Solve the stress tensor at the location of strain gauge (red dot). Find the principle stresses and maximum shear stress. b) What is the strain tensor at the red-dot location? c) What are the readouts of each strain gauge?

Q4

A bar ABC of length L consists of two parts of equal lengths but different diameters. Segment AB has a diameter d 1 = 100 mm and segment BC has a diameter d 2 = 60 mm. Both segments have a length L / 2 = 0.6 m. A longitudinal hole of diameter d is drilled through segment AB in the middle of its length (distance L / 4 = 0.3 m). The bar is made of plastic with a modulus of elasticity. E = 4.0 GPa. Compressive loads P = 110 kN act at the ends of the bar. (a) If the shortening of the bar is limited to 8.0 mm, what is the maximum allowable diameter d max of the hole? (See figure part a.) (b) Now, if d max is set to d 2/2, at what distance b from the end C must the load P be applied to limit the shortening of the bar to 8.0 mm? (See Figure part b.) (C) Finally, if the loads P are applied at the ends and d max = d 2/2, what is the allowable length x of the hole if shortening is limited to 8.0 mm? (See figure part c.)

For a conductive wire with length L=1cm,w=1mm, h=1mmunder uniaxial strain, the resistance change is given as. If the uniaxial strain is e= 1 and the Poisson’s ratio is n= 0.3. What is the gauge factor?