The objective of this paper is to study the residual ultimate strength of box beams with impact-induced damage,as a model of what may occur in ship hulls.The bottom and side plates of ship hulls can suffer denting or ...The objective of this paper is to study the residual ultimate strength of box beams with impact-induced damage,as a model of what may occur in ship hulls.The bottom and side plates of ship hulls can suffer denting or fracture damage due to grounding,collision and other contacts during the ship’s service life and these impact-induced damages could result in considerable strength degradation.Box beams are firstly subjected to impact loading and then four-point bending loading is imposed on the damaged structures to assess the residual strength using ANSYS/LS_DYNA.The ultimate moment and collapse modes are discussed considering the effect of impact location.The impact-induced deformation is introduced in the four-point bending simulation,and the impact-induced stress is included or not to determine the effect of residual stress and distortion after impact.It is shown that impact location has significant influence on the residual ultimate bending moment of the damaged box beam providing that the impact energy is kept constant.The collapse modes also change when the impactor strikes on different locations.Damaged hard corner and inclined neutral axes might explain the reduction of ultimate strength and diverse collapse modes.The residual stress in the box beam after impact may increase or decrease the ultimate strength depending on impact location.展开更多
Impact damage tolerance is provided in intensity design on composites. The compression intensity of impacted composites requires more than 60% of its original intensity. The influence of impact on compressive intensit...Impact damage tolerance is provided in intensity design on composites. The compression intensity of impacted composites requires more than 60% of its original intensity. The influence of impact on compressive intensity and electrical resistance of carbon fabric/epoxy-matrix composites was studied in this paper. The experimental results shows that impact can cause damage in composites, degenerate compressive intensity, and increase resistance. The electrical resistance change rate was used as an evaluation indicator of impact damage tolerance of composites. Impact damage, which results from the applying process of composites, can be identified in time by electrical resistance measurement. So, the safety performance of composites can also be improved.展开更多
基金This work contributes to the Strategic Research Plan of the Centre forMarine Technology and Ocean Engineering(CENTEC),which is financed by the Portuguese Foundation for Science and Technology(Fundação para a Ciência e Tecnologia-FCT)under contract UIDB/UIDP/00134/2020.
文摘The objective of this paper is to study the residual ultimate strength of box beams with impact-induced damage,as a model of what may occur in ship hulls.The bottom and side plates of ship hulls can suffer denting or fracture damage due to grounding,collision and other contacts during the ship’s service life and these impact-induced damages could result in considerable strength degradation.Box beams are firstly subjected to impact loading and then four-point bending loading is imposed on the damaged structures to assess the residual strength using ANSYS/LS_DYNA.The ultimate moment and collapse modes are discussed considering the effect of impact location.The impact-induced deformation is introduced in the four-point bending simulation,and the impact-induced stress is included or not to determine the effect of residual stress and distortion after impact.It is shown that impact location has significant influence on the residual ultimate bending moment of the damaged box beam providing that the impact energy is kept constant.The collapse modes also change when the impactor strikes on different locations.Damaged hard corner and inclined neutral axes might explain the reduction of ultimate strength and diverse collapse modes.The residual stress in the box beam after impact may increase or decrease the ultimate strength depending on impact location.
基金Funded by Key Laboratory of Nondestructive Testing (Nanchang Hangkong University)Ministry of Education, China(No. ZD200829001)Department of Education of Jiangxi Province, China(No. GJJ10531)
文摘Impact damage tolerance is provided in intensity design on composites. The compression intensity of impacted composites requires more than 60% of its original intensity. The influence of impact on compressive intensity and electrical resistance of carbon fabric/epoxy-matrix composites was studied in this paper. The experimental results shows that impact can cause damage in composites, degenerate compressive intensity, and increase resistance. The electrical resistance change rate was used as an evaluation indicator of impact damage tolerance of composites. Impact damage, which results from the applying process of composites, can be identified in time by electrical resistance measurement. So, the safety performance of composites can also be improved.
