9634570 Elgaaly Economical design of girders normally requires thin webs. The use of corrugated webs is a possible way of achieving adequate out-of-plane stiffness without recourse to using stiffeners. A report by the Principal Investigator summarizing the results from a research project, to investigate the behavior of beams with corrugated webs under static loading has been completed. This project will investigate the behavior of girders with corrugated webs under repeated loading. Preliminary results from very limited tests indicate that the fatigue strength for the girders with corrugated webs can be higher than for conventionally stiffened girders. This project will determine the behavior of bridge girders with corrugated webs under repeated loading and establish the fatigue strength for such girders. The optimum shape of the corrugation under static loading may not be the optimum shape under repeated loading. ***