Characterization of Mechanical Damage Mechanisms in Ceramic and Polymeric Matrix Composite Materials.

摘要

In order to better establish the fundamental mechanisms responsible for the onset of microstructural instability during compressive loading, several fiber-reinforced polymeric matrix composites were tested under conditions involving hydrostatic confinement. It was found that the dependence of strength upon pressure was mild, indicating that the overwhelming factor in the compressive failure of these materials, irrespective of fiber type, matrix, composition, and composite architecture, is resistance to shear loading; dilatational mechanisms, certainly ones associated with microfracture, are relatively insignificant. Specific strength levels do appear to be controlled by both inelastic and plastic flow properties of the matrix, and reflect the degree to which the matrix can restrain either the flexure of locally misaligned fibers, or the shear displacement of non-axial cross-plied fibers in more complex composite lay-ups.