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1.
曾德顺  邱笑农 《力学季刊》1996,17(3):173-181
本文对厚圆柱壳的非轴对称振动进行了分析,其中除包含通常的薄膜和弯曲效应外,还反映了转动惯性,横向剪切变形和横向挤压的影响,数值结果表明:对于厚圆柱壳来说存在着频率密集区,频率位置发生移动,横向挤压的影响必须要考虑。  相似文献   

2.
研究了功能梯度材料扁薄锥壳在横向非均匀升温场中的几何非线性大变形问题.基于von Kármán几何非线性理论推导出了以中面位移为基本未知量的功能梯度扁薄锥壳在横向非均匀热载荷作用下的轴对称大挠度控制方程.采用打靶法数值求解所得非线性常微分方程边值问题,得到了锥壳的大挠度弯曲变形数值解.给出了锥壳的变形与其形状参数、载荷和材料参数等变化的特征关系曲线,分析和讨论了温度参数和材料梯度变化参数对变形的影响.  相似文献   

3.
爆炸冲击下复合材料层合扁球壳的动力屈曲   总被引:1,自引:0,他引:1  
研究计及横向剪切的复合材料层合扁球壳在爆炸冲击载荷作用下的非线性轴对称动力屈曲问题。通过在复合材料层合扁球壳非线性稳定性的基本方程中增加横向转动惯量项并引入R.H.Cole理论的爆炸冲击力,得到爆炸冲击下复合材料层合扁球壳的动力控制方程,应用Galerkin方法得到用顶点挠度表达的爆炸冲击动力响应方程,并采用Runge-Kutta方法进行数值求解,采用Budiansky-Roth准则确定冲击屈曲的临界载荷,讨论了壳体几何尺寸对复合材料层合扁球壳冲击屈曲的影响;数值算例表明,此方法是可行的。  相似文献   

4.
采用六模态的中厚壳理论研究了可压缩流体中球面各向同性球壳的自由振动,即在分析中考虑了剪切变形,旋转惯量和横向正应变的影响,引入5个辅助变量可以理到两类振动及其频率方程,对频率方程作了简化并算例进行了相应的探讨。  相似文献   

5.
轴向应力波作用下圆柱壳塑性轴对称动力屈曲   总被引:2,自引:0,他引:2  
运用有限元特征值分析方法对应力波作用下圆柱壳塑性轴对称动力失稳问题进行了研究。基于应力波理论和相邻平衡准则导出了圆柱壳轴对称动力失稳时的特征方程,在分析中同时考虑了应力波效应及横向惯性效应,把圆柱壳塑性动力失稳问题归结为特征值问题。通过引入圆柱壳动力失稳时的波前约束条件实现了此类问题的有限元特征值解法。计算结果揭示了圆柱壳塑性轴对称动力屈曲变形发展的机理,以及轴向应力波和屈曲变形的相互作用规律。  相似文献   

6.
本文用考虑横向剪切变形的精化理论研究正交各向异性圆柱形中厚壳的轴对称自由振动问题。把六阶的偏微分控制方程分解成一个二阶和一个四阶的偏微方程,从而方便地求出各种边界条件下壳体自振问题的显式解。  相似文献   

7.
复合材料层合扁球壳的非线性强迫振动   总被引:4,自引:0,他引:4  
刘人怀  王王番 《力学学报》1997,29(2):236-241
研究了考虑横向剪切的对称层合圆柱正交异性扁球壳的非线性强迫振动问题,得到了共振周期解和非共振周期解.最后,还分析了横向剪切对幅频特性曲线的影响  相似文献   

8.
本文动用有限元法,采用九结点超参数壳单元计算放置园柱壳的振动特性,考虑了横向剪切以及轴向变形的影响。对于旋转园柱壳达到平衡位置以前的状态,用大变形非线笥板壳理论处理,并假设园柱壳在平衡位置附近作微振动,建模中考虑了科氏力,离心力,初应力以及由大变形引起的几何非线性的影响,通过对一个一固定一端自由的旋转园柱壳在考虑和不考虑大变形几何非线性这两种情况下的比较,阐明了在高速时大变形下几何一性对旋转壳的固  相似文献   

9.
本文用三维弹性力学理论求得球壳轴对称扭转振动问题的解析解。揭示了壳体在子午线方向和半径方向的耦合振动,研究了厚度方向剪切振动的固有频率和振型。文末给出顶端封闭和开孔球壳固有频率和振型的数字结果。对于各种不同厚度球壳的振动特性作了详细的讨论。  相似文献   

10.
复合材料的多层、夹层和加筋圆柱曲板的稳定和振动   总被引:1,自引:0,他引:1  
本文在文献〔1,2〕的基础上,考虑了沿壳体厚度方向的剪切变形,探讨周边简支的纤维增强复合材料的正交各向异性的多层、夹层和加筋矩形圆柱曲板(与圆柱壳),在轴压、侧压和剪切(扭矩)作用下的临界载荷和横向振动固有频率的计算问题。在编成计算程序后,用一些算例将用文献〔1〕中的扁壳方程(Donnell壳体理论) 和文献〔3〕中的非扁壳方程(Love的壳体一阶近似理论) 算得的结果作了比较;将轴压下轴对称失稳和非轴对称失稳的临界载荷作了比较;将在轴压和侧压作用下失稳时外加筋曲板和内加筋曲板的临界载荷作了比较;将有薄膜力N_x~0和N_y~0同时和分别作用时与没有薄膜力作用时的横向振动固有频率作了比较;将按壳体的剪切变形理论和经典理论算得的临界载荷作了比较;将铺层情况对临界载荷的影响作了比较。  相似文献   

11.
(杨宜谦)(马和中)(王俊奎)DYNAMICRESPONSEOFLAMINATEDORTHOTROPICSPHERICALSHELLSINCLUDINGTRANSVERSESHEARDEFORMATIONANDROTATORYINERTIA¥Yang...  相似文献   

12.
In this paper, the nonlinear equations of motion for shallow spherical shells with axisymmetric deformation including transverse shear are derived. The nonlinear static and dynamic response and dynamic buckling of shallow spherical shells with circular hole on elastically restrained edge are investigated. By using the orthogonal point collocation method for space and Newmark-β scheme for time, the displacement functions are separated and the nonlinear differential equations are replaced by linear algebraic equations to seek solutions. The numerical results are presented for different cases and compared with available data.  相似文献   

13.
研究了计及横向剪切的复合材料层合扁球壳在矩形脉冲载荷作用下的非线性动力屈曲问题;采用Galerkin方法得到以顶点挠度表达的动力响应方程,并用Runge-Kutta方法进行数值求解,应用Budiansky-Roth准则(简称B-R准则)确定冲击屈曲的临界荷载;讨论了壳体几何尺寸和物理参数对复合材料层合扁球壳冲击屈曲的影响;数值算例表明,该方法是可行的.  相似文献   

14.
Summary The static and dynamic responses of anisotropic spherical shells under a uniformly distributed transverse load are investigated. Analytical solutions using the mixed variational formulation are presented for spherical shells subjected to various boundary conditions. Numerical results of a refined mixed first-order shear deformation theory for natural frequencies, critical buckling, center deflections and stresses are compared with those obtained using the classical shell theory. A variety of simply-supported and clamped boundary conditions are considered and comparisons with the existing literature are made. The sample numerical results presented herein for global structural behaviour of monoclinic spherical shells should serve as references for future comparisons.  相似文献   

15.
Based on Timoshenko-Mindlin kinematic hypothesis, the shallow shell theory is extended to include the transverse shear deformation for the nonlinear axisymmetric dynamic analysis of the symmetric cross-ply shallow spherical shell. Using the orthogonal point collocation method and the Newmark scheme, an iterative solution is formulated. The numerical results for the nonlinear static and dynamic responses and dynamic buckling of these shallow spherical shells with circular holes under uniformly distributed static or dynamic normal impact loads are presented and compared with available data.  相似文献   

16.
This paper deals with nonlinear free vibration of reticulated shallow spherical shells taking into account the effect of transverse shear deformation. The shell is formed by beam members placed in two orthogonal directions. The nondimensional fundamental governing equations in terms of the deflection, rotational angle, and force function are presented, and the solution for the nonlinear free frequency is derived by using the asymptotic iteration method. The asymptotic solution can be used readily to perform the parameter analysis of such space structures with numerous geometrical and material parameters. Numerical examples are given to illustrate the characteristic amplitude-frequency relation and softening and hardening nonlinear behaviors as well as the effect of transverse shear on the linear and nonlinear frequencies of reticulated shells and plates.  相似文献   

17.
This paper is concerned with the transient deformation of functionally graded (FG) shallow spherical shells subjected to time-dependent thermomechanical load. Based on Timoshenko- Mindlin hypothesis and yon Karman nonlinear theory, a set of nonlinear governing equations of motion for FG shallow spherical shells in regard to transverse shear deformation and all the inertia terms are established using Hamilton's principle. The collocation point method and Newmark- beta scheme in conjunction with the finite difference method are adopted to solve the governing equations of motion and the unsteady heat conduction equation numerically. In the numerical examples, the transient deflection and stresses of FG shallow spherical shells with various material properties under different loading conditions are presented.  相似文献   

18.
傅衣铭 《力学学报》1995,27(5):624-630
基于Timoshenko-Mindlin假设及Hamilton原理,建立了一般纤维叠层圆柱厚壳在参数激励下的非线性振动方程;应用多模态近似和增量谐波平衡法求解了叠层圆柱厚壳的非线性动力稳定性问题。横向剪切变形、端部支承条件等因素的影响被讨论。  相似文献   

19.
A dynamic, shear deformation theory of a doubly curved shell is used to develop a finite element for geometrically non-linear (in the von Karman sense) transient analysis of laminated composite shells. The element is employed to determine the transient response of spherical and cylindrical shells with various boundary conditions and loading. The effect of shear deformation and geometric non-linearity on the transient response is investigated. The numerical results presented here for transient analysis of laminated composite shells should serve as references for future investigations.  相似文献   

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