基于dic的非接触式全场应变测量系统设计 - 图文(2)

燕山大学本科生毕业设计（论文）

Abstract

In recent years，with the digital image correlation method to measure the deformation has become a measurement method of world attention ，and more and more extensive application，since 2007，method based on digital image correlation（digital image correlation ，dic）of strain measurement technology has been widely used in many disciplines，such as mechanics of materials，fracture materials，micro nano strain measurement ，various new materials measurement etc，this method of measurement is non-contact，wide application，high precision，full-filled measurement，data collection is simple，measurement environmental requirements is not high， easy to realize automation etc.accompanied by a variety of high resolution microscopy，this measurement technique can be the deformation measurement of micron and nanometer，so it has more development space.

The diploma by the domestic and foreign research results in this field as a basis for this method, the measurement accuracy of the problem, research on Simulation and actual experiment, influence the precision of calculating focuses on analysis of various experimental factors and external disturbance on digital image correlation method. The simulation study, simulation to generate the speckle pattern by using numerical method, analyzed the ideal speckle and related effects on the precision of calculation. By the simulation analysis result as the basis, to carry out verification experiments, the optimal calculation precision in practical reference value. To analyze the causes for various errors, and puts forward the methods and measures to eliminate the error or the suppression error.

Keywords digital image correlation method; strain and displacement

measurement; measuring accuracy; force sensor

II

目 录

摘要 ............................................................................................................................................... I Abstract ...................................................................................................................................... II 第1章 绪论 ............................................................................................................................. 1 1.1 背景和意义 .................................................................................................... 1 1.2 国内外研究现状及趋势 ........................................................................... 2 1.3 本文的研究内容 ....................................................................................... 4 第2章 数字图像相关法基本理 ....................................................................................... 5 2.1 数字图像相关法基本原理 ....................................................................... 5 2.1.1 二维数字图像相关基本原理 .......................................................................... 5 2.1.2 物体面内变形的表征 ........................................................................................ 6 2.1.3 相关标准 ................................................................................................................ 7 2.2数字图像相关搜索方法 ............................................................................ 9 2.3亚像素位移定位法 .................................................................................. 11 2.3.1 灰度插值法 ......................................................................................................... 12 2.3.2 相关系数拟合法 ................................................................................................ 13 2.4基于位移场的应变估计 .......................................................................... 14 2.5 本章小结 ................................................................................................. 16 第3章 基于仿真数字散斑图像的变形测量分析 ....................................................... 17 3.1 模拟散斑图的生成原理 .......................................................................... 17 3.2于仿真散斑图的数字图像相关方法变形测量精度析 ................................ 19 3.2.1计算窗口大小对计算精度的影响 ................................................................ 19 3.2.2 散斑颗粒大小对计算精度的影响 ............................................................... 21 3.2.3 散斑颗粒数量对计算精度的影响 ............................................................... 23 3.2.4相关函数对计算精度的影响 ......................................................................... 25 3.3.本章小结 ..................................................................................................................... 28 第4章 数字图像相关变形测量实验研究及误差析 ....................................... 29

III

燕山大学本科生毕业设计（论文）

4.1 随机散斑生成 ........................................................................................... 29 4.2 单向拉伸试验 .......................................................................................... 30 4.3 实验数据处理 .......................................................................................... 31 4.4 实验影响因素分析 .................................................................................. 32 4.5 本章小结 .................................................................................................. 34 结论 ...................................................................................................................... 35 参考文献 .............................................................................................................. 36 致谢 ...................................................................................................................... 38 附录1 ................................................................................................................... 39 附 …… 此处隐藏：6189字，全部文档内容请下载后查看。喜欢就下载吧 ……