(Solved): The composite shaft, consisting of aluminum, copper, and steel sections, is subjected to the loadin ...

The composite shaft, consisting of aluminum, copper, and steel sections, is subjected to the loading shown. Determine the displacement of end \( \mathrm{A} \) with respect to end \( \mathrm{D} \). The cross-sectional area and modulus of elasticity for each section are shown in the figure. Neglect the size of the collars at \( \mathrm{B} \) and \( \mathrm{C} \). Section \( A B \) is Aluminum with Young's modulus of \( 70 \mathrm{GPa} \) and an area of 64 \( \mathrm{mm}^{2} \). Section BC is Copper with Young's modulus of \( 126 \mathrm{GPa} \) and an area of 78 \( \mathrm{mm}^{2} \). Section CD is Steel with Young's modulus of \( 200 \mathrm{GPa} \) and an area of \( 42 \mathrm{~mm}^{2} \). The displacement of end A with respect to end \( D \) is ............... \( \mathrm{mm} \)