摘要
为研究缝合线分形特征及其对石灰岩强度的影响,基于数字图像处理技术,采用功率谱密度方法和数字图像盒维数方法分析水平缝合线和垂直缝合线的分形维数,通过实验和数值模拟研究缝合线对石灰岩强度的影响和石灰岩内部裂纹演化过程.研究结果表明:采用两种分形分析方法得出缝合线分形维数介于1和2之间,表明缝合线是自然界一种自仿射分形构造,且垂直缝合线的粗糙度较大.缝合线平均弱化石灰岩强度约20%,不同倾角缝合线石灰岩强度没有明显的各向异性现象,缝合线对石灰岩弹性模量影响很小.石灰岩失稳破坏过程中,裂纹的萌生发展与缝合线息息相关,缝合线加快了石灰岩的损伤破坏.数值模拟表明缝合线厚度、位置、数量、分形维数等发育因素对石灰岩的强度有着显著的影响.
To study the fractal characteristics of stylolite and its influence on the strength of limestone,the fractal dimension of horizontal stylolite and vertical stylolite was analyzed using the power spectral density method and the digital image box dimension method based on digital image processing technology. The influence of the stylolite on the limestone strength and the crack evolution process of the limestone were studied through experimental tests and numerical simulations. The results show that the fractal dimension of stylolite lies between 1 and 2,indicating that the stylolite is a self-affine fractal structure in nature,and the vertical stylolite has a large roughness. The stylolite weakens the strength of limestone by about 20% on average,the strength of limestone with different inclinations of stylolite shows less obvious anisotropy and stylolite has negligible effect on the elastic modulus of limestone. In the failure process of limestone,crack initiation and propagation in limestone is closely related to the stylolite,and the stylolite accelerates the damage and failure of the limestone. Numerical simulations show that the thickness,position,numbers,and fractal dimension of the stylolite have significant effect on the strength of the limestone.
出处
《工程科学学报》
EI
CSCD
北大核心
2017年第12期1802-1808,共7页
Chinese Journal of Engineering
基金
国家重点基础研究发展规划资助项目(2014CB047100)
国家自然科学基金资助项目(41672301
51474051)
中央高校基本科研业务费资助项目(N150102002)
中法蔡元培资助项目(36605ZB)
关键词
缝合线
数字图像
分形
强度
各向异性
stylolite
digital image
fractal
strength
anisotropy
