The Destruct Probability Of Complicated Plate-shell Structure Under Impulsive Load

It is very complicated that the subject about the destruction of plate-shell under impulsive load. The understanding of the subject is helpful to design structures that more efficient at withstanding projectile impact or in order to design improved ballistic missiles. The thesis aims to the destruct probability of plate-shell structures and gives the main conclusions as follows:The energy loss of warhead is analyzed in the process of penetrating thin plate, and the minimal initial penetrating velocity of projectile is derived with the two kinds of destruct forms considered that plastic yield and petallike destruction. Furthermore the paper analyzes the penetration of projectiles to the stiffened plates, gains the close equation group of solving the displacements of the stiffened plates.It is analyzed that the destruction of stiffened plate under osculant detonation loads. The approximate crevasse formula is introduced. And the crevasse radius of several stiffened plates under different dynamite quantity is calculated. Then the effects of stiffen and dynamite quantity is discussed.The destruct probability of single layer stiffened plate and two layer plates penetrated by projectiles, which have an angle of incidence from 0 angle, 30 angle and 45 angle. The Monte Carlo simulation is introduced. During the process of calculation, the relative ubiety between impactive location and stiffener is taken into account. The rule of velocity is adopted, that is to say, the plate is thought disabled when the velocity of projectiles in positive normal panel is bigger than zero. The velocity and mass of projectiles as well as elastic module and yield stress of stiffened plates are considered as random variables. The more samples are need when the Monte Carlo simulation is adopted. Because more computer time is needed during the simulation of LS-DYNA, the more samples are difficult to get. The distributing of random variable is got through drawing the fewer samples.The initial value of random variables can be gotten through random data programmers, then the process of penetration is simulated by LS-DYNA, and the end velocity of projectiles in positive normal panel can be gotten. The distributing of the end velocity of projectiles in positive normal panel is gained, then the destruct probability can be calculated.