基于变厚度壳单元的旋转叶片固有特性分析

针对1个扭型、变截面旋转叶片，基于ANSYS有限元软件，采用变厚度壳单元来模拟真实叶片的方法建模，并与实体单元模型对静频和固有振型进行对比，验证了该建模方法的准确性；在此基础上分析了科氏力、旋转软化、离心刚化以及三者耦合对叶片动频特性的影响规律；基于壳单元动频数据，对现在常用的动频系数经验公式的适用性进行了简单评价。研究结果表明：2种模型的动频规律一致，对系统影响由大到小依次为离心刚化、旋转软化和科氏力；叶片A0振型的动频系数吻合较好，A1振型的反之

Natural Characteristic Analysis of Rotating Blade Based on Variable Thickness Shell Element

Taking a rotating variable cross-section twisted blade as the research object, the finite element model of the blade was established using variable thickness shell element based on ANSYS software. The comparison between static frequencies and their model shapes was conducted to validate the accuracy of modeling method. Then the influences law of Coriolis force, spin softening, centrifugal stiffening and coupling of them on dynamic frequencies of the blade were analyzed based on the model. Finally, the common empirical formulas of dynamic frequency coefficients were evaluated based on the dynamic frequency data of the shell element model. The study shows that the law of dynamic frequencies received from the shell element model is in good agreement with that from a solid element model. The effects are listed from large to small as follows: centrifugal stiffening, spin softening and Coriolis force. In addition, dynamic frequency coefficients of the A0 vibration mode are in good agreement with the results from other references, whereas the result of A1 vibration mode is just the reverse of that of A0.