Abstract:
In this study the web crippling behavior of a hot-rolled rectangular hollow section (RHS) with web holes is demonstrated experimentally and numerically. A series of experiments were conducted to test the behavior of 20 rectangular hollow sections for web crippling strength subjected to interior-two-flange (ITF) and end-two-flange (ETF) loading conditions. The experimental program was made to get web crippling of specimen having slenderness (h/t) value of 21.32, by varying size and offset distance of web holes under two flange loading conditions. Web holes were either located centered underneath the load or at some offset distance. Finite element models of experimentally tested beams were developed, and results of finite element analysis agreed well with experimental results. A parametric study was then conducted using finite element analysis on different cross section sizes, to demonstrate the effect of size and position of web holes on web crippling capacity of rectangular hollow steel sections. The primary factors influencing the web crippling strength were determined to be the ratio of the diameter of the web hole to the depth of the flat portion of the web (a/h) and the ratio of the offset distance of the web hole to the flat portion of the web (x/h). Through the analysis, correlations were established between the ratios (a/h and x/h) and the reduction in web crippling strength. The web crippling capacities of specimens without web holes were compared to codified design provisions, and assessments were made regarding their accuracy. In both load cases, design recommendations were provided in the form of reduction factors that were both accurate and conservative. To assess the reliability of these design recommendations, reliability analyses were conducted. The results indicated that the proposed design recommendations are both safe and reliable.
