Two 3/8 in thick steel plates are fastened "clamped" together by a 1/2 in -13 UNC bolt as shown in the previous figure (i.e. problem 2). When the plates are initially assembled (i.e. before an external load is applied), the bolt is tightened to a torque of 57 ft lb. The "screw coefficient of friction" and the "collar coefficient of friction" are μ = μc = 0.15. The collar diameter d. 1.5d. What maximum external load "F" can be applied to the bolted connection if the minimum allowable clamping force "F" is 2000 lb? The elastic modulus for the bolt is E₂ = 30 x106 psi and the elastic modulus for the plates is E₁ = 26 x10 psi. (Hint: Use Equation 10.14 Pg 401 (Textbook) and Figure 10.28 Pg 402 (Textbook) to determine the bolt stiffness k, and the clamped member stiffness k. Assume that the threads stop immediately above the nut.) Ans. Fe 6131 lb d₁ 30° Conical effective clamped volume d3- (Hexagonal bolt head and nut)