U型波纹管的扭转振动固有频率的计算

采用等效的薄壁圆管模型来分析U型波纹管的扭转振动固有频率,为此要确定U型波纹管的等效半径和扭转刚度。等效半径采用两种计算方法。扭转刚度的计算即采用了钱伟长关于旋转壳的扭转刚度积分公式,也采用了等效的圆管模型方法,由此得到的相应的U型波纹管扭转固有频率的计算方法分别称为积分法和简化法。没有关于波纹管扭转固有频率的实验见诸文献。采用有限元法来验证上述计算方法,取得了很好的一致。积分法更为精确,简化法更适于工程计算。

CALCULATION OF TORSIONAL NATURAL FREQUENCY OF U-SHAPED BELLOWS

An equivalent thin-walled circular pipe model is used to analyze torsional natural frequency of U-shaped bellows. The equivalent radius and the torsional stiffness of U-shaped bellows are defined. Two methods are used to calculate the equivalent radius. Torsional stiffness of U-shaped bellows is calculated using Chien’s integration formula for torsional stiffness of revolutionary shells and the equivalent circular pipe model, respectively. The corresponding calculation methods for torsional natural frequency of U-shaped bellows are called integrated method and simplified method, respectively. Finite element analysis is performed to verify the results from the two methods, and good agreement is reached between them. The results from the integrated method are found more accurate, while the simplified method is more suitable for engineering calculation.