Bending Fatigue Tests and Finite Element Models of Steel Rectangular Hollow Sections [SRHS]

The Welding in cold formed areas is not only an open question for statically loaded sections (brittle fracture) but also for dynamically loaded structures (fatigue resistance). A lot of structures are subjected to dynamic loadings and unfortunately very little information about the influence of welding in the cold formed areas on fatigue resistance is available. In order to establish the fatigue behavior of welded and non-welded rectangular hollow sections specimens, a large number of 4-point bending tests are performed at the Saud Bin Laden Group SBG with cooperation with Buro Happold UK, Laboratory for Steel. Because these tests are very expensive, and because of the large number of parameters regarding the RHS to be investigated (steel grade, wall thickness, load distribution, boundary conditions), a number of finite element models for these specimens are made. By modeling the specimens with different types of finite elements (shells, solids) and taking into account some types of loading distributions and boundary conditions, the obtained results (stresses, strains, displacements) from a static analysis are compared with those obtained from the real 4-points bending tests. In this way, the obtained conclusions would lead to decrease of the number of the specimens that need to be tested as well as the costs of the project. Furthermore, by using finite element analysis, many factors with direct influence on the fatigue resistance can be considered.