【作者】 张春；

【导师】 李建军； 肖祥芷；

【作者基本信息】 华中科技大学 ， 材料加工工程， 2004， 硕士

【摘要】 坐标网格分析技术是板材成形中的一种物理模拟技术,已在冲压生产实践中得到了广泛应用。传统网格应变的测量以及对大量离散数据的处理的方法均采用手工进行,其测量和计算的工作量很大,精度也难以保证。运用计算机图像处理和立体视觉测量技术对变形网格进行测量不仅可以将人们从繁重工作中解放出来,获得理想精度,而且将拓展网格应变分析技术在冲模调试中的应用。本文针对坐标网格分析技术的应用现状,提出了基于视觉测量计算机辅助模具调试分析系统的组成,讨论了视觉测量应变分析子系统的框架结构及其数据接口,并详细介绍了其后处理模块的功能组成。本文还针对视觉测量对网格的要求,研究了适合视觉测量的网格形态,采用了热转印和电化学浸蚀快速制作高精度网格的方法。在分析了网格圆的变形特点基础上,提出了基于欧拉法和有限应变解析的方网格应变计算方法,并研究了基于线性孔斯曲面片的空间网格应变计算方法。在文章的最后研究了基于MATLAB的三维网格应变的计算以及可视化技术,并针对一个具体的实例进行了应变计算与可视化,将计算结果与某商品化的系统进行了比较。结果表明通过应变场的可视化,可以直观地找到冲压生产中存在的问题,并便于找到引起这些问题的原因。更多还原

【Abstract】 The analysis technique based on coordinate grid, as a kind of physical method for simulating forming process, has been widely applied in the production of sheet metal parts. The conventional measurement of deformed grids and the processing methods of large quantity of scattered data are both made manually, which are time-consuming and inaccurate. Computer image processing and stereo vision measure techniques which collect the data of the formed grids can not only relieve people from boring works and get reasonable accuracy, but also expand the application of the technique into the die try out.Based on the applied actuality of analysis technique of grid, the concept of computer aided die try out system is put forward. In this article, system architecture and their function are discussed. Moreover, aim at the demand for the vision measurement of grids, the grid shape which fits in with the vision measurement is studies, and the methods of hot transfer press and electro-chemical etching are used to produce the accurate grids on sheet metal quickly. According to the deformed characteristic of circle grids, Euler equation and the strain incremental theory, the calculation method for the strain of square grids that are put forward, and the method of space constructional grids that are supposed to linear Coons surface is derived too.Matlab is applied to deal with the vision measurement data and get the strains of all square grids at the last of this article. A case study by using the method mentioned above is done and compared with a commercial system. The results demonstrate, that the method is reasonable and can be used to show, the reasons which cause the defects of a sheet metal part.更多还原