Abstract The paper aims to study the characteristics of the wave propagation paths in reinforced concrete and to improve the existing velocity models. Therefore, coefficients of reflection and transmission with regard to energy were analyzed for each component of the reinforced concrete (cement matrix, aggregate grains, air voids and reinforcement bars) in case of a free- and joint-material boundary, respectively. The findings were employed to investigate the wave propagation paths in cracked concrete and reinforced concrete. Three-dimensional numerical models to approximate the heterogeneous concrete (numerical concrete model, NCM) and reinforced concrete (numerical reinforced concrete model, NRCM) were implemented in a rotated staggered-grid finite-differences scheme. Numerical simulations of the elastic wave propagation were performed to illustrate the interaction of waves with boundaries. Both velocity models, NCM and NRCM, were applied to localize acoustic emissions (AE). An established source localization estimation method (FastWay) served as a tool to validate the heterogeneous velocity models. FastWay was applied to a synthetic cracked reinforced concrete beam to localize six randomly located AE sources. The influence of non-straight wave propagation paths on the performance of the localization method was discussed.

中文翻译：

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数值钢筋混凝土模型中波传播路径的分析

摘要 本文旨在研究钢筋混凝土中波传播路径的特性，改进现有的速度模型。因此，在自由和接缝材料边界的情况下，分别针对钢筋混凝土的每个组分（水泥基体、骨料颗粒、空隙和钢筋）分析了与能量相关的反射和透射系数。研究结果被用来研究波在开裂混凝土和钢筋混凝土中的传播路径。在旋转交错网格有限差分方案中实现了近似异质混凝土（数值混凝土模型，NCM）和钢筋混凝土（数值钢筋混凝土模型，NRCM）的三维数值模型。进行了弹性波传播的数值模拟，以说明波与边界的相互作用。两种速度模型 NCM 和 NRCM 都用于定位声发射 (AE)。已建立的源定位估计方法 (FastWay) 作为验证异构速度模型的工具。FastWay 应用于合成裂纹钢筋混凝土梁，以定位六个随机定位的 AE 源。讨论了非直线波传播路径对定位方法性能的影响。FastWay 应用于合成裂纹钢筋混凝土梁，以定位六个随机定位的 AE 源。讨论了非直线波传播路径对定位方法性能的影响。FastWay 应用于合成裂纹钢筋混凝土梁，以定位六个随机定位的 AE 源。讨论了非直线波传播路径对定位方法性能的影响。