LAUSR

This study aims to correlate a newly proposed local time-dependent indicator of the damage accumulation in a thermoplastic laminate matrix with the degradation of the mechanical properties of the material as a whole. The material tested here is a carbon fiber–reinforced plastic used in the aircraft industry. Isothermal fatigue transient tensile loading and three-point bending are used for full-scale tests. The results of fatigue pulsating tension loading of the laminate are presented together with the outcomes of nondestructive measurements of the residual stiffness of the laminate. Local elastic and time-dependent properties of the laminate matrix, used as nondestructive indicators of the degradation of the matrix caused by repeatedly applied loads, are compared with the full-scale outcomes. The results confirm that the microindentation technique applied to the laminate matrix can be a suitable method for assessing the influence of fatigue tensile loading on the basic and time-dependent properties of the laminate.