【作者】 潘大为；

【导师】 毛新勇；

【作者基本信息】 华中科技大学 ， 机械工程， 2015， 硕士

【摘要】 机床动力学特性是影响机床加工质量和加工效率的重要因素之一,随着机床动力学的发展,人们发现机床结构的动力学特性对机床的加工性能不可忽略。从目前已有的关于机床结构动力学特性的研究中可以发现,机床结构的动力学特性会受到机床速度因素的影响,但是目前的这些研究分析仅仅是限于机床结构动力学特性在运行状态与静止状态条件下两者的差异方面,并没有关于速度因素对运行状态下机床结构动力学特性的影响情况的针对性研究。因此,结合相关的研究课题,对机床单轴和多轴运行状态下的速度相关动态特性进行了深入地研究。本论文的主要研究内容如下:提出了一种机床结构运行状态下主振模态的识别方法,并运用实验验证了该方法的正确性和有效性。该方法的提出为识别对机床结构振动影响最大的主振模态提供了有效的手段,同时也为机床结构速度相关动力学特性研究提供了一种有效的工具。对机床结构单轴运行状态下的速度相关动态特性进行了深入研究,用实验研究的手段分别研究了机床结构在X,Y和Z方向单轴运行状态下不同速度水平的固有频率,阻尼比,主振模态以及对应各阶模态的分布状态,并分析了单轴运行下状态下速度因素对机床结构动力学特性的影响特点。研究了机床结构多轴运行条件下的速度相关动态特性,同样运用实验研究的手段研究了机床结构分别以不同速度在XY和XZ方向多轴联动运行时的固有频率,阻尼比,主振模态以及对应各阶模态的分布状态,并得到了在这两种不同的运行方式下的机床结构动力学特性分别受速度影响的特点。初步探究了数控机床空运行状态下的结构动力学特性速度谱,基于主振模态识别方法,提出了一种描述不同速度水平下机床结构的主振模态及其对应分布状态受速度因素影响特点的速度谱。该研究为找到一种能简单直观描述速度因素对机床结构动力学特性的影响特点的描述方式进行了初步探索。更多还原

【Abstract】 Dynamic property of machine tool is an important factor which affects machining quality and machining efficiency. With the development of researches in dynamic property of machine tool, people found that the influence on machining capability by structural dynamics of machine tool should not be ignored. According to the previous researches on the dynamics of machine tool structure, we can find that the dynamic properties can be influenced by the speed factor of machine tool. But these researches are only about the differences of machine tool structural dynamic properties when the machine tool is under static states and under operating conditions. There is no related research on how the dynamic properties of machine tool structure are influenced by the speed factor of machine tool. So, with the help of related project, we had a deep and systemic research on the speed-depended dynamic properties of machine tool structure. In this paper, the main research contents are as follows:A method to analysis the main mode of machine tool structure under operating conditions is put forward in this paper, and this method is also verified by the following experiments in the paper. This method offers an effective tool to analysis the main mode which has the greatest influence on the vibration of machine tool structure and to the do following researches on speed-depended dynamic properties of machine tool structure.Has a research on the speed-depended dynamic properties of machine tool structure when the machine tool is under one-axis operating condition. With the experimental method, studies on natural frequencies, damping ratio, main modes and the corresponding distribute states of machine tool structure when the machine tool is under one-axis operating condition of X direction, Y direction and Z direction respectively. And analyzes the characteristics of speed factor influence on dynamic properties of machine tool structure when the machine tool is under one-axis operating condition.Researches the speed-depended dynamic properties of machine tool structure when the machine tool is under two-axis operating condition. With the similar experimental method, studies on natural frequencies, damping ratio, main modes and the corresponding distribute states of machine tool structure when the machine tool is under two-axis operating condition of XY direction and XZ direction respectively. And obtains the characteristics of speed factor influence on dynamic properties of machine tool structure when the machine tool is under two-axis operating condition.Establishes the dynamic speed-spectrum of machine tool structure when the machine tool is under no machining conditions. Puts forward a speed-spectrum which is used to describe the characteristics of speed factor influence on main modes and the corresponding distribute states of machine tool structure. This research is a preliminary research to find out an appropriate way to describe the characteristics of speed factor influence on dynamic properties of machine tool structure.更多还原