Cracked Membrane Model: Finite Element Implementation

In this paper, the cracked membrane model is developed into a finite element formulation for the analysis of orthogonally reinforced structural elements in plane stress (such as deep beams and walls). The cracked membrane model falls into the category of "compression field models" combining elemental components from the modified compression field approach with those of the tension chord model. The tension stiffening effect is modeled using a stepped, rigid-plastic steel–concrete bond relationship. The tension stiffening and tension softening components of the concrete tension resistance mechanism are decoupled. As equilibrium is fully satisfied at the cracks and not expressed in terms of average stresses across the element, the link to limit analysis is maintained. The model has been incorporated into a finite element program for the analysis of reinforced concrete structures with verification against experimental data presented.