高速转向架焊接工艺设计及接头疲劳强度评定系统

发布时间：2018-11-14 12:13

【摘要】：高速转向架是机车车辆最重要的承载结构,转向架的强度可靠性对机车整体安全性和运行平稳性具有重要的影响。高速转向架是典型的焊接结构,焊接接头是其最薄弱的环节,接头疲劳是常见的失效形式。焊接工艺设计及疲劳强度的评定成为保障高速转向架焊接质量的关键。本文针对企业实际需求,设计并开发了高速转向架焊接工艺设计及接头疲劳强度评定系统。首先,本文根据高速转向架焊接工艺设计和疲劳强度评定工作的特点,对系统知识进行分类,并分别制定知识获取方法和表达方式,形成了系统知识库整体结构;根据焊接工艺设计及接头疲劳强度评定问题求解的过程,设计了系统推理机的推理原则和流程;通过对系统整体功能分析完成了系统整体结构设计。其次,根据高速转向架焊接工艺设计的主要工作内容,结合相关标准和经验的研究,通过对焊接工艺规程相关参数确定方法的研究,形成了焊接工艺设计流程,并建立了工艺设计方案,通过多层次推理过程实现了对焊接工艺的设计。然后,本文根据焊接接头疲劳强度名义应力评定法原理,设计了系统疲劳强度评定的流程和模块结构。系统利用雨流计数法实现了对名义应力谱的统计,编制了接头疲劳质量等级匹配程序以获取接头S-N特征曲线,并最终实现不同疲劳评定计算方法对接头疲劳强度的评定。最后,以保证系统知识库的可扩充性、准确性和安全性为目标,设计了知识库管理系统的实现方式和知识库安全保障方法,建立了完整的系统知识库管理体系,保证了系统知识库持续学习和不断完善的专家系统知识库特性,使其能够适应高速转向架焊接技术的新变化。
[Abstract]:High speed bogie is the most important bearing structure of locomotive and rolling stock. The strength reliability of bogie has an important influence on the overall safety and running stability of locomotive. High speed bogie is a typical welding structure, welding joint is the weakest link, joint fatigue is a common failure form. Welding process design and fatigue strength evaluation are the key to ensure welding quality of high speed bogie. In this paper, the welding process design and fatigue strength evaluation system of high speed bogie are designed and developed according to the actual demand of enterprises. Firstly, according to the characteristics of welding process design and fatigue strength assessment of high speed bogie, the system knowledge is classified, and the knowledge acquisition method and expression method are formulated respectively, forming the whole structure of system knowledge base. According to the process of welding process design and fatigue strength evaluation of joints, the reasoning principle and flow of the system inference machine are designed, and the whole system structure is designed by analyzing the whole function of the system. Secondly, according to the main work content of welding process design of high-speed bogie, combined with the research of relevant standards and experience, the welding process design flow is formed through the research on the determination method of the relevant parameters of welding process rules. The process design scheme is established, and the welding process design is realized by multi-level reasoning process. Then, according to the principle of nominal stress evaluation method of welded joint fatigue strength, the flow chart and module structure of fatigue strength evaluation system are designed. In this paper, the nominal stress spectrum statistics is realized by the rain flow counting method, and the fatigue quality grade matching program is compiled to obtain the S-N characteristic curve of the joint. Finally, the fatigue strength of the joint is evaluated by different fatigue evaluation calculation methods. Finally, in order to ensure the expansibility, accuracy and security of the system knowledge base, the realization mode of the knowledge base management system and the knowledge base security guarantee method are designed, and the complete system knowledge base management system is established. It ensures the continuous learning of the system knowledge base and the continuous improvement of the knowledge base characteristics of the expert system, so that it can adapt to the new changes of the welding technology of the high-speed bogie.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U270.64;TG44

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