摘要
混凝土构件中存在的诸如松散、空洞、缝隙夹层等缺陷,不仅造成声波速度的变化,而且对声波具有较强的吸收衰减作用,利用声波速度CT和衰减CT联合检测技术是检测混凝土构件工程质量的有效方法。介绍了声波速度CT检测原理和SIRT算法、接收波信号频移与介质衰减吸收系数的关系,导出了适用于CT成像反演算法的介质吸收因数沿射线路径的积分与频移参数的关系表达式。对存在松散和空洞缺陷的两种混凝土构件模型的声波检测结果,分别进行了速度CT和频移衰减CT处理,处理结果表明,声波速度和频移衰减联合层析成像检测技术能够获得更加准确可靠的检测效果。
Concrete components have flaws, such as loose, hole, slit band and so on. These flaws not only lead to the change of acoustic velocity, but also have strong absorption and attenuation action to the acoustic wave. It is an effective method to detect engineering quality of concrete components by using acoustic velocity CT and attenuation CT combined detection technology. The acoustic velocity CT detection principle and the SIRT algorithm are described, the relationship between received wave signal frequency shift and attenuation absorption coefficient of medium is introduced. The relational expression of integral of dielectric absorption coefficient along the ray path with frequency shift parameters, which is suited to CT tomography inversion algorithm is derived. The results of acoustic detection of two kinds of concrete component models which are loose and have holes separately are processed by velocity CT and frequency shift attenuation CT. The results indicate that acoustic velocity and frequency shift attenuation combined tomography detection technology can obtain more accurate and reliable detection effects.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2009年第3期659-663,共5页
Rock and Soil Mechanics
基金
国家自然科学重大基金(No.50534080)资助
关键词
声波
速度
频移
层析成像
检测
acoustic wave
velocity
frequency shift
tomography
detection
