Effective stiffness of coupling beams connected to walls in out-of-plane directions

Abstract

Based on recent studies on local deformations at coplanar and nonplanar beam-wall joints, the structural behavior of oblique beam-wall joints (joints at which the beams are at oblique angles to the walls) is analyzed and a joint element developed to model their behavior. Both in-plane and out-of-plane wall deformations at the beam-wall joints are taken into account. For general application to analysis of coupled shear/core walls, the stiffness matrix of oblique coupling beams (beams connected to walls at oblique angles) with local deformations at the joints allowed for, is derived. Using this stiffness matrix, the effective stiffness of coupling beams connected to walls in any direction is evaluated, and its dependence on the angles of connection studied. It is also shown through numerical examples that the coupling effect of oblique coupling beams can be quite substantial and thus, should not be neglected.