Material Nonlinearity Effects in the Stress Analysis of Conical Disk Springs

The influence of material nonlinearity on the behavior of conical disk springs (Belleville springs) is investigated by means of finite element models. Both the load-deflection curve and the stress field of this kind of spring are shown to be significantly affected by the elastic-plastic behavior of the material. In particular, as far as the actual stress field is concerned, consideration of the material nonlinearity explains some apparent contradictions of well-known analytical formulations, such as the Almen-La´szlo´ theory, based on the usual assumption of linear elastic behavior of the material.