柔性结构分布式光纤变形监测技术研究

发布时间：2018-07-22 15:18

【摘要】：航空航天结构在长期服役过程中,容易因自身激励和外界环境的扰动,诱发结构的形态变化。一方面,这会对结构自身安全和使用寿命带来损害;另一方面,还会导致结构功能的可靠性产生偏差。因此,开展针对航空航天结构的变形监测,不仅能够为结构形态精确控制、振动主动抑制提供依据,而且对于结构健康状态评估具有重要意义。为此,本文将光纤光栅传感器分别应用于对不同柔性结构对象上的变形监测。通过研究不同的变形重构算法,实现针对不同属性柔性结构的变形状态监测。主要研究内容可分为以下几个方面:首先,结合光纤光栅传感器的应变感知原理,研究了光纤光栅传感系统与被测结构对象的集成方法。考察了光纤光栅传感器应变感知特性如灵敏度、线性度、精度、迟滞性以及重复性等,为后续的变形监测提供基础。其次,根据目前航空航天结构的特殊性和变形特征,分别研究了基于Ko位移理论和基于平面坐标变换的两类板状结构分布式光纤变形监测与重构方法,并构建了相应的复合材料板结构变形监测系统。采用有限元仿真和试验方法,引入多种误差形式作为变形重构效果评价指标。再次,构建了铝合金翼形结构分布式光纤变形监测系统。采用基于Ko位移理论和基于平面坐标变换的两类板状结构变形重构算法,分别实现不同加载模式下变截面翼形结构变形状态反演。在此基础上,开发了基于LabVIEW显示界面的变形监测与实时显示系统。最后,根据柔性管状结构的变形特点,研究了基于空间坐标变换的管状结构分布式光纤三维变形的变形监测方法,初步实现了柔性管状结构的三维变形重构。
[Abstract]:During the long service of aerospace structure, it is easy to induce structural changes due to self-excitation and disturbance of external environment. On the one hand, it will damage the safety and service life of the structure itself; on the other hand, it will lead to the deviation of the reliability of the structure function. Therefore, the deformation monitoring for aerospace structures can not only provide the basis for precise structural shape control and active vibration suppression, but also be of great significance for the assessment of structural health status. Therefore, the fiber Bragg grating sensor is applied to the deformation monitoring of different flexible structures. The deformation state monitoring for flexible structures with different properties is realized by studying different deformation reconstruction algorithms. The main research contents can be divided into the following aspects: firstly, combining the strain sensing principle of the fiber grating sensor, the integration method between the fiber grating sensor system and the tested structure object is studied. The strain sensing characteristics of fiber Bragg grating sensors such as sensitivity linearity precision hysteresis and repeatability are investigated in order to provide a basis for further deformation monitoring. Secondly, according to the particularity and deformation characteristics of aerospace structures at present, two kinds of distributed optical fiber deformation monitoring and reconstruction methods based on Ko displacement theory and plane coordinate transformation are studied respectively. The deformation monitoring system of composite plate structure is constructed. Finite element simulation and test methods are used to evaluate the effect of deformation reconstruction by introducing a variety of error forms. Thirdly, a distributed optical fiber deformation monitoring system for aluminum alloy airfoil is constructed. Based on Ko displacement theory and plane coordinate transformation, two kinds of plate structure deformation reconstruction algorithms are adopted to realize the inversion of deformation state of variable section airfoil structures under different loading modes. On this basis, the deformation monitoring and real-time display system based on LabVIEW display interface is developed. Finally, according to the deformation characteristics of flexible tubular structure, the 3D deformation monitoring method of distributed optical fiber for tubular structure based on spatial coordinate transformation is studied, and the 3D deformation reconstruction of flexible tubular structure is preliminarily realized.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：V467;TP212

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