【作者】 刘明；

【导师】 安伟光；

【作者基本信息】 哈尔滨工程大学 ， 工程力学， 2012， 博士

【摘要】 由于超空泡航行体结构一般为细长体，并且航行体在高速运动时所受的轴向力和尾部冲击力非常大，因此航行体结构在这些载荷的作用下极易受到破坏。长期以来人们对超空泡航行体结构的振动特性进行了大量的理论分析和试验研究,取得了一些重要的研究成果。然而,这些研究大多都忽略了结构的物理和几何参数的随机性的影响。但在实际的操作过程中,由于材料特性的随机性，以及航行体结构在制造、安装过程中可能会受到各种各样随机因素的影响,这些因素都会对结构动力特性产生一定的影响。因此，研究具有随机参数的超空泡航行体结构的动力稳定性，以及航行体结构的动力可靠性是很有意义的，本文的主要内容如下：1、建立了超空泡航行体稳定滑行和局部空泡运动状态时的平衡方程，得到了空化器和尾部受力的平衡关系式，通过迭代得到了航行体角度的平衡值。最后比较了超空泡的两种基本形态模型，分析了不同参数条件下两种空泡模型的变化规律。针对超空泡航行体入水时的水动力特征，给出了超空泡航行体入水时不稳定空泡形状的表达式。2、针对超空泡射弹水下高速航行时前端空化器受纵向随机载荷作用时的动力稳定性问题，建立超空泡射弹结构的运动偏微分方程。根据Bolotin方法，给出了超空泡射弹的动力不稳定性区域。3、当考虑超空泡射弹结构在加工、安装过程中存在的误差等不确定性因素，利用随机因子法求出随机参数超空泡射弹结构的动力不稳定区域边界。应用代数综合法，得到了含随机参数的超空泡射弹动力不稳定区域边界的数字特征（均值和方差）。并分析了参数的随机性对射弹结构动力不稳定性的影响。数值计算表明，参数的随机性对超空泡射弹动力不稳定性有一定的影响，本文的方法可为随机参数超空泡射弹的设计提供参考。4、对于具有随机参数的超空泡鱼雷结构在随机激励下的动力可靠性问题，使用八节点超参数壳单元对超空泡鱼雷建模。将超空泡鱼雷尾部受到的冲击载荷及滑行力，简化成两个存在某一相位差的平稳随机过程，并考虑冲击力与滑行阻力之间的相关性,利用虚拟激励法将超空泡鱼雷所受的随机过程载荷精确地转化成确定性简谐载荷问题。5、应用Newmark法结合虚拟激励摄动法计算出随机结构的随机应力响应，进而求出随机参数超空泡鱼雷结构动力可靠性所需的全部数字特征。由首次超越破坏准则，得到了随机参数超空泡鱼雷结构动力可靠度的均值和方差，解决了具有随机参数的超空泡鱼雷结构的动力可靠性问题。更多还原

【Abstract】 Because the structure of supercavity vehicle generally has to be designed as slenderconfiguration, and the high longitudinal force and the tail impact force are both very likely tolead to the structure of supercavity vehicle in damage. A large number of theory analysis andexperimental research have been made on structural vibration characteristics of supercavityvehicle, and people had made some important research results. However, these studies did nottake into account the randomness of physical and geometrical parameters of structure. But inactual operation process, because the randomness of the material properties, as well as thestructure of supercavity vehicle may subject to the effect of various random factors in themanufacture, installation processes, they are all produce certain effect on dynamiccharacteristics of structure.So it is necessary to research dynamic stability and reliability onthe structure of supercavity vehicle with stochastic parameters. The major content of thethesis as follows:1. The equilibrium equation when supercavity vehicle in the steady-state motion and inthe partial cavitaion regime were established, and the relations for the balanced forces on thecavitator and the tail were obtained, The balanced values of the angles are founded by theiteration process, At last we analysis the changing regularity of the two cavity models bycomparing the two basic form models under the conditions of the different parameters.According to the hydrodynamic characteristic when the supercavity vehicle enters into water,we can infer the calculating formula of the unsteady cavity configuration.2. Taking aim at the problems of dynamic stability when the head of supercavitatingprojectile subject to the axial random load at high speed motion underwater, the dynamicpartial differential equation of supercavitating projectile structure was established, then thenumerical calculation for the dynamic stability of supercavitating structure was performedwith Bolotin method.3. In consideration of the stochastic parameters, the regions of dynamic instability ofprojectile with stochastic parameters were constructed based on the random factor method,the mean value and the variance of the boundary of dynamic instable regions were thenderived by using the random variable’s algebra synthesis method. The influence of stochasticparameters on the dynamic instability of supercavitating projectile was also analyzed. The computational results indicated that the stochastic parameters have certain influence on thedynamic instability. The results provided a certain theoretical foundation for the design ofsupercavitating projectile.4. Dynamic reliability of stochastic parameters supercavitating torpedo under the randomexcitation is investigated. The supercavitating torpedo is modeled by using eight-nodesuper-parametric shell elements. The impact loads and planing forces of the tail onsupercavitating torpedo structures are simplified into two stationary random processes with acertain phase difference, and considering the correlation between the impact loads and planingforces of the tail on supercavitating torpedo structures, the random excitations are transformedinto sinusoidal ones in terms of the pseudo excitation method.5. The structural stress response can be obtained through combining Newmark methodwith pseudo excitation perturbation method, and then all required digital features for dynamicreliability of supercavitating torpedo have be calculated. The expressions of the mean valueand the variance of stochastic supercavitating torpedo dynamic reliability are educed from thefist excursion probability mechanism of calculating dynamic reliability, the structure dynamicreliability problems of supercavitating torpedo with random parameter have be solved. Finally,the method of this paper was proved feasible and available comparing with the Monte Carlomethod by an example.更多还原