The Dynamic Response Of Fiber Reinforced Composite Plate Subjected To Underwater Impulsive Loading

Fiber reinforced composite material has lots of excellent characteristics,such as high specific stiffness,high specific strength and lightweight.Because of its excellent characteristics,this composite material has been widely applied in high-tech domain,such as automobile industry,aerospace,shipbuilding,marine protection and so on.Since 1990 s,Europe and United States and other countries have taken the applying of the composite materials in the structures of all kinds of vessels as the development direction of the future.So,it can be foresee that the advanced composite materials will get increasing application in ship industry.Hence,in order to give the protection full play,it's necessary to understand the underwater shock resistance of the composite materials,In this paper,in order to validate the reliability and feasibility of the Underwater Shock Loading Simulator simulating the underwater explosive shock waves,the model of this equipment was performed in LS-DYNA to study the dynamic response of circular 5A06 aluminum alloy plates subjected to underwater shock loading.Then,utilizing the Underwater Shock Loading Simulator,the dynamic response of carbon fiber reinforced composite material subjected to underwater impulsive loading was investigated experimentally.The deformation and failure modes of carbon fiber reinforced composite plates were subdivided preliminary.And the effects of the peak pressure and decay time of underwater shock waves on the damage of the carbon fiber reinforced composite material,respectively.Finally,the shock resistance and protection of the carbon fiber reinforced composite material were analyzed by comparing the composite material with 5A06 aluminum alloy and Q235 steel.In this study,we get the following conclusions:(1)The Underwater Shock Loading Simulator can simulate the underwater explosive shock waves well,and the peak pressure and the decay constant can be set independently by suitable adjustment of the striker velocity and mass.(2)The deformation and failure modes of carbon fiber reinforced composite plates can be subdivided into three modes.At low impulsive pressures,the plates experienced plastic deformation without rupture referred to as mode I.At intermediate impulsive pressures,the fiber tensile damage at the center of the plates referred to as mode II.At high impulsive pressures,fiber shear damage at the supports referred to as mode III.(3)By analyzing the damage of the target plates subjected to underwater shock waves with different intensities,the failure modes were mainly affected by the peak pressure of underwater shock waves,and the severity of the damage of the plates was affected by the decay time of underwater shock waves changing the parameter of fluid-structure interaction.(4)The underwater shock resistance of the carbon fiber reinforced composite material was higher than the 5A06 aluminum alloy and Q235 steel under the condition of the same surface density.