Strut-and-Tie Models of Deep Beams Influenced by Size and Location of Web Openings  An Optimization Approach

Abstract

The strut-and-tie models of a total of fourteen (14) concrete deep beams with varying size and location of web openings are developed herein using a topology optimization approach. By systematically eliminating inefficient materials from an over-designed discretized domain, the load transfer mechanism in deep beams is progressively characterized by the residual part of the structure. Both von Mises stress and displacement sensitivity number are calculated and used as deletion criteria. The performance indices in terms of von Mises stress and nodal displacement are evaluated to monitor the optimization process and to determine the optimal topology which is transferred to the strut-and-tie model. The relationship between the strut-and-tie models and the ultimate load-carrying capacity of the beams are discussed in some detail. A series of comparisons offer an insight into the varying characteristics of the strut-and-tie models influenced by the size and location of web openings.