Enhancing plate girder shear performance using low-frequency sinusoidal webs

Thin plates in shear are used in many applications such as the webs of steel plate girders, shear walls, ships, and aircraft and are typically designed to maximize plate depth and minimize plate thickness. However, the capacity of slender plates is limited by shear buckling. Conventional solutions to shear buckling include welded transverse stiffeners or corrugated plate shaping, but these strategies introduce the potential for fatigue cracking and fabrication challenges, respectively. Alternatively, the authors propose forming low-frequency sinusoidal (LFS) patterns along the plate’s longitudinal axis as a novel, less fabrication-intensive approach to enhancing the shear capacity of thin plates. The low frequencies utilized in this study are much lower than those used in commercial corrugated products and previous research, resulting in lower forming stresses and potentially improved fatigue behavior. Experimentally validated finite element models are used to parametrically evaluate the effects of sinusoidal frequency and initial geometric imperfection. Measurements of elastic shear buckling load, ultimate shear load, and shear yielding are used to evaluate the effects of the parameters. The results show that significant increases in shear strength and material efficiency can be achieved using an LFS approach. LFS plates combine durability, material efficiency and ease of fabrication in a strategy that can benefit the industry.