Trusses, although geometrically simple, constitute rather complex structures when one considers their true behavior. Even though they are... Show moreTrusses, although geometrically simple, constitute rather complex structures when one considers their true behavior. Even though they are designed considering pin connections for their joints, in practice joints are neither pinned nor fixed. For this reason, the behavior of a truss at its joints is rather complicated; and to a great extent depends on the method of fabrication used including the weld patterns and the geometry and design of gusset plates used. This study focuses on the behavior of welded truss joints by using a three-dimensional finite element analysis in an effort to provide an insight into how stress patterns are developed at a joint when it is subject to loads from adjoining truss members. The research included a series of simulation analyses on a simple truss joint with welded connections. The typical joint is those that can be found in the lower chords of trusses used in highway bridges. The simulations employed linear finite element analyses utilizing solid elements to model the weld, connecting elements and the gusset plates. Stresses obtained from these analyses were compared with those through conventional methods. At points of stress concentrations, stresses from the finite element (FE) analyses showed stresses can be as high as 5 – 10 orders of magnitude higher than those from conventional methods. The results are presented in the form of graphs showing the ratio of FE-based results to those from conventional methods for several different configurations for weld length. M.S. in Civil Engineering, December 2011 Show less
