An Analysis of Interlaminar Stress Gradients and Impact Damage in Graphite-Epoxy Laminates

摘要

Interlaminar stress gradients caused by an internal disbond and by low velocity impact are analyzed using 3D finite elements. The disbonded (O/+ or -45/O2//-45/45/O) laminate warps out-of-plane under biaxial compression without large stress gradients. A much thicker 48 ply laminate (+ or -45/O2/+ or -45/O2/+ or -45/O/90)2S is analyzed for impact by a steel sphere that strikes the laminate off-center. Large subsurface shear stresses occur around the perimeter of the contact area with a sinusoidal distribution. These results were obtained using the PATCHES-III program with new constraint elements for modeling laminates. (Author)