Updating finite element model of structures with semi-rigid joints and boundary

Updating the finite element models of structures with semi-rigid joints and boundary are studied. While most researches in this field are on updating semi-rigid joints with moment-rotation effect, in this paper a hybrid finite element to consider both the moment-rotation and shear-displacement effects of joint are proposed. The hybrid element is composed of a beam element with two connections at both ends, and the semi-rigidity of joints of both rotational and shear effects are simulated at the two ends. The stiffness matrix and mass matrix of the hybrid finite element are formulated. A hybrid optimization technique is applied to update structures with semi-rigid joints and boundary. The method proposed is experimentally studied by updating the finite element of a 14-bay beam. The results show that the method can produce an analytical model that better duplicates the dynamic property of actual structure while keep physical connectivity between them.