The present work is concerned with the crushing resistance of web girders subjected to large localized in-plane loads. A new theoretical model is proposed on the basis of a comparative study of the existing simplified methods and the analysis of the progressive deformation process from rational nonlinear finite element simulations. The behavior of web girders under in-plane loads is a relevant subject in both ship collision and grounding process as well as in the area of civil engineering.
The loading pattern for plated structures can be categorized into two characteristic groups: in-plane loading and out-of-plane loading. Both types of loads are experienced when ships are exposed to collision and grounding. The problem of in-plane loading of plated structure has been studied by numerous authors, in which many are concerned with the so-called plate cutting problem, refer e.g. [1], [2], [3], [4] and [5]. In addition to the plate cutting problem, the in-plane crushing problem of plated structures is also of importance. In ship grounding, the transverse members attached to the bottom shell plating, e.g. primary bulkheads, deep frames in single bottom ships and floors in double bottom ships, will suffer large in-plane forces. The decks, side stringers, deep stiffeners and bulkheads may also suffer substantial damage due to large in-plane loads in a collision situation. In the following, all these structural components are uniformly termed as web girders. Fig. 1 shows different types of web girders in a typical ship structure.