- To understand the principle of uniaxial tensile testing and collect the required mechanical properties by operating the tensile testing machine.
- To be able to explain stress-strain relationships and represent them in graphical forms.
- To evaluate the values of ultimate tensile strength, yield strength, percent elongation, fractural strain, and Young's Modulus of the selected metals of aluminum when subjected to uniaxial tensile loading.
- Finally, to be able to explain deformation characteristics of the selected material when subjected to uniaxial tensile loading.
Each laboratory group will test at least one sample each of Aluminum, Brass or steel for tensile testing.
1. Measure the diameter and length of each test sample using a ruler and Vernier calipers. Find out the type of sample, alloy type, and chemical composition.
2. Mark a gage length of 2" on the sample.
3. Load the sample into the tensile testing machine. Follow instructor's guidelines in loading the sample.
4. Select the appropriate testing parameters. Note down all the selected test parameters in your note book.
5. Perform a uniaxial loading test, using a deformation rate specified by the instructor.
6. Record the load and extension in the sample at frequent intervals.
7. Save a screenshot of the uniaxial loading tests for each of the samples tested.
8. Save the acquired data.
9. Measure the change in length and diameter of the sample after fracture. The fractured surface of the sample should not be touched. A photograph of the fractured surface should be included in the Laboratory Report.
10. Repeat Steps 1 through 1 for 6 for all samples.
Prepare a report of the type set forth in the course syllabus. The report is to include the following data and analysis:
1. Using complete load-elongation data, prepare and plot an Engineering Stress-Strain curve for all the specimens tested. Engineering Stress shall be plotted as the ordinate.
2. Collect the test data from other groups in your laboratory section and include in your analysis and laboratory report.
3. Perform statistical analysis, such as finding the mean and standard deviation for the collected and analyzed data.
4. All the raw data could be included in the appendix and report the average value of the mechanical properties in the report in a tabular form.
5. Data should be reported in a tabular form as well as in graphical form, as shown in Figure 6.20(b) of the text book: Materials Science and Engineering, W.D. Callister, Jr., and D. G., Rethwisch, 9th Edition, Wiley, 2014.
6. The data points should include the average mechanical property; error bars that indicate the degree of scatter corresponding to the average value plus and minus the standard deviation. Use appropriate units for all the mechanical properties.