【作者】 李长玉；

【导师】 毛宽民；

【作者基本信息】 华中科技大学 ， 车辆工程， 2007， 硕士

【摘要】 随着科学技术的发展,机床日益向高速、高效、精密和自动化方向发展,因此对其加工性能的要求也越来越高。为了使机床能够高速、高效、高质量地工作,其结构必须具有良好的动态特性。又由于机床结构的动态特性对其工作性能、效率、稳定性和可靠性等有很大的影响,目前它已经成为衡量机床结构性能好坏的重要指标。因此,提高机床结构的动态性能已经成为机床行业走向现代化的研究课题之一。鉴于此,本文结合国家973计划“高速数控机床动态行为演变及其高精度控制”项目对基于响应信号的机床模态参数提取方法做了研究。本文主要研究成果有:(1)系统地总结归纳了机床动力学研究概况和模态参数识别技术研究概况。(2)对机床激振方法做了概括总结,设计了一种利用机床自身随机运动的激振方式,并且对这种激振情况下所采集的信号进行分析,剔除其中的周期信号。验证了剔除周期激励后的激励为随机激励。(3)研究了一种只基于响应信号的模态参数识别方法(峰值法),并且通过MATLAB软件实现了这种方法,然后对一自由钢梁用两种方法(传统方法和峰值法)进行试验模态分析,通过对传统方法,峰值法分析结果的比较,验证了峰值法的可靠性。(4)利用机床自身随机运动的激励方式和峰值法对XHK5140机床进行了试验模态分析,得出了机床前几阶模态的固有频率、振型,并且将试验结果和有限元结果进行了比较。更多还原

【Abstract】 With the developments in science and technology,the machine tool also tends to high-speed, efficient, precise and automation. The requirement of performance is also higher and higher. In order to make machine tool have high-speed,high-efficient and high-quality capability, the structures must have good dynamic characteristics. The dynamic characteristics of machine tool influence the performance , efficiency , stability and reliability of the mechanical structure greatly. It has become an important evaluation target of the performance of machine tool. Therefore,the improvement of the dynamic characteristic has become the most important research subject of the mechanical industry. In this paper, study a method of machine tool’s modal parameters identification based on only response signal. The main work of the article is as follow:(1) The actuality of dynamic characteristics research for machine tools’ structure and the method of Modal parameters identification was analyzed roundly and systematically, and the problem and shortage was pointed out.(2) Introduced the traditional exciting method for machine tool experimental modal analysized. Designed an exciting method using its own random moving. Analysis the signal was acquisitioned in such circumstances and then Removed the cycle signal.(3) Studied a method of Modal parameters identification based on only response signal (peak picking method), and realized this method through MATLAB software. And then do experimental modal analysis for a free beam with two method(traditional method and peak picking method),comparison the analysis result of two method,proven the reliability of peak picking method. The weakness of XHK5140 machine tool is revised, implement method of revision is discussed更多还原