摘要
简述管道导波检测理论基础。运用有限元分析法,对目前现场检测中应用的L(0,2)及T(0,1)模态导波在管中传播过程进行数值模拟研究。在模型的特定部位删除部分单元模拟腐蚀缺陷,分别对管一端加载轴向和切向瞬时位移载荷模拟L(0,2)模态和T(0,1)模态入射波,计算得到管道的瞬时动力学响应,对回波信号作频谱分析。计算结果表明,缺陷位置可以根据缺陷处回波信号到达时间和波速确定。给出缺陷回波反射系数与缺陷横截面积各影响因素之间的关系曲线,可以近似判定缺陷的几何尺寸。并提出以回波信号对缺陷横截面尺寸大小的综合灵敏度来检测、评价管道腐蚀缺陷的思路。
The basic theory of the ultrasonic guided wave detection technique is reviewed. Using the finite element method, nu- merical simulation studies were performed about the L（0,2） and T（0,1）modules which are applied in the current detection in field. In finite element models, the corrosion defect was simulated by getting rid of some cells at specific position, and the L（0,2） and T（0,1） modules wave-input were simulated with axial and tangent transient displacement applied at one end of pipe respectively. The results showed that the corrosion defect is located by the time of the echo wave and the wave velocity. At the same time, by frequency spectrum analysis of the signal, the relationship between reflection coefficient and the geometrical dimension of defection is made, and an idea of inspecting and appraising corrosion defect in pipes, which is the integrated sensitivity of echo signal to defect cross section dimension, is put forward.
出处
《机械强度》
EI
CAS
CSCD
北大核心
2008年第6期988-993,共6页
Journal of Mechanical Strength
关键词
管道检测
超声导波
数值模拟
反射系数
频谱分析
缺陷识别
Pipeline detection
Ultrasonic guided wave
Nmnerical simulation
Reflection coefficient
Frequency spec- trum analysis
Defect identification
