A composite bar is constructed from a steel rod of 50 mm surrounded by an aluminum tube of 100 mm outside diameter and 51.60 mm inside diameter. The rod and tube are joined by two 25 mm diameter pins. After pinning, the temperature is raised by 20 C. For steel E 200 GPa and = 11.7x10-6/C. For aluminum E 70 GPa and a = 23.0x10-6/C. = = a. Determine the internal force induced by changed in temperature and the partial retraining of the material due to pinning. b. Determine the shear stress develop in the pin. 100mm 2.5mm Aluminum Pins Steel 50mm 25mm