摘要
针对液层负载作用下薄板结构中的损伤检测,建立液层负载作用时薄板中Lamb波的传播理论模型。通过傅里叶变换和拉普拉斯变换求解外力作用时板中的响应,并得到板中Lamb波传播的特征方程,绘制不同厚度液层的频散曲线。利用有限元模拟液层负载作用时薄板中Lamb波与腐蚀坑的相互作用过程。研究结果表明,薄板开始有液层负载作用时Lamb波相速度与群速度变化较大,随着液层厚度逐渐增加,频散曲线逐渐趋近于某一曲线。Lamb波与腐蚀坑相互作用时发生波型转换,在腐蚀初始阶段反射波和透射波的强度变化缓慢,当腐蚀坑超过一定深度后,反射波中各模式以及透射波强度变化加剧。
A model based on the theory of fluid-structure interaction is developed to simulate the Lamb waves propagation in a plate bordered with liquid layers according to the corrosion detection in submerged structures. The responses of external load in the plate, including displacement and stress, are derived by Fourier and Laplace transform. The characteristic equation of Lamb waves was obtained and the dispersion curves with different thickness liquid layers were plotted. The interaction between Lamb waves and corrosion in submerged plates was studied by finite element method. The results show that the phase velocity and group velocity of Lamb waves vary greatly when the plate began to border with liquid layers.With the thickening liquid layer, the dispersion curve gradually approaches a curve. Mode conversion occurs during the interation process. At the beginning of corrosion, the intensities of the reflected wave and transmitted wave change slowly. When the depth of the corrosion pitting exceed a certain depth, the corresponding intensities vary greatly.
出处
《振动．测试与诊断》
EI
CSCD
北大核心
2013年第S1期41-44,217,共5页
Journal of Vibration,Measurement & Diagnosis
基金
江苏省博士创新基金资助项目(1221190024)
关键词
液层
LAMB波
腐蚀检测
有限元
liquid layer,Lamb waves,corrosion detection,finite element method
