Shear buckling and stress distribution in trapezoidal web corrugated steel beams

Due to their lightweight and superior load carrying capacity, corrugated web steel beams (CWSBs) have gained popularity in the last few decades. CWSBs are known to fail at much higher loads compared to stiffened flat web beams. To understand their shear response, a series of three-point load tests were performed on five shear-critical trapezoidal corrugated web beams. The test results confirmed the existence of the three shear buckling modes of failure: local, global, and interactive. In addition, all tested beams were observed to have a residual strength that is about half of their ultimate load carrying capacity regardless of the shear buckling mode. Results of the nonlinear finite element analysis showed that the shear stress is at its maximum and uniformly distributed throughout the web until buckling, afterwards, it decreases and its distribution is uneven while the entire resistance is provided by the increased tensile stress. Furthermore, stocky corrugated webs were shown to reach shear yield strength. Comparison between existing analytical models for the estimation of shear strength against test data showed that EN-1993-1-5 is accurate and conservative enough for an economic design.