基于向量残差SVD的混凝土超声测试温度效应研究

Research on temperature effect of concrete ultrasonic testing based on vector residual SVD

为研究温度对混凝土超声测试尾波信号的影响规律;将信号向量间的归一化夹角作为波动指标,反映温度效应引起的信号变化;通过向量残差矩阵SVD获得表征温度效应大小的特征向量,建立向量空间映射和温度差的数学关系。在实验室采集混凝土梁尾波信号进行验证,结果表明,随温度升高尾波信号的波形发生后移,文中方法可分段线性量化温度效应;基于量化结果,得到常温下超声尾波信号最敏感的温度区间;任意4.5℃范围内,可去除74%~90%的温度效应。

In order to study the influence of temperature on the coda wave signal of concrete ultrasonic test,the normalized angle between signal vectors is used as the fluctuation index to reflect the signal change caused by temperature effect.The eigenvectors characterising the magnitude of the temperature effect are obtained by SVD of the vector residual matrix,and the mathematical relationship between the vector space mapping and the temperature difference is established.Verification of concrete beam code wave signals are collected in the laboratory.The results show that the waveform of the coda wave signal shifts backward with increasing temperature,and the proposed method can quantify the temperature effect piecewise and linearly.Based on the quantization results,the most sensitive temperature range of ultrasonic coda wave signal at room temperature is obtained.When the temperature span is 4.5℃,74%~90%of the temperature effect can be removed.