Methodology of residual strength prediction of composite structures with low-velocity impact damage based on NDT inspections and numerical-experimental CAI testing

Abstract

One of the most challenging tasks is to evaluate a structural condition and predict a residual strength when damage is present in a composite structure. Such a prediction is usually performed based on experimental destructive testing on specimens, which often does not reflect the geometrical complexity of a component with damage, or based on numerical simulations, which are difficult to parametrize due to the complexity of fracture mechanisms of composite materials. In this paper, we proposed a hybrid methodology based on evaluation of results of the ultrasonic non-destructive testing technique supported with numerical modeling and compression after impact (CAI) tests to evaluate residual strength of glass- and carbon-reinforced polymer composite structures. Based on ultrasonic C-scans processing and incorporation of impact damage shapes in numerical models and further evaluation of the obtained results in the light of CAI tests, the model for the prediction of residual strength in composites was developed.