用于结构损伤监测的新型应变梯度传感器研制

Based on the recent progress from our research team on the characteization of giant flexoelectric materials, piezoelectric sensor as well as micro/nano manufacture technology, this research proposal aims at exploring a new class of strain gradient sensor (SGS) for structural damage monitoring. The project is first to reveal the relationships between the flexoelectric coefficient and dielectric property, temperature, scale effect, mechanical/electrical energy conversion of nano-powder flexoelectric materials. With preparation of high performance flexoelectric nano-powder, optimal design of a sensor element and fabrication of the SGS with micron-sized structure, the strain gradient in damage prone areas can be in-situ monitored, then the damage initiation in critical structural areas will be pre-monitored. A verification platform for damage monitoring using SGS will be constructed and then compared by analytic solutions of plates with a circular hole and a sharp crack. It is envisioned that the ralevant theories, methods and technologies developed and verified by the the proposed work are expected to promote the wide application of micro/nano sensors/actuators, nanogenerators and micro/nano-energy harvesters and greatly enhance capability of early damage detection and in-situ structural health monitoring, which will be of profound significance to the academic and engineering application of structural damage sensing technology.

在课题组近年来对挠曲电材料、压电传感器技术和微/纳米加工技术等相关研究基础上，研制用于监测结构损伤的新型应变梯度传感器。揭示微米级挠曲电材料的力/电耦合系数与介电特性、温度、尺度效应等内在联系以及力/电能量转换关系；制备高性能的挠曲电材料纳米粉体，优化设计传感单元，制作高灵敏的微米级挠曲电应变梯度传感器，实现在线监测损伤导致的应变梯度，进而达到超前监测结构中应力集中区域损伤的萌生；构建应变梯度传感器损伤监测验证平台，结合工程实际用已有确定解析解的圆孔、裂纹试样进行验证。可以预期项目研究所形成的相关理论、方法及其成果，将有望促进微纳米传感/驱动器、纳米发电机、纳米能量收集器等开发和广泛应用，极大地推进结构中早期损伤检测技术和结构健康在线监测技术的发展，对结构损伤传感技术领域的学术和工程应用有着重要而又深远的意义。