Drone and bird strike on a polycarbonate helicopter windshield

Kurzfassung

A helicopter is especially at risk to bird and drone strikes due to its flight envelop, whereby the windshield is the most frequently affected component. In recent years, several helicopters have had to make emergency landings due to impact damaged windshields. Polycarbonate can be used to achieve high impact resistant windshields as some already existing solutions show. In the present contribution the impact resistance of polycarbonate windshields is studied using numerical simulation. Therefore, an impact simulation model of a helicopter canopy with an adhesively bonded polycarbonate windshield is created. The impactors were modelled using SPH (bird) or solid elements (drone) and validated with impact tests. The behavior of transparent polymers like polycarbonate is rate and temperature dependent, which is why different rate dependent material models were studied. To characterize the polycarbonate, tensile tests at different rates were performed. This data combined with test data from four-point-bending and plate impact tests as well as literature data were used to calibrate the material models. The material damage was considered using *MAT_ADD_DAMAGE_GISSMO.