Natural frequencies of prismatic and tapered composite girders with corrugated steel webs

Abstract

The present study proposed an analytical formula to predict the natural frequencies of prismatic and tapered composite girders with corrugated steel webs (CSWs), and rigorously provides the derivation process. It is experimentally and numerically verified that the proposed formula is more applicable for predicting the natural frequencies of girders with CSWs, in comparison to the traditional formula based on Euler-Bernoulli beam theory. The study demonstrates that the traditional formula used for determining the natural frequencies of prismatic girders with CSWs leads to significant overestimation, mainly because it ignores the effects of shear deformation. The finite element (FE) simulation suggests that the free vibration mode shapes of tapered girders with CSWs exhibit sinusoidal patterns. Consequently, an equivalent stiffness method has been developed for accurately and conveniently estimating the natural frequencies of tapered girders with CSWs. This paper establishes a theoretical foundation for modifying the natural frequency calculation formula of prismatic and tapered girders with CSWs in current specifications, the research findings hold significant implications for the structural dynamic analysis and design of such girders.