A novel meso-scale method to study the damage evolution of composite film layer in the aircraft windscreen film–substrate system

Purpose In order to study the failure mechanism of micro-nanometer film layers on aircraft canopy, a method to simulate the damage process of composite film layers at mesoscopic scale is proposed and validated. Design/methodology/approach We proposed a finite element methodology for the failure study of micro-nanometer film layers in aircraft windscreen covers. Findings (1). The relative error between the two proposed equivalent algorithms is small, only 5.7%, which effectively verifies the reasonableness of the calculation model. (2). The loading mode affects the transmission process of the stress wave in the film–substrate system. (3). The cohesive model accurately simulates the bonding behavior between the film layers, and the cohesive interface is not degraded, indicating that the composite films designed in this paper have a strong bonding force between the layers. Research limitations/implications The limitation of the study lies in the fact that the meso-scale failure simulation method proposed in this paper requires further experimental validation. Practical implications A solution for failure assessment and optimal design of micro-nanometer composite film layers on the fighter aircraft windscreen is provided. Social implications This study is conducive to a more comprehensive understanding of the failure mechanism of the composite film layer on the windscreen of fighter aircrafts. Originality/value (1).The two equivalent algorithms proposed in this paper can simulate the damage evolution of windscreen composite film layers on mesoscopic scale, determine the destructive strains of the key film layer under the corresponding loading environments. (2).The mesoscopic failure mechanism of the key film layer was revealed by a proposed new methodology. (3). The effect of the four-point bending loading mode on the stress propagation process in composite film layers is innovatively discussed and ideas for improvement are presented.