预应力车削加工工艺数据库系统的研究

发布时间：2018-04-28 01:12

本文选题：预应力 + 基于实例推理　；参考：《湘潭大学》2015年硕士论文

【摘要】：预应力加工是一种通过在切削前预先施加预应力就能控制工件表面残余应力的高效加工方法,它对高强度合金特别是高温合金的加工正受到越来越广泛的关注,因为相对于其它改善工件表层残余应力的方法,预应力切削加工方法具有工艺简单、节省时间和成本,且加工后不会产生额外的加工表面硬化等优点,但是一直以来,高强度合金的预应力切削加工由于缺乏专业工艺数据库的指导,零件加工质量不稳定。本文在了解了预应力加工方法和数据库系统用户的需求后,针对高强度合金的车削加工,建立了预应力车削加工工艺数据库系统,将高强度合金的预应力车削加工的实验数据、有限元模拟数据和离散元模拟数据加以结合,并通过基于实例推理方法,使这些数据能在符合用户需求的基础上传递给用户。在建立预应力车削加工工艺数据库系统的过程中,本文主要描述了如下问题:1.研究了预应力车削加工工艺数据库系统的整体设计,通过对预应力切削加工数据结构的研究以及用户的需求分析,得到了整个系统的框架结构,系统参量的设计模型和系统能实现的功能。2.采用了基于实例推理(Case-based Reasoning,CBR)的推理方法,研究了采用最近邻居法和局部相似度计算进行实例检索的过程,描述了实例重用后的实例修改及实例保存,实现了预应力切削加工数据库系统进行自学习的功能。3.研究了预应力切削加工数据库系统整体的推理流程和预应力知识的实例表达方法以及实例库的建立,分析了如何利用最近邻居法和局部相似度在配合权值分配的情况下进行预应力加工实例的检索,阐述了现阶段预应力切削加工实例重用后的修改方法,以及人工干预修改方法采用上的优点与不足。4.在研究了预应力切削加工的整体结构以及实例库的建立细节后,经过开发语言和数据库管理系统的选取,开发了预应力切削加工的人机交互界面,实现了用户进行预应力工艺查询、有限元模拟数据查询和离散元模拟数据查询,同时设计了管理员界面,使其能够进行用户管理及预应力加工工艺实例、有限元模拟数据实例和离散元模拟数据实例的添加,使数据库系统实例能通过管理员的添加实现主动增长。
[Abstract]:Pre-stress machining is a kind of high-efficiency machining method which can control the residual stress of workpiece surface by prestressing before cutting. The machining of high-strength alloys, especially superalloys, is receiving more and more attention. Compared with other methods to improve surface residual stress of workpiece, prestress cutting method has the advantages of simple process, saving time and cost, and no additional surface hardening after machining, but all the time, The machining quality of high strength alloy is unstable due to the lack of professional process database. Based on the understanding of the pre-stress processing method and the needs of the users of the database system, a pre-stress turning process database system is established for the turning of high-strength alloys, and the experimental data of pre-stress turning of high-strength alloys are put forward in this paper. The finite element simulation data and the discrete meta-simulation data are combined and the data can be transferred to the user on the basis of the user's demand through the method of case-based reasoning. In the process of establishing the database system of prestressed turning process, this paper mainly describes the following question: 1. 1. The whole design of the database system of pre-stressed turning process is studied. The frame structure of the whole system is obtained by studying the data structure of pre-stress cutting and analyzing the needs of users. Design model of system parameters and function of system. 2. 2. The reasoning method based on Case-based reasoning (CBR) is used to study the process of case retrieval using nearest neighbor method and local similarity calculation. The case modification and case preservation after case reuse are described. The function of self-learning of prestressing cutting database system is realized. 3. In this paper, the reasoning flow of the database system of prestressing cutting process, the method of case representation of prestress knowledge and the establishment of case library are studied. This paper analyzes how to use the nearest neighbor method and the local similarity to retrieve the pre-stressed machining cases under the condition of matching the weight distribution, and expounds the modified method of reusing the pre-stressed machining cases at the present stage. And the advantages and disadvantages of artificial intervention modification method. 4. After studying the whole structure of prestress cutting and the details of the establishment of case library, the man-machine interface of prestressed cutting is developed through the selection of development language and database management system. The prestressing process query, finite element simulation data query and discrete meta-simulation data query are realized. At the same time, the administrator interface is designed to enable the user to manage and prestress process examples. The addition of finite element simulation data instances and discrete meta-simulation data instances enables the database system instances to grow actively through the addition of administrators.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG51;TP311.13

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