An FSRW numerical simplification approach for vehicle frontal crashworthiness analysis

Vehicle frontal crashworthiness analysis is an important topic in the field automotive community, as it relates to legislative requirements. Frontal crash models contain a large number of elements and therefore present a high computational cost, especially when performing crashworthiness structural performance optimisations. A new numerical methodology is proposed in this paper with the aim to increase computation speed by implementing a sub-modelling approach on the frontal structure-rear wheels (FSRW) method. In this new method, the vehicle body structure behind the rear seats is replaced by a point mass, with an equivalent mass to the rear structure removed, and attached to the rear frame of the front structure and its wheels. This new method was rigorously tested against validated full size vehicle computer models of different classes provided by NHTSA, and included MPV, SUV, van, and sedan, against fixed rigid barrier (FRB), small overlap and a mobile progressive deformable barrier (MPDB) tests. The research has demonstrated that this new sub-modelling approach correlated against all the full size NHTSA computer models in deformations, intrusions, velocities, and accelerations, as well as providing a runtime average reduction between 7% and 23%. This new simplified method, which can be easily implemented, is innovative and will have an important impact vehicle design, as it will allow an easier use of optimisation techniques, which will lead to safer vehicles.