Research on theoretical modeling and numerical simulation of viscoelastic-plastic bending neutral layer in T-welding stiffened panels-based aged stress relaxation forming

Abstract

A new mathematical model-based on aging-stress relaxation forming for heterogeneous stiffened panel that is T-welded together is developed. The corresponding theoretical method for calculating its neutral layer positions and forming die shapes in viscous-elastic-plastic bending is obtained by gradually deriving the modeling process of age forming of T-section beam, and comparisons of the theoretical data and simulated solutions are presented. It is found that the hot form solutions can be obtained for cylindrical die shapes, and the actual neutral layer position of stiffened panel can be accurately determined by the established theoretical model. Meanwhile, for the elastic bending and plastic bending stages, the neutral layer positions of stiffened panel are greatly different. The neutral axis of the former passes through its section centroid, while the latter does not, but it gradually, but significantly shifts to the outer layer of thin plate as the bending radius of die decreases.