Post-buckling Behavior and Imperfection Sensitivity of L-frames

In this paper, a detailed analysis is conducted to study the influence of the geometric parameters, boundary conditions as well as initial imperfections on the nonlinear response and imperfection sensitivity of L-frames. An efficient nonlinear finite element formulation for the analysis of planar elastic frames is used together with incremental-iterative strategies. This enables one to obtain the highly nonlinear equilibrium paths exhibited by L-frames under certain loading conditions and identify the bifurcation and limit points along these equilibrium paths. These results provide some insight as to the source and mechanism of asymmetric bifurcation and imperfection sensitivity in frames thus helping engineers to evaluate the importance of geometric nonlinearities in the analysis and design of slender elastic frames.