RDX基含铝炸药JWL-Miller状态方程标定及对舰船结构的毁伤特性

Calibration of JWL-Miller Equation of State for RDX-Based Aluminized Explosive and Damage Characteristics of Ship Structure

为了精确计算某RDX基含铝炸药近场水下爆炸对舰船结构的毁伤特性,提出了一种基于水下爆炸试验和OPTIMUS的炸药JWL-Miller状态方程参数标定优化方法,建立了该型炸药水下爆炸载荷计算模型及对舰船结构毁伤的有限元模型。通过任意拉格朗日-欧拉方法(ALE)和引入JWL-Miller模型数值模拟研究不同爆距、不同攻角工况对舰船结构的毁伤特性,分析冲击波载荷和气泡载荷传播过程,计算得到爆距、攻角对局部结构毁伤影响规律,给出了断裂部位破口尺寸和外板最大凹陷距离。结果表明,运用优化得到的炸药状态方程仿真计算的冲击波压力峰值、冲击波能量结果与试验结果吻合较好;船体结构随着气泡的膨胀和收缩会呈现先中拱弯曲、后中垂弯曲的运动变形过程,随着近距爆距的改变,结构的破坏模式逐渐从冲塞形破口、四周花瓣开裂向长条形撕裂状破口再向外板向内凹陷改变;随着近距攻角的增加,舰船舷侧外板边界处剪应力在冲击波和气泡脉动载荷作用下达到应力衡准,破口面积进一步增加,气泡的溃灭速度随药包与结构之间攻角的增大而加快。

In order to accurately calculate the damage characteristics of ship structure caused by near-field underwater explosion of an RDX-based aluminized explosive,an optimization method of JWL-Miller equation of state parameter calibration based on underwater explosion experiment and OPTIMUS software was proposed,and the calculation model of explosion load and the finite element model of ship structure damage were established.Through arbitrary Lagrange-Euler method(ALE)and the introduction of JWL-Miller model,the damage characteristics of ship structures under different blasting distance and different attack angles were studied,and the propagation process of shock wave load and bubble load was analyzed.The influence law of blasting distance and attack angle on ship local structural damage characteristics was calculated,and the fracture size and maximum depression distance of the outer plate were given.The results show that the calculation results of shock wave peak pressure and shock wave energy obtained by using the optimized equation of state agree well with the experimental results.With the expansion and contraction of the bubble,the hull structure will show the motion deformation process of first middle arch bending and then middle vertical bending.With the variation of the short-distance blasting distance,the failure mode of the structure gradually transforms from the plug fracture,the petal cracking around to the strip tear fracture and then to the inward depression of the outer plate.With increasing the attack angle,the shear stress at the boundary of the ship′s side plate attains the stress criterion under the effect of shock wave and bubble pulsation load,the fracture area further expands,and the collapse velocity of the bubble accelerates along with increasing the angle of attack between the charge and the structure.