基于有限元模型修正的破碎机减振垫刚度识别

Identification of stiffness of damping pad of crusher based on correction of finite element model

采用运行模态分析的方法,辨识出颚式破碎机3向平动模态频率和振型,利用有限元软件NASTRAN六面体单元建立破碎机、混凝土基础的有限元模型;用BUSH单元模拟减振垫刚度特性,选取BUSH单元的3向刚度参数进行灵敏度分析,验证待修正参数选取的可行性;再利用基于灵敏度分析的有限元模型修正技术,参考模态试验辨识结果,对减振垫的3向刚度参数进行修正。修正后,有限元模型计算得到的破碎机3阶刚体模态频率和试验结果完全吻合,同时得到精确的减振垫3向刚度值,可为后续的计算提供准确的有限元模型。

The operational modal analysis （OMA） method was applied to identify the frequency and vibration mode of 3D translational model of the jaw crusher. Hexahedral element of NASTRAN was applied to build the finite element model of the crusher and its concrete foundation, and BUSH element was applied to simulate the stiffness characteristic of the damping pad. Moreover, 3D stiffness parameters of BUSH element were selected to conduct sensitivity analysis, so as to check whether the selected parameters were appropriate. And then, finite element model correction technology based on sensitivity analysis was applied to correct the 3D stiffness parameters of the damping pad based on modal test identification results. After correction, the modal frequency of three orders of rigid body of the crusher obtained from the finite element computation totally coincided with test results, and precious 3D stiffness values of the damping pad were obtained, which offered accurate finite element model for subsequent computation.