Finite Element Model-based Design of Stiffened Welded Plated Structures Subjected to Combined Loading

Abstract

Resistance calculation of steel bridges with orthotropic plates subjected to combined loading situation (bending moment, shear and transverse forces called as M-V-F interaction) can be challenging for designers due to the interactive stability behavior and combined buckling phenomena. The current EN 1993-1-5 standard provides a design method using analytical design equations checking the pure (bending, shear and patch loading) and interaction resistances separately. This design process is complex in the case of steel bridges, especially for box-section bridges having numerous longitudinal and transverse stiffeners. Finite Element Model (FEM) based design can provide suitable design tools for efficient and accurate resistance calculation of these structure types. However, within the modelling process there are numerous questions to be answered regarding material models and imperfections to ensure required accuracy and safe resistance. A new standard prEN 1993-1-14 is currently under development which will provide design rules to finite element model-based design of steel structures, having the aim to answer the main part of the above mentioned questions and standardize the design process. The current paper discusses and demonstrates the methodology of the FEM based design for welded plated structures. Benchmark example for a Hungarian steel box-section bridge subjected to combined loading situation is presented. Effect of different meshing, imperfection combinations and material models are presented and evaluated in the paper. Efficiency of the numerical model and the obtained resistance on the input parameters are evaluated and design example is given for the application of the FEM based design method.