壳体约束对液体爆炸抛撒流场特性的影响

进行了不同壳体约束条件下的液体爆炸抛撒实验,讨论了壳体对起爆后早期抛撒流场特征的影响,分析了爆炸分散过程中液体的状态变化和破碎分散机理,并通过数值模拟进行了对比分析。结果表明,在爆炸反射稀疏波的作用下液体发生空化现象,壳体强度越高,空化发生的延迟越大,发生位置越靠近爆心,同时,爆炸产物气体与液体在其界面附近越早发生掺混。     

Explosive projection of liquid from a thick-walled cylindrical container

The process of projection of a layer of an ideal liquid enclosed into a cylindrical elastoplastic shell by products of instantaneous detonation of a high explosive charge is studied numerically in a two-dimensional plane formulation. The processes of shell fracture and liquid exhaustion through the resultant slots are considered. Numerical results are analyzed, and analytical relations for angular distributions of radial velocity and mass of the liquid escaping through the slots are derived. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 3, pp. 56–63, May–June, 2009.     

Study of dynamic processes in a rigid cylindrical vessel with elastic bottom partially filled with a liquid

The paper reports on the results from an experimental study of the nonlinear deformation of the elastic bottom of and the free liquid surface in a rigid shell. The shell and liquid interact with each other and with a cluster of gas bubbles produced by vibrational excitation __________ Translated from Prikladnaya Mekhanika, Vol. 42, No. 11, pp. 114–120, November 2006.     

Analysis of Nonlinear Bulging of Liquid-Filled Cylindrical Shells Under Local Dynamic Loading

Consideration is given to a nonlinear problem on the nonstationary deformation of cylindrical shells filled with a perfect incompressible liquid and subjected to radial pulse loading distributed along a part of the lateral surface     

On Multimode Nonlinear Vibrations of Filled Cylindrical Shells

A technique is proposed to study the multimode nonlinear vibrations of circular shells fully filled with a perfect incompressible liquid. This technique is used to study the basic laws of modal interaction at nonlinear, including sub-harmonic resonances     

具有约束层阻尼贮液圆柱容器的耦振与减振特性分析

该文在对空圆柱层合壳(不充液)振动分析研究的基础上,借助线性势流理论,进一步考虑液固耦合效应,导出了敷有CLD贮液圆柱层合壳谐耦振的一阶常微分矩阵方程,该方程右边多了液动压力项.由于它不能预先给定,导致方程中出现未知项.为了克服这一困难,文中研究了液动压力的解式,并采用新型齐次扩容精细积分技术,提出了一种高效率和高精度的半解析半数值解法.进而还求解了CLD贮液圆柱容器在地面谐运动激励下的响应;通过大量数值计算分析了CLD的厚度、长度、敷设位置以及粘弹芯的复剪切模量对减振效果的影响.计算还表明了有液体的存在,这些影响和空容器时是不一样的.文中方法为CLD贮液容器的控制优化提供了有力手段.     

圆柱壳撞水时的弹塑性动力屈曲研究

本文研究圆柱壳在流固中冲击载荷下的弹塑性动力曲问题。建立了液体－气体－固体三相的数学模型。其中结构部分控制方程由弹塑性力学中关于加速度的最小原理获得，本构关系采用增量理论，液体假设为不可压缩，空气层认为最等熵压缩。分别讨论了不同冲击高度时压力变化规律，屈曲对载荷的影响。屈曲沿壳长的分布及发展规律等。     

On Modes of Flexural Vibrations of Initially Bent Cylindrical Shells Partially Filled with a Liquid

Flexural modes are determined for initially bent cylindrical shells partially filled with a perfect incompressible liquid     

Propagation of Harmonic Waves in a Cylindrical Shell (Timoshenko Model)

Equations for studying the axisymmetric deformation of a cylindrical shell are derived on the basis of Timoshenko shell theory. A dispersion equation is set up to study natural harmonic waves in a cylindrical isotropic shell. A numerical approach to plotting dispersion diagrams is proposed. The wave velocities obtained coincide with analytical solutions     

半圆柱壳挠曲问题解析解精确性的研究

壳体力学已于上世纪由多位专家发展成熟,其中简支柱壳挠曲问题采用改进莱维解法的三角级数法解出,但是其解法复杂,手算难以完成．为讨论其结果的精确性,通过编写运行基于MATLAB的运算程序导出实例化解析解,与基于力学基本理论的推想假设对比,再引入有限元计算结果进行比较研究．最终发现,理论解析解应力和位移具有分布形式大致准确性,但仍存在不容忽视的细节与局部性问题．研究表明,理论解法工程意义有限,结果尚需改进．     

The Problem of Forced Nonlinear Vibrations of Cylindrical Shells Completely Filled with Liquid

The forced nonlinear vibrations of a thin cylindrical shell completely filled with a liquid are studied. A refined mathematical model is used. The model takes into account the nonlinear terms up to the fifth power of the generalized displacement of the shell. The Bogolyubov’Mitropolsky averaging method is used to plot amplitude’frequency response curves for steady-state vibrations. The steady-state vibrations at the frequency of principal harmonic resonance are analyzed for stability__________Translated from Prikladnaya Mekhanika, Vol. 41, No. 2, pp. 52–59, February 2005.     

Incremental analysis of the nonlinear behavior of thin shells

The paper proposes a method of incremental loading for solving nonlinear problems of shell theory. A feature of this method is that the same algorithm is used before buckling, at the limit point, and after buckling. The method is based on the assumption that all the unknowns, including the load parameter, are on an equal footing. It is shown that the method can be used to solve algebraic equations with Cramer's rule involved to avoid numerical instability in the neighborhood of the limit point. Test problems confirm the validity of the approach Translated from Prikladnaya Mekhanika, Vol. 44, No. 9, pp. 85–93, September 2008.     

The Stress State of Multilayer Flexible Cylindrical Shells of Variable Stiffness

The deformation of flexible multilayer circular cylindrical shells of variable stiffness is studied under a refined theory that accounts for the inhomogeneity of transverse shear strains. The effect of variation in the thickness at constant weight on the stress–strain state of a shell is analyzed     

Nonlinear Bending Theory of Diagonal Square Pyramid Reticulated Shallow Shells

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应用平板壳单元DKQl6分析板壳结构的几何非线性

应用新近开发的四边形十六自由度离Kirchhoff平板壳单元DKQl6，分析了板壳结构的几何非线性问题，采用Total Lagrange格式，在小应交、中等转动的假定下，建立了该单元几何刚度阵和大位移矩阵．非线性方程采用位移引导或弧长引导的牛顿-拉夫森增量迭代法求解．讨论了网格和加载步效对收敛性的影响，通过对典型算例的计算以及与其它单元的比较，说明了DKQl6单元在板壳结构几何非线性分析中也有良好的精度．     

The variational principle of thin shell in stability

ＴＨＥＶＡＲＩＡＴＩＯＮＡＬＰＲＩＮＣＩＰＬＥＯＦＴＨＩＮＳＨＥＬＬＩＮＳＴＡＢＩＬＩＴＹＨｕａｎｇｙａｎ黄炎,ＨｕａｎｇＲｅｉｆａｎｇ黄瑞芳（ＲｅｃｅｉｅｄＮｏｖ．１８．１９９４ＣｏｍｍｕｎｉｃａｔｅｄｂｙＣｈｉｅｎＷｅｉｚａｎｇ）Ａｂｓｔｒａｃｔ...     

碟形薄壳的塑性屈曲

本文采用非线性前屈曲一致理论分析均布外压下碟形薄壳的塑性屈曲问题，建立了这类壳体的能量表达式和屈曲方程，给出了简明的计算格式。数值分析结果表明，所导出的算法具有较好的精度，计算过程也简单方便。     

Dynamics of reinforced compound shells under nonstationary loads

The nonstationary behavior of reinforced compound structures is analyzed within the framework of the geometrically nonlinear Timoshenko theory of shells and rods. The numerical method used to solve the problem is based on the finite-difference approximation of the original differential equations. The dynamic behavior of a reinforced compound structure under nonstationary loading is demonstrated by way of a numerical example. The numerical results are compared with experimental data __________ Translated from Prikladnaya Mekhanika, Vol. 42, No. 4, pp. 100–107, April 2006.     

THE ANALYSIS OF SHALLOW SHELLS BASED ON MULTIVARIABLE WAVELET FINITE ELEMENT METHOD

Based on the generalized variational principle and B-spline wavelet on the interval (BSWI), the multivariable BSWI elements with two kinds of variables (TBSWI) for hyperboloidal shell and open cylindrical shell are constructed in this paper. Different from the traditional method, the present one treats the generalized displacement and stress as independent variables. So differentiation and integration are avoided in calculating generalized stress and thus the precision is improved. Furthermore, compared with commonly used Daubechies wavelet, BSWI has explicit expression and excellent approximation property and thus further guarantee satisfactory results. Finally, the effciency of the constructed multivariable shell elements is validated through several numerical examples.     

Nonlinear vibrations of orthotropic shallow shells of revolution

A set of nonlinearly coupled algebraic and differential eigenvalue equations of nonlinear axisymmetric free vibration of orthotropic shallow thin spherical and conical shells are formulated.following an assumed time-mode approach suggested in this paper. Analytic solutions are presented and an asymptotic relation for the amplitude-frequency response of the shells is derived. The effects of geometrical and material parameters on vibrations of the shells are investigated.