Numerical Prediction of Local Instability in Double Corrugated Profiles

The technological process of forming the double-corrugated structures of the K-span system causes deep transverse embossing on the surface of the profiles. Such profile geometry makes it difficult to apply classical theories related to plastic failure mechanisms to identify the formation of local instabilities. This article presents an original method for the prediction of local instabilities of double-corrugated structures. The method was developed on the basis of a hierarchical validated FEM model. The geometrically and materially nonlinear analysis method was adopted to perform numerical calculations. The results of calculations enabled the determination of reference equilibrium paths for the eccentrically compressed shell element. Based on the analysis of nonlinear equilibrium paths, a method for predicting the beginning and the end of the appearance of local instabilities in the elastoplastic pre-buckling range was developed.