文档介绍：摘 要
旋压技术已经广泛应用于回转体工件的加工,例如车轮、灯罩、导弹外壳等。在生产过程中坯料易产生拉裂、起皮、鼓包等工艺缺陷,因此对旋压成形机理和变形规律的研究成为亟待解决的关键问题。
本文建立了锥形件和车轮轮辐旋压成形的有限元模型,并采用ANSYS/LS-DYNA软件进行了数值模拟,结合实验研究了旋压变形机理,分析了工艺参数对成形过程和工件质量的影响。
本文首先分析了旋压生产的工艺特点,基于塑性变形理论及有限元技术,采用 ANSYS/LS-DYNA建立了旋压成形有限元模型。在建模过程中对比了体网格和面网格的优劣,利用旋轮轴、数组和坐标运算,解决了接触、旋轮运动轨迹描述等多个关键问题, 并对运算过程中易出现的数据中断问题进行了调整。分别采取调整单元类型、增大变形体的刚度、增大部件之间的间隙等措施,改进了模拟中存在的负体积、穿透、网格畸变严重等问题。有限元模型的建立为之后对成形规律和工艺参数的研究奠定了基础。
基于有限元模型,分别分析了锥形件和车轮轮辐旋压成形的变形特征和应力应变规律,并分析了工艺参数对旋压成形的影响。在锥形件旋压成形过程中,分析了应力应变对坯料中心孔及整体成形精度的影响、坯料内外表面应变差异;同时也分析了进给率、偏离率等工艺参数对应力应变及工件成形质量的影响,解释了起皮、拉裂等缺陷的产生原因。在车轮轮辐成形过程中,获得了应力应变的分布,分析了旋轮圆角半径、旋轮安装角和主轴转速等工艺参数对应力应变、壁厚及壁厚减薄率的影响,预测了过度减薄和开裂等缺陷易产生的位置。
最后根据模拟结果进行了实验验证,利用优化后的工艺参数,得到了质量良好的工
件。
关键词:旋压成形,锥形件,车轮轮辐,ANSYS/LS-DYNA,数值模拟
ABSTRACT
Spinning technology has been used widely in the machining process of axia lly symmetrica l workpiece, such as wheels, la mpshade s, missile shells, etc. Some process defects easily appeared in the product ion , such as cracking, peeling, bulging. So the research of forming mecha nism and deformation regularities e to a key problem urgently to be solved.
The finite element model of the spinning process for cone parts and wheel spokes were established . ANSYS/LS-DYNA was used to carry out numer ica l simulation. Combined with the exper iment, spinning deformation mecha nism was researched . The influence of process parameters to the forming process and workpiece quality was analyzed.
Spinning process feature s was analyzed first ly. Based on plast ic deformation theor y and finite element technology, finite element model of spinning forming was established using ANSYS/LS-DYNA. Volume mesh and area mesh pared in modeling. Some key problems, such as contact and path of the roller, were solved by using axle of the roller, array and coordinate operations. Data interruption puting was adjusted. Some measures, such as adjust ing element type, increasing the stiffness of deformable objects and gap of parts, were adopted to improve problems lik