基于数字图像相关的刚体面内微小转动测量及转动中心定位

基于刚体面内微小转动测量在实验力学测量中的必要性和重要性,开展了利用数字图像相关方法(DICM)定量测量转动角度和准确定位转动中心的研究。从理论上分析了刚体面内转动角度与面内位移分量之间的关系,运用计算机仿真散斑图进行数值模拟研究,得到的转动角度和转动中心位置测量误差都在2%以内,模拟结果验证了数字图像相关法进行刚体面内微小转动定量测量的可行性。运用数字图像相关法对刚体面内未知微小转动进行了实测,并与几何光学实验方法所得到的结果进行了比较,两者结果误差为3.1%,符合较好。实验结果表明数字图像相关方法可以作为定量测量刚体面内微小转动的有效方法。

Measurement of in-Plane Micro-Rotations and Rotation-Center Location of a Rigid Body by Using Digital Image Correlation

Due to the necessity and importance of the measurement of in-plane micro-rotations of a rigid body in the field of experimental mechanics, an investigation of quantitative measurement of rotation angle and rotation-center location is developed with digital image correlation method (DICM). The relation between the rotation angle and the in-plane displacement components is analyzed through theoretical analysis. The study of numerical simulation is carried out by specklegram produced by computer simulation. The measurement errors of both rotation angle and rotation-center location are within 2%. It shows that digital image correlation method is quite competent for the quantitative measurement of in-plane micro-rotations. The unknown in-plane rotation of a rigid body is practically measured by using digital image correlation method. The obtained rotation angle is compared with the result obtained from the geometrical optics experiment. The relative error is 3.1%. It shows that they are in good agreement. Experimental results indicate that digital image correlation method can be regarded as an efficient method to measure in-plane micro-rotations of a rigid body quantitatively.