*10-68. A rod is made from two segments: AB is steel and BC is brass. It is fixed at its ends and subjected to a torque of T = 680 N-m. If the steel portion has a diameter of 30 mm, determine the required diameter of the brass portion so the reactions at the walls will be the same. Ga = 75 GPa, Ge = 39 GPa. 10-69. Determine the absolute maximum shear stress in the shaft of Prob. 10-68. i.60m 680 N-m 0.75 m

Part 2,3,4

Pin-connected rigid bars AB, BC, and CD are initially held in the positions shown by taut wires (1) and (2). The bar lengths are a = 36 ft and b = 27 ft. Joint Cis given a horizontal displacement of 5.7 in. to the right. (Note that this displacement causes both joints B and C to move to the right and slightly downward.) What is the change in the average normal strain in wire (1) after the displacement? B (1), a (2) Answer: = i (0)

Determine the maximum moment in kip-ft for the beams shown below using th method of consistent deformations. Select the reaction at the interior support to b the redundant. Express your answer in absolute value and use two decimal places 3 k/ft -B 25 ft 15 ft 21 E = 29,000 ksi I= 2,500 in.+