某高精密设备平台基础隔振措施分析

结合某高精密设备平台基础隔振实际工程,基于UPFs(User Programmable Features)二次开发特点,提出考虑基础-地基-基础动力相互作用计算基础隔振分析的三维有限元方法。该方法首先将动力机器、周围地基以及高精密设备平台基础作为完整的研究对象,通过引入三维紧支黏弹性边界单元模拟半无限地基辐射阻尼效应和远场介质的弹性恢复性能,并在通用有限元软件ANSYS中实现。进而基于最小二乘方法回归分析得到振动衰减关系曲线,通过其与数值分析结果的对比验证计算模型的合理性。最后针对此工程场地条件建立隔振沟减振隔振措施的有限元模型,并对隔振沟影响因素的减振效果进行分析。计算结果表明,隔振沟的位置、深度以及长度是实际工程中需要考虑的重要因素,对其进行合理的选取可获得较好的隔振效果。

Vibration Isolation Measures of High Precision Equipment Platform Foundation

The study of vibration isolation for a foundation platform is of great practical significance to high precision equipment. In this study, along with the vibration isolation project for the foundation of a high precision equipment platform, a 3D finite element method is presented for foundation vibration isolation analysis by considering the foundation-ground-foundation interaction, on the basis of User Programmable Features (UPFs). The dynamic machine, its surrounding ground, and the high precision equipment platform foundation are taken as an integrated coupling object. A 3D compact viscous-spring boundary was constructed, which can simulate not only the radiation damping of semi-infinite soil, but also the elasticity recovery capacity of the far field media on the boundary. The boundary was implemented with the ANSYS software. Then, the rationality of the model was verified by comparing the vibration attenuation curves obtained from the regression analysis by using the least squares method with the results of the numerical simulation. Finally, according to ground conditions, the finite element models, which take different vibration isolation measures were established, and the damping effect of isolation trenches with different influence factors were analyzed. The calculation results indicate that the location, depth, and length of vibration isolation trench were important factors in practical projects, and that a reasonable selection of these factors would obtain a better vibration isolation effect.