基于DIC方法的土样剪切带倾角的演变规律研究  

Study on Evolution of Shear Band Inclination Angles of Clay Specimens Based on a DIC Method

作　　者：杜亚志[1,2] 王学滨 董伟[1] 侯文腾 冯威武 Du Yazhi;Wang Xuebin;Dong Wei;Hou Wenteng;Feng Weiwu(College of Mechanics and Engineering,Liaoning Technical University,Fuxin,Liaoning 123000,P.R.China;Architecture&Civil Engineering,Zhongyuan University of Technology,Zhengzhou 450007,P.R.China;Institute of Computational Mechanics,Liaoning Technical University,Fuxin,Liaoning 123000,P.R.China)

机构地区：[1]辽宁工程技术大学力学与工程学院,辽宁阜新123000 [2]中原工学院建筑工程学院,郑州450007 [3]辽宁工程技术大学计算力学研究所,辽宁阜新123000

出　　处：《地下空间与工程学报》2019年第6期1749-1756,1857,共9页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(51374122);辽宁省百千万人才工程资助项目;辽宁省高等学校优秀人才支持计划(LR2015029)

摘　　要：采用数字图像相关(DIC)方法测量了单轴压缩长方体土样变形破坏过程中表面的应变场,并根据最大剪应变场研究了土样剪切带倾角的演变规律。剪切带倾角是通过对包含剪切带的四边形区域内最大剪应变逐行或逐列搜索获得的最大值对应的坐标进行线性拟合得到的。首先,分析了搜索方式及插值点的数量对剪切带倾角的影响,发现采用逐行搜索方法且当插值点的数量与原始测点的数量之比大于16时,获得的剪切带倾角比较准确;然后,对12个土样中24条剪切带的倾角的演变规律进行了测量,发现在剪切带发展过程中,剪切带的形状逐渐由不规则向规则转变,剪切带倾角的最大及最小变化量分别为9°和0.6°,剪切带倾角的范围为46.5°~72.3°,随着纵向应变的增加,剪切带倾角的演变规律主要包含5种模式。Strain fields during the deformation and failure processes of cuboid clay specimens under uniaxial compression were measured by digital image correlation(DIC) method,and the evolution of shear band inclination angles was studied according to the maximum shear strain fields. Maximum values of maximum shear strains were searched at each row or column in a quadrilateral region with a shear band,and coordinates corresponding to maximum values of maximum shear strains were linearly fitted to obtain shear band inclination angle. First,effects of search directions and numbers of interpolated points on shear band inclination angles were analyzed. When maximum values of maximum shear strains were searched at each row and the ratio of the number of interpolation points to the number of original points was over 16,it was found that the measured shear band inclination angle was accurate Then the evolution of shear band inclination angles of 24 shear bands of 12 clay specimens were measured,and results show that the shape of a shear band changes from irregular to regular during its developing process. Maximum and minimum of variations of shear band inclination angles are 9° and 0.6°,and the shear band inclination angles range from 46.5°to 72.3°. With an increase of the longitudinal strain,the evolution of shear band inclination angles contains five modes.

关 键 词：剪切带 倾角 数字图像相关方法 最大剪应变 土样 

分 类 号：TU454[建筑科学—岩土工程]