Nonlinear finite element modelling and progressive collapse analysis of a product carrier under longitudinal bending

• Application of nonlinear finite element method for evaluating ultimate strength of a product carrier.
• Assessment of the effects of initial geometrical imperfections.
• Consideration of material and geometrical nonlinearities in an easy manner.
• Development of a numerical bending test setup for progressive collapse analysis.
• Evaluation of the accuracy of the approximate or simplified approaches.

This paper deals with evaluating the ultimate hull girder strength of a product carrier. Progressive collapse of the hull girder subjected to pure bending is investigated using the nonlinear finite element analysis. Both material and geometrical nonlinearities are taken into account. The initial geometrical imperfections are also considered in the analyses. In order to validate the adopted procedure in nonlinear finite element modelling and progressive collapse analysis, some available experimental collapse tests are simulated using a numerically developed bending test setup. After successful validation attempts, the moment–curvature relationships are obtained for the product carrier in both hogging and sagging conditions, again using the numerical bending test setup. The numerically obtained values of the ultimate strength are compared with the results of other approximate or simplified procedures and equations. It is shown that the nonlinear finite element method can simulate very well the full-range collapse behaviour of hull girder. The results of the nonlinear finite element analysis can be used as a benchmark reference to the analyses based on the approximate or simplified approaches.