分析圆板横向振动的动态有限条法

本文首次将动态有限元法应用于轴对称圆板的振动特性分析,采用了位移函数沿周向按三角级数展开的环板弯曲单元,发展成为只需沿径向划分单元的动态有限条法。用单元谐振变形作为形状函数,按频率的升幂级数展开,建立了动态单元的质量和刚度矩阵,并使它的特征值求解问题与常规分析方法相协调。     

厄密多项式在结构动力响应计算中的应用

本文利用正交多项式级数部分和的"最佳近似"性,推出了求解结构动力响应的付里叶-厄密多项式展开法.文中详细推导了振动系统的位移和速度响应的分步解析表达式,并讨论了计算格式的稳定性条件,通过了实例考核与精确度对比分析.     

THE FINITE DYNAMIC ANNULAR ELEMENT FOR THE VIBRATION ANALYSIS OF VARIABLE THICKNESS DISCS

According to the gyro-periodicity of dynamic displacements, the two-dimensional problems of circular plates with variable thickness are simplified into one-dimensional ones in this paper. Taking the expanded form of frequency power series of the dynamic displacement functions as the dynamic shape functions of the finite annular element, the mass and stiffness matrices as well as their one-order revised matrices are given succinctly. The dynamic method is used to analyse the vibration characteristics of a bladed disc assembly and is compared with conventional finite element method and experiment, and is proved to be superior to other numerical methods.     

THE USAGE OF HERMITE POLYNOMIAL IN THE CALCULATION OF STRUCTUBAL DYNAMIC RESPONSES

This paper employs the best approximation of part series sum of normal polynomials, and proposes a new method with the Fourier-Hermite polynomial expansion expressing structural dynamic responses. Analytic expressions of displacement and velocity responses of vibrational systems are established in this paper, and stability condition of the step-by-step algorithm is discussed. Finally, a computational example is demonstrated, and the precision of its results is compared with conventional methods.     

压电陶瓷片在振动试验中的应用

通过压电陶瓷片在平板上进行激振和拾振试验,实测压电陶瓷片的某些性能及其对试件固有频率和振型的影响,获取压电陶瓷片的有关数据,以便对实际机械构件作分离纯模态时选配合理的激励方案。     

正弦型扁拱的动力稳定特性

本文阐述了简支正弦型扁拱在时跃式载荷作用下的平衡及其稳定性问题。针对承受有二阶不同谐波分量的空间分布载荷下的正弦初态拱,详细给出了扁拱在所有可能的这类载荷下的平衡形式和特征,并判定了它们的稳定性。从而为扁拱型元件的设计和应用提供了分析运动特性的便利。     

THE DYNAMIC STIFFNESS MATRIX OF THE FINITE ANNULAR PLATE ELEMENT

The dynamic deformation of harmonic vibration is used as the shape functions of thefinite annular plate element.and some integration difficulties related to the Bessel’sfunctions are solved in this paper.Then the dynamic stiffness matrix of the finite annularplate element is established in closed form and checked by the direct stiffness method.Thepaper has given wide converage for decomposing the dynamic matrix into the power seriesof frequency square.By utilizing the axial symmetry of annular,the modes withdifferent numbers of nodal diameters are separately treated Thus some terse and completeresults are obtained as the.foundation of structural characteristic analysis and dynamicresponse computation.     

用于变厚度圆盘振动分析的动态环形元

本文利用动态位移的回转周期变化规律,将变厚度圆板弯曲振动的二维问题化为一维形式.并将环形单元的位移函数以频率的升幂形式展开,作为动态形状函数,进而推导了动态环形元的质量和刚度矩阵及其一次动态修正矩阵,并以简洁的形式给出.最后作为本文方法的直接应用,计算了叶盘组合件的固有特性与实验值及其它方法进行了比较,说明动态的变厚度环板元的优越性.