【作者】 张丽梅；

【导师】 杜守军；

【作者基本信息】 河北农业大学 ， 水利水电工程， 2004， 硕士

【摘要】 钢结构由于自重轻、强度高、塑性及韧性好、工业化程度高和造型美观等许多优点，被广泛应用于各类建筑中。但是由于钢结构的锈蚀、超载等许多原因，使得钢结构发生损伤的情况日趋增多。近年来，国内外许多学者一直在努力寻找能够准确对钢结构进行检测的方法。这些研究取得了显著的成绩，但是也存在许多不足。特别是，这些方法需要已知结构原始数据，才能进行检测。然而，在实际检测过程中，原始数据很难得到。为了解决这一问题，本文在分析许多学者研究成果的基础上，找到了一种基于柔度的对钢结构损伤敏感的动力学参数——柔度曲率幅值突变系数。该系数可以在未知结构初始数据的情况下，直接利用实际测量数据判断结构是否发生损伤，找到结构的损伤位置，并对结构的损伤程度做出判断。本文首先利用ANSYS的APDL语言编制的程序，以一个平面钢桁架模型为例进行数值模拟。根据结构本身的受力特点，给定损伤情况，进而计算出结构损伤时的柔度曲率幅值突变系数。通过该系数可以找到结构的损伤位置，并且对结构的损伤程度做出初步判定。然后，本文对一个平面钢桁架模型进行实际测试，根据测试数据求出结构损伤时的柔度曲率幅值突变系数。结果表明，柔度曲率幅值突变系数能够对平面钢桁架结构的单根杆件和多根杆件损伤的位置做出比较准确的判断，并且对结构的损伤程度也可以进行初步的判定。同时也验证了数字仿真理论的正确性。本文还提出了将节点质量的增加作为一种结构损伤形式的理论。经过数值模拟和实际实验验证，结果表明，柔度曲率幅值突变系数可以较好的对一个或多个节点质量增加的情况进行检测。该方法只要已知实际结构的数据，就可以进行检测。而且简单、高效、具有很高的实用价值。本文根据前面的分析情况，在文章最后提出了钢结构动力学检测的发展前景和亟待解决的问题。更多还原

【Abstract】 Steel structures have been extensively used in different constructions, because they possess many merits, for example, light deadweight, high strength, good plasticity and toughness, high industrialization and beautiful form, etc. However, the condition of the steel structures’ damage are increasing day by day with the courses of corrosion and overload, and so on. So, many interior and oversea scholars devote all out to finding the methods that can accurately judge the conditions of the steel structures’ damage. These studies solve a lot of problems, but many shortcomings also exist. Especially, only the intact structure initial data is known, can these methods be used to measure the condition of the structure’s damage. But in fact, it’s difficult to know the intact structure initial data. To solve this problem, in this paper, a dynamic sensitive parameter to the steel structure’s damage in the view of flexibility ,naming as "the abrupt coefficient of flexibility curvature", was found on the basis of the research achievements of many other scholars. This coefficient can be used to judge whether the structure is damaged, find the damage position and determine the damage degree of the structure in the case of unknown structures’ initial data. At first, the programming code of ANSYS’s APDL is used to compile procedures and the numerical simulation are carried out by taking a plane steel truss as an example in this paper. According to the structure’s behavior, if the structure’s damage was given, the abrupt coefficient of flexibility curvature can be calculated out. Using this coefficient, the structure’s damage position can be found and it’s damage degree could be determined initially. On the other hand, damaged structure’s abrupt coefficient of flexibility curvature can be obtained on the basis of the measuring data from a practical plane steel truss. The result shows that the plane steel truss’s damage position of single member or many members can be found accurately, and the structure’s damage degree can also be determined initially using the abrupt coefficient of flexibility curvature. At the same time, the theory of numerical simulation is proved correct. A new theory considering the nodal mass’s increasing as a form of damage was put forward. The numerical simulation and practical experiment results indicate that single or several nodes’ mass increasing can be measured by the abrupt coefficient of flexibility curvature. This method can be used only if the data of the real structure is known. And using this method to test structure is simple, high-efficient and with high practical value. According to theformer analyses, the method of the nondestructive testing and the problems needed to solve in the steel structure is presented.更多还原