变锥度组合圆锥壳结构振动特性分析

Vibration Characteristic Analysis of Combined Conical Shell Structures with Variable Taper

摘要: 变锥度组合圆锥壳结构是一种典型的工程结构，被广泛应用于水下航行器等工程领域。首先基于一阶剪切变形壳理论，采用微分求积法(DQM)建立了五自由度变锥度组合圆锥壳结构振动特性分析模型，采用罚函数法模拟其两端的边界条件；紧接着，对所建立模型进行收敛性分析，确定了最佳微分求积节点数和惩罚因子的取值；然后采用有限软件验证了所建立模型的有效性；最后根据已建立模型，研究结构几何参数对变锥度组合圆锥壳结构振动特性的影响。结果表明，增加半锥度角差，会提高变锥度组合圆锥壳结构的稳定性，使得共振频率向高频移动；增加半锥度角和半径R₁会降低其固有频率，使得共振频率向低频移动。

Abstract: Combined conical shell structure with variable taper is a typical engineering connection structure, which is widely used in rocket, submarine, satellite and other important engineering fields. Based on the theory of first-order shear-deformed shell, a five-degree-of-freedom model of combined conical shell structure with variable taper is established by employing differential quadrature method, the boundary conditions are simulated by using penalty function method. Then, the convergence analysis of the proposed model is carried out for determining the optimum number of differential quadrature nodes and the value of penalty factor. Then, the validity of the proposed model is verified by finite software. Finally, the influence of structural geometric parameters on vibration characteristics of combined conical shell structure with variable taper is studied according to the established model. The results show that the increase of semi taper angle difference can improve the stability of combined conical shell structure with variable taper, make the resonant frequency move to high frequency. The increase of semi taper angle and radius R₁ will reduce its natural frequency, make the resonance frequency move to the lower frequency.