(Solved): ? Problem 2: Three wooden planks are fastened together by a series of bolts to form a column. The di ...

Problem 2: Three wooden planks are fastened together by a series of bolts to form a column. The diameter of each bolt is \( 12 \mathrm{~mm} \) and the inner diameter of each washer is \( 16 \mathrm{~mm} \). Determine the smallest allowable outer diameter " \( \mathrm{d} \) " of the washers, knowing that the average normal stress in the bolts is \( 36 \mathrm{~N} / \mathrm{mm}^{2} \) and that the bearing stress between the washers and the planks must not exceed \( 8.5 \) \( \mathrm{N} / \mathrm{mm}^{2} \). (25 pts).