论文部分内容阅读
将数字图像测量技术应用于常规土工三轴试验,解决了常规土工三轴试验传统变形测量中的一系列难题。自主研发了三轴图像测量系统,发展历程可概括为3个阶段:(1)基于边缘识别的三轴试样变形图像测量,通过跟踪边缘位置的变化确定土样的径向变形,识别橡皮膜上的白色标志线确定土样的轴向变形;(2)基于角点识别的三轴试样变形图像测量,用方形标志块将橡皮膜表面离散成若干单元,测量跟踪单元每一角点(节点)的位置,可得任意时刻的土样表面节点的位移,应用有限元技术,可以得到土样表面的位移(变形)场和应变场;(3)三轴土样变形全表面数字图像测量,以基于角点识别的前表面三轴试样变形测量为基础,增设一组平面镜,用一台摄像机实现了圆柱体土样360度全表面的变形测量,得到每一时刻的表面变形场和应变场。三轴土样变形数字图像测量系统具有传统测量方法无可比拟的优点,对于推动土力学,特别是土的本构关系研究具有重要价值。
The digital image measurement technology is applied to the conventional geotechnical triaxial test, which solves a series of problems in the conventional deformation measurement of the conventional geotechnical triaxial test. Independent research and development of the three-axis image measurement system, the development process can be summarized as three stages: (1) edge recognition based on the three-axis deformation of the sample image, by tracking the change of edge position to determine the radial deformation of soil samples to identify the rubber membrane (2) Demarcation image measurement of triaxial specimens based on corner recognition, the surface of the rubber membrane is dispersed into a number of units with a square mark block, and the angle of each track point ), The displacements (deformation) field and strain field of the soil surface can be obtained by using the finite element method. (3) The whole surface digital image measurement of three-axis soil deformation, Based on the deformation measurement of the front surface triaxial specimen based on corner recognition, a set of plane mirrors was added, and a camera was used to measure the entire surface deformation of the cylindrical soil samples by 360 °. The surface deformation field and strain at each moment were obtained field. Triaxial soil deformation digital image measurement system has the incomparable merits of traditional measurement methods, and is of great value to the study of soil mechanics, especially soil constitutive relations.