HRB400钢筋金纳米复合材料光声传感微裂纹检测

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关键词：光声传感；超声检测；HRB4OO钢筋；多物理场仿真；微裂纹生长中图分类号：TB559；TG115.28 文献标识码：Adoi：10.37188/OPE.20253315.2365 CSTR：32169.14.OPE.20253315.2365

Crack detection of HRB4oo steel reinforcement bar using AuNPs-based nanocomposites photoacoustic sensing

SUN Yumeng，SUN Zihui，DU Cong*，CHEN Zhigang，SUN Yinnan （School ofMechanical-electronic and Vehicle Engineering，Beijing University of Civil Engineering and Architecture，Beijin lO26l6，China） *Correspondingauthor， E -mail：ducong@bucea.edu.cn

Abstract： To overcome the limited electromagnetic-interference resilience and poor adaptability of conventional approaches，an ultrasonic detection method based on AuNPs-reinforced nanocomposite photoacoustic sensing Was developed for high-precision microcrack detection in HRB4OO steel reinforcement bars used in high-speed rail sleepers. Au-PDMS films with Au nanoparticle concentrations of ，5.23 （204号 40t% ， 6.01≈% ，and 7.69≈70t% were fabricated，and their photoacoustic conversion characteristics were characterized. Ultrasonic signals were generated by a 532nm pulsed laser and processed using a hybrid algorithm combining Butterworth bandpassfiltering and db4 wavelet decomposition.A finite-element model of HRB4O0 reinforcement was constructed in COMSOL Multiphysics to quantify the relationship between multidimensional ultrasonic features and crack depth. Experimental results indicate that the 5.23≈t% AuPDMS sample exhibited a dominant frequency of 4.58MHz and a signal-to-noise ratio of 19.56 dB， achieving a measured crack-depth detection resolution of 640μm . Quantitative analysis showed an increase in first-wave amplitude for 1mm deepcracks，whereas 3mm deep cracks produced waveform splitting into a dual-peak structure with a peak interval of 1.50μs . A multiparameter synergistic response model integrating peak amplitude，energy，dominant frequency，and time-of-arrival enabled quantitative microcrack assessment. The proposed system provides micron-level resolution， strong immunity to electromagnetic interference，and adaptability to complex environments，ofering reliable technical support for structural health monitoring of high-speed rail infrastructure.

Key words： photoacoustic sensing；ultrasonic detection；HRB4OO steel reinforcement bar；multiphysics field simulation；microcrack growth

1引言

铁路安全始终是发展的关键，铁路事故主要包括人为因素、轨道沉降和路基失效、设备和信号故障等。（剩余15587字）