【作者】 贾宪振；

【导师】 刘家骢； 许学忠； 胡毅亭；

【作者基本信息】 南京理工大学 ， 工程力学， 2008， 博士

【摘要】 本学位论文的工作主要是运用AUTODYN、ABAQUS和LS-DYNA这三个通用程序,研究水下爆炸及其对平板、圆柱壳和鱼雷壳体结构的作用。研究内容包括:(1)水下爆炸过程的数值模拟研究;(2)基于Taylor平板理论和DAA方法的ABAQUS程序的二次开发及其应用;(3)深水爆炸冲击波作用下圆柱壳动态响应的数值模拟研究;(4)对于LS-DYNA程序远场水下爆炸模拟方法的修正;(5)水下爆炸冲击波毁伤鱼雷的终点效应初步分析;(6)近场和远场水下爆炸冲击波作用下鱼雷壳体结构动态响应的数值模拟研究。第一章:介绍了本文的研究对象、研究方法和研究背景,综述了国内外相关研究的进展,简要介绍了所采用的通用程序,并给出了模拟结果的验证方法。第二章:运用AUTODYN程序的一维模拟方法,对无限水域中的水下爆炸冲击波以及深水爆炸冲击波和气泡脉动进行了数值模拟研究,并将模拟结果与经验公式、理论公式和实验结果进行了比较。最后总结了模拟结果,得出了对工程应用有益的结论。第三章:根据Taylor平板理论和一阶逼近DAA方法,建立了水下爆炸冲击波作用下结构高频响应时湿面的总压力载荷的计算模型,并将该模型嵌入到了ABAQUS程序的用户子程序当中,完成了ABAQUS程序的二次开发,从而实现了在不建立流场模型的情况下平板和圆柱壳结构的水下爆炸冲击响应模拟。并根据平板和圆柱壳的水下爆炸实验结果验证了该方法的模拟精度。第四章:基于通用程序ABAQUS,运用静力分析和动力分析相结合的研究方法,对深水环境中圆柱壳在水下爆炸冲击波作用下的动态响应进行了数值模拟研究,分析了深度、爆心方位和预应力对圆柱壳动态响应的影响,研究了圆柱壳的破坏载荷和破坏模式随深度而变化的规律。第五章:对水下爆炸冲击波硬毁伤鱼雷的终点效应进行了初步分析,建立了该问题的分析模型,并以此得到了简化模型。然后分析了水下爆炸冲击波毁伤鱼雷过程中主要的影响因素,并根据现有条件确定了研究思路。然后,针对LS-DYNA程序在计算远场水下爆炸时存在的不足,提出了等效质量法,并验证了该方法的有效性。在此基础上模拟了鱼雷壳体结构在远场水下爆炸作用下的动态响应,研究了鱼雷内部构件的惯性效应对于壳体毁伤的影响,分析了鱼雷壳体的冲击环境。最后,运用LS-DYNA模拟了鱼雷壳体结构在近场水下爆炸冲击波作用下的动态响应,研究了鱼雷壳体的毁伤规律,分析了鱼雷内部构件的影响,研究了鱼雷不同舱室壳体的冲击环境和易损性。第六章:总结了研究结果,并给出了下一步研究工作的建议。更多还原

【Abstract】 Underwater explosion and its effect on structures including flat plate, cylindrical shell and torpedo shell were studied in this dissertation by using commercial software AUTODYN, ABAQUS and LS-DYNA. The main work includes: （1） Numerical simulation of underwater explosion process, （2） The re-exploitation of ABAQUS based on Taylor’s plate theory and the first-order doubly asymptotic approximation and its application, （3） Numerical study of dynamic response of cylindrical shell subjected to deep water blast wave, （4） The modification of the simulation method of LS-DYNA to calculate far-field underwater shock wave, （5） The elementary analysis of the terminal effect of torpedo-damaging by underwater shock waves, （6）Numerical simulation of the dynamic response of torpedo shell structure subjected to near-field and far-field underwater shock waves.Chapter 1: The research content in this dissertation, as well as the research method and background, were concisely presented, and the evolvement of relative research, as well as the software of numerical simulation and the method to validate the calculation results, were given.Chapter 2: Underwater explosion shock wave and bubble pulse were simulated by using the hydrocode AUTODYN. By comparing calculation results with empirical formulas, theoretical formulas and experimental results, one can conclude that AUTODYN can simulate much of the important physics of underwater explosion, and the suggestion for the engineering application of AUTODYN was given.Chapter 3: Based on Taylor’s plate theory and the first-order doubly asymptotic approximation （DAA₁） without considering low-frequency response, a simple and practical method has been presented to simulate the high-frequency dynamic plastic response of basic structure including flat plate and cylindrical shell subjected to underwater explosion shock waves without modeling the fluid field. Commercial finite element code, ABAQUS, was used to conduct this simulation. In order to validate this method, two examples including a fixed flat plate and a free cylindrical shell, all subjected to underwater explosion shock waves, were simulated by the method, and the simulation results are in good agreement with experiment results.Chapter 4: Numerical investigation was carried out on a cylindrical shell subjected to underwater explosion shock waves in deep water by using both static state analysis and dynamic analysis via ABAQUS software package. The influence of the depth of the cylindrical shell lies, orientation of the explosion and prestress were identified, and the breakage of the cylindrical shell in deepwater was also studied.Chapter 5: The elementary analysis of the terminal effect of torpedo-damaging by underwater shock waves was presented, and a simple model to analyze this problem was given. Then the main factors to influence the terminal effect were identified, and an idea was given to direct the following numerical study. Aim at the problem that the peak pressure of shock waves induced by far-field underwater explosion are smaller than actual magnitude when using LS-DYNA to simulate underwater explosion, a equivalent mass method which had been validated was presented to solve it. After this, the dynamic response of a lightweight torpedo shell structure subjected to shock waves induced by far-field underwater explosion was simulated by LS-DYNA, and influence of the torpedo insides and shock environment of the torpedo shell structure were studied. The damage mechanism of torpedo shell subjected to underwater explosion shock waves was simulated by using LS-DYNA. The damage mechanism of the torpedo shell, as well as shock environment and vulnerability of the different torpedo cabin shell, were investigated.Chapter 6: The main conclusions and suggestions for the following investigation are given.更多还原