficulties.

The learning experience is personal. Each member of

the team is trying to help make the vehicle more competitive.

They are willing to learn whatever they need in order toaccomplish their objectives. The most dedicated members of

the team are willing to devote countless hours to this effort.Often this means that the students are learning subjects on

their own, long before they take a class on the subject (or forthat matter long before they take the prerequisite to the class

on the subject).The learning is establishing connections that place the

science in context. For example the concept of stress has real

meaning to these students, particularly if a part fails in a race

or in practice. The goal for the students is clear to build a

winning car. Engineering becomes a tool to help them reach

their goal.

In many ways the members of the FSAE teams should beconsidered non-traditional or adult learners. There

learning behaviors are not characteristic of typical

undergraduate students. They are self-directed in their

learning and they tend to act more mature than theirclassmates. The behavior of FSAE team members fits neatly

into several of the key assumptions that help define Knowlesandragogy [12]. These behaviors include:

The need to know. Adult learners need to know whythey need to learn something before they undertake

learning it. In this case if FSAE team members are

shown that something is important to be learned (by aninstructor or by a team mate) they are much more likely

to attempt to learn it.

Learner self-concept. Adult learners need to beresponsible for their own decisions and need to be treated

as being capable of self-direction. Advising the FSAEteam is often challenging because the students often tend

to think that they dont need advising. On the other handit is also quite easy, since the team members dont have

to be told what to do and how to do it. They readily take

on that responsibility.

Orientation to learning. Adult learners are motivatedto learn what they perceive will be helpful in their own

life situations. In this case if the FSAE team members

see that what they are learning in the classroom can be

applied to making their vehicle more competitive, theypay much more attention in class.

This same orientation to learning is what drives the

students to tackle learning advanced CAE tools. They never

seem to stop to think Gee, I havent had that class yet, so Icant do it. They look at what they need to do to accomplish

a task, and then they proceed to learn what they need to learnin order to accomplish the task. This leads the team members

to conduct advanced engineering analysis that their school

mates would never considering doing.

CONCLUSION

The early introduction of CAE tools and the students high

degree of motivation allows them to accomplish tasks that

one would expect to be well beyond their capability. Formany students participation in the FSAE competition is the

educational highlight of their time spent at the University.The use of CAE tools clearly enhances the teams success in

the competition and better prepares them for their engineeringcareers.

8/2/2019 01408744

6/6

Session S2G


34th


S2G-23

REFERENCES

[1] Formula SAE Rules, Society of Automotive Engineers, Warrendale,PA, 2004. (www.sae.org/students/fsaerules.pdf)

[2] Bransford, J.D., Brown, A.L., Cocking, R.R., Donovan, M.S.,Bransford, J.D., and Pellegrino, J.W.,How People Learn: Brain, Mind,Experience and School, National Academy Press, Washington, DC,2000. (http://www.nap.edu/catalog/9853.html)

[3]

NSF Foundation Coalition website (www.foundationcoalition.org)[4] NSF Gateway Coalition website (www.gatewaycoalition.org)[5] NSF Greenfield Coalition website (www.greenfield-coalition.org)

Author's Last name,

[6] NSF SUCCEED Coalition website (www.succeednow.org)[7] NSF Synthesis Coalition website (www.synthesis.org)[8] Official SAE Formula Car website

(www.sae.org/students/formulaseries.htm)

[9] Unofficial SAE Formula Car website (fsae.com)[10] Official IMECHE Formula Student website

(www.imeche.org.uk/formulastudent/index.htm)

[11] Official SAE Formula Australasia web site (www.sae-a.com.au/fsae/)[12] Knowles, M.S., Swanson, R.A., Elwodd, F.H., The Adult Learner: A

Neglect Species (5rth Edition), Elsevier Science & Technology, 1998.

Documents

01408744