摘要数控机床向高速度、高精度、高效率的方向发展，这就对车床的加工性能和车床的重量提出了很高的要求。机床关键的零部件是车床的床身，结构性能包含了热特性、静态特性、动态特性，机床的加工性能受到结构的影响。其中提高态特性在很大的意义上能减小机床的振动。本论文研究CA6140车床床身的结构性能，并进行模态分析和应力分析。52343

静态特性的研究有很重要的意义，在UG中建车床床身的三围模型，保存成(IGS)格式并导入ANSYS中进行有限元分析。经过模态分析和应力分析得知，车床有很高的强度和刚度，还可以减去一部分不必要的材料。

1,采用静力学理论,对机床整体结构强度和刚度进行分析，经过研究发现该机床床身在极限荷载下整体的应力水平比较合理,但仍有进一步改进的余地，对结构进行结构优化以后,结构应力和变形水平可以进一步改善。

2,采用模态分析对机床床身和对比的平板模拟结构进行模态分析,找出两种不同结构的模态特点，研究发现床身的模态样式比较多,有局部模态和整体模态；相对比而言平板模拟结构的振型简单,激振点和支撑点更容易选取。

3,采用静力学分析对机床的主要受力结构进行了局部应力分析,找出此类结构的受力特点，分析结果表明键和键槽的区域的应力情况比较合理，局部变形很小。同时经过研究发现局部结构问题会造成该结构特殊位置的应力水平偏高,应该对局部进行改进以平均键的应力水平，降低局部过高的应力。

通过实验结果得知，建立复杂的三维模型，导入ANSYS中可以对车床床身进行整体分析和局部分析，可以知道车床哪些部分受到的应力比较大，得到模态图形和变形云图，可以通过有限元分析方法对她的结构进行深入研究，进一步改善车床床身结构在产品加工中的性能，提高加工精度，速度和加工的稳定性。

毕业论文关键词：车床床身；有限元技术；模态分析；应力分析。

Abstract CNC machine tools to high-speed, high-precision, high-efficiency direction, which on the lathe lathe machining performance and weight made high demands. The key components are machine lathe bed, structural performance include thermal characteristics, static characteristics, dynamic characteristics, the machining performance by the structure. State properties which enhance the sense of a large vibration of the machine can be reduced. This thesis CA6140 lathe bed structural properties and modal analysis and stress analysis.

Static characteristics of a very important significance, built in UG measurements lathe bed model, save as (IGS) format and import the ANSYS finite element analysis. After modal analysis and stress analysis showed that the lathe has high strength and stiffness, you can also subtract a portion of unnecessary material.

First, using the static theory, analysis of structural strength and stiffness of the whole machine, the machine structure after a study found the overall level of stress in the ultimate load more reasonable, but there is still further room for improvement, structural optimization of the structure, the structural stress and deformation level can be further improved.

Second, using the main force structure of local stress analysis to identify the mechanical characteristics of such structures, analysis showed that the area of the key and keyway stress situation is more reasonable, local deformation is small. After the study also found that the local structure of the special structure of the problem will result in high levels of stress positions, should be improved to an average of the local bond stress levels, reduce the local high stress.

Third, Using modal analysis and comparison of the machine bed flat analog structure modal analysis to identify two different modal characteristics, the study found the bed more modal style, there are local and global modal; flat compared to simulate the structure in terms of simple shapes, exciting anchor point and easier selection.