THE YIELDING BEHAVIOR OF UNIDIRECTIONAL METAL-MATRIX COMPOSITES.

摘要

The primary yielding behavior of unidirectional metal-matrix composites (aluminum alloy reinforced with high strength stainless steel wire) was shown to be dependent on the residual stress state of the matrix when the composite is subjected to uniaxial loads applied parallel or perpendicular to the fiber direction. More specifically, the yield point was found to be elevated if the sign of the deviatoric component of the residual stress state, associated with the matrix, in a direction parallel to the test axis, opposes that of the applied load. Further, the onset of yielding was accelerated if the sign of the matrix deviator and applied load were the same. These conclusions were based on a number of experiments which included tensile and compressive prestraining, refrigeration and completely reversed strain cycling of composite specimens. In addition, analytical techniques were used to estimate the residual stress distributions and predict composite behavior.