A theoretical and experimental study on in-plane buckling of orthotropic composite arches under an arbitrary radial point load

Nonlinear in-plane buckling behavior of fixed orthotropic composite arches under an arbitrary radial point load is investigated theoretically, numerically and experimentally in this paper. Analytical solutions that include the bending-stretching coupling effect are developed for both critical buckling load and nonlinear equilibrium path and are validated by the finite element model. A variable-speed displacement control loading system with automatic loading direction adjustment is designed and set up for the test to record the complete buckling evolution process. Comprehensive analytical and experimental results for the critical buckling load and nonlinear equilibrium path of the arches are presented in both tabular and graphical forms, followed by a parametric study with a particular focus on the influences of loading position, stacking sequence as well as the rise-span ratio on the buckling load. Research results indicate that the buckling mode of the composite arch is highly dependent on the modified slenderness ratio. Both buckling mode and the switching modified slenderness ratio are significantly influenced by the loading position. The buckling load is also highly sensitive to stacking sequence and decreases as the 90 degrees lamina is placed far away from the mid-plane.