Abstract: Subsea pipelines are prone to developing cracks during long-term service, and traditional methods often suffer from low localization accuracy and poor stability in complex noisy environments. This study investigates defect localization based on an improved cross-correlation time delay estimation method for acoustic emission (AE) signals, which is significant for identifying and localizing sudden AE events under challenging conditions. AE detection technology, as a dynamic, real-time, and non-destructive evaluation method, captures transient elastic waves generated by internal structural changes due to stress or environmental variations, enabling early warning of potential damage and accurate health monitoring of structures. Experimental results demonstrate that the improved cross-correlation time delay method effectively enhances the localization accuracy for AE sources, achieving an average localization error of 0.0133 m and a relative error of 2.67%, which sufficiently meets practical requirements. The findings indicate that this method possesses high practical value for damage detection and localization analysis in complex structures.

Key words: acoustic emission, cross-correlation time delay estimation, cross-correlation coefficient, time difference of arrival (TDOA)

摘要： 海洋管道在长期使用过程中易产生裂纹，传统定位方法在复杂噪声环境下精度低、稳定性差。故基于互相关时延法开展裂纹缺陷损伤定位研究，对复杂环境下识别突发性声发射信号具有重要意义。该文聚焦声发射检测技术在海洋管道健康评估中的应用，通过改进互相关时延法捕捉外部作用或环境变化下材料内部自发产生的声发射信号，实现潜在损伤早期预警和结构健康的精准监测。实验结果表明，改进的互相关时延法能够有效提高声发射的定位精度，平均定位误差为0.013 3 m，相对误差为2.67%，满足实际需求。研究成果表明，该改进算法在复杂结构的损伤检测和定位分析中具有较高实用价值。

关键词: 声发射, 互相关时延法, 互相关系数, 到达时间差