基于細觀損傷模型的NVA船用鋼臨界孔洞體積分數

作者：宋子杰,胡志強,Jonas W.Ringsberg

摘要：NVA mild steel is a commonly used material in the shipbuilding industry.An accurate model for description of this material’s ductile fracture behaviour in numerical simulation is still a challenging task.In this paper,a new method for predicting the critical void volume fraction fc in the Guson-Tvergaard-Needleman(GTN)model is introduced to describe the ductile fracture behaviour of NVA shipbuilding mild steel during ship collision and grounding scenarios.Most of the previous methods for determination of the parameter fc use a converse method,which determines the values of the parameters through comparisons between experi-mental results and numerical simulation results but with high uncertainty.A new method is proposed based on the Hill,Bressan,and Williams hypothesis,which reduces the uncertainty to a satisfying extent.To accurately describe the stress-strain relationship of materials before and after necking,a combination of the Voce and Swift models is used to describe the material properties of NVA mild steel.A user-defined material subroutine has been developed to enable the application of the new parameter deter-mination method and its implementation in the finite element software LS-DYNA.It is observed that the model can accurately describe structural damage by comparing the numerical simulation results with those of experiments;thus,the results demon-strate the model’s capacity for structural response prediction in ship collision and grounding scenario simulations。

發文機構：State Key Laboratory of Ocean Engineering School of Engineering Department of Mechanics and Maritime Sciences

關鍵詞：ShipCOLLISIONandGROUNDINGGuson-Tvergaard-NeedlemanmodelNVAsteelDUCTILEfractureFiniteelementmethodShip collision and groundingGuson-Tvergaard-Needleman modelNVA steelDuctile fractureFinite element method

分類號： TG1[金屬學及工藝—金屬學]