Assignment-1

1. A uniform tensile specimen of 30 mm length and 6 mm dia is strained upto 0.1%. Calculate the load exerted on the specimen and elongation of the specimen when half the current load was applied. 2. A thin cylindrical pressure vessel with flat end caps are designed to withstand internal pressure. The space provided to accommodate the vessel is 1.6 m x 1.6 m x 3 m. The maximum wall thickness of the vessel can be 8 mm. If the allowable working stress is half the yield strength, calculate maximum internal pressure the vessel can withstand, without failure. 3. A biaxial state of stress at a point is given as σx = -560 kg/cm2, σy = -280 kg/cm2 and τxy = 140 kg/cm2. Construct the Mohr’s circle to find out the principal stresses, orientation of the principal planes and maximum shear stress plane from current orientation. 4. Derive the membrane equation for thin shell. What will be the value of circumferential stress in a thin walled spherical vessel? 5. A hollow cylindrical steel shaft is 1.5 m long and has inner and outer diameters respectively equal to 40 and 60 mm. i) What is the largest torque that can be applied to the shaft if the shearing stress is not to exceed 120 MPa? ii) What is the corresponding minimum value of the shearing stress in the shaft?