变厚度圆柱壳的强度优化设计

对在任意轴对称分布荷载作用下体积保持常数的变厚度圆柱壳的强度优化设计问题进行了研究。当中面形状固定时 ,采用阶梯折算法 ,用传递矩阵导出了变厚度圆柱壳的初参数解的显式表达式。根据Huber-Mises-Hencky强度准则 ,将变厚度圆柱壳的强度优化转化为极小化当量应力的非线性规划问题 ,并采用投影梯度法建立了问题的优化方法。文中对几个典型问题进行了计算。与等厚度圆柱壳相比较 ,优化圆柱壳的最大当量应力得到了显著降低。本文的研究方法和结果可以用于指导大型圆柱壳体的加肋设计     

Some dynamical properties of a viscoelastic cylindrical shell

IntroductionTherearerarepapersonthedynamicPropertiesofviscoelasticshells.~ulosl']discussesthecaseofshallowsphericalshellandDrozdov[ZIgivesasufficientcondihonofstabilityfortheviscoelasticcylindershellbyusingtheLyapunovfunchonal.UsingtheLyapunovdirectmethod,Tyllkowski[']establishesasufficientconditionfortheasymptohcstabilityofviscoelasticcylindricalshell.ItisnotdifficulttofindthattheseexistingresultSmainlyconcentrateonthedynamicstabilityofviscoelasticshell.Thediscussionaboutthedynamicalsyste…     

Natural vibrations of a cylindrical shell reinforced with rectangular plates

This paper outlines a technique of determining the natural frequencies and modes of an elastic structure consisting of a cylindrical shell and noncrossing rectangular plates inserted into it. The influence of the position, number, and thickness of the plates on the natural frequencies and modes is analyzed __________ Translated from Prikladnaya Mekhanika, Vol. 42, No. 3, pp. 89–96, March 2006.     

Dynamics of an elastic cylindrical shell with a gas–liquid medium subject to two-frequency vibrational excitation

The paper presents experimental results on nonlinear dynamic processes such as the deformation of the elastic wall of a cylindrical shell filled with a fluid and the formation and clustering of gas bubbles, which interact under two-frequency excitation Translated from Prikladnaya Mekhanika, Vol. 44, No. 11, pp. 112–122, November 2008.     

Free vibration of circular cylindrical shell with constrained layer damping

Free vibration characteristics of circular cylindrical shell with passive constrained layer damping (PCLD) are presented. Wave propagation approach rather than finite element method, transfer matrix method, and Rayleigh-Ritz method is used to solve the problem of vibration of PCLD circular cylindrical shell under a simply supported boundary condition at two ends. The governing equations of motion for the orthotropic cylindrical shell with PCLD are derived on the base of Sanders’ thin shell theory. Numerical results show that the present method is more effective in comparison with other methods. The effects of the thickness of viscoelastic core and constrained layer, the elastic modulus ratio of orthotropic constrained layer, the complex shear modulus of viscoelastic core on frequency parameter, and the loss factor are discussed.     

Analysis of the eccentric cylindrical thin shell

ＡＮＡＬＹＳＩＳＯＦＴＨＥＥＣＣＥＮＴＲＩＣＣＹＬＩＮＤＲＩＣＡＬＴＨＩＮＳＨＥＬＬＣｈａｎｇＭｉｎｇ（常明）ＣｈａｎｇＬｉ－ｌｉ（常）（ＴａｉｙｕａｎＨｅａｙｙＭａｃｈｉｎｅｒｙＩｎｓｔｉｔｕｔｅ,Ｔａｉｙｕａｎ）（ＲｅｃｅｉｖｅｄＮｏｖ．３０．１...     

Post-buckling behavior of a point-supported cylindrical liner shell of concrete pressure vessels

Using W. T. Koiter's initial post-buckling theory, this paper deals with the critical load and post-buckling behavior of a point-supported cylindrical liner shell encased in a concrete pressure vessel while the liner shell is subjected to axial and lateral compressions. The reasonable spacing of anchors is given. The results show that the point-supported cylindrical liner shell has a relatively complicated post-buckling behavior. The behavior is subject to the change of anchor spacing in both axial and circumferential directions. When the ratio of the anchor spacing in the two directions satisfies a certain condition, the liner shell will carry the maximum load.     

轴压随机几何缺陷圆柱壳可靠性分析

轴压随机几何缺陷圆柱壳屈曲的失效函数具有较强的非线性，对于该结构已应用的可靠性分析方法不能同时满足计算精度和计算效率的要求。本文发展一个修正的ＭｏｎｔｅＣａｒｌｏ法，由两个步骤执行：应用一阶可靠性方法计算Ｈａｓｏｆｅｒ－Ｌｉｎｄ可靠性指标β；将简单ＭｏｎｔｅＣａｒｌｏ法的采样区域限制在基本随机变量构成的ｎ维β－球外部，采样点由一个χ２分布的随机半径Ｒ≥β和（－１，１）均匀分布的随机方向组成，该修正的ＭｏｎｔｅＣａｒｌｏ法用于轴压随机几何缺陷圆柱壳屈曲强度可靠性分析表明，在相同精度的情况下修正的ＭｏｎｔｅＣａｒｌｏ法的样本容量比简单ＭｏｎｔｅＣａｒｌｏ法要低３个数量级，一阶可靠性方法的计算误差随着与分支屈曲模态一致的初始几何缺陷项数的增加越来越显著     

Analyses of stresses in cylindrical shells of medium length with arbitrary open-section

Based on (1), we discuss the method of solution for the stress states in cylindrical shells of medium length with arbitrary open-section. As an example, the stresses in a channel with semi-circle section were calculated, and the results were compared with those from the elementary beam theory.     

An exact axisymmetric solution for a simply supported piezoelectric cylindrical shell

Summary Three-dimensional axisymmetric solution is presented for a simply supported piezoelectric cylindrical shell. The variables are expanded in Fourier series to satisfy the boundary conditions at the ends. The solution of the governing differential equations with variable coefficients is constructed as a product of an exponential function and a power series. The coefficients of terms of all degrees in the governing equations are set to zero, yielding a characteristic equation for the exponent and recursive relations for the coefficients of the power series. Results are presented illustrating the effect of thickness parameter of the shell. An inverse problem of inferring the applied temperature from the measured potential difference has been solved. Accepted for publication 26 July 1996     

Nonlinear forced vibrations of a cylindrical shell with two internal resonances

Forced vibrations of cylindrical shells described by a system of three ordinary differential equations are studied. There are two internal resonances. Standing and traveling waves in the shells are described by a system of six modulation equations derived using the multiple-scales method. These waves are analyzed for stability __________ Translated from Prikladnaya Mekhanika, Vol. 42, No. 2, pp. 51–58, February 2006.     

局部约束阻尼开口柱壳的减振分析及优化

为了缩减开口柱壳结构的振动,本文基于Lagrange方程以及Sanders薄壳理论建立了局部约束阻尼开口柱壳的动力学模型,分析了粘弹性单元分段数和厚度、阻尼单元占空比以及约束层敷设角和厚度对结构前三阶模态损耗因子和固有频率的影响,得到了各参数对结构振动特性的影响规律.并以前三阶损耗因子为目标,应用NSGA-Ⅱ遗传算法对...     

Vibrations of a corrugated orthotropic cylindrical shell with free edges

The natural vibrations of a corrugated elastic orthotropic cylindrical shell with a directrix perpendicular to its edges that are free are examined __________ Translated from Prikladnaya Mekhanika, Vol. 42, No. 12, pp. 97–114, December, 2006.     

ON THE GENERAL SOLUTION OF CYLINDRICAL SHELL EQUATIONS

ＯＮ　ＴＨＥ　ＧＥＮＥＲＡＬ　ＳＯＬＵＴＩＯＮ　ＯＦ　ＣＹＬＩＮＤＲＩＣＡＬ　ＳＨＥＬＬ　ＥＱＵＡＴＩＯＮＳＰｅｔｅｒＹｉＸｕｅ（薛毅）；ＸｕｅＤａｗｅｉ（薛大为）（ＲｅｃｅｉｖｅｄＯｃｔ．１６，１９９５）Ａｂｓｔｒａｃｔ：Ｉｔｉｓｐｒｏｖｅｄｍａｔ...     

Static analysis of a long and thick orthotropic circular cylindrical shell of revolution

Summary An elasticity solution has been obtained for a long, thick transversely isotropic circular cylindrical shell subjected to distributed pinch load using a set of three displacement functions. Numerical results are presented for different materials and thickness to mean radius ratios. The results obtained from this analysis have been compared with classical and first-order shear deformation shell theories of Flugge, Sanders, Love and Donnell.     

Parametric instability of cylindrical thin shell with periodic rotating speeds

Parametric instability of a cylindrical thin shell with periodically time-varying rotating speeds is studied in the paper. Energy formulation based upon Love's thin shell theory and the assumed mode method is utilized to obtain the governing equations of a rotating cylindrical shell under simply supported condition. Considering the time-varying rotating speeds, the second order differential equations of the system have time-periodic gyroscopic and stiffness coefficients. The multiple scales method is utilized to obtain the boundaries of both primary and combination instabilities analytically. The primary instability occurs when the excitation frequency is near twice of the natural frequency. The excitation frequency close to the sum of two natural frequencies might lead to the occurrence of combination instability. Numerical simulations are conducted to verify the analytical results. It is shown that the primary instability regions for each mode always appear in the periodically rotating cylindrical shell. Their widths increase continually with excitation amplitude of the time-periodic rotating speed. For certain modes, the combination instability region might not exist. The conditions for its existence are obtained analytically and verified by numerical simulations. Increasing the constant rotating speed would greatly enhance the instability regions. Moreover, it might also cause the appearance of combination instability region.     

Wave transmission through laminated composite double-walled cylindrical shell lined with porous materials

A study on free harmonic wave propagation in a double-walled cylindrical shell, whose walls sandwich a layer of porous materials, is presented within the framework of the classic theory for laminated composite shells. One of the most effective components of the wave propagation through the porous core is estimated with the aid of a fiat panel with the same geometrical properties. By considering the effective wave component, the porous layer is modeled as a fluid with equivalent properties. Thus, the model is simplified as a double-walled cylindrical shell trapping the fluid media. Finally, the transmission loss (TL) of the structure is estimated in a broadband frequency, and then the results are compared.     

Analysis of thermal-elastic coupling vibration of large deflection cylindrical shell

The governing equation and energy equations for thermal-elastic coupling vibration of cylindrical shell were developed. The Garlerkin method was used in numerical process. Some useful result can be concluded from numerical result. With the increase ofthe amplitude of temperature and coupling coefficient, the speed of vibration decaying becomes slower and the coupling effect becomes weaker. The larger the ration of length to radius and length to thickness, the faster the decaying of the vibration amplitude and the vibration frequency increase. It means the coupling effect gets stronger. The larger the coupling coefficient, the smaller the axial stress, the axial force and the bendind moment are.     

激光辐照下圆柱壳结构的稳定性分析

针对航天工程中常用的承受轴压作用的薄壁圆柱壳,分别采用解析方法与特征值屈曲有限元方法分析了圆柱壳结构在均匀轴压作用下的稳定性能,得到了屈曲承载力.并进行了对比,验证了有限元模型的合理性.采用线性屈曲特征值有限元方法分析了强激光辐照作用下圆柱壳的稳定性能,分析表明激光辐照导致壳体局部温度上升并由此带来材料参数的改变,是因为激光辐照在壳体中引起了热应力与热应变,使轴压圆柱壳的屈曲承载力明显降低.论文还着重对加筋圆柱壳结构的稳定性进行了研究,数值分析结果表明,加筋能有效提高圆柱壳结构的抗压承载力,激光辐照作用下,加筋对轴压作用下圆柱壳的屈曲承载力的提高作用更为明显.     

THEORY OF THICK-WALLED SHELLS AND ITS APPLICATION IN CYLINDRICAL SHELL

In this paper, a theory of thick-walled shells is established by means of Hellinger-Reissner's variational principle, with displacement and stress assumptions. The displacements are expanded into power series of the thickness coordinate. Only the first four and the first three terms are used for the displacements parallel and normal to the middle surface respectively. The normal extruding and transverse shear stresses are assumed to bt, cubic polynomials and to satLyfy the boundary stress conditions on the outer and inner surfaces of the shell. The governing equations and boundary conditions are derived by means of variational principle. As an example, a thick-walled cylindrical.shell is disscussed with the theory proposed. Furthermore, a photoelastic experiment has been carried out, and the results are in fair agreement with the computations.