For linear elastic systems, the type of displacement function for the strain energy is

A simply supported beam of uniform rectangular cross-section of width $$b$$ and depth $$h$$ is subjected to linear temperature gradient, $${0^ \circ }$$ at the top $${T^ \circ }$$ at the bottom, as shown in the figure. The coefficient of linear expansion of the beam material is $$\alpha .$$ This resulting vertical deflection at the mid-span of the beam is

A stepped steel shaft shown below is subjected to $$10$$ $$N$$-$$m$$ torque. If the modulus of rigidity is $$80$$ $$GPa,$$ the strain energy in the shaft in $$N$$-$$mm$$ is

A truss, as shown in the figure, is carrying $$180$$ $$kN$$ load at node $${L_2}.$$ The force in the diagonal member $${M_2}{U_4}$$ will be