a circular aluminum tube of L=600 mm is loaded in compression by forces P. The outside and inside diameters are d2=75 mm and d1=63mm, respectively. A strain Gage is placed on the outside of the tube to measure normal strains in the longitudinal direction. Assume that E=73 GPa and Poisson's ration v=.33.
a) If the compressive stress in the tube is 57 MPa what is the load P?
b)If the measured strain is e=781x10^-6, what is the shortening of the tube? What is the percent decrease in its cross-sectional area? What is the volume change of the tube?