Q.12. In a tensile test a test piece of 25 mm diameter, 200 mm gauge length, stretched 0.0975 mm under a pull of 50 kN. In torsion test, the same rod twisted 0.025 radian over a length of 200 mm when torque of 0.4 kNm was applied. Evaluate poisson's ratio and three elastic moduli for the material. Ans. Young's Modulus Using the relation, we have

An aluminum pipe (modulus of elasticity 10.1x10^6 psi) is fixed at one end and is subjected to a tensile load of 127.5 kips at the free end. The length and cross-sectional area of the pipe is given as 36.1 in and 9.11 in^2. Assume that the aluminum pipe has clockwise torques (100 lb-in) acting at the midpoint and free end of the pipe. (a) Derive the element stiffness matrix

Stress (MPa) 2000 Using the stress-strain results shown in the figure, determine the 0.2% offset yield strength and the strain at the onset of necking. Indicate both on the graph and write the value along with units in the space provided. MPa 2000 1000 1000 0.000 0.005 0.010 0.015 Strain 0 0.000 0.020 0.040 0.060 0.080 Strain 100 300 Yield Strength units: 200 Stress (10³ psi) Strain at the onset of necking: units:

The beam shown in Fig QB1 is made from aluminium tube of rectangular cross-section having a vertical height of 50mm, a horizontal width of 30mm and a wall thickness of 3mm. The dimensions given in the figure are in millimetres. The yield stress in tension is 200MPa; Young's modulus is 71GPa. Determine: an expression for the bending moment at every point in the beam and draw the bending moment diagram a) b) c) d) the maximum bending moment the maximum longitudinal stress the maximum vertical deflection 200 3kN 200 1kN 100