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

This article presents the results of a combined experimental and analytical study of the fatigue and fracture behavior of a polymer/metal composite wh ich was developed recently for self-lubricating applications in automotive engines that utilize liquefied natural gas as fuel. For comparison, the mic rostructure and the fatigue and fracture behavior of a nonpolymer-containin g "matrix" material are also presented. Since the crack profiles observed i n both systems under monotonic or cyclic loading reveal significant compone nts of ligament bridging, micromechanics models are presented for the model ing of crack bridging. The resulting predictions of resistance-curve behavi or are compared with measured resistance curves. The shielding effects of l igament bridging are also quantified under cyclic loading. The implications of the work are also discussed for the modeling of fatigue damage and frac ture in polymer/metal coatings.