A Systematic Approach Towards Integrated Safety Modelling for Aerospace Applications - Preliminary Results on Rigid Seat Simulations

Kurzfassung

In the aviation sector, the historically evolved crashworthiness requirements prescribe seat certification separately from the airframe structure. Based on historical test and accident data the airframe crash behaviour is presumed in terms of crash pulses, which are applied to the seat structure for seat certification (e.g. EASA CS-23/25.562). Certification authorities have recently started to change the regulations from a prescriptive to a performance-based certification, considering the crash performance with the seats integrated in the airframe structure (EASA CS-23 Amendment 5). With this, occupant safety and structural crashworthiness is combined to an integrated safety approach. Due to the high cost of full-scale testing in the aviation sector, extensive use of simulation is of interest. Modelling methods are continuously being developed for crash loading conditions relevant to aerospace, which significantly differ from automotive ones. The German Aerospace Center (DLR) Institute of Structures and Design has extensive experience in developing simulation methods for aircraft crash analysis. In an effort to develop an integrated safety modelling approach for aviation, a research initiative was launched to incorporate advanced passenger safety considerations. In the first phase, methodologies for modelling and simulation of current certification tests are developed. This includes seating procedures for finite element (FE) anthropomorphic test devices (ATDs) and seat belt modelling methods. Future steps include the investigation of advanced ATDs and human body models, the implementation of seat and passenger systems into structural crash models and the consideration of novel cabin layouts. SAE Aerospace Recommended Practice 5765B defines a means of assessing the credibility of computer models of aircraft seating systems used to simulate dynamic impact conditions. This includes supplementary test data of sled tests with aerospace approved ATDs on a rigid seat, which are the basis for validation of the developed methodologies in this first phase of the project. This paper describes a systematic approach to integrated safety modelling for aerospace applications. Additionally, preliminary results of the first phase for LSTC Hybrid 3 and Humanetics Hybrid 2 ATD models on a rigid seat are presented. The simulation study was conducted using LS-DYNA®.