用数字图像相关技术进行岩石损伤的变形分析

DEFORMATION MEASUREMENT OF ROCK DAMAGE BY DIGITAL IMAGE CORRELATION METHOD

提出用数字图像相关技术研究含微裂纹的岩石的变形。在不同载荷作用下,用扫描电镜获得细砂岩表面的灰度分布图,用相关分析处理灰度分布图获得位移分量。将加载和卸载试件表面的灰度分布图进行相关计算,得到的位移分布与微裂纹分布密切相关,在裂纹附近,位移指向裂纹,大小和方向都很不规则,而远离裂纹,位移的方向较一致,大小变化也不大,表明在微裂纹所分隔的不同区域内,位移场是不同的,表现出岩石损伤中的微裂纹的张开或闭合效应。最后对该系统在地震、滑坡、岩体工程和地形变等领域非接触变形测量中的应用前景进行了讨论。

The digital image correlation technique is used to determine the deformation field of the rock material involving the microcracks. The light intensity pattern of the fine grain sandstone surface is taken from thescanning electron microscope,corresponding to different loading steps. Correlation computation is performed a pair of light intensity images to evaluate the displacement components. The results show that the deformation varies in different areas separated by subcracks,which implies the effect of crack opening and closing in rock.