Q2: The two wooden boards shown in figure are connected by a 12.7 mm diameter bolt. Washers are installed under the head of the bolt and under the nut. The washer dimensions are D 50.8 mm, and d = 15.875 mm the nut is a 12.7 mm zinc finish grade A finished Hex Nut. The nut is tighten to cause tensile stress of 62 MPa in the bolt. a) Determine the bearing stress between the washer and the wood. b) Determine the bearing stress between the nut and the wood if there is no washer is used in the connection. Bolt D Washer Nut Washer Q2 A bending moment of 4 kNm is found to cause elastic failure of a solid circular shaft. An exactly simila shaft is now subjected to a torque T. Determine the value of T which will cause failure of the shaft according to the following theories: (a) maximum principal stress; (b) maximum principal strain; (c) maximum shear strain energy. (v = 0.3.) Which of these values would you expect to be the most reliable and why?