EMM 302: Solid and Structural Mechanics I First Semester Examination

Solid mechanics paper. A steel bar loaded along three axes gives the change in volume and the adjustment to one load that would leave the volume unchanged. Two wires of copper and steel carrying the same load provide the elongations needed to find the modulus of copper, and a stepped bar held between two stops gives the stresses in its parts when the gap closes. A steel rod inside a brass tube closed by washers and nuts is worked twice: the stresses after the nuts shorten the tube, and the resultant stresses after the assembly is heated. A rosette of strain gauges on a loaded aluminium structure gives the missing reading, the principal stresses, the maximum shear stress and Mohr's circle, while a stepped partially hollow shaft under opposite torques gives the diameter that equalises shear stress between sections and the total angle of twist. Closes on a thin cylindrical vessel under internal pressure with longitudinal and circumferential joint efficiencies.