Coupled Shear Wall Analysis by Lagrange Multipliers

A special finite element technique is described which permits interconnection of line elements in flexure and first-order plane stress elements. Continuity of displacements and rotations at the junction of the two types of elements is satisfied by imposing certain constraint conditions through use of Lagrange multipliers. The method can be employed to analyze coupled shear walls as well as frame-shear wall systems. Accuracy is checked by analyzing a coupled shear wall system with three degrees of mesh refinement. Results are further compared with those from a conventional finite element scheme, which idealizes the coupling beams by plane stress elements. The proposed method is shown to be more accurate and more efficient than the conventional method.