Full vehicle crash tests are never fully identical in terms of their results, even when conducted with the same configuration. This variability arises from the existence of a diverse set of uncertain input parameters, which induces uncertainty in the relevant quantities of interest (QoI). The classical engineering approach, dealing with scattering system behavior and QoI, is to introduce safety factors and thus ensuring the system’s robustness with respect to the adherence of performance-relevant criteria. However, using this strategy within the vehicle safety design process carries the risk that the margins to specific limits might be exceeded in initial hardware tests.
Attributable to model size and complexity of numerical crash simulations, it is not feasible for the engineers to analyze each area or component in detail, especially when these are not the core subject of investigation. In the field of occupant safety, the main explanatory objective is given by the signals of anthropometric test devices (ATD), as they are relevant for the fulfillment of legal regulations and consumer protection guidelines. Hence, this study proposes a data-driven methodology to automatically determine deviations in ATD behavior in a set of simulations and provide possible causes for the prevalence helping the engineer to understand simulations faster and to ensure quality.
In 2024 the European New Car Assessment Programme (Euro NCAP) Virtual Testing Crashworthiness (VTC) procedure for far-side impact is introduced. The LS-DYNA DYNAmore WorldSID 50th dummy model will be part of this procedure. Separate qualification criteria must be satisfied for the WorldSID model. They are specified in Technical Bulletin TB043-1 [1]. LS-DYNA DYNAmore WorldSID 50th version 8 will be the first model with the official certificate to satisfy all the defined criteria of TB043-1. TB043-1 includes three different stages of certification. Normative dummy requirements are checked in the first stage. Component level tests of head-neck and lumbar spine represent the second stage. The last stage includes a new full dummy sled test scenario representing the far-side load case. The dummy model must pass all three stages to be fully certificated.
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.
Uncertainty Sources in WorldSID-50M Dummy