Research On Identification Of Damping Coefficient Of Machine Tool's Joint-Plane

The paper is concerned with the method of joint梡lane?s natural parameter identification based on the experimental modal analysis method, finite element method (FEM) and optimum design method. This method can be applied to any spring梔amp system. The dynamics model on joint?plane is given in the paper. By this model, we construct a mathematical model pursuing the minimal error between ideal shift and experimental shift. Program based on this mathematical model, can identify damping parameter on fixed joint梡lane.In this study, The experiment model, made of iron, is the sample for machine tool experiment, consists two crutches and one lathe bed and all be bold. This big crutch and little one are jointed with the bed by 10 equational bolts separately. The joint character is: whetting, and touching spot is 24*24/cm2 joint media: dry surface (washed by acetone) ; joint roughness: 3.2. The natural frequency, vibration, and shift of each point can be acquired through excitation experiment and modal analysis for this sample, separately with impulse excitement, steady sine scan and sine excitation method.By finite梕lement modeling analysis, the theoretical vibration, natural frequency, and shift of finite梟ode corresponsive to examined point can be acquired. Referring to the paper of Linyaoming(Beijing Polytechnic university),we discern the stiffness, then work out the program pursuing the minimal error between ideal shift and experimental shift. The result is satisfying.In this paper, we consider the affection of material damping so as to decrease the frequency error between theory and experiment. We finish the program for identifying joint梡lane parameter, and build the identification system for joint梡lane抯 natural parameter.