The Dynamic Characteristics Analysis And Optimization Of DK7735 Machine Tool Base On LMS.Test.Lab

WEDM have a great advantage for the processing of high hardness of metallic materials. However, WEDM-HS still has much space for improvement in its processing capacity, its automation degree and the energy-saving. Totally, the mechanical structure of WEDM-HS is simple. DK7735 machine tools are studied by the modal testing, the modal analysis and the optimization to improve its dynamic characteristics. If its dynamic characteristics are improved, its processing capacity and working life will be enhanced.The main contents of this paper are as follows:1. DK7735 machine tools are measured by LMS Test Lab, in order to know its modal parameters and PSD (power spectral density) of two guide wheels. Firstly, DK7735 machine tools are conducted five hammering tests to test the whole modal parameters. Every test has various distances between the upper arm and the lower. Secondly, the PSD of two guide wheels are measured, and it will be input loads in the next random vibration analysis.2. Components model of the machine tool are built by Creo2.0, and the finite element analysis was carried out on the models. The result of modal analysis and the result of modal testing are reviewed to confirm the accuracy of two results. Firstly, the support frame model of machine tool and parts model are established and simplified by Creo2.0. Secondly, these models are carried out pre-stressed modal analysis to calculate their modal parameters. Results from the modal testing and the modal analysis are compared each other to confirm the accuracy of two. Finally, the PSD from the modal testing are used for random vibration analysis of wires model which their length are all 280 mm. From two analysis results, it can understand that Wire guides can reduce the amplitude of vibration of wire electrodes itself and obtain the PSD in the middle of wire electrodes.3. Comparing the result of the analysis and the test, it can know what DK7735 machine tool'dynamic characteristics have a need to improve, but the result of the test show the lower arm'damping ratio is smaller than others, and that needs to carry on the optimization design. Firstly, dimensions of the lower arm, as variables, are used for the lower arm optimization design, in order to reduce responses of vibration of the lower arm. Secondly, combination surface parameters between the stand column and the lower arm, as variables, are used for the modal of support frame of machine tool to obtain optimal combination surface parameters. After the optimization, responses of vibration of the lower arm are markedly reduced, and the whole machine tool' dynamic characteristics has an improvement.