结构损伤阻抗识别方法试验与应用研究

发布时间：2018-12-15 02:58

【摘要】：球罐、换热器、塔等焊接制造的设备在石油化工、航空航天、船舶运输等行业得到广泛应用。随着设备的大型化、高温高压等高参数化，其焊缝中易出现的裂纹等损伤对其安全构成巨大威胁，有必要进行健康监测。本论文就压电阻抗技术应用于石化领域中焊接结构焊缝损伤识别进行了分析和试验研究。具体分析了压电阻抗法应用于焊接制造的设备中焊缝损伤识别的可行性，完成了对金属材料中出现的裂纹、孔洞等损伤进行模拟定位试验以及数值模拟分析，初步得到阻抗曲线变化与损伤位置的关系，从而提出了可行的监测方法，，并进行了初步试验。本文主要研究内容如下： 1、分析了当前焊接结构安全保障手段的现状以及当前各种无损检测手段的不足，阐述了将压电阻抗法应用于焊接结构损伤识别的意义。 2、介绍了当前国内外压电阻抗技术的发展，就其力学模型建立和试验情况做了详细分析； 3、完成了压电阻抗法试验，从一定量的试验数据中整理得出其损伤出现前后阻抗-频率曲线相关系数与损伤所处位置距离成线性关系的规律； 4、运用ANSYS有限元分析软件对压电陶瓷片及平板裂纹损伤情形下的阻抗特性变化进行了数值模拟分析，其变化规律与实际试验结论基本一致； 5、基于试验及数值模拟结论，提出了一种针对焊接结构焊缝处进行损伤定位的健康监测方法并进行了试验，试验结果表明该种方法测量结果的误差在可接受范围内。
[Abstract]:Spherical tanks, heat exchangers, towers and other welding equipment have been widely used in petrochemical, aerospace, shipping and other industries. With the large scale of equipment and the parameterization of high temperature and high pressure, the damage such as cracks in the weld is a great threat to its safety, so it is necessary to carry out health monitoring. In this paper, the application of piezoelectric impedance technique to weld damage identification of welded structures in petrochemical field is analyzed and tested. The feasibility of the application of the pressure impedance method in welding equipment damage identification is analyzed, and the simulated localization test and numerical simulation analysis of the cracks and holes in metal materials are completed. The relationship between the change of impedance curve and the damage location is obtained, and a feasible monitoring method is put forward, and a preliminary test is carried out. The main contents of this paper are as follows: 1. The present situation of safety and security means of welding structures and the shortcomings of various nondestructive testing methods are analyzed. The significance of applying the voltage impedance method to the damage identification of welded structures is expounded. 2. The development of piezoelectric impedance technology at home and abroad is introduced, and the establishment of mechanical model and the experimental situation are analyzed in detail. (3) the voltage impedance test was completed, and the correlation coefficient between the impedance and frequency curve before and after the damage appeared was linear with the location distance of the damage from a certain amount of test data. 4. The ANSYS finite element analysis software is used to simulate the impedance characteristics of piezoelectric ceramic plates and plates under crack damage, and the results are in good agreement with the experimental results. 5. Based on the results of experiment and numerical simulation, a health monitoring method for weld seam location of welded structure is proposed and the results show that the error of the method is within the acceptable range.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH165.3

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