基于模态分析的塔式起重机结构损伤研究

发布时间：2018-05-08 22:08

本文选题：塔式起重机 + 金属结构　；参考：《太原科技大学》2012年硕士论文

【摘要】：金属结构是塔式起重机重要的组成部分，塔机金属结构的破坏主要是疲劳断裂，因此，，本文致力于研究塔式起重机金属结构的裂纹损伤识别。本文结合理论，应用机械桁架结构静力学分析、桁架结构动力学分析、非线性分析、固有频率模态识别等理论，取得了以下研究结论：以单吊点塔式起重机为例，运用APDL语言对单吊点塔式起重机金属结构进行整体建模。对我们所用的塔式起重机模型进行静力学分析，得到了塔机的应变情况、应力和力矩，为塔机的后续工作做了铺垫，用静力学方法识别出塔机危险点大致位置。对建立的塔机模型进行动力学分析，得到了前十阶模态变化固有频率，这样为我们的后续裂纹故障识别做了进一步的工作。金属结构裂纹识别主要解决两大问题：是否存在裂纹、裂纹的位置和裂纹大小。本章主要用有限元模态分析对金属结构裂纹进行精确识别。基于有限元法建立裂纹金属结构的精确辨识模型，通过对结构模型的固有频率分析，建立金属结构固有频率精准数据库，从而当金属结构出现裂纹时，利用四线等高相交裂纹识别技术定量找出裂纹的位置和裂纹的大小。最后，通过数值仿真证实了方法的有效性，为金属结构裂纹识别提供了可靠的依据。塔式起重机结构裂纹识别主要解决两个大的方面的问题：一个是塔机裂纹杆件的个数和裂纹存在的位置，另一个是裂纹杆件的损伤程度。在对裂纹识别时，主要用有限元模态分析对塔机塔臂结构裂纹进行精确识别理论的模型的建立。基于有限元法建立塔臂裂纹结构的精确辨识塔机模型，通过对塔机塔臂金属结构模型的固有频率分析，建立塔臂结构固有频率精准单裂纹数据库，从而当塔臂结构出在裂纹时，利用四线等高相交裂纹识别技术定量找出裂纹的个数、位置和裂纹的大小。最后，通过数值仿真证实了方法的有效性，为塔机金属结构裂纹识别提供了可靠的依据。
[Abstract]:Metal structure is an important part of tower crane, and the damage of tower crane metal structure is mainly fatigue fracture. Therefore, this paper is devoted to study the crack damage identification of tower crane metal structure. Combined with the theory of mechanical truss structure static analysis, truss structure dynamics analysis, nonlinear analysis, natural frequency modal identification and other theories, the following conclusions are obtained: Taking single point tower crane as an example, the metal structure of single point tower crane is modeled by APDL language. The statics analysis of the tower crane model is carried out, and the strain, stress and torque of the tower crane are obtained. The statics method is used to identify the general position of the tower crane danger point. Based on the dynamic analysis of the tower crane model, the natural frequencies of the first ten modes are obtained, which makes further work for the subsequent crack fault identification. There are two main problems in metal structure crack identification: whether there are cracks, the location of cracks and the size of cracks. In this chapter, the finite element modal analysis is used to identify the crack of metal structure. The accurate identification model of cracked metal structure is established based on finite element method. By analyzing the natural frequency of structural model, the accurate database of natural frequency of metal structure is established. The crack location and crack size are quantitatively found by using the four-line high intersecting crack identification technique. Finally, the validity of the method is verified by numerical simulation, which provides a reliable basis for crack identification of metal structures. There are two major problems in structural crack identification of tower crane: one is the number of cracked members and the location of cracks, the other is the damage degree of cracked members. In the process of crack identification, the finite element modal analysis is mainly used to establish the model of accurate identification theory for tower crane tower arm structure crack. Based on finite element method, the accurate identification tower crane model of tower arm crack structure is established. By analyzing the natural frequency of tower arm metal structure model, the accurate single crack database of tower arm structure is established. The number, position and size of cracks are quantitatively found by using the technique of four-line high intersecting crack identification. Finally, the validity of the method is verified by numerical simulation, which provides a reliable basis for the identification of cracks in metal structures of tower cranes.
【学位授予单位】：太原科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH213.3

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