جستجوی مقالات مرتبط با کلیدواژه « نرم افزار اتوداین » در نشریات گروه « مواد و متالورژی »

In addition to the inherent characteristics of explosives, the power of the detonation is affected by arrangement of the explosive train. Therefore, the correct design of the explosive train, especially for insensitive explosive charges containing aluminum, play a fundamental role in order to be more effective. In the current research work, by changing the dimensions of the booster pellet and its position relative to the main charge; the detonation behavior of the main charge has been investigated. In this study, the booster pellet (COMP-A3) is modeled with JWL equation of state and the main charge (PBXN-111) is modeled with ignition and growth equation of state. The simulations has been done using AUTODYN software. The coefficient used in the equation of state (ignition and growth) has been evaluated with experimental results. The simulation results show that by reducing the diameter of the booster pellet from 5cm to 3cm, for a certain length of the booster pellet, reaching to the steady detonation increases due to the greater divergence of pressure wave into the charge. In the case where the booster is inside the charge, the peak pressure values increase in the corners of the charge and adjust the pressure drop due to the divergence. The simulation shows that for the case where the booster and the main charge are placed on top of each other, the booster with a diameter of two centimeters with any length of the booster pellet is not able to create stable detonation in the main charge. For a submerged condition of the same diameter, the booster can produce stable detonation in the main charge. This study showed that a booster pellet with a diameter of 5 cm and a length of 4 cm can cause a complete detonation in PBXN-111. The length of the region to reach stable detonation with this booster is 15 cm.

Due to the importance of concrete structures, the field of projectile penetration into concrete targets has attracted increasing research efforts. Gao et al. presented a new method for penetration analysis into concrete targets. Propagation of shock waves due to impact is the base of this method. The aim of the present study is to investigate and modify this model. In this research, first a brief explanation of extracting Gao’s method formulas is provided. Then, the validity of the model results is investigated. Considering the errors and contradictions observed in this method, a modified model is introduced. This modification is done by developing a relation for distance between shock front and surface of projectile. By exploiting this modified model, the penetration depths and the instantaneous deceleration curves are calculated‬. In addition numerical simulations are performed by using the finite element code AUTODYN. Good agreement between numerical, experimental and analytical results can be observed.