Q.4) By using the strain rosette shown in figure below, we obtained the following normal strain data at a point on the surface of a machine part made of steel [E = 207 GPa, v= 0.29]: Eg = 770 µ , & = 520 µ, & = - 435 µ (a) Determine the strain components &, &y, and %y at the point. (b) Determine the principal strains and the maximum in-plane shear strain at the point using Mohr's circle. (c) Draw a sketch showing the angle p, the principal strain deformations, and the maximum in-plane shear strain distortions. (d) Determine the magnitude of the absolute maximum shear strain.

A strain rosette was attached to the outer surface of stainless vessel when the vessel is in a stress-free state. The vessel was then put under a complex loading (pressure, bending and torsion) state. The train readings for the three strain gage elements in the strain rosette were recorded as: Ea=210, Eb=160, Ec-330, all in micro-strains. The mechanical properties of the stainless material are known: E=193 GPa, G=76 GPa, v=0.27, oy=205 MPa. Calculate the following: 1. Principal strains and in-plane maximum shear strain. 2. Principal stresses and absolute maximum shear stress. 3. The factor-of-safety based on the maximum shear stress failure theory. 4. The factor-of-safety based on the maximum distortion energy failure theory. 45° 45° b 45° strain rosette X

2. The stress-strain behavior of a ductile cast iron of diameter 15.8mm and a gauge length of 60.80mm is shown below, 400 300 200 100 0.00 0.10 Strain Determine the following: (a) the modulus of elasticity (b) yield strength at a strain offset of 0.002. Stress (MPa)

Three readings are obtained from an equiangular strain gage rosette mounted on a free and unloaded surface of a part. Determine the magnitude of the principal strains and their orientation with respect to the 0° gage. Check the results with a Mohr circle.Assume The three known strains are all linear strains