曲面零件单点渐进成形刀具轨迹优化及数值模拟

发布时间：2018-01-10 00:04

本文关键词：曲面零件单点渐进成形刀具轨迹优化及数值模拟　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：板料数控单点渐进成形是一种先进的塑性成形技术,该技术早在上世纪90年代就被有关学者提出,但至今为止仍没有大规模的应用于工业生产中,成形质量差是制约该技术发展的重要因素。曲面零件成形角度是不断变化的,采用传统固定增量步长方法单点渐进成形该类零件时,增量步长不能随着成形角度的变化调整大小,零件存在表面质量差、平缓区域成形不充分、成形精度差、成形效率低等问题,因此传统固定增量步长方法并不适合加工曲面零件。本课题主要针对曲面零件单点渐进成形质量问题展开研究,提出两种刀具轨迹优化方法,即基于增量角度Δθ的优化方法和基于增量弧长S_0的优化方法,试验验证两种优化方法可行性,基于有限元软件ANSYS/Workbench显式动力学数值模拟曲面零件单点渐进成形过程,探讨不同成形参数对曲面零件单点渐进成形性能的影响规律。主要工作内容如下:1)总结归纳曲面零件单点渐进成形主要成形缺陷及其原因,发现这些成形缺陷都与增量步长Δz有关。2)试验结果表明:与传统成形方法相比,加工层数相同时,两种优化方法不仅能有效改善曲面零件单点渐进成形质量还能显著提高零件成形效率。3)模拟结果表明:优化方法能改善曲面零件平缓表面处壁厚减薄现象,Δθ或S_0越小,改善越明显;优化方法能明显提高曲面零件平缓表面处成形精度,平缓表面处成形精度跟Δθ或S_0取值大小关系不大;优化方法能改变零件应力分布,提高板件成形应变,但无论Δθ或S_0取何值板料最大应变值趋于一致。
[Abstract]:NC single point incremental forming of sheet metal is an advanced plastic forming technology, which was put forward by relevant scholars as early as -10s, but it has not been applied in industrial production on a large scale so far. The forming quality difference is an important factor that restricts the development of the technology. The angle of curved surface parts is constantly changing, when the traditional fixed increment step method is used to form this kind of parts at single point gradually. The incremental step can not be adjusted with the change of the forming angle, the surface quality of the parts is poor, the forming area is not sufficient, the forming accuracy is poor, the forming efficiency is low, and so on. Therefore, the traditional fixed incremental step method is not suitable for machining curved surface parts. This paper mainly focuses on the quality of single point incremental forming of curved surface parts, and proposes two kinds of tool path optimization methods. The optimization method based on increment angle 螖胃 and the optimization method based on incremental arc length S0 are used to verify the feasibility of the two optimization methods. Based on the finite element software ANSYS/Workbench explicit dynamic numerical simulation of curved surface parts single point incremental forming process. This paper discusses the influence of different forming parameters on the single point incremental forming performance of curved surface parts. The main work is as follows: 1) summarize the main forming defects and their causes of single point progressive forming of curved surface parts. It is found that these forming defects are related to the increment step 螖 z. 2) the experimental results show that: compared with the traditional forming method, the number of layers is the same. The simulation results show that the two optimization methods can not only improve the quality of single point progressive forming of curved parts but also improve the forming efficiency of the parts. The simulation results show that the optimization method can improve the thinning of the smooth surface of curved parts. The smaller 螖胃 or S0 is, the more obvious the improvement is. The optimization method can obviously improve the forming accuracy of the flat surface of the curved surface, and the forming accuracy of the flat surface has little to do with the value of 螖胃 or S0. The optimization method can change the stress distribution of the parts and increase the forming strain, but the maximum strain value of sheet metal tends to be the same no matter what value 螖胃 or S0 takes.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG306

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