OPTIMAL SYNTHESIS OF HOT COMPOSITE LAMINATES WITH INTERPHASE LAYERS

A method for the optimal grading of a single interphase layer in metal -matrix composite laminates for the minimization of residual stresses is described. The capability to simultaneously ailor some fabrication parameters is also incorporated. Applications for unidirectional, cros s-ply and quasi-isotropic graphite/copper laminates are investigated t o assess the potential of the interphase layer in reducing matrix resi dual stresses in various laminate configurations. Simultaneous optimiz ation of interphase and fabrication characteristics appears to be more effective in decreasing residual stresses. The results also indicate that the interphase layer is more effective in lowering residual stres ses in unidirectional composites and selectively within individual pli es of a laminate. Embedded interphase layers in all the plies did not produce a significant global reduction in residual stresses.