基于Abaqus的铣削仿真前处理关键技术研究及二次开发

发布时间：2018-11-03 15:03

【摘要】：运用“单元生死”技术可以有效地解决物理仿真难以模拟工件实际加工过程的问题,但目前这种人力选择“单元生死”的方法还存在一些问题,如工作量巨大甚至难以胜任、无法精准地进行单元选择、物理仿真与几何仿真的结合性差等。本文通过对基于Abaqus“单元生死”技术的铣削仿真前处理关键技术的研究,如数控刀轨的离散化、刀具扫描体建模、网格单元干涉切除以及铣削力的加载等,实现了根据不同刀具形状和刀轨路径自动地、精准地设置“单元生死”和加载铣削力,将几何仿真与物理仿真有效地结合,大大提高了该仿真方法的准确性和实用性。本文完成的主要研究工作如下:(1)通过Python语言编程,读取UG数控铣削刀轨并进行离散化处理,结合六参数立铣刀模型,运用基于高斯映射的刀具扫描体建模原理,建立刀具扫描体微元集,有效地解决了物理仿真与几何仿真结合性差的问题。(2)运用奇偶判别法原理,计算得到刀具扫描体“切除”的工件网格集,并设置“生死单元”;根据刀轨路径,计算铣削力在X、Y、Z三个方向上的分力,并将其加载到对应网格的节点上,从而模拟铣削过程中铣削力对工件的作用。(3)基于上述前处理关键技术的研究,针对三轴铣削加工仿真,开发Abaqus前处理插件,使该插件适用于各种工件、刀具和铣削刀轨的三轴铣削仿真中。(4)运用插件对具有代表性的薄壁件铣削加工仿真进行前处理,并进行Abaqus仿真、薄壁件实际加工和测量,通过比较仿真变形结果与实际加工变形结果,从而验证前处理关键技术和前处理插件的正确性。
[Abstract]:The application of "unit life and death" technology can effectively solve the problem that physical simulation is difficult to simulate the actual processing process of workpiece. However, there are still some problems in this method of manpower choosing "unit life and death", such as heavy workload or even incompetence. The unit selection can not be carried out accurately, and the combination of physical simulation and geometric simulation is poor. In this paper, the key technologies of milling simulation pre-processing based on Abaqus "Unit birth and death" technology are studied, such as the discretization of NC cutter tracks, tool scanning volume modeling, mesh element interference removal and milling force loading, etc. According to different tool shape and path of tool path, automatic setting of "unit life and death" and loading milling force is realized. The geometric simulation and physical simulation are effectively combined, which greatly improves the accuracy and practicability of the simulation method. The main work of this paper is as follows: (1) through Python language programming, read UG NC milling tool track and discrete processing, combined with six-parameter end milling cutter model, using the principle of tool scanning volume modeling based on Gao Si mapping. The problem of poor combination of physical simulation and geometric simulation is effectively solved by establishing tool scanning volume micro-element set. (2) the workpiece grid set of tool scanning volume "excision" is calculated by using the principle of odd-even discriminant method, and the "life and death unit" is set up. According to the path of the cutter path, the milling force is calculated in three directions, and loaded on the node of the corresponding mesh. In order to simulate the effect of milling force on workpiece in milling process. (3) based on the research of the key technology of pre-processing, the Abaqus pre-processing plug-in is developed for three-axis milling simulation, which makes it suitable for all kinds of workpieces. In the three-axis milling simulation of cutting tools and milling tool tracks. (4) preprocessing the typical thin-walled milling simulation by using plug-in, and carry out Abaqus simulation, practical machining and measurement of thin-walled parts, By comparing the simulation results with the actual deformation results, the correctness of the pre-processing key technology and pre-processing plug-in is verified.
【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】：2017
【分类号】：TG547

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