Measurement of curved-surface deformation in cylindrical coordinates |
| |
Authors: | P F Luo J N Chen |
| |
Institution: | (1) Department of Mechanical Engineerings, Chung Hua University, 30067 Hsin Chu, Taiwan |
| |
Abstract: | Stereo vision is used to measure the strain field of a round tension test specimen in a cylindrical coordinate system. Initially,
the displacement fields of the specimen are measured relative to a world coordinate system erected by the stereo vision. Through
coordinate transformations, the measured displacement fields expressed in world coordinates are then converted to the displacement
fields expressed in cylindrical coordinates. By differentiating the axial and circumferential displacements in the axial and
circumferential directions, the axial, circumferential and shear strains are determined. Results indicate that the measured
mean value of the axial strains is in good agreement with the measurements of the extensometer and the strain gage. The Poisson's
ratio obtained by the circumferential and axial strains is close to .33 in the elastic state. The mean error of the computed
shear strain is approximately .03 percent in the smaller elastic deformation and .08 percent in the larger plastic deformation. |
| |
Keywords: | Strain fields cylindrical coordinate computer vision/digital image processing |
本文献已被 SpringerLink 等数据库收录! |
|