Resarch On The Experimental Model Analysis Method Of Turret Style Composite Grinding Machine’s Virbaration Characteristics

With the rapid development of manufacturing technology, manufacture industry put forward higher requirements of the machining precision for the machine tools. The machine tools’ dynamic characteristics play an important factor to effect the machine’s machining precision. Grinding machine is usually as a high precision machine should have a good dynamic characteristics too.Now the modal analysis method is the main method of research dynamic characteristics of machine, is also be a method in dynamic performance evaluation for the existing machine.This paper takes H405-BE composite grinding machine which produced by shanghai machine plant as the research object. Its processing parts has the chatter mark because of the grinding carriage system have larger vibration during in processing parts time. So in this paper,using experimental modal analysis method to research the vibration characteristics of the grinding carriage system, identify the former seven modal parameters, calculated modal vibration mode and made the mode animation. Finally fine out the reason of the vibration, puts forward some suggestion for improvement. Its main work as follows:(1) Introduce the overseas and domestic research status of experiments modal analysis. At the same time introduced the basic theory of complex modal analysis of multiple-freedom general viscous damping system, from this established SIMO modal parameters modal for grinding structure.(2)Design the experiment scheme basic on the theory of SIMO modal parameters modal for grinding structure. According to the experiment scheme, using EMA method to the grinding carriage system, then get the data of FRF.(3)Using PLSCF method to identified the former seven modal parameters form the FRF data which obtained by the experiment,then calculate the modal shape and make the mode animation.(4)Using time-frequency analysis based on the SFTF to analysis the vibration signal which generate on the grinding carriage system. Using MATLAB to analysis the vibration signal and obtain the spectrogram and time-frequency picture. Through the spectrogram and time-frequency picture we can get the message of distribution of frequency and amplitude from the wholeoperation process.(5)Combined with the two kinds of conclusion by EMA method and time-frequency analysis method, find out the reason of the grinding carriage’s vibration.In this paper, throwing analysis the modal of the grinding carriage, we find out the reason of which cause the vibration of grinding carriage. In this way, demonstration that EMA is play a important role in the evaluating dynamic characteristics of exist machines. In fact we can use the method of EMA to analysis the vibration characteristics of machine, then we can reduce the benefit loss by prevent or diagnose the weakness part from machine.