用于任意曲表面变形分析的便携式原位三维变形测量系统研制

IIt has a very important significance for stress analysis of components surface to measure three-dimensional deformation of their surface. By measuring the three-dimensional deformation of the component surface, it can be used for the local strength analysis of components directly and can also be used as verification condition for the numerical simulation. Deformation measurement commonly used by the resistance strain gage and rosette, which can only measure the average strain in a certain area, it is difficult to obtain the strain distribution of the local area. In recent years, in Germany and the United States many three-dimensional deformation of the optical measurement systems were developed, but there are some limitations. Just market-based strain measurement system based on digital image technology, handheld measuring head, contingency reset measurement, but not for curved surface measurement. With the various products (such as aircraft, automobile components) performance requirements for continuous improvement, the surface shape of the parts have become increasingly complex, many around the corner is often the place of stress concentration. Regarding the requirements of strain analysis of the curved surface of the components in the static and dynamic loading, the project will develop a set of in situ three-dimensional deformation measurement system based on digital image correlation. The system consists of two parts measuring head and analysis software, it to achieve a truly portable, and once calibration for long-term use. This system will have important application value and broad application prospects in the structural optimization, research and product development.

构件表面三维变形测量对其力学分析有着十分重要的意义。通过测量构件表面三维变形，可对构件表面直接进行局部强度分析，也可用作对数值模拟计算结果进行验证。目前，应变测量普遍采用电阻应变计或应变花技术，只能测量一定区域内的平均应变，难以获取局部区域的应变分布。近年来，德国和美国分别研制了三维变形光学测量系统，但均存在一定的局限性。美国刚面市的基于数字图像技术的应变测量系统利用手持测量头，实现了应变复位测量，但不能用于曲表面测量。随着各类产品（如飞机、汽车零部件）性能要求不断提高，零部件的表面形状也越来越复杂，许多拐角处往往是应力集中的地方。针对零部件在载荷作用下曲表面的应变分析需求，本项目将基于数字图像相关测量技术，研制一套原位三维变形测量系统。该系统包括测量头和分析软件两部分。将实现真正的手持便携，且一次标定长期使用。所研制的测量系统在结构优化和产品研发等方面将具有重要应用价值和广阔的应用前景。

构件表面三维变形测量对其力学分析有着十分重要的意义。通过测量构件表面三维变形，可对构件表面直接进行局部强度分析，也可用作对数值模拟计算结果进行验证。目前，应变测量普遍采用电阻应变计和应变花技术，只能测量一定区域内的平均应变，难以获取局部区域的应变分布。随着各类产品（如飞机、汽车零部件）性能要求不断提高，零部件的表面形状也越来越复杂，许多拐角处往往是应力集中的地方。针对零部件在载荷作用下曲表面的应变分析需求，在国家自然科学基金的资助下，本项目成功研制了基于数字图像相关（DIC）测量技术的便携式表面三维变形测量仪。仪器采用由棱镜和反射镜组合而成的双向光学成像装置，实现了单镜头、单相机的立体视觉图像采集。配以功能强大的三维DIC分析软件和以载荷、温度、压力等为触发信号的图像采集同步装置，以及磁性支架固定和内置照明等装置，不仅可以用于标准式样的材料力学性能测试，而且由于其安装调试极为方便，特别适用大型结构的局部变形在线实时测量，进行表面三维应力分析。仪器重量仅250g，平均直径60mm，高度70mm，工作距离60mm，测量面积30mmX30mm；位移分辨率0.3微米，应变分辨率10微应变。