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On behalf of NHTSA and the Dutch Ministry of Traffic and Transport the Safety department of TNO Automotive is performing numerical fleet studies using multi-body models. Aim is to develop strategies for optimization of front-end structures minimizing the total harm in car-to-car crashes on a fleet-wide basis. For these studies multi-body models are being constructed from existing finite element models. Front-end structure and passenger cell are modeled in detail to provide realistic deformation modes. Furthermore dummies, airbags, belts and main interior parts like dashboard and steering wheel are included. Currently four models are available, each of a different vehicle class. To indicate the performance of the multi-body vehicle models for crashworthiness optimization of a fleet a study on offset frontal impacts is performed. Using the multi-body models a series of parameter sweeps over relevant accident and design parameters were performed.

This paper discusses the structural assessment of a heavy truck cabin with respect to occupant response in test designed to simulate a frontal collision. ECE R29 describes a series of test conditions to which truck cabins should comply, however these tests do not consider the occupant directly. ECE-R29 uses prescribed limits of cabin crush to ensure occupant protection rather measuring occupant injury based on Anthropomorphic Test Devices (ATDs), or dummies. The “Swing Bob” dynamic test procedure prescribed by ECE R29 is used as a basis for assessing survivability. An existing Finite Element model of the truck cabin has been used in conjunction with a Hybrid III 50th%ile dummy model in the Crash Victim Simulator, MADYMO. A computer analysis has been performed and found that injury to the occupant in the lower leg region in this kind of impact is likely to be survivable.

The vehicle design environment from a crashworthiness and safety perspective has become increasingly complex in recent years. New legal requirements imposed by the European Union (EU) and the United States National Highway Traffic Safety Administration (NHTSA) have created a design space of great complexity with many parameters that must be balanced to arrive at an overall design that performs adequately in all of these situations. The customer introduces further complexity through the addition of Consumer requirements in many markets that will influence a purchasing decision. In order to design to all of these conditions, an approach of using physical testing solely has problems associated with it. Due to the prohibitive nature of vehicle prototypes and limited availability during Engineering Development, other tools such a Computer Aided Engineering (CAE) have become popular.

The objective of this work was to create mathematical models of the BioSID side impact test dummy, for use in side impact simulation studies. Two dummy models were created - a multibody model, and a finite element model. The models have been validated according to the procedures described in the BioSID User's Manual[1]. The responses of both models were within the required corridors for most of the specified calibration tests, and during these test conditions the behaviour of the models correlated well with physical dummies. The models are now being tested in numerical side impact models of the vehicle. Each dummy model is particularly suited to different tasks: The multibody model is used in a lumped-mass model of the vehicle side structure, for studying the door padding and door intrusion characteristics.