Abstract
Coiled springs are often subjected to lateral loads and bending moments in addition to longitudinal loads. Moreover, the nonlinearity increases as the longitudinal load increases. In this paper, two-dimensional deformation of the coiled springs were analyzed under the longitudinal loads, the lateral loads and the bending moments, namely complex loads, by means of the theory of large deformation. Through this analysis, the relation between complex load and displacement was obtained, and it was made clear that the nonlinearity increases as the longitudinal load increases. The behavior of coiled springs which have a slenderness ratio less than the theoretical buckling limit was also obtained, from the relation between the eccentric load and the deformation. Moreover, an experiment was carried out and the results agreed well with the theoretical value.
