SINGLE-ANGLE COMPRESSION MEMBERS WELDED BY ONE LEG TO A GUSSET PLATE - II - A PARAMETRIC STUDY AND DESIGN EQUATION

Single-angle compression members are complex members to analyze and de sign. The two generally accepted design procedures, the simple-column and the beam-column approaches, in general, underestimate the load-car rying capacity of single-angle compression members welded by one leg t o a gusset plate fixed to a rigid support. One of the reasons is that these approaches do not properly account for the end constraint provid ed by the gusset plate. The effective length factor can be adjusted, b ut this is difficult to do as the end restraint is not easy to evaluat e in many practical cases. Another reason is that these approaches are not based on a rational understanding of the failure mechanism of the se members. An experimental program confirmed that the finite element method can be used, with a reasonable degree of accuracy, to predict t he behavior and load-carrying capacity of single-angle compression mem bers welded by one leg to a gusset plate fixed to a rigid support. The finite element method was used to study some 1800 different combinati ons of parameters. It was found that out-of-straightness, residual str esses in the angle section, Young's modulus of elasticity, and the unc onnected gusset plate length do not have a great effect on the load-ca rrying capacity. The most significant parameter is the gusset plate th ickness with the gusset plate width being the second most important pa rameter. An empirical design equation is proposed.