Modeling of Micromechanisms of Fatigue and Fracture in Hybrid Materials.

摘要

The obvious benefits of the design of aerospace structures using lighter materials with high specific strengths and stiffnesses had led to the development of numerous reinforced composite metallic and intermetallic materials, which have become serious commercial competitors to traditional monolithic metallic alloys. While significant advances in processing technology have made the fabrication of such hybrid materials more of an economic reality, their widespread use in airframes or other structures has been limited by serious deficiencies in mechanical properties, particularly ductility, toughness and fatigue. This problem is compounded by the lack of fundamental studies which provide a rational basis for the underlying sources of crack-propagation resistance, and in particular which define the critical role of composite microstructure. Keywords: Fatigue; Fracture toughness; Subcritical crack growth; Metal-matrix composites; Laminates; Fatigue cracks; Crack closure; Crack bridging; Aluminum alloys; Titanium alloys. (JES)