Rout Suraj Kumar, Kapuria Santosh
Department of Applied Mechanics, Indian Institute of Technology Delhi, New Delhi 110016, India.
Department of Applied Mechanics, Indian Institute of Technology Delhi, New Delhi 110016, India.
Ultrasonics. 2025 Nov;155:107695. doi: 10.1016/j.ultras.2025.107695. Epub 2025 May 28.
Despite numerous studies on flexoelectric devices for actuation, sensing, and energy harvesting applications, their potential for generating and sensing guided waves in thin-walled structures has been largely unexamined. This article presents a theoretical model for the actuation and sensing of Lamb waves in thin isotropic plates, utilizing physically modelled adhesively bonded flexoelectric transducers. The model incorporates shear and peel stresses in the bonding layers to facilitate stress transfer between the transducers and the host plate. The tractions induced by the actuator onto the plate surface are determined by modelling the actuator and plate as Kirchhoff plates. The Lamb wave response of the plate is obtained using elasticity theory in the wavenumber domain spatially and frequency domain temporarily, then converted to space and time domains using the residual theorem and inverse Fourier transform. The strain transfer from the plate to the flexoelectric sensor, along with the resulting electric potential, is evaluated utilizing Kirchhoff plate theory assumptions for the sensor and the plate. For validation, the longitudinal strain at the substrate's top surface is compared with ABAQUS' continuum-based finite element results. Numerical studies are presented to demonstrate the influence of the electric field gradient and the thickness of the transducer and adhesive on the time- and frequency-domain Lamb wave response of the plate and the sensor output. The characteristics of the Lamb wave signals produced by flexoelectricity and piezoelectricity are illustrated. The developed model is crucial for realizing applications of flexoelectric materials in material characterization, medical diagnosis, and structural health monitoring.
尽管针对用于驱动、传感和能量收集应用的挠曲电装置开展了大量研究，但其在薄壁结构中产生和传感导波的潜力在很大程度上仍未得到研究。本文提出了一种用于在各向同性薄板中激励和传感兰姆波的理论模型，该模型采用了物理建模的粘结挠曲电换能器。该模型考虑了粘结层中的剪切应力和剥离应力，以促进换能器与主体板之间的应力传递。通过将致动器和板建模为基尔霍夫板来确定致动器在板表面上产生的牵引力。利用弹性理论在空间波数域和时间频率域中获得板的兰姆波响应，然后使用留数定理和傅里叶逆变换将其转换到空间和时间域。利用基尔霍夫板理论对传感器和板的假设，评估从板到挠曲电传感器的应变传递以及由此产生的电势。为进行验证，将基板顶面的纵向应变与ABAQUS基于连续体的有限元结果进行比较。通过数值研究展示了电场梯度、换能器和粘合剂厚度对板的时域和频域兰姆波响应以及传感器输出的影响。阐述了由挠曲电效应和压电效应产生的兰姆波信号的特性。所开发的模型对于实现挠曲电材料在材料表征、医学诊断和结构健康监测中的应用至关重要。
