机匣静叶耦合振动分析的有限元建模方法研究

Study of FE Modeling Method in Casing and Stator Blade Couping Vibration Analysis

悬臂静子叶片连同机匣是航空发动机静子系统的典型结构。应用有限元法分析结构周向弯曲振动的模态频率和振型,分别采用实体单元建模、梁壳单元建模、质量单元取代叶片的三种建模方法建立结构的有限元模型。通过对比分析三种有限元模型的计算结果和计算规模,结构的梁壳有限元模型有较好的计算精度并减小计算规模;在分析低阶模态中用质量单元取代叶片的建模方法满足计算精度,有限元的计算规模大为减小。

Cantilever slator blades together with casing is the typical structure in the aero-engine slator system. Modal analysis of the structure is performed with finite element method to analyze the modal frequency of circumferential bending vibration mode. The finite element model of the structure is built by solid elements, beam and shell elements and mass elements replacing blades. Compared calculation results and calculation scale of three finite element models, beam and shell finite element model has good calculation precision and can reduce the computational scale. In the low order modal analysis, the modeling method of blades is replaced by mass elements to meet the precision requirement, the scale of the finite element calculation is reduced greatly.