Three-field mixed formulation for the non-linear analysis of composite beams with deformable shear connection

A three-field mixed finite element is proposed for the non-linear analysis of composite beam with deformable shear connection. The formulation considers the non-linear behaviour of materials and shear connectors. The established mixed element is compared to the locking-free displacement element from which it derives and to a refined locking-free displacement element previously tested by the authors. In order to evaluate the way to better improve the solution in the non-linear range (three-field mixed formulation or refined displacement formulation), numerical applications are performed using, as working example, a steel-concrete cantilever, representing a difficult test for composite beam elements. (C) 2003 Elsevier B.V. All rights reserved.