The vehicle design process for occupant safety is becoming more and more demanding. Design requirements defined by (new) regulations and consumer tests are continuously increasing in both stringency and complexity, making the optimization process for restraint systems increasingly complex. Virtual testing can make a valuable contribution to the design process, as it reduces development time. It also allows engineers to test for solution robustness and determine the sensitivities of the design parameters. For the virtual testing approach to be successful, simulations must be acceptable in terms of accuracy and efficiency.
MADYMO has introduced new Quality rated (Q) dummy models using advanced multi body techniques, in order to obtain short computation times combined with the geometry and accuracy of finite element models. Together with this new generation of numerical dummy models, objective rating methods have been introduced in the Quality reports that are delivered with the Quality rated dummy models.
The objective rating method is completely integrated in the numerical dummy design process. After two years of experience using this method, remarkable conclusions can be drawn. This paper will describe these conclusions both with respect to hardware repeatability and with respect to numerical model accuracy. For studying the repeatability of hardware dummies, the objective rating method was applied on the test signals from repeated tests. Two questions that are answered in this paper are (1): how should the numerical model address hardware repeatability issues and (2): what can be expected from the accuracy of numerical models when the variability in experimental results is considered?