A body structure for an automotive vehicle includes an enclosure for a power source, an upper shear structure assembly and a lower shear structure assembly. The enclosure includes a front cross-member, a rear cross-member, a left rocker and a right rocker. The upper and lower shear structure assemblies are disposed across the top and bottom of the enclosure, respectively, and are fastened to respective top and bottom surfaces of the cross-members and rockers. The upper and lower shear structure assemblies may include respective front and rear generally trapezoidal sections configured for attachment to respective front and rear box structures. Each of the shear structure assemblies is effective to dissipate in-plane a portion of an external load imposed upon the enclosure.