MEC2402: An aluminum solid round bar is clamped at one end and loaded in torsion at the other end. The loaded end of the bar is constrained: Stress Analysis Report, USQ, Australia

Torsion test analysis

Review the video record of the torsion test within the Assignment 2 folder: “torsion_test.mp4”. For this experiment, an aluminum solid round bar is clamped at one end and loaded in torsion at the other end. The loaded end of the bar is constrained with a roller bearing so that no vertical deflection of the bar occurs. Torque is applied through a load cell at the end of a lever arm and the angle of twist is determined from the measured linear displacement of the end of the lever arm.

• Calculate the value of J for the section
• Plot the data available from the video showing the relationship between the torque and the angle of twist. By adopting this axis arrangement, you achieve a plot that is analogous to the load-displacement diagram conventionally presenting the tension test results.
• On the plot produced for the part, also include a line representing the theoretical result from Module 4 based on the geometry and relevant material properties for the aluminum shaft.
• Discuss the comparison between the experimental results (part b) and the theoretical results (part c) and identify possible reasons for any differences you observe.
• Calculate the maximum value of shear stress which would have been acting within the circular bar when the highest load was applied.
• Design a hollow shaft made from steel that has the same length and stiffness as the aluminum shaft, but carries a maximum value of shear stress that is 2.5 times larger than that of the aluminum shaft when the highest load is applied. Specify the outer and inner diameters of this steel shaft.