【作者】 王庭辉；

【导师】 宋顺成；

【作者基本信息】 西南交通大学 ， 固体力学， 2010， 博士

【摘要】 本文基于目前陶瓷复合装甲防护应用的需要,开展了相关方面的研究工作。包括对一些陶瓷、金属材料在高温高压条件下的状态方程计算、纤维束的动态拉伸试验研究、一些陶瓷材料的动态三点弯曲实验研究、陶瓷片在应力波作用下的破坏研究以及陶瓷纤维复合板的抗侵彻研究等内容。文中相关的实验结果可以作为相应理论分析和数值模拟的实验依据。对陶瓷片及陶瓷复合板的破坏实验研究和数值模拟分析可以为抗弹陶瓷研究和复合靶板设计提供思路,也可用于装甲防护结构的优化。本文主要研究内容和结论如下：利用描述晶格热振动贡献特性的Gruneisen状态方程、结合冲击绝热关系,在不考虑电子项及晶格非简谐振动项对压力、内能贡献情况下给出的Walsh求解方法基础上,利用Runge-Kutta数值解法求解了相关微分方程组。研究了金属铝、45钢、钨、钼和陶瓷的内部压力、Gruneisen系数、冷压、冷能与比体积之间的数值关系,得出Gruneisen系数、冷压、冷能及常温下压力随比体积的变化曲线。给出三个压缩状态(比体积分别为V1,V2,V3)下压力随温度变化的曲线,说明温度的变化对压力的影响远小于比体积变化的影响。同时根据求解出的Hugoniot冲击温度,把温度升高引起的热压部分考虑到了状态方程中,并和相关文献中的计算结果进行了比较。利用函数f(γ,V)=0,得到了定容比热Cv和冲击温度T与比容之间的数值关系。研究了弹性应力波在T型杆和锥形杆中的传播规律。基于实验结果,给出应变相容假定,通过理论分析和实验验证成功解决了实验中所测入射应力波前后幅值不一致的问题；数值模拟了锥形过渡杆对反射应力波波形和幅值的影响,结果表明在一定条件下,锥形过渡杆对反射应力波的影响近似于阶梯过渡杆。测试了五种纤维束的准静态和动态应力应变关系,并比较了它们对应变率的敏感性。利用HOPKINSON压杆实验原理,用改装的HOPKINSON压杆实验装置测试了陶瓷材料三点弯曲动态力学性能,给出了几种陶瓷材料在不同挠度变化率下的挠度-最大拉应力曲线。给出了陶瓷材料的动态抗弯刚度模型和动态抗弯强度模型,并利用试验数据拟合得到了模型中的参数。测试了五组陶瓷的动态断裂韧性,所测断裂韧性的动态结果是静态结果的1.08～2.83倍。实验研究了陶瓷／金属复合板在应力波作用下的破坏行为,分析了应力波波头在陶瓷面板中的传播叠加规律。计算了陶瓷面板中的应力分布规律,理论分析得到陶瓷破坏锥的半锥角为41.5°。采用球面应力波的传播理论,求解了距离球腔中心不同远处界面上的应力时间历程,揭示了陶瓷面板中放射状裂纹的形成机制。进一步分析说明了放射状裂纹开始出现时刻早于陶瓷破坏锥形裂纹开始出现时刻。利用有限元软件ANSYS/LS-DYNA对应力波作用下陶瓷复合板的破坏进行了数值模拟,研究了陶瓷面板中的应力分布规律,吻合理论计算结果。对陶瓷／金属复合靶板和陶瓷／陶瓷／金属复合靶板进行了侵彻实验和数值模拟计算,模拟所得金属背板中的残余穿深和实验所得基本一致。在一定条件下,把同一厚度的陶瓷面板分为两种不同厚度的陶瓷面板组合,研究了它们的抗弹性能变化规律。更多还原

【Abstract】 Based on the demand of ceramic composites applied in armor defense, developed a series of relative researches in this work, including the calculation of state equations about ceramic and some metals at high temperature and high pressure, experimental study on dynamic tensile properties of fiber bundles, experimental study on dynamic three-point bending properties of ceramic, researches on breakage of ceramic plate under the effect of stress wave and the penetration resistance of ceramic composite target. Some of experimental results are helpful for theoretical analysis and numerical simulation. The experimental study and numerical simulation on ceramic plate and ceramic composite target can give a guide for the investigation in ballistic resistance ceramics and design of ceramic composite armor; it also can be used for the optimization of armor protection structure. This thesis is mainly concerned with the following studies:Ignoring the contribution of electron part and crystal lattice non harmonic vibration part, the Gruneisen state equation described the contribution of crystal lattice thermal vibration was solved and the relationship about P-V-T was obtained with Walsh formula by Walsh numerical method and adiabatic relation. The theory was applied in calculating the relationship of Gruneisen coefficient y and specific volume V of metals of aluminum, steel, tungsten, molybdenum and ceramic. The relations of Cv vs T, T vs V, Pth vs T and P(V,T) were also obtained. Numerical results about f(P, T, V1)=0 f(P,T,V2)=0 and f(P,T,V3)=0 in three compressive states show that the effect of temperature is less than that of specific volume. The predicted results and the relation between P and V are in good agreement with references.The propagation of stress wave in T-type bar and conical bar was investigated. Based on the experiment results, the assumptions that strain satisfies coordinative relations were proposed. The variance of incident wave shape measured in experiments can be explained and the solution is also given by theoretical analysis and experimental verification. Numerical simulation about the effect of conical bar on reflected wave show that the formulas of stress amplitude in variable cross-section could be used for approximate calculation at a certain condition. The dynamic tensile properties of five types of high strength fiber bundles were measured and the sensitivity of strain rates was investigated.Using the experimental principle of HOPKINSON press bar, the dynamic three-point bending properties of ceramic were tested by the refitted HOPKINSON press bar. The relation between deflection and maximum tensile stress is given. The dynamic flexural rigidity model and dynamic bending strength model of ceramic were also provided and the material parameters used in the model were obtained by fitting the experimental data. The dynamic fracture toughness of five groups ceramic were tested and the obtained results are 1.08-2.83 times of static results.The damage behaviors of ceramic/metal composite plate under the effect of stress wave were studied. The propagation and superposition of front stress wave in ceramic were analyzed. The distribution of stress in ceramic was computed. It can be obtained that half cone angle of ceramic smash cone is 41.5°. Adopting the spherical wave propagate law, the course of stress vs time at different distances from the center of spherical cavity was solved and the radial crack formation mechanism in ceramic is revealed. It can be obtained that the radial crack appears earlier than smash cone crake by further analysis.The ceramic damage behaviors under the effect of stress wave were simulated by ANSYS/LS-DYNA. Distributions of stress by the numerical calculation in ceramic plate were in agreement with theoretical calculated results. The obtained depth of penetration of ceramic/metal and ceramic/ceramic/metal composite target by experiments and numerical simulations are almost identical. Finally, anti-bullet properties of ceramic plates were investigated by two ceramic plates with same total thickness instead of one ceramic plate make of a composite target.更多还原