基于有限元的螺栓连接参数化建模技术研究

Parameterized Modeling Technology of Bolted Joints

关键词:  有限元方法  螺栓连接  参数化建模  涡扇发动机  模态试验

Key words:  Finite element method  Bolted joints  Parameterized modeling method  Turbofan engine  Modal test

摘要:

为有效解决机械结构中众多螺栓连接力学特性的模拟问题，研究了基于有限元的螺栓连接不同刚度特性的参数化建模方法，形成了具有一定指导意义的参数化建模理论。基于两个典型实例研究，螺栓连接的参数化有限元模型固有频率计算值与试验值误差很小，都在5%以内，充分验证了螺栓连接参数化建模理论和建模方法的准确性和有效性。成功应用于现代高推重比涡扇发动机系统中，计算结果表明，参数化模型计算值与目标值的固有频率误差均在1%以内，且两种模型振型基本一致，模态置信度准则(MAC)值均接近于1，有效模拟了转、静子中关键螺栓连接结构的力学特性。

Abstract:

To effectively solve the simulation problem of bolted joint mechanics characteristics in engineering structure，the parameterized modeling method (PMM) of stiffness characteristic for bolted joints based on finite element (FE) has been researched，and a certain guiding significance theory of parameterized modeling (PMT) has been formed. Firstly，in light of two typical examples，the error of natural frequency results between parameterized finite element model (PFEM) of bolted joints and experimental test is small，which is all within 5%. The accuracy and effectiveness of the developed PMT and PMM are validated lightly. Then，the developed PMT and PMM have been successfully applied to a certain type of modern high ratio turbofan engine system. The calculated results indicate that the natural frequency errors between PFEM calculated values and experimental test values are all within 1%，and the mode shapes are also much similar，the values of MAC (modal assurance criterion) are all closed to 1. The key bolted joint structures in rotor and stator are established equivalently.