Study On Impact Damage Of Ship Composite Structures Based On Peridynamics

In the modem ocean warfare,the threat situation faced by ships is becoming more and more complicated.The high-speed fragments and shock wave loads generated by the explosion of anti-ship weapons such as torpedoes and missiles pose a severe test on the ship's protective performance.Advanced composite materials have gradually become the new choice for ship materials due to their light weight,specific strength and stiffness,and good impact resistance.However,the anisotropic characteristics of composites make the damage form of them more complex than that of traditional isotropic metal materials.Therefore,how to accurately analyze and predict the damage and fracture behavior of composites has always been a difficult problem in engineering and academic fields.The classical medium mechanics method used at present leads to singularity in the discontinuous position of displacement field when solving the damage and fracture problems However,an emerging meshless method—Peridynamics,replaces the partial derivative term in the constitutive model of traditional classical mechanical with integral form,and its constitutive model contains the method of damage definition.Therefore,the method can well simulate the damage of the composite structures under the impact of the fragments and the shock wave loads.Firstly,the historical development process and research status of Peridynamic method are reviewed,and the application and development status of the method in the impact field are emphatically introduced in this paper.Then,the motion equation,deformation function and boundary constraint conditions of the Peridynamics are derived in detail,and on this basis,the bond-base Peridynamic model which is suitable for composite analysis is introduced.Based on the bond-based Peridynamic model,the impact calculation programs of composite lamina laminates and stiffened plates are compiled.Through several examples,the response of elastic stage is compared with the results of finite element calculation,and some damage results are compared with the experimental results to verify the effectiveness of the programs.In this paper,the above calculation programs are used to analyze the damage mode of the composite laminate and the stiffened plate structures under the impact of high-speed fragments and the residual speed of fragments,and comprehensively consider the influence of speed and geometry of the fragments,the layup configuration of the laminates,the size of stiffeners,and the impact position of the fragments relative to stiffeners.Subsequently,the danage and deformation of composite laminates and stiffened plates under the underwater shock wave loads are analyzed.The effect of explosion impact factor,properties of fiber and layup configuration,the size and distribution distance of stiffeners are considered.A series of meaningful conclusions are obtained by analyzing the simulation results.