| RMC(resin mineral composites) is a kind of new composite material, using natural granites as the aggregate and organic resins as the binder, which possesses excellent performance of vibration reduction, low thermal expansion coefficient, high corrosion resistance and good mechanical properties. It is suitable to manufacturing the foundation and bed of high speed and precision machine tools and Laser electronic equipment. In this article, the static and dynamic performance of the bed of RMC precision machine tool has been simulated and some experiments have been done to verify the analysis results.The results of force analysis of the chosen typical RMC precision machine tool bed show that under the combined function of gravity and cutting forces, the front and side load of the NO.1and NO.2slides distributed gradient. While the front load of the NO.3and NO.4slides distributed uniformly, the side load of the NO.3and NO.4slides distributed gradient, and the load concentrates on the fixed bolt of the spindle head.The results of the static simulation analysis of the beds of HT200machine tool and RMRC machine tool with the same structure using AN SYS show that, in the identical working condition, the deformation of all directions of RMR machine tool beds is larger than HT200machine tools. The deformation of X direction have the largest influence on the whole deformation of tool bed, while Y direction following behind, and Z direction the least. After local enhancement on RMC machine tool bed by increasing the tool bed size, the deformation of all directions of tool bed decreases largely and the distribution of stress is improved, reducing the stress concentration.By studying the damping performance of RMC, the effect of resin content, maximum aggregate size and the contents of diluting agent, toughening agent and curing agent on the damping performance of RMC, has been defined quantitatively. The mathematical model of the damping property of RMC is established and is verified by experiments. These studies illustrate that:when the dosage of resin increases, the damping ratio of RMC gradually increases; with the increase of maximum aggregate size, the damping ratio of RMC decreases, with a gradually slow downward trend; as the increase of the content of diluents and curing agent, the damping ratio of RMC decreases first and then increases, but the change is slight; with the increase of toughening agent content, the damping property of RMC increases first and then decreases, and at the content of1.3%showing the best damping performance.By the ANSYS analysis of dynamic performance of HT200tool bed and strengthened RMC tool bed, the first eight-order modal performance of the two kinds of tool beds indicates that:after strengthened the RMC tool bed became heavier. Strengthened guide rail changes the dynamic parameters of bonded surfaces, thus enhancing the dynamic performance of RMC tool bed. All natural frequencies of first eight-order modal of RMC tool bed are higher than HT200, and with the modal order increasing, the natural frequency becomes higher with a steady growth; the modal vibration mode of the first eight-order of the RMC machine tool bed and the HT200machine tool bed are not completely identical, the locations where the maximum displacement occurs are not uniform, and the maximum relative displacement are not equal. The harmonic response analysis of tool bed of these two materials and the research of mode order which largely influence the tool bed deformation can avoid resonant and provide useful information for industrial production.This paper conducts the static-dynamic performance analysis and structural strength of the RMC precision tool bed, laying a foundation of the design and development of the RMC precision machine tool. |
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