Effect Of Constraint On The Crushing Behavior Of Ceramic Interface Defeat

Ceramic materials have the characteristics of low density and high strength.The use of ceramic composite targets as armor targets can greatly reduce the quality of armor protection systems.When the long rod projectile hits the ceramic composite armored target,phenomenon that the mass of long rod projectile head is eroded and the ceramic target is not penetrated directly is called the interface defeat.The interface defeat phenomenon of ceramic target can effectively ensure the tolerance and durability of composite armor target.This paper mainly aims at the semi-infinite thickness composite ceramic target,and establishes the model of long rod projectile impacting the composite ceramic armor target under different constraints through simulation to study the destruction process of the ceramic target when the interface of the ceramic target defeats the long rod projectile and the resistance of the ceramic target to different constraints.Study on the impact of thorough performance and its mechanical mechanism.The main research contents are as follows:Establish an effective simulation model of ceramic target interface destruction.Based on the existing experimental model of long rod projectile impacting ceramic targets,the AUTOHN software uses the method of combining SPH algorithm and Lagrange algorithm,and uses the JH-1 model and JC model as the constitutive model of long rod projectile impacting ceramic target model.Numerical simulation model of rod bomb impacting ceramic target.The effectiveness of the established simulation model is verified by comparing the crushing characteristics of the ceramic target interface in experiments and simulations.The effect of the front restraint plate on the on the interface defeated of ceramic target.On the basis of the initial model,a ceramic target with a front restraint plate and a cylinder connected and unconnected is set.Adjust the thickness of the front restraint plate separately,and study the influence of the front restraint thickness and whether it is connected with the cylinder on the interface breaking behavior of the ceramic target.Observe the time for the ceramic target to crush the long shot at different speeds and the critical speed of interface breakdown/penetration.Analyze the data to study the type of damage of the ceramic target and the destruction process and mechanism of the ceramic target when the thickness of the front restraint plate is different.The study found that the ceramic target has different failure modes when the thickness of the front restraint plate is different.There are two failure modes: positive compression failure and secondary compression failure.The ceramic destruction process is related to the pressure on the surface and the flow of erosion products.The effect of the front restraint plate on the ceramic surface pressure can improve the ceramic penetration resistance.Study on the effect of circumferential constraint on the interface defeated of ceramic target.Based on the initial model,the thickness and radial ratio of the cylinder are changed to change the restraining effect of the cylinder on the ceramic target.The study found that the thicker cylinder has greater stiffness,which provides circumferential restraint to the ceramic target,and the ceramic target has better resistance to penetration.Through the interference fit method to explore the effect of prestress on the ceramic target,the study found that increasing the prestress can improve the penetration resistance of the ceramic target.When the radial ratio increases to a certain value,the ceramic target receives the most prestress,and the ceramic target has the best penetration resistance.Study on the effect of weak interface layer on the interface defeated of ceramic target.The interface defeated behavior of the ceramic target is affected by the pressure of the erosion products on the ceramic surface.Adding weak interface layers of different thickness between the front restraint plate and the ceramic surface can guide the flow of erosion products.Observe the pressure process on the ceramic surface and the destruction process when the ceramic target penetrates when the thickness of the weak interface layer is different.The study found that the thickness of the weak interface layer increases and the penetration resistance of the ceramic target decreases.The destruction process of the ceramic target is related to the pressure distribution of the sub-compressed area on the ceramic surface and the positive pressure area of the ceramic surface.