Response of thin flexible compression columns with self-reacting lateral constraint

Abstract

The study investigates the effects of self-reacting lateral constraint on the compression load capacity of thin composite columns. A dynamic finite element analysis model is developed to aid in the optimization of the column lateral constraint which leads to a 50-fold increase in load capacity over the first critical buckling load. First, the model is compared against known analytical solutions for a column buckling between bi-lateral constraints. Next, the constraints are made to float and self-react, and the model is developed to study the role of column geometry, material properties, and initial gap between the column and lateral constraint on post-buckling response. Experiments are conducted over a wide range of column lengths and gap thicknesses and the load-deformation response including snap-through buckling loads, and buckling modes are measured and compared to model predictions. It is shown that the load capacity of thin composite columns can be increased to an upper bound governed by the membrane compressive strength of the column by using optimal constraint conditions.