基于同步挤压小波变换和超声导波的锈蚀钢筋直径评估方法研究  

Research on Diameter Evaluation of Corroded Rebar Based on Synchrosqueezing Wavelet Transform and Ultrasonic Guided Wave

作　　者：孙祥涛 俞承序 杨霞 马彬[1,2] 孔庆钊 SUN Xiangtao;YU Chengxu;YANG Xia;MA Bin;KONG Qingzhao(State Key Laboratory for Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China;Department of Disaster Mitigation for Structures,Tongji University,Shanghai 200092,China;Department of Bridge Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学土木工程防灾国家重点试验室,上海200092 [2]同济大学结构防灾减灾工程系,上海200092 [3]同济大学桥梁工程系,上海200092

出　　处：《应用基础与工程科学学报》2025年第1期50-59,共10页Journal of Basic Science and Engineering

基　　金：国家自然科学基金项目(5202105005);上海市科技计划启明星项目(23QA1409600)。

摘　　要：锈蚀引起的钢筋直径缩减显著降低了钢筋混凝土结构的承载力和可靠性.本研究采用同步挤压小波变换(SWT)技术获取超声导波的群速度,进而评估钢筋的直径变化.首先,基于导波的传播特性选取L(0,1)模态作为探测波,并通过敏感性分析确定140kHz为最优探测频率.随后,通过频散方程计算得出不同直径钢筋中L(0,1)导波在140kHz的理论群速度.利用SWT的高时频分辨率特性,精确提取L(0,1)导波信号在140kHz的到达时间并计算群速度.通过对比试验群速度与理论值,实现对钢筋直径的准确评估.为验证该方法的准确性和适用性,进行了裸钢筋和埋入钢筋的加速锈蚀试验.裸钢筋试验结果表明,SWT能够准确获取导波群速度,并有效评估锈蚀钢筋的直径;而埋入钢筋试验结果表明该方法适用于锈蚀钢筋与混凝土脱粘后的钢筋直径评估.Corrosion-induced diameter reduction of reinforcing bars significantly diminishes the load-bearing capacity and reliability of reinforced concrete structures.This study employs synchrosqueezing wavelet transform(SWT)to extract the group velocity of guided wave for corroded rebar diameter evaluation.Initially,the L(0,1)mode is selected as the probing wave based on the propagation characteristics of guided wave.The optimal frequency is determined as 140kHz via the sensitivity analysis.The arrival time of the L(0,1)mode at the optimal frequency is precisely extracted by the SWT because of the high-resolution in time-frequency domain,enabling accurate calculation of the group velocity and assessment of the rebar diameter.To verify the feasibility and applicability of the proposed method,the accelerated corrosion tests of bare rebar and embedded rebar are conducted.The results of bare rebar tests demonstrate that the SWT could precisely determine the group velocity and effectively evaluate the rebar diameter.The results of embedded rebar tests show that the proposed method could evaluate the residual diameter of rebar after the debonding between the corroded rebar and concrete.

关 键 词：钢筋锈蚀 超声导波 同步挤压小波变换 时频分析 群速度 锈蚀钢筋直径评估 

分 类 号：TU437[建筑科学—岩土工程]