Abstract
In this paper, we propose a finite displacement modeling technique based on the total Lagrangian formulation for the structural analysis of two-dimensional (2D) framed structures connected by flexible joints. Our proposed model consists of beam segments with three-node elements and flexible joints with multi-rotational nodes, which have higher rotational degrees of freedom for deformation compared with those of a classical continuum beam model. Therefore, the category of this model can be regarded as a piecewise C1 continuum beam model with rotational discontinuity on the joints. The objective of this study is to understand both the buckling modes and the post-buckling behaviors, which are key issues to understanding the integrity of the framed structures. Large elastic deformation simulations of the proposed model reveal that a 2D repetitive structure with finite square grids has biaxial symmetry buckling as a higher-order mode under uniaxial compression and has redundant post-buckling deformability, which rigid-jointed structures might not have.
