非轴对称多元载荷条件下管道中纵向模态导波激励

发布时间：2018-12-15 03:39

【摘要】：轴对称载荷是管道中轴对称模态导波激励的有效方法。然而,受换能器安装误差等因素的影响,激励载荷多会变为非轴对称载荷,进而使激励出的导波模态变得复杂。对非轴对称多元载荷条件下纵向模态导波的激励问题进行了深入研究。考虑两种典型的非轴对称载荷,采用简正模态展开技术,建立了导波激励声场与边界载荷的量化关系,进而分析了各模态导波的产生机理及载荷阵列对纵向导波激励的影响。采用有限元数值模拟验证了理论预测结果。考虑实际管道检测中出现的非轴对称载荷,提出了一种载荷补偿策略并进行了实验验证。结果表明,该方法能够有效抑制弯曲模态导波的产生,同时也有助于改善导波信号的噪声水平。
[Abstract]:Axisymmetric load is an effective method for axisymmetric modal guided wave excitation in pipeline. However, under the influence of the transducer installation error, the excitation load will be changed into non-axisymmetric load, which makes the guided wave mode complicated. The excitation problem of longitudinal mode guided waves under non-axisymmetric multivariate loads is studied. Considering two kinds of typical non-axisymmetric loads, the quantitative relationship between guided wave excitation sound field and boundary load is established by using normal mode expansion technique, and the generation mechanism of guided wave and the effect of load array on longitudinal guided wave excitation are analyzed. The finite element numerical simulation is used to verify the theoretical prediction results. Considering the non-axisymmetric loads in actual pipeline detection, a load compensation strategy is proposed and verified by experiments. The results show that the proposed method can effectively suppress the generation of guided waves in the bending mode and improve the noise level of the guided wave signals.
【作者单位】：大连理工大学工业装备结构分析国家重点实验室;
【基金】：国家科技重大专项(2008ZX05026) 国家自然科学基金(91016024) 教育部新世纪人才(NCET-11-0055) 中央高校基本科研业务费(DUT12LK33)
【分类号】：TG115.285

【共引文献】