Collapse behaviour and simplified modeling of triangular cross-section columns

This paper investigates and develops the collapse behaviours and characteristics of thin-walled columns with triangular cross-section under axial compression and pure bending. Two bending modes, inward bending and outward bending are discussed. The axial and bending resistances of the triangular columns are formulated with mathematical equations of simple forms. Simplified finite element models for the triangular columns are then developed based on the derived equations to simulate their axial buckling and bending collapse behaviours during crashes. The developed simplified models consist of beam elements and spring elements. Numerical results and comparisons show that the developed simplified models can replace detailed models using for crashworthiness analysis and save a lot of computing time and modeling efforts. The presented simplified models and modeling efforts can be extensively applied in thin-walled structural analysis and design.