Compression-compression fatigue of quasi-isotropic laminates: Failure mechanisms and link between dissipative behavior and fatigue life

Few studies have investigated the fatigue of composite laminates under cyclic compression loading. Moreover, the self-heating approach to rapidly predict fatigue life has rarely been applied to this type of material. The objective of this work is to study the fatigue of a quasi-isotropic laminate under compression-compression loadings and to assess the possibility of rapidly determining an endurance limit from a self-heating test. Compression-compression fatigue and self-heating tests were carried out on a carbon/epoxy quasi-isotropic laminate with a stress ratio of 10. Fatigue tests were conducted for lifetimes up to 108 cycles. The damage scenario is investigated by interrupting fatigue tests and conducting subsequent observations of the samples using scanning electron microscopy and X-ray micro-computed tomography. A methodology for analyzing self- heating tests is applied, which allows the determination of the mean volumetric intrinsic cyclic dissipation of the laminate from surface thermal measurements. A method using a viscoelastic constitutive law is proposed to estimate the endurance limit from the self-heating curve.