圆环镦粗分流面变化规律的研究

发布时间：2018-04-27 13:24

本文选题：圆环镦粗 + 分流面　；参考：《武汉理工大学》2015年硕士论文

【摘要】：在塑性体积成形中,金属流动规律的研究是当今最受人关注的问题之一。金属的流动决定了体积分配和成形后的工件形状,在成形过程中如何准确的控制金属流动,这对塑性体积成形工艺的成功与否起到关键性的作用。然而分流面是金属成形过程中体积分配的重要依据,实际工艺中经常需要对分流面进行控制以达到成形合格零件的要求。圆环是研究分流面理想的研究对象,计算机模拟技术的不断发展对研究分流面提供了很大的帮助——目前的研究只是对分流这一现象进行了说明,但对分流面的变化规律和内在特征并没有深入的分析和总结。本文拟通过数值模拟与理论计算相结合,对圆环镦粗成形过程中分流面的变化规律和内在力学特征予以研究,并指导环形件成形。通过对圆环镦粗变形规律进行探究,分析圆环与模具间的摩擦因子m、圆环变形程度(压下量ε)、圆环初始尺寸(形状因子λ)及圆环内外侧压力p四个因素对圆环镦粗变形分流面形状和位置的影响,由此得出分流面两边的体积分布规律,间接的反映了金属的流动规律和模式。通过进一步分析不同尺寸的初始圆环,得出了三种模式下的分流面(实体外、与内径重合、在实体内)和与之对应的摩擦因子和压下量的范围以及相应的临界值,并推导出两者的对应关系。通过理论方法和数值模拟结合证明了分流面与罗德参数值为0的面重合,由此可建立应力应变特征量及变形类型与分流面的关系。并以圆环镦粗为研究对象进一步揭示了分流面及两侧区域的应力应变分布特征,与此同时分析了侧压力对圆环镦粗变形应力应变及分流面的影响,由此可以深入了解圆环镦粗变形分流面变化和金属流动规律。最后,以某一类典型环形件进行说明,结合圆环镦粗变形金属流动规律,详细的说明了环形件成形过程中不同摩擦条件和初始圆环尺寸对金属流动模式的影响。通过分析从中得出了合理的金属流动路径,并以变形功和最大变形载荷值为优化目标,得出最合理的摩擦条件和初始圆环坯料尺寸,由此总结出相应环形件成形的一些规律。
[Abstract]:The study of metal flow law is one of the most concerned problems in plastic volume forming. The flow of metal determines the volume distribution and the shape of the workpiece after forming. How to control the flow of metal accurately in the forming process plays a key role in the success of the plastic bulk forming process. However, the shunt surface is an important basis for the volume distribution in the forming process. In order to meet the requirements of forming qualified parts, it is often necessary to control the shunt surface in the actual process. The circle is an ideal research object for studying the distributary surface. The continuous development of computer simulation technology has provided a great help to the study of the distributary surface. However, there is no in-depth analysis and summary of the variation law and internal characteristics of the distributary surface. In this paper, through the combination of numerical simulation and theoretical calculation, the variation law and internal mechanical characteristics of the shunt surface in the forming process of ring upsetting are studied, and the forming of annular parts is guided. By exploring the deformation law of ring upsetting, The effects of friction factor m between ring and die, ring deformation degree (reduction 蔚), ring initial size (shape factor 位) and pressure p inside and outside of ring on the shape and position of diversion surface of ring upsetting deformation are analyzed. The volume distribution on both sides of the distributary surface is obtained, which indirectly reflects the flow law and mode of metal. Through further analysis of the initial rings of different sizes, the distribution surface (outside of the entity, coincidence with the inner diameter, inside the entity) and the corresponding range of friction factor and reduction amount and the corresponding critical values are obtained in three different modes. The corresponding relationship between them is deduced. By combining theoretical method and numerical simulation, it is proved that the split-flow surface overlaps with the plane with Luo De parameter value 0, and the relationship between the stress-strain characteristic quantity and the deformation type and the distributary surface can be established. Furthermore, the characteristics of stress and strain distribution on the split surface and its two sides are revealed, and the influence of the lateral pressure on the stress strain and the flow plane of the ring upsetting is analyzed. Thus, the variation of diversion surface and metal flow law of ring upsetting deformation can be deeply understood. Finally, the influence of different friction conditions and initial ring size on the metal flow mode during the forming process of annular parts is explained in detail, which is explained by some typical annular parts and combined with the metal flow law of ring upsetting deformation. The reasonable metal flow path is obtained from the analysis, and the most reasonable friction conditions and initial ring blank size are obtained by taking the deformation work and the maximum deformation load value as the optimization objectives, and some rules for the forming of the corresponding annular parts are summarized.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG316.11

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