An investigation of fracture and fatigue in a metal/polymer composite

This paper presents the results of a combined experimental and analytical s tudy: of the fatigue and fracture behavior of a polymer/metal composite tha t was developed recently for self-lubricating applications in automotive en gines that utilize liquefied natural gas as fuel. For comparison, the micro structure and the fatigue and fracture behavior of a non-polymer containing "matrix" material are also presented. Since the crack profiles observed in both systems under monotonic or cyclic loading reveal significant componen ts of ligament bridging, micromechanics models are presented for the modeli ng of crack bridging. The resulting predictions of resistance-curve behavio r an compared with measured resistance curves. The shielding effects of lig ament bridging are also quantified under cyclic loading. The implications o f the work are also discussed for the modeling of fatigue damage and fractu re in polymer/metal coatings.