Optimization of ultrasonic guided wave inspection in structural health monitoring based on thermal sensitivity evaluation
Optimization of ultrasonic guided wave inspection in structural health monitoring based on thermal sensitivity evaluation
复制标题
DOI：
10.1177/1461348419886189
复制
发表时间：
2020-01-06
影响因子：
2.3
通讯作者：
Tu, Xiaotong
中科院分区：
文献类型：
--
作者：
Abbas, Saqlain;Li, Fucai;Tu, Xiaotong
当考虑到环境和操作条件（诸如机械噪声、温度、流速、内部压力等）的变化的影响时，使用超声导波的机械结构中的损伤检测变得甚至更成问题。这些环境和操作条件的变化会降低损坏检查过程的准确性。本研究工作的基本目的是提出一种基于有限元模型的仿真模型，识别和估计环境温度对被测信号的影响，同时感知温度不变点，为实时超声导波检测中的热衰减提供最佳基线。该模型反映了材料的弹性性质、热敏性以及S-0波的群速度和相速度随温度的突变。在Abaqu's T M中，基于应变率和应力的变化、位移的幅值、对称和反对称色散曲线、飞行时间、群速度和梁的固有频率等六个参数进行了数值研究。在Matlab（R）环境中生成了波速函数，以计算导波的群速度，同时考虑温度和激励频率的影响。在此函数中利用线性拟合曲线（一次多项式）来分析温度对群速度的影响。分析估计也被应用到评估温度对材料性能和损伤检测的影响。仿真模型与群速度分析结果和实验波振幅结果进行了对比验证。以令人信服的方式实现了与微小百分比误差的比较。与最优基线选择和基线信号拉伸相比，所提出的热灵敏度仿真模型更有效和可靠。它不仅检测损伤的发生，而且还检查环境温度对超声导波传播的影响，并感知温度不变点，为实时超声导波检测中的热衰减提供最佳基线。该模型也可以在交通运输和工业应用中实际实施，以确保结构可靠性。
Damage detection in a mechanical structure using ultrasonic guided waves becomes even more problematic when the effect of variation in environmental and operating conditions, such as mechanical noise, temperature, flow rate, inner pressure, etc. is taken into account. The variation in these environmental and operating conditions can degrade the accuracy of the damage inspection process. The basic purpose of current research work is to propose a finite element model-based simulation model to identify and estimate the influence of environmental temperature on the measured signal and meanwhile perceive the temperature invariant points to provide an optimal baseline for thermal attenuation in real-time ultrasonic guided wave inspections. This model signifies the variation in material elastic properties, thermal sensitivities, and the abrupt changes in group and phase velocities of S-0 wave mode with temperature. A low bandpass filter is used to keep the excitation frequency in a certain range and remove the noise from it. The numerical investigation is achieved in Abaqu s T M on the basis of six parameters, including variation in strain rate and stress, the amplitude of displacement, symmetric and anti-symmetric dispersion curves, time of flight, group velocity, and natural frequency of the beam. A wave velocity function has been generated in the Matlab (R) environment to calculate the group velocity of guided waves considering the effect of both temperature and excitation frequency. A linear fit curve (first-degree polynomial) is utilized in this function to analyze the effect of temperature on group velocity. An analytical estimation has also been applied to evaluate the impact of temperature on the material properties and damage detection. The simulation model is validated against the analytical group velocity results and experimental wave amplitude results. The comparison with minute percentage error is achieved in a convincing manner. The proposed thermal sensitivity simulation model is more efficient and reliable as compared to optimal baseline selection and baseline signal stretch. It detects not only the occurrence of damage but also examines the influence of environmental temperature on ultrasonic guided wave propagation and perceives the temperature invariant points to provide an optimal baseline for thermal attenuation in real-time ultrasonic guided wave inspections. This model can also be implemented practically in transportation and industrial applications to ensure structural reliability.