A single 6 -mm-diameter steel pin $B$ is used to connect the steel strip $D E$ to two aluminum strips, each of 20 -mm width and $5-\mathrm{mm}$ thickness. The modulus of elasticity is 200 GPa for the steel and 70 GPa for the aluminum. Knowing that for the pin at $B$ the allowable shearing stress is $\tau_{\mathrm{all}}=85 \mathrm{MPa}$, determine, for the loading shown, the maximum strain energy that can be acquired by the assembled strips.