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A thin cylindrical shell with 2500mm length,300mm internal diameter and 6mm thick., is subjected to an internal pressure of 2MPa.Calculate the change in length, change in diameter and change in volume

Mumbai university > mechanical engineering > sem 3 > strength of materials

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$\eta_L = 80\% = 0.8\ \eta_c = 50\% = 0.5\ E = 200GPa = 200\hspace{0.05cm}\times\hspace{0.05cm}10^3\ \mu = 0.286\ d = 300\hspace{0.05cm}mm\ l = 2500\hspace{0.05cm}mm\ t = 6\hspace{0.05cm}mm\ P = 2\hspace{0.05cm}MPa = 2\hspace{0.05cm}N/mm^2$ Circumferential stress $\sigma_c = \frac{Pd}{2t.\eta_L} = \frac{300\hspace{0.05cm}\times\hspace{0.05cm}2}{2\hspace{0.05cm}\times\hspace{0.05cm}6\hspace{0.05cm}\times\hspace{0.05cm}0.8} = 62.5\hspace{0.05cm}N/mm^2$ Longitudinal stress $\sigma_L = \frac{Pd}{4t.\eta_c} = \frac{2\hspace{0.05cm}\times\hspace{0.05cm}300}{4\hspace{0.05cm}\times\hspace{0.05cm}6\hspace{0.05cm}\times\hspace{0.05cm}0.5} = 50\hspace{0.05cm}N/mm^2$ For $\delta d\ e_c = \frac{\sigma_c}{E} - \mu\frac{\sigma_L}{E} = \frac{62.5}{200\hspace{0.05cm}\times\hspace{0.05cm}10^3} - 0.286\frac{50}{200\hspace{0.05cm}\times\hspace{0.05cm}10^3}\ e_c = 2.41\hspace{0.05cm}\times\hspace{0.05cm}10^{-4}\ e_c = \frac{\delta d}{d}\ \delta d = 0.0723\hspace{0.05cm}mm$ For $\delta L\ e_l = \frac{\sigma_L}{E} - \mu\frac{\sigma_c}{E}\ e_L = 1.606\hspace{0.05cm}\times\hspace{0.05cm}10^{-4}\ e_L = \frac{\delta L}{L}\ \delta L = 0.4015\hspace{0.05cm}mm$ For $\delta v\ e_v = e_L + 2e_c\ \hspace{0.25cm} = 6.426\hspace{0.05cm}\times\hspace{0.05cm}10^{-4}\ e_v = \frac{\delta v}{V}\ \delta v = 113556.79\hspace{0.05cm}mm^3$

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