Collapse of channel section composite profile subjected to bending. Part I: Numerical investigations

The paper deals with four-point bending tests of thin-walled channel section beams, made of eight-layer GFRP laminate. In the performed tests two scenarios were investigated: beams were bent in the plane with lowest second moment of area and beams were subjected to bending in the plane passing through the geometrical centre of the flanges of channel section profile and parallel to the plane with the highest second moment of area. Six arrangements of layers were analysed: [0/−45/45/90]S, [90/−45/45/0]S, [90/0/90/0]S, [0/90/0/90]S, [45/−45/45/−45]S, [45/−45/90/0]S. The experimental research was conducted with the use of the ultimate testing machine, additionally designed test stand and the digital image correlation system Aramis®. Numerical analyses have been performed in the Ansys® software, based on the finite element method. In geometrically nonlinear analysis two algorithms, indicating failure mechanisms, were applied: progressive failure analysis with material property degradation method and anisotropic Hill potential theory with assumption of perfect plasticity.