航空发动机静子系统中螺栓连接结构的建模与修正

关键词:有限元建模；模型修正；概率设计；蒙特卡洛；接触单元

关键词:  有限元建模  模型修正  概率设计  蒙特卡洛  接触单元

Key words:  Finite element modeling  Model updating  Probabilistic design  Monte Carlo method  In?

摘要:

基于概率设计方法对航空发动机静子系统中螺栓连接结构进行模型修正研究。静子系统中不同的机匣结构由螺栓连接在一起，采用具有一定材料属性的层单元法来等效模拟螺栓连接结构，通过调节层单元材料属性来提高有限元模型精度。首先采用灵敏度分析方法确定修正区域，然后基于概率方法设计修正参数，利用蒙特卡洛抽样法选取样本点，最后基于静力学试验数据选择合理的目标函数，通过迭代优化计算得到修正后的模型参数。结果表明，修正后的静子系统有限元模型计算得到的刚度值与试验数据更加接近，修正后的相对误差都在5%以内。

Abstract:

Model updating for bolted joints structure in the aero-engine stator system was carried out using a probabilistic design method. These casing components in the stator system were assembled together with differ ent kinds of bolted joints and modeled with a method of thin layer elements having a certain material properties，which may be adjusted to improve the prediction accuracy of the finite element model. For the typical structure of the aero-engine stator system，the sensitivity analysis was performed to select modified region. Then，the proba bilistic method was used to design updating parameters and through Monte Carlo method to select sampling points. An effective objective function was determined based on the static stiffness testing and finally the updated parameters could be obtained by optimization iteration computation. The results show that the casing stiffness cal culated from the updated model agrees better with the measured data，the relative errors were all within 5% after updating.