On the Separation Zones in Aluminium Base-Plate Connections. Numerical Simulation and Laboratory Testing

Abstract

The present paper deals with the study of the separation problem under combined loading conditions of aluminium base-plate connections. The classical unilateral contact law of Signorini is applied in order to describe the contact conditions between the contact surfaces and the separation process along the connection. Thus the problem is formulated as a variational inequality that expresses the principle of virtual work of the connection at the state of equilibrium, where the unilateral contact is included in the formulation. The application of an appropriate finite element discretization scheme leads to the formation of a quadratic optimization programming problem which is coupled by inequality constraints with respect to the displacements. The latter problem expresses from the standpoint of mechanics, the principle of minimum potential energy of the connection at the state of equilibrium. The aforementioned problem can be numerically and effectively treated by the application of two easy–to–use solution strategies based on quadratic optimization algorithms. This technique is illustrated by means of a numerical application. Due to the great significance of the problem, laboratory testing has been carried to extensively investigate the phenomenon. The numerical results are compared with respective laboratory testing results.