【作者】 杨新伟；

【导师】 计欣华；

【作者基本信息】 天津大学 ， 固体力学， 2008， 博士

【摘要】 白光数字图像频域分析法的二维测量技术现已日益成熟,特别是相移法的引入,实现了全自动测量。但是该方法还没有实现三维位移与变形的测量,尤其是大变形的测量。本论文结合立体摄影术、摄像机标定方法和白光数字图像频域分析法,首次提出了利用白光数字图像频域分析法测量物体三维位移与变形的实验方法,把该方法应用于动态、大变形的测量。首先,本论文提出了结合白光数字图像频域分析法原理,立体摄影术原理和Tsai摄像机标定方法三者来测量三维位移与变形的实验方法,并根据白光数字图像频域分析法全自动测量的优点,提出了三维位移测量方法中的位移投影法。用平移实验和四周固支,中心受集中力的薄板的离面位移测量实验验证两种方法的正确性。实验数据表明,误差在允许的范围之内。其次,本论文提出了利用白光数字图像频域分析法标定CCD摄像机测量系统的实验方法。利用具有随机斑点特征的模板,结合白光数字图像频域分析法和三维精密调节架来标定CCD摄像机的实验方法,并实现该方法的三维测量。利用四周固支,中心受集中力的薄板的离面位移测量实验验证了该方法的可行性。最后,本论文将三维位移的测量方法应用到实际测量中,分别测量了薄壁圆筒压缩变形,橡胶管受内压时的变形和特殊工程材料III型裂纹尖端应力强度因子。三个实验的结果表明了该方法适合测量动态变形,大变形和小区域位移。对该方法的精度和一些影响位移测量的因素如图像大小,拍摄角度,离焦,镜头畸变等进行了分析,探讨了方法的适用范围。更多还原

【Abstract】 2D measuring technique of white light digital image analysis in frequency domination area was developed and especially, when phaseshift method was introduced, all-automatic measurement of this method was realized. But 3D displacement and deformation of this method has not been developed, especially large deformation.In this paper, combining stereo photography,camera calibration method and white light digital image analysis in frequency domination area, the method for 3D displacement and deformation measurement by white light digital image analysis in frequency domination area was presented and used to measure dynamic and large deformation.Firstly, combining the principle of white light digital image analysis in frequency domination area, stereo photography and Tsai camera calibration method, the experimental method for 3D displacement and deformation measurement were presented in this paper. According to all-automatic measurement of white light digital image analysis in frequency domination area, displacement-projection method for 3D displacement and deformation measurement by white light digital image analysis in frequency domination was presented. Translation experiment and out-of-plane displacement measurement of all-round-fixed sheet were used to examine this method. The experimental results showed that the errors were acceptable.Secondly,the experimental method for camera calibration by white light digital image analysis in frequency domination area was presented. Combining white light digital image analysis in frequency domination area and a 3D precision adjusting device, a board coated with random speckle was used to calibrate cameras and 3D displacement and deformation measurement by this method was realized. The availability of this method was certified by the experiment of out-of-plane displacement measurement of all-round-fixed sheet.Finally, the compression deformation of thin-wall cylinder,Шtype crack stress intensity factor of engineering material and the deformation of rubber pipe which was pressed internally were measured. The experimental results show that this method is proper to measure dynamic, large deformation and little displacement. The accuracy of this method and some influencing factors such as image dimension, shooting angle, defocus and lens distortion were analyzed and the scope of application was studied.更多还原