Load-Carrying Capacity of Steel Girders and Panels with Thin-Walled Trapezoidally Corrugated Webs

Abstract: This thesis concerns the load-carrying capacity of steel girders and panels with thin-walled trapezoidally corrugated webs. Computer-based numerical methods are used as a tool and emphasis is placed on various parametric studies, covering geometric parameters, initial imperfections, material strain-hardening models, loading types and loading positions, and so forth.

Trapezoidally corrugated steel panels are first considered. A B3-spline finite strip method is formulated and implemented for the analysis of elastic buckling of such panels. Various numerical experiments are made and compared with available laboratory tests. Geometric parameters with which a panel is able to achieve the highest elastic buckling load are identified. Simplified formul and interaction curves for predicting the elastic buckling load of such panels under shear, compression and combined loadings, are proposed.

Steel girders with thin-walled trapezoidally corrugated webs are then considered. A non-linear finite element method is applied for the investigation of the load-carrying capacity and the buckling and post-buckling behaviour. Effects of large deflection and material non-linearity are taken into account. Material models of von Mises, either without strain-hardening (elastic-perfectly plastic) or with strain-hardening obeying Ramberg-Osgood's equation, are assumed. In order to establish suitable non-linear finite element models for the analysis of girders with variable geometric parameters, several series of laboratory tests are numerically simulated up to an advanced post-buckling range. With those established non-linear finite element models a rather comprehensive parametric study is carried out. Based on numerical results, empirical formul that were proposed earlier for estimating the load-carrying capacity are examined. An improved empirical formula for predicting the ultimate strength of steel girders under patch loading is proposed. Suggestions for an optimal design of steel girders in shear and under patch loading are given.