基于CT扫描图形的混凝土单轴压缩动力破坏过程分形研究
详细信息 本馆镜像全文    |  推荐本文 | | 获取馆网全文
摘要
当前利用CT研究混凝土处于"观察研究阶段",未能对CT试验资料进行定量地描述,严重浪费了CT数资源。本文利用与CT扫描仪配套的便携式动力加载设备,进行了混凝土动力加载实时扫描试验;记录了混凝土动力加载破坏的全过程。根据所获混凝土各受力阶段的CT扫描图,借助于数字图像处理技术和差分盒维数方法,得出了混凝土试样的裂纹演化图像,并计算了试样CT扫描图的分形维数,从细观层面上对混凝土在动荷载作用下的裂纹演化规律进行了定量化研究。在动力单轴压缩荷载作用下,混凝土试样的裂纹穿越骨料追随能量释放最快路径发展;混凝土试样的CT扫描图像有很好的分形特征;以分形维数建立的损伤变量能较好地反映出混凝土试样损伤裂纹的演化规律;分形维数可作为研究混凝土裂纹演化的定量参数。
The current studies of the concrete mechanic behavior using CT scan images are not quantitative but qualitative. The resource of the concrete CT data is wasted seriously. In this study,the dynamic loading equipment combined with the X-Ray CT scanner was used to process the real-time scanning test on the concrete samples. The whole rupture process of the concrete samples was recorded. According to the CT images of the concrete samples obtained for each loading step,the crack evolution images of the concrete samples were obtained using the digital image processing technology,and the fractal dimension of the CT slice figure was calculated via the method of Differential Box Counting( DBC). Finally,the mesoscopic crack evolution law of the concrete samples was analyzed quantitatively. It can be concluded that,the crack propagation of the concrete samples under the condition of dynamic uniaxial compression is passes through the aggregate,and follows the fastest path in which the energy is released. The CT images have very good fractal feature. The crack evolution law of the concrete samples can be reflected by the damage variable which is established by the fractal dimension. The fractal dimension can be used as a quantitative parameter to analyze the crack evolution law of the concrete.
引文
[1]陈厚群,丁卫华,党发宁,等.混凝土CT图像中等效裂纹区域的定量分析[J].中国水利水电科学研究院学报,2006,4(1):1-7.CHEN Houqun,DING Weihua,DANG Faning,et al.Quantitative analysis of equivalent crack region in CT images of concrete[J].Journal of China Institute of Water Resources and Hydropower Research,2006,4(1):1-7.(in Chinese)
    [2]杜修力,田瑞俊,彭一江.预静载对全级配混凝土梁动弯托强度的影响[J].地震工程与工程振动,2009,29(2):98-102.DU Xiuli,TIAN Ruijun,PENG Yijiang.Influence of initial static loading on dynamical bending strength of fully-graded concrete beam[J].Earthquake Engineering and Engineering Dynamics,2009,29(2):98-102.(in Chinese)
    [3]张翠然,陈厚群.基于渐进谱的幅值和频率非平稳人造地震动拟合[J].地震工程与工程振动,2009,29(3):24-32.ZHANG Cuiran,CHEN Houqun.Prediction of non-stationary earthquake accelerograms compatible with design evolutionary spectra[J].Earthquake Engineering and Engineering Dynamics,2009,29(3):24-32.(in Chinese)
    [4]杨更社,刘慧.基于CT图像处理技术的岩石损伤特性研究[J].煤炭学报,2007,(32):464-468.YANG Gengshe,LIU Hui.Study on the rock damage characteristics based on the technique of CT image processing[J].Journal of China Coal Society,2007,(32):463-468.(in Chinese)
    [5]党发宁,尹小涛,丁卫华,等.基于CT试验的岩体分区破损本构模型[J].岩石力学与工程学报,2005,(22):4004-4009.DANG Faning,YIN Xiaotao,DING Weihua,et al.Subarea breakage constitutive model of rock mass based on CT test[J].Chinese Journal of Rock Mechanics and Engineering,2005,(22):4004-4009.(in Chinese)
    [6]任建喜,葛修润,蒲毅彬.岩石卸荷损伤演化机制CT实时分析初探[J].岩石力学与工程学报,2000,19(6):697-701.REN Jianxi,GE Xiurun,PU Yibin.Primary study of real time CT testing of unloading damage evolution law of rock[J].Chinese Journal of Rock Mechanics and Engineering,2000,19(6):697-701.(in Chinese)
    [7]陈厚群,丁卫华,蒲毅彬,等.单轴压缩条件下混凝土细观破裂过程的X射线CT实时观测[J].水利学报,2006,37(9):1044-1050.CHEN Houqun,DING Weihua,PU Yibin,et al.Real time observation on meso fracture process of concrete using X-ray CT under uniaxial compressive condition[J].Journal of Hydraulic Engineering,2006,37(9):1044-1050.(in Chinese)
    [8]党发宁.岩土破损演化理论(I):破损空间[J].岩土力学,2005,26(4):513-519.DANG Faning.Damage-fracture evolution theory of rock and soil(I):damage-fracture space[J].Rock and Soil Mechanics,2005,26(4):513-519.(in Chinese)
    [9]梁昕宇,党发宁,田威.单轴压缩条件下混凝土破裂过程的CT试验[J].煤炭学报,2010,35(增刊):63-67.LIANG Xinyu,DANG Faning,TIAN Wei.CT testing on fracture process of concrete under uniaxial compression[J].Journal of China Coal Society,2010,35(Supplement):63-67.(in Chinese)
    [10]周尚志,党发宁,陈厚群,等.基于单轴压缩CT实验条件下混凝土破裂分形特性分析[J].水力发电学报,2006,25(5):112-117.ZHOU Shangzhi,DANG Faning,CHEN Houqun,et al.Fractional characteristics of damage and fracture of concrete under the uniaxial compression CT test[J].Journal of Hydroeleetie Engineering,2006,26(5):112-117.(in Chinese)
    [11]田威,党发宁,丁卫华,等.适于CT试验的动态加载设备研制及其应用[J].岩土力学,2010,31(1):329-313.TIAN Wei,DANG Faning,DING Weihua,et al.Development of a dynamic loading apparatus for CT experiment and its application[J].Rock and Soil Mechanics,2010,31(1):329-313.(in Chinese)
    [12]张志,董福安,伍友利.二维灰度图像的分形维数计算[J].计算机应用,2005,25(12):2853-2867.ZHANG Zhi,DONG Fuan,WU Youli.Estimation of fractal dimension for 2-D gray image[J].Computer Applications,2005,25(12):2853-2867.(in Chinese)
    [13]Sarkar N,Chaudhuri B B.An efficient differential box-counting approach to compute fractal dimension of image[J].IEEE Transactions on Systems,1994(1):115-120.
    [14]Chaudhuri B B,Sarkar N.Texture segmentation using fractal dimension[J].IEEE Transactions Pattern Analysis and Machine Intelligence,1995,17(1):72-77.
    [15]田威,党发宁,陈厚群.基于CT图像处理技术的混凝土细观破裂分形分析[J].应用基础与工程科学学报,2012,20(3):424-431.TIAN Wei,DANG Faning,CHEN Houqun.Fractal analysis on meso-fracture of concrete based on the technique of CT image processing[J].Journal of Basic Science and Engineering,2012,20(3):424-431.(in Chinese)

版权所有:© 2023 中国地质图书馆 中国地质调查局地学文献中心