摘要
针对输电铁塔角钢缺陷检测中传统超声导波法因多模态干扰与频散现象导致频率选择盲目、检测效率低的问题,文章提出了一种基于兰姆波频散特性与有限元仿真的频率优化算法。通过构建角钢-混凝土复合结构三维模型,量化分析不同频率下导波模态的传播规律及缺陷响应特征,并结合多目标决策模型(权重系数α=0.6、β=0.4)优化激发频率。结果表明,反对称模态(A_(0))在低频范围内(50~200kHz)具有高灵敏度与低衰减特性;120kHz激励频率下,信噪比(18.6dB)与波包宽度(0.7ms)综合性能最优,有效解决了多模态干扰与信号展宽问题。有限元仿真验证了该算法在自由边界与混凝土固定约束条件下的适用性,为复杂结构的无损检测提供了可靠的理论支持与技术参考。
In order to address the issues of blind frequency selection and low detection efficiency caused by multimodal interference and dispersion phenomena in traditional ultrasonic guided wave methods for detecting defects in angle steel components of transmission towers,this paper proposes a frequency optimization algorithm based on Lamb wave dispersion characteristics and finite element simulation.By establishing a three-dimensional model of an angle steel-concrete composite structure,quantitative analyses of guided wave mode propagation patterns and defect response characteristics were conducted at various frequencies.A multi-objective decision-making model(weight coefficientsα=0.6,β=0.4)was employed to optimize the excitation frequency.The results demonstrated that the antisymmetric mode(A _(0))exhibited high sensitivity and low attenuation characteristics within the low-frequency range(50~200kHz).At the excitation frequency of 120kHz,the comprehensive performance,characterized by a signal-to-noise ratio(SNR)of 18.6dB and wave packet width of 0.7ms,was optimal,effectively resolving issues related to multimodal interference and signal widening.Finite element simulations verified the applicability of this optimized algorithm under both free boundary conditions and concrete-fixed constraints,providing reliable theoretical support and technical reference for nondestructive testing of complex structural components.
作者
邓勇
刘传乐
董国香
DENG Yong;LIU Chuanle;DONG Guoxiang(College of Quality Inspection and Information,Hunan Vocational Institute of Labour and Personnel,Changsha 410100,China)
出处
《中国水能及电气化》
2025年第8期56-64,共9页
China Water Power & Electrification
基金
2024年度湖南省教育厅科学研究项目“输电铁塔角钢缺陷的超声导波检测方法研究”(24C0944)。
关键词
输电铁塔角钢
兰姆波
频散曲线
有限元仿真
频率优化
无损检测
transmission tower angle steel
Lamb waves
dispersion curves
finite element simulation
frequency optimization
nondestructive testing
