Determining the Optimum Geometric Shape for Web Opening of Wide Flange Beams using Response Surface Methodology

Abstract

In the field of civil engineering, the priority of a structural engineer is the safeness and stability of each structural element present in the structure. However, there were some concerns with regards to easy access and flexibility of the utilities such as electrical and mechanical systems. In response to these concerns, web opening was introduced to wide flanges to give way for the utilities, provided that the strength and durability of the structure will not be compensated. This study aims to obtain the optimum geometric shape of web opening for wide flange beams with regards to its performance for bending stress. The web opening on the wide flanges was designed first based on the parameters of the web opening. Then, the effects of circular, square, hexagonal and elliptical web openings were analyzed using Finite Element Analysis (FEA). Three varying support conditions in each opening case were used and analyzed using nonlinear static and nonlinear dynamic analysis in the finite element modeling software called Abaqus. During the FEA, deflection control method was used to obtain the value of force and stress upon reaching the deflection control value. Values of maximum stress and maximum force for each case were then obtained from the analysis, were used as factors for the Response Surface Methodology (RSM), which will define which shapes performed the best under specific conditions. Results obtained from RSM showed that considering value of the stress and deflection from nonlinear static and nonlinear dynamic analysis, elliptical web opening produced the largest force and smallest stress. Thus, elliptical web opening, considering bending stress, performed better compared to the other web openings.