Development of a FEM Pelvis Model for Analysis of Pressure Distributions

Higher demands by people on the performance of vehicles and the comfort-related physical complaints by professional drivers have led to an increasing demand for more comfortable cars. Car manufacturers use comfort as an item to distinguish themselves from their competitors. However, the development and introduction of a new, more-comfortable car seat or interior is time consuming and costly. The use of computer models of human and seat could facilitate this process.

Literature showed that pressure distribution is proposed as an objective factor relating to the personal subjective feeling of comfort. For that reason, a detailed finite element model of the pelvis and the thighs has been developed in MADYMO, an explicit non-linear dynamic code with combined multibody-FE capabilities. In the model, the bony structures of the iliac wings, sacrum, coccyx and femora have been represented. The soft tissues (such as muscles and fat) have been lumped together and the skin has been modelled separately. The element size was set to 1 cm to accurately predict the pressure under the bony structures. The effects of variations in human flesh and cushion stiffness on the predicted pressure distribution have been analysed in a parametric study with the FE model. The results of this study show the promising possibilities and applications of the model.