David — A Multybody Virtual Dummy for Vibrational Comfort Analysis of Car Occupants

Abstract

The development of virtual simulators can avoid to set-up expensive test rigs, time-consuming tests, and is a winning strategy to be more competitive in road-vehicles market. Moreover vibrational comfort analysis is an important topic in vehicle design [1] and the possibility to perform virtual vibrational tests on the effects of changing some parameters is useful tool for the designer. A literature search reveals that most of the simulation models in the field are based on elementary linear models [12]. In some cases, finite elements are used, but this approach involves a large amount of parameters to be defined and managed. Thus the authors of this paper developed a virtual dummy model by means of multibody techniques. The formulation is the one described in Haug’s text book [4]. The code, named DAViD (the acronym of Dynamic Automotive Virtual Dummy), can mimic the non linear behaviour of a 3D human body model and requires a very small set of body data. The model is completely parametric and can be automatically scaled to simulate a significant portion of population. The code can be also linked to experimental results of accelerometers time histories to perform multi-input analysis based on seat input (translational and rotational), steering wheel input and pedals input. Driver and occupants can be both simulated.