An identification method of stiffness of mechanical joint

A method based on finite element model is presented that is used to identify stiffness of mechanical joint. By means of shock excitation, response of the system is obtained in which joints are included. Fourier Transform is used to obtained response spectrum of system. Based on FEM, the system model including joints is build and then low order natural frequencies are obtained by modal analysis. Natural frequencies of finite element model are compared with resonance frequencies from response spectrum, data of joint stiffness in finite element model are modified. Through iterative computations, suitable data of joint stiffness are identified. Experiment result shows that the method is valid.