Fatigue analysis and instability problems of plate girders with corrugated webs.

摘要

Using corrugated webs in plate girders can eliminate using stiffeners and the web height to thickness ratio can be increased significantly. This type of girders has more fatigue life than plate girders with stiffened flat webs under cyclic loading. In this research, an experimental program was conducted on plate girders with corrugated webs under both monotonic and repeated loading. The study included stress distribution and failure modes of plate girders with corrugated webs. This experimental study was followed by a finite element analysis for different models with different geometrical configurations to study the effect of the stress concentrations on the fatigue life of plate girders with corrugated webs. Fracture mechanics analysis was used to obtain equations relating the stress concentration factor and the applied stress range to the expected number of cycles up to failure. The instability problem including lateral torsional buckling and local buckling of the compression flange was also studied. The investigation included analytical studies, finite element studies and experimental work. An approach for solving this problem was introduced in both the elastic and inelastic range. Finally, finite element analysis was developed to predict the behavior and capacity of test specimens to be tested for a bridge, which will be build in Pennsylvania using plate girders with corrugated webs.