Dynamic crack propagation
Taking into account the lightweight design concept, composite materials are increasingly used in primary and secondary structural components of modern airplanes such as the A 350 or the B787. Composite materials are characterized by excellent in-plane properties but are susceptible to damage by loading in thickness direction due to their layered structure. A tool drop onto the wing of an airplane, hail damage, or the collision with a bird are typical examples of such loading scenarios.
During the design of aircraft structures, numerical simulation methods are increasingly used in order to guarantee the safety of aircraft structures under impact loading. The determination of strain rate dependent material properties is indispensable for predictive simulations but is often difficult. At Fraunhofer EMI, a novel experimental setup for measuring fracture mechanical parameters under dynamic loading using the Hopkinson Bar has been developed in cooperation with a customer. Thus, significant contributions to the safety of new generations of airplanes can be made.