考虑预应力和液体影响的圆柱壳颤振分析

 为了研究预应力和液体对圆柱壳颤振的影响,采用杂交元方法,建立了圆柱壳的气动弹性方程。由Sanders薄壳理论和经典有限元理论,从壳的精确解推导节点位移函数入手,并由一阶活塞理论得到结构的气动阻尼矩阵和刚度矩阵,最终推导出考虑预应力和内部液体影响的圆柱壳的混合有限元公式和气动弹性方程。通过特征值法验证了此种有限元方法的正确性,并重点研究了预应力和内部注有液体对圆柱壳稳定性的影响。计算结果表明:预应力和液体对圆柱壳的颤振特性有显著的影响。

Effects of Initial Stress and Internal Liquid on Flutter Analysis of Cylindrical Shell

In order to study the effects of initial stress and internal liquid on the flutter of a cylindrical shell, the aeroelastic equations of the cylindrical shell are established, while a hybrid finite element method of analyzing cylindrical shell flutter is employed. The structural formulation is a combination of Sanders shell theory and the classic finite element method. The nodal displacements are found from the precise solution of shell governing equations. The influence of the initial stress and internal liquid is also taken into account. The first-order piston theory is applied to derive the aerodynamic damping and stiffness matrices. Hybrid finite element formulation and aeroelastic equations are derived and solved numerically. The validity of such a finite element method is verified by the eigenvalue method. The paper focuses on an investigation of the impact of initial stress and internal liquid on the aeroelastic stability of a cylindrical shell. Numerical solutions demonstrate that they do have a marked impact on the flutter characteristics of a cylindrical shell.