复杂零件的3D打印实现技术研究

发布时间：2018-04-12 13:03

本文选题：3D打印 + 分层　；参考：《兰州理工大学》2017年硕士论文

【摘要】：3D打印技术从20世纪80年代开始兴起到目前为止已经历了三十多年的发展,形成了几十种工艺方法。能够打印结构极为复杂的零件,打印精度也在快速提高,但由于打印材料、打印时间、打印成本等诸多因素,所以目前依旧制约着3D打印技术的普及和深入发展。本文从提高精度、节约材料、降低成本的目的出发,利用现有资源,将复杂曲面零件(以曲面无线鼠标为例)从设计到打印出实物,对其中各环节关键技术进行分析,以提高打印精度和打印效率。首先,利用Solidworks软件设计鼠标三维模型,经干涉检查后转换为3D打印技术中普遍采用的STL文件格式。针对STL容易出现的裂缝、孔洞、数据冗余、逆向法向量等错误,利用Netfabb软件进行修复,最终生成能够正常进行打印的STL模型文件。但在此过程中,原模型的尺寸数据和表面精度将发生改变。其次,在3D打印技术中,如何为模型选择正确的分层方向和分层厚度,是提高模型打印精度和打印效率的先决条件。以Meshmixer、Cura软件为例为鼠标模型自动添加树状支撑、分层并设置分层软件基本参数,最终将模型分层后的二维轮廓数据转化为3D打印机中打印头的运动轨迹。接着,通过ProJet 3510 HD型打印机对鼠标模型进行打印,发现在成型过程中成型件表面会出现凹陷等失真现象,导致打印失败。经过多次试验得出失败原因:在打印过程中材料会发生线性收缩和体积收缩。通过将鼠标模型抽壳优化,最终得到质量良好的曲面制件(鼠标打印件)。在此基础上,利用Metra-SCAN 750光学扫描仪通过对鼠标打印件表面轮廓的扫描以获取三维坐标点云数据,并将其导入到Geomagic Control中,与鼠标三维CAD模型对比进行质量检测,得到3D彩色偏差图及相关图表,对所产生的数据偏差进行说明并分析其原因。最后,利用有限元分析软件Solidworks Simulation对鼠标实体跌落碰撞过程进行动态模拟,设置相关模拟条件,以动画的形式把鼠标的跌落碰撞过程展现出来,得出跌落碰撞瞬间的试验数据,为今后鼠标结构的参数化改进提供帮助。
[Abstract]:The 3D printing technology has been developed for more than 30 years since it began to rise in the 1980s, and dozens of process methods have been formed.The printing accuracy of parts with extremely complicated structure can be improved rapidly. However, due to many factors, such as printing materials, printing time, printing cost and so on, the popularization and further development of 3D printing technology are still restricted.In order to improve the precision, save the material and reduce the cost, using the existing resources, this paper analyzes the key technologies of the complex curved surface parts (taking the curved wireless mouse as an example) from the design to print out the object.To improve printing accuracy and printing efficiency.Firstly, the 3D mouse model is designed by using Solidworks software and converted into STL file format which is widely used in 3D printing technology after interference checking.Aiming at the errors such as cracks, holes, data redundancy, reverse normal vector and so on, which are easy to appear in STL, the Netfabb software is used to repair the errors, and finally the STL model file which can be printed normally is generated.However, the size data and surface accuracy of the original model will change in the process.Secondly, in 3D printing technology, how to choose the correct delamination direction and delamination thickness for the model is the prerequisite to improve the printing accuracy and efficiency of the model.Taking Meshmixer Cura software as an example, the mouse model automatically adds tree support, delaminate and set the basic parameters of the layered software. Finally, the 2D contour data of the model after stratification is transformed into the movement track of the print head in the 3D printer.After many tests, the reasons of failure are obtained: linear shrinkage and volume shrinkage will occur in the process of printing.By optimizing the mouse model, the surface parts with good quality can be obtained.The 3D color deviation map and related chart are obtained, the data deviation is explained and the reasons are analyzed.Finally, using the finite element analysis software Solidworks Simulation to carry on the dynamic simulation to the mouse entity drop collision process, sets the related simulation condition, displays the mouse drop collision process in the form of animation, obtains the test data of the drop collision moment.It is helpful to improve the parameterization of mouse structure in the future.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP391.73

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