动力荷载作用下混凝土破裂特征的CT试验研究
|
摘要
汶川地震后,强震作用下的大坝混凝土动态力学性能研究广受关注。本文利用CT技术对动力荷载作用下混凝土细观破裂过程进行实时扫描观测,获得了混凝土试件在动力荷载作用下裂纹的开裂、扩展、贯通的全过程CT图像,并给出了动力压缩、动力拉伸CT试验的初步成果。结果表明:动力压缩荷载条件下混凝土破坏时裂纹起裂点多,裂纹演化速度快,能够解释其动态强度提高的原因;而动力拉伸荷载条件下破裂面较平整,当加载速率较高时,裂纹穿越骨料非常明显。该研究为探索混凝土材料在动力荷载作用下的损伤演化规律提供新的研究途径。
After the Wenchuan Earthquake,the dynamic behavior of concrete dams subjected to strong earthquake is widely paid attention to.The real time scanning observation of meso fracture in concrete under dynamic load is carried out by means of CT technology,so the CT image of crack propagation,coalescence and failure is obtained in the whole process under dynamic compression and the preliminary dynamic compression and tension results of concrete by CT are given.Based on all these analyses,when the concrete is to be failure,the crack points are increased and the crack evolution velocity is high.It is one of the reasons to make concrete dynamic strengths increase.Meanwhile,when the loading rate is higher,the crack will cut through the aggregate obviouly and the failure plane is relatively smooth under dynamic tension.It will put forward some new ideas to the study of dynamic behavior and damage law of concrete material under dynamic loading.
After the Wenchuan Earthquake,the dynamic behavior of concrete dams subjected to strong earthquake is widely paid attention to.The real time scanning observation of meso fracture in concrete under dynamic load is carried out by means of CT technology,so the CT image of crack propagation,coalescence and failure is obtained in the whole process under dynamic compression and the preliminary dynamic compression and tension results of concrete by CT are given.Based on all these analyses,when the concrete is to be failure,the crack points are increased and the crack evolution velocity is high.It is one of the reasons to make concrete dynamic strengths increase.Meanwhile,when the loading rate is higher,the crack will cut through the aggregate obviouly and the failure plane is relatively smooth under dynamic tension.It will put forward some new ideas to the study of dynamic behavior and damage law of concrete material under dynamic loading.
引文
[1]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.
[2]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.
[3]杜修力,田瑞俊,彭一江.预静载对全级配混凝土梁动弯拉强度的影响[J].地震工程与工程振动,2009,29(2):98-102.
[4]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.
[5]Chen Houqun,Ma Huaifa,Tu Jin,et al,Parallel computation of seismic analysis of high arch dam[J].Eagineering And Engineering Vibration2008,7(1):1-11.
[6]田威,党发宁,陈厚群.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.
[7]丁卫华,陈厚群,张建军,等.高应变率作用下混凝土破裂过程的X射线CT观测[J].建筑结构学报,2006,增刊(2):758-762.
[8]党发宁,刘彦文,丁卫华,等.基于破损演化理论的混凝土CT图像定量分析[J].岩石力学与工程学报,2007,26(8):1588-1594.
[9]田威,党发宁,陈厚群.基于图像处理技术的混凝土细观动力破损过程CT分析[J].水利发电学报,2009,28(5):147-151.
[2]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.
[3]杜修力,田瑞俊,彭一江.预静载对全级配混凝土梁动弯拉强度的影响[J].地震工程与工程振动,2009,29(2):98-102.
[4]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.
[5]Chen Houqun,Ma Huaifa,Tu Jin,et al,Parallel computation of seismic analysis of high arch dam[J].Eagineering And Engineering Vibration2008,7(1):1-11.
[6]田威,党发宁,陈厚群.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.
[7]丁卫华,陈厚群,张建军,等.高应变率作用下混凝土破裂过程的X射线CT观测[J].建筑结构学报,2006,增刊(2):758-762.
[8]党发宁,刘彦文,丁卫华,等.基于破损演化理论的混凝土CT图像定量分析[J].岩石力学与工程学报,2007,26(8):1588-1594.
[9]田威,党发宁,陈厚群.基于图像处理技术的混凝土细观动力破损过程CT分析[J].水利发电学报,2009,28(5):147-151.
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