Incorporation of measured geometric imperfections into finite element models for cold-rolled aluminium sections

Abstract

Geometric imperfections have a significant effect on both buckling and strength capacities of structural members. It is essential to accurately measure the geometric imperfections for finite element simulation especially for thin-walled sections. This paper presents the procedure to measure and incorporate geometric imperfections into finite element models using ABAQUS software package with the focus of attention for cold-rolled aluminium sections. Laser scanners are firstly used to measure geometric imperfections along high-precision tracks while recording the distances to corresponding points on the surface of specimen. The measurement lines are located around the cross-section. Subsequently, a MATLAB code is developed to incorporate the measured imperfection magnitudes into a perfect mesh of the finite element model. The Fourier series approximation is used in the longitudinal direction along measurement lines while the linear interpolation is used for flanges, lips and web in the transverse direction.