Quality evaluation of concrete material by attractor analysis for Coda waves

弹性波在混凝土材料中传播时受到骨料的相互干扰和反射，观测到的弹性波变得非常复杂，但必须包含骨料或其他影响因素的信息。因此，在本研究中，混沌理论被用于评估在混凝土材料中传播的波的复杂性。结果发现，接收信号的预测误差与材料的均匀性有一定的相关性，相关维数和最大Lyapunov指数与聚集体周围的键矩阵有很强的相关性。

The elastic waves propagating in concrete material are interfered with each other and reflected by aggregates and then the observed waves become much complicated but must have the information of aggregates or other influential factors. Thus in this study chaotic theory is applied to evaluate the complicity of the waves transmitted throughout concrete material. As a result it is found that prediction error of the received signal has some correlation with the homogeneity of the material, and that correlation dimension and maximum Lyapunov exponent have strong correlation with the bond matrix around the aggregates.