FE simulation of soft wing impactor for aviation mast frangibility testing - sensitivity to model assumptions

摘要

In 1981, the International Civil Aviation Organization (ICAO) instigated the Frangible Aids Study Group' (FASG), with the aim to define design requirements and crash test procedures addressing the frangibility of airport navigation aids and their support masts. The FASG group soon stated that a specific wing section model should be used as a standard test impactor. This paper describes an attempt to model and verify a virtual model of a wing impactor based on static and dynamic compression test sensitivity analyses. The motivation is to define a standard FE model that will ultimately reduce the need for physical testing, while providing improved opportunities for understanding mechanisms and design parameters related to frangibility. The sensitivity to finite element (FE) model assumptions is studied to ensure a representative deflection-force characteristic for crash tests. The study shows that strain at a fracture value of 15% combined with a bi-linear hardening model gives the most reliable simulation results. This material combination also seems to give the most correct wing impactor behaviour in high-speed crash simulations. The simulations also prove that 1kHz low pass filtering of reaction forces efficiently eliminates artificial peak forces not contributing to wing damage.