基于断裂力学的工程起重机疲劳寿命评估

发布时间：2018-06-21 13:13

本文选题：工程起重机 + 疲劳寿命　；参考：《大连理工大学》2012年硕士论文

【摘要】：随着现代经济的快速发展,工程起重机的工作强度日趋繁重,由于结构的失效造成的事故频频出现,其安全性能受到广泛关注。在工程起重机的设计阶段,人们主要重视结构的强度和刚度问题。由于工程起重机使用工况、寿命影响因素复杂,因此,工程起重机的疲劳寿命评估一直以来都是工程难题。因此,对工程起重机进行疲劳寿命评估研究具有重要意义。介绍了现有的疲劳寿命估算方法和工程起重机疲劳寿命评估的现状,针对工程起重机的结构特点和疲劳破坏的原因,确定采用断裂力学理论进行起重机疲劳寿命评估。总结了采用断裂力学理论进行工程起重机疲劳寿命评估的流程和具体步骤,为起重机疲劳寿命评估提供新思路。采用有限元法对起重机结构进行分析,结合疲劳破坏的方式,确定疲劳危险部位；在前人对起重机动力学研究的基础上,根据统计的载荷数据获得载荷谱,为进行疲劳寿命评估奠定基础。以某公司的一台50吨履带起重机为例,采用总结的评估流程进行疲劳寿命评估。臂架是起重机非常重要的部件。根据表面裂纹的扩展方式,运用ANSYS软件中的应力强度因子模块计算出了应力强度因子表达式。分别计算了含表面裂纹和埋藏裂纹的臂架结构的疲劳寿命,得到了相应的临界条件,为设备维修和报废提供依据。通过该起重机的评估,验证了该评估流程的合理性。本文的研究不仅对工程起重机疲劳寿命评估具有指导意义,而且为其他机械产品的寿命评估提供借鉴。
[Abstract]:With the rapid development of modern economy, the work intensity of engineering crane is becoming more and more heavy. Due to the frequent accidents caused by structural failure, the safety performance of the crane is paid more and more attention. In the design stage of engineering crane, people mainly pay attention to the strength and stiffness of structure. The fatigue life evaluation of engineering cranes is always a difficult problem because of the complex factors affecting the life of engineering cranes under the working conditions. Therefore, it is of great significance to evaluate the fatigue life of engineering crane. This paper introduces the existing fatigue life estimation methods and the present situation of engineering crane fatigue life evaluation. According to the structural characteristics of engineering crane and the cause of fatigue failure, the fracture mechanics theory is adopted to evaluate the crane fatigue life. This paper summarizes the process and concrete steps of fatigue life evaluation of engineering crane based on fracture mechanics theory, which provides a new idea for crane fatigue life evaluation. The structure of crane is analyzed by finite element method and the fatigue damage mode is used to determine the dangerous part of the crane. On the basis of the previous research on crane dynamics, the load spectrum is obtained according to the statistical load data. It lays the foundation for fatigue life evaluation. Taking a 50 ton crawler crane of a company as an example, the fatigue life evaluation is carried out by using the summarized evaluation procedure. Jib is a very important part of crane. According to the growth mode of the surface crack, the expression of the stress intensity factor is calculated by using the stress intensity factor module in ANSYS software. The fatigue life of boom structures with surface cracks and buried cracks are calculated, and the corresponding critical conditions are obtained, which provide the basis for equipment maintenance and scrapping. Through the evaluation of the crane, the rationality of the evaluation process is verified. The research in this paper not only has the guiding significance for the fatigue life evaluation of engineering cranes, but also provides reference for the life evaluation of other mechanical products.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH21

【引证文献】