Upload
omar-bapokutty
View
150
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Chapter 1
Citation preview
BMCU 1022
EXPERIMENTAL METHOD
CHAPTER 1Introduction to Experimental
Method
Importance of experiment in science and engineering
Problem in engineering can be divided into 2 approaches:
1. Theoretical method
2. Experimental methodWorks on explaining or
forecasting the result of an experiment based on analytical model and physical concept regarding on some phenomenon.
The theory suggested will be tested, measurement of quantity, deciding conclusion and will be used for building a good exercise in conducting an experiment.
• Basic concept
• Main principle
• Analysis method
• Measurement system
• Apparatus system
• Hardware/ software
Knowledge needed: Knowledge needed:
List down the criteria for each theoretical method and experimental method.
CLASSIFICATION OF EXPERIMENT
Theoretical method Experimental method
Mathematical model analysis on real world, where assumption is needed
Analysis on real situation; assumption is not needed
Give general results for all type of problems
Give specific results
Relaxation in assumption lead to complexity of mathematical model
Measurement devices with high accuracy are needed, if use apparatus is more complex
Not need to have many accommodations (trained person, pen, pencil )
Complete and expensive laboratory accommodation is needed
Research can be started immediately
Time delay is needed for equipment’s preparing and testing
Criteria of theoretical method and experimental method
Experimental methodExperimental method involves manipulating one variable to determine if changes in one variables cause changes in another variable.
Objective: to determine the optimum strength of composite materials with different nanoclay loading amount.
Example
Variables:
1. Composite materials’ strength, Mpa
2. Nanaclay amount, wt% Varied, 1wt%, 2wt%, etc
Change/affected/result
This method relies on controlled methods, random assignment and the manipulation of variables to test a hypothesis.
Generally, the experiment will be conducted based on scientific method, which is basically been used for all type of experiment.
Scientific method1. Change only one variable at
one time,2. To test the method of
experiment3. To test the reproducibility
Experiment
Scientist
Engineer
To design an experiment that be used to prove the theory
To find the differences between result that been gathered from theory and experimental results
Generalized experimental methodObjective and preliminary planning of an exp.
Detail planning
Continuing on planning the methodology
Select instrumentation
Collect a few data & conduct a preliminary analysis
Collect the bulk exp. data & analyze the results
Organize, discuss and publish the findings
Modify the exp. Apparatus and/or procedure
Storing an experimental record“Main attention for experiment must be given to record each procedure in steps..”
Why we should record?
• next analysis can be implemented without many problems
• May be required to change a procedure, improvement of procedure or change in setting of equipment, etc.
• Reproducibility of an experiment
•…
“Main attention for experiment must be given to record each procedure in steps..”
Storing an experimental record
How to record?
• electronic devices – computer(Ms Words, etc.)• logbook/ laboratory journal
• Tools for arrangement and references when writing a report
• Main record in patent law
• Preparing the record for overall experiment
• Information storage regarding on the procedure that is difficult to find from journal articles
• As a note that explain the success or failure of an experiment
Logbook
Logbook has their role as:
Logbook
Must be binding; piece of paper are not allowed
All the pages must be numbered
• Design concept• first drawing or sketch• first explanation (writing)• first test or design• information regarding on first announcement to outside world
(Generally), must be included
Logbook for engineering studentFor engineering students, usually the experiments that been conducted are for:
• to understand a concept in textbook
• to implement a standard test; e.g. hardness test, tensile test
• to check performance of a machine
• to find physical coefficient; e.g. gravitational acceleration, elastic modulus for a metal, etc.
1.Use a bound notebook for your log2.Handwritten (exception: research is
primarily on the computer or use a handled PDA to records)
Recommended
Logbook for engineering student• Date of experiment
Date• Objective(s)
Objectives• Apparatus that been prepared; take note
regarding on how to use the apparatus, preparation, etc.
Apparatus• Create a table for the reading that been
taken, together with their UNITSTable/ Result• Record all information needed to decide an
overall experimental errorsAnalysis/
Data• Make a necessary decision in order to
evaluate an effectiveness and level of success for an exp. Plot a graph required together with their estimation error
Discussion• Give a comment regarding on the
experiment and discuss the result that been gathered through crotical thinking
Conclusion
• Experimental design can be concluded as: – Objective – Planning – Evaluation – Uncertainty analysis – Cost – Calibration – Data gathered – Data reduction
Conclusion1. Problem in engineering can be divided into 2 approaches:
a) Theoretical methodb) Experimental method
1. Concept2. Knowledge
3. Criteria
2. Stages of experimental method3. Storing an experimental method 4. Logbook
5. Logbook for engineering students
Date
Objectives
Apparatus
ResultsAnalysis/ Data
Discussion
Conclusion