(Solved): 5. A bimetallic strip 200mm long with steel and brass strips each 1.5mm thick rests on a le ...

5. A bimetallic strip $200\mathrm{mm}$ long with steel and brass strips each $1.5\mathrm{mm}$ thick rests on a level surface with the brass up most. If the strip is initially straight, find the maximum 1 clearance between it and the surface, and the maximum stress in the brass and the steel following a temperature rise of $60^{\circ }\mathrm{C}$. Take ${\alpha }_{\mathrm{br}}=1.9\times 10^{-5}\rho {}^{\circ }\mathrm{C},{\alpha }_{\mathrm{st}}=1.1\times 10^{-5}{\rho }^{\circ }\mathrm{C},{\mathrm{E}}_{\mathrm{st}}$ $=205\mathrm{GPa},{\mathrm{E}}_{\mathrm{br}}=97\mathrm{GPa}$ (Ans. $1.2\mathrm{mm},26\mathrm{MPa},44\mathrm{MPa}$ ).