加筋肋是提高薄壁机匣刚度普遍采用的结构形式,合理的加筋肋形式及位置可以起到抑制薄壁机匣振动的效果。采用有限元法对某型航空发动机加筋肋薄壁机匣模型振动特性进行分析计算,并利用锤击法对其进行模态试验,通过结果分析验证了计算结果的准确性。研究加筋肋位置和截面几何参数变化对机匣固有频率的影响;采用响应面法对加筋肋位置进行优化设计,通过有限元验证优化结果的准确性。分析表明在保证质量不变的情况下,加肋结构减振效果明显。 Ribbed stiffeners are commonly used to improve the stiffness of thin-walled casings. The reasonable form and location of ribbed stiffeners can restrain the vibration of thin-walled casings. The finite element method is used to analyze and calculate the vibration characteristics of a type of aeronautic engine-stiffened rib cage model. The modal test is carried out by the hammering method. The accuracy of the calculation results is verified by the analysis of the results. The influence of the change of geometry parameters on the casing natural frequency was studied. The response surface method was used to optimize the position of stiffened rib. The accuracy of the optimization results was verified by finite element analysis. The analysis shows that the damping effect of ribbed structure is obvious under the condition of ensuring the same quality.