5.1

A pair of 48-in-long bars and a pair of 60-in-long bars are symmetrically attached to a rigid disc at a radius of 2 in at one end and built into the wall at the other end, as shown in Figure P5.l. The shear strain at point A due to a twist of the rigid disc was found to be 3000 ?rad. Determine the magnitude of shear strain at point D.

Figure P5.1

5.2

If the four bars in Problem 5.1 are made from a material that has a shear modulus of 12,000 ksi. determine the applied torque T on the rigid disc. The cross sectional areas of all bars are 0.25 in ².

5.3

If bars AB in Problem 5.1 are made of aluminum with a shear modulus G _al = 4000 ksi and bars CD are made of bronze with a shear modulus G _br = 6500 ksi, determine the applied torque T on the rigid disc. The cross-sectional areas of all bars are 0.25 in ².

5.4

Three pairs of bars are symmetrically attached to rigid discs at the radii shown in Figure P5.4. The discs were observed to rotate by angles ?; ₁ = 1.5 ?, ? ₂ = 3.0 ?, and ? ₃ = 2.5 in the direction of the applied torques T ₁, T ₂, and T ₃, respectively. The shear modulus of...