A thin-walled cylinder with closed ends contains oxygen at a high internal pressure, which creates a hoop tensile stress twice the axial tensile stress in its wall. Assume that the fibers carry all load and there is no interaction between the layers. Show that the optimum winding angle in the filamentwound cylinder is 54.740 . (10’)

In a unit cell of fcc structure, indicate the position of one of the tetrahedral interstitial sites by plotting the corresponding tetrahedron. do the same for one of the octahedral interstitial sites (in a separate fcc unit cell). mark the positions of all the tetrahedral and octahedral interstitial sites in the unit cells. how many equivalent tetrahedral sites and how many equivalent octahedral sites are contained in a fcc unit cell, respectively. what is the coordination number for a tetrahedral site and what is the coordination number for an octahedral site?