Plastic Behavior of Web Girders in Ship Collision and Grounding

Some recent studies on the plastic behavior of web girders are described in the present paper. During the process of ship collision and grounding, various web girders will be subjected to large impact loads from various directions. Therefore, different deformation patterns can be identified. The recent developed plastic mechanism for local denting of web girders is depicted briefly and compared to various existing theoretical models. On the other hand, as a newly identified problem in ship grounding and collision process, the problem of lengthwise sliding deformation of web girders is described. Emphasis is placed on the description of the plastic mechanism and various energy dissipation patterns. The developed simplified methods on local denting and sliding deformation of web girders are compared with the results of experimental tests and finite element analysis respectively, both show satisfactory agreement. The proposed models will contribute substantially to the establishment of efficient methods for fast and reliable assessment of the outcome of accidental collision and grounding events. Such methods may in turn be incorporated into decision support tools for crisis handling in emergency situations, e.g. for tankers in disabled conditions.