提出了一种基于双目体视显微镜和数字图像相关技术来解决细观材料三维全场应变测量的方法,举例说明了传统的校准技术在校正立体显微镜畸变过程中存在的问题,进而提出了一种新颖的校准方法来对显微镜进行标定,从而获得较高的三维位移场和应变场测量精度。液压胀形实验的应变测量结果表明,该细观应变测量系统在测量细观材料表面全场应变时具有可行性,同时有限元模拟的结果与实验结果比较吻合,最大主应变的偏差在10%之内,证明了该系统可以准确地测量微小尺寸的材料应变。
A novel full field three-dimensional strain measurement method to observe the microscopic material was proposed based on ster- eo microscope and digital image correlation technology. The problems existed in distortion process of calibrating stereo microscope by tradi- tional calibration technology were illustrated, further, a new calibration method to calibrate microscope was proposed in order to obtain the higher measuring accuracy of three-dimensional displacement field and strain field. The strain measurement of hydraulic bulging test shows the measurement system of microscopic strain is of good feasibility when the full field strain of microscopic material surface is measured. At the same time, the result of finite element simulation agrees with the measurement result well, and the maximum principal strain devia- tion is less than 10%. It is indicated that the system is able to measure the strain of micro-sized material accurately.