基于荧光量子点的裂纹实时在线监测及影响因素研究

发布时间：2018-03-26 11:20

本文选题：量子点　切入点：环氧树脂复合材料(QD-Ep)　出处：《华东理工大学》2017年硕士论文

【摘要】：裂纹作为结构中最危险的一种缺陷,往往容易导致设备的失效甚至造成重大安全事故。然而,工业生产过程由于经济性及结构复杂性等因素的制约,对于裂纹的实时在线监测始终难以实现大面积覆盖,因此,新的实时在线监测手段的开发便显得尤为重要。由于量子点(QD)对于应力应变具有相应的荧光响应,基于此,本文主要使用CdSe/ZnS量子点环氧树脂复合材料,并覆于被测试样表面成膜,从而实现对于裂纹的实时监测,并对相关影响因素进行考察。论文主要获得以下研究结果:(1)实验发现在宏观裂纹监测的过程中,膜裂纹处会出现一条荧光亮线,而在微裂纹的监测过程中,通过荧光显微镜会在裂纹周围发现明显的荧光增强区域。(2)实验通过对相应宏观裂纹与微裂纹监测过程进行观测,确立了监测不同尺寸大小的裂纹所适用的最佳覆膜厚度。同时通过对宏观裂纹与微裂纹二者荧光增强情况进行相应的表征,提出了二者之间形成荧光增强现象机理的差异。(3)对于宏观裂纹,进行了相应膜裂纹与金属基底裂纹在长度方向同步性的考察;对于微裂纹,通过模拟以及相关因素的实验探究,进一步证明了该荧光增强现象与基体的应力分布,量子点与基体之间的相互作用息息相关。
[Abstract]:As one of the most dangerous defects in structures, cracks often lead to equipment failure and even serious safety accidents. However, the industrial production process is restricted by economy and structural complexity. It is always difficult to realize large area coverage for the real-time on-line monitoring of cracks, so it is very important to develop a new real-time on-line monitoring method. Because quantum dots (QD) have a corresponding fluorescence response to stress and strain, based on this, In this paper, the CdSe/ZnS quantum dot epoxy composite is used to form film on the surface of the tested sample, so that the crack can be monitored in real time. The main results of this paper are as follows: 1) in the process of macroscopic crack monitoring, there will be a fluorescent bright line in the film crack, while in the process of microcrack monitoring, there will be a fluorescent bright line in the film crack monitoring process. The obvious fluorescence enhancement region around the crack can be found by fluorescence microscope. The experiment observed the corresponding macroscopic crack and microcrack monitoring process. The optimum film thickness for monitoring cracks of different sizes was established. Meanwhile, the fluorescence enhancement of macroscopic crack and microcrack were characterized accordingly. It is suggested that the mechanism of fluorescence enhancement is different between them.) for macroscopic cracks, the synchronism of the corresponding film cracks and metal substrate cracks in the length direction is investigated, and for microcracks, the simulation and experimental investigation of related factors are carried out. It is further proved that the fluorescence enhancement phenomenon is closely related to the stress distribution of the matrix and the interaction between the quantum dots and the matrix.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.3

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