Low-Strain Damage Imaging Detection Experiment for Model Pile Integrity Based on HHT

With the advancement of computer and mathematical techniques,significant progress has been made in the 3D modeling of foundation piles.Existing methods include the 3D semi-analytical model for non-destructive low-strain integrity assessment of large-diameter thin-walled pipe piles and the 3D soil-pile dynamic interaction model.However,these methods have complex analysis procedures and substantial limitations.This paper introduces an innovative and streamlined 3D imaging technique tailored for the detection of pile damage.The approach harnesses the power of an eight-channel ring array transducer to capture internal reflection signals within foundation piles.The acquired signals are subsequently processed using the Hilbert-Huang Transform(HHT),a robust analytical tool known for its effectiveness in handling non-stationary signals.Through the development of a sophisticated multi-channel ring array imaging algorithm,this technique empowers engineers and researchers to identify various pile defects,including their specific type,precise location,and obtain detailed 3D imaging representations.The findings of this research offer a valuable blend of theoretical insights and practical guidance,significantly advancing the state-of-the-art in the realm of concrete pile integrity inspection.By simplifying and enhancing the assessment process,this innovative approach not only addresses the complexities of existing methods but also contributes to the overall safety and reliability of concrete engineering structures.

变化温度下的超声导波板状结构健康监测

超声导波结构健康监测技术在板状构件的缺陷诊断中易受温度干扰,影响阵列对损伤成像的精度。在不同温度下进行兰姆(Lamb)波损伤检测的实验,基于最优基线法(OBS)和基线信号拉伸法(BSS),引入了局部时移,对时域信号进行精确补偿。通过最优基线法筛选出参考信号,添加局部时移实现各波包上的时间补偿,通过基线拉伸完成温度补偿。改进后的温度补偿法能够将温度采集范围由1℃拓宽至10℃,且能够对信号上各波包进行温度补偿。结合椭圆定位法,确保在变化温度下成像的相对误差低于9%。通过实验验证了优化后的温度补偿法的有效性,能够准确识别环境温度变化下的结构损伤。