An analytic method of dynamic modeling on fixed joint interface

The dynamic characteristics of joint interfaces affect the dynamic behaviors of a whole machine tool structure notably. An analytic method of virtual material hypothesis-based dynamic modeling on fixed joint interface in machine tools was conducted so as to improve the modeling accuracy of whole machine tools. The micro contact part of two contact surfaces in fixed joint interface was assumed as a virtual isotropic material, which is rigidly connected with two components composing fixed joint interface. Considering the interaction between normal and tangential characteristics of fixed interface, a set of analytic solutions of elastic modulus, shear modulus, Poisson ratio and density were deduced from virtual material by adopting Hertz contact theory and fractal theory. By using the finite element structural dynamic modeling approach in existence, when some parameters of material´s elastic modulus, Poisson ratio, density, et al. are known, the dynamic model for virtual material composing a component could be established, therefore, the dynamic model for whole structure including joint interface would be obtained.