Finite element analysis of a thin-shell concrete sandwich panel under eccentric loading

This paper presents finite element (FE) analysis of the structural behavior of a concrete sandwich panel that is 210 mm thick. The analyzed section is composed of two concrete layers that are 70 mm thick, and a thermal polystyrene insulation layer that is 70 mm thick placed in between. This wall section is commonly used as a precast non-bearing external wall. However, the intent of this study is to investigate the structural performance of such a sandwich panel as a load-bearing element under eccentric axial loading. A nonlinear FE model for a concrete sandwich panel was developed for this purpose using ABAQUS commercial software, implementing a displacement-controlled analysis to trigger failure of the wall element. The composite action of the sandwich panel resulted in a ductile failure mode instead of sudden crushing, and its ultimate capacity exceeded the design load expected for a typical G + 2 residential building. The load vs axial displacement response of the panel exhibited a linear behavior up to 70% of the ultimate capacity in which the two concrete layers displayed equal lateral displacements. However, different lateral displacements were encountered along the height of the two concrete layers during the nonlinear stage, starting from the top and continuing to grow down to separate the two layers. First and second modes of buckling were observed at the linear and nonlinear stages, respectively.