Research on Vibration Behavior of the Plate-Like Joint Interfaces Based on Comprehensive Unit Stiffness Matrix

The dynamic characteristics of joint interfaces have significant effect on both static and dynamic behaviors of the whole machine tool structures. Its dynamic model can be simplified as a group of equivalent spring-damping elements, that is, an ‘elastic interlayer’ without mass. The unit area dynamic characteristic parameters are the key to analyze the dynamic properties of joint interfaces. However, when building the stiffness and damping matrices of the joint interfaces, the interaction between the ‘elastic interlayer’ and the conjunctions are always ignored, which leads to errors arising. A test system for identifying the unit area dynamic characteristic parameters of different kinds of joint interfaces are represented based on Equivalent Single Degree Of Freedom (ESDOF) system theory. The unit area dynamic characteristic parameters can be applied under all kinds of conditions (including different materials, pre-tightening force, surface roughness, lubricating conditions, media, etc). Then a comprehensive unit stiffness matrix is derived from these parameters. The presented method is compared with the conventional method on analyzing the vibration behavior of an assembled beam structure. The comparison results show that the presented method is in excellent agreement on the actual conditions, which has an obvious advantage on accuracy. The presented method can be used as an effective way for precisely analyzing vibration behavior of complicated mechanical structures with plate-like joint interfaces. Copyright © 2014 IFSA Publishing, S. L.