网孔板渐进成形性能研究

发布时间：2018-11-22 07:39

【摘要】：板料渐进成形技术作为一种柔性制造技术,相关研究已经取得长足的进展,但是网孔板渐进成形工艺目前尚处于初始研究阶段。随着网孔板广泛应用,深入研究网孔板渐进成形性能,对于发展新型网孔板成形工艺和扩大渐进成形应用领域均具有较好的推动作用。本文分别采用连续接触式渐进成形工艺和锤击式渐进成形工艺成形网孔板,这两种成形方式均是基于板料渐进成形技术的柔性制造加工工艺,通过实验和数值模拟对网孔板渐进成形性能相关的基础性问题展开研究。通过定角度锥杯实验验证了网孔板渐进成形的可行性,结果表明:两种渐进成形中,网孔板变形区域圆孔均变成椭圆孔;相对于锤击式渐进成形,连续接触式渐进成形网孔板成形角度相对较大,网孔变形相对较小。通过网孔板渐进成形数值模拟,结果表明:两种渐进成形中,网孔板变形均属于平面应变,且成形区域圆孔均变成椭圆孔,与实验相一致;板料厚度变化均遵循正弦定理;相对锤击式渐进成形,连续接触式渐进成形网孔板主应变波动范围、厚度和减薄率波动范围都较小;而锤击式渐进成形中,网孔板米塞斯等效应力波动范围较小,且成形力也较小。基于数值模拟,采用CockcroftLatham准则对网孔板渐进成形破裂失效进行预测,结果表明:网孔板锤击式渐进成形破裂失效判定结果与实验结果相符,而连续接触式渐进成形判定结果有一定的误差。此外,还通过实验和数值模拟研究了工艺参数对网孔板成形性能的影响。结果表明:连续接触式渐进成形中,网孔板随着层进给量的增加,成形极限角减小,而工具头直径和进给速度对成形极限角度影响不大;锤击式渐进成形中,当网孔板圆孔直径不变,增加圆孔中心距尺寸,成形极限角度并不增加,且保持网孔板圆孔中心距不变,相应的增加网孔直径时,成形极限角度增加。此外,随着成形深度的增加,连续接触式渐进成形区域的网孔变形均是先增加后减小,且随着层进给量和进给速度的增加而整体变形相对增加。
[Abstract]:As a kind of flexible manufacturing technology, sheet metal incremental forming technology has made great progress, but the mesh plate incremental forming process is still in the initial stage. With the wide application of the mesh plate, the research on the progressive forming performance of the mesh plate has a good role in promoting the development of the new mesh plate forming process and expanding the application field of the incremental forming process. In this paper, continuous contact incremental forming process and hammer progressive forming process are used to form mesh plate, both of which are flexible manufacturing processes based on sheet metal incremental forming technology. The basic problems related to the progressive forming properties of mesh plate were studied by experiment and numerical simulation. The feasibility of mesh plate forming is verified by constant angle cone cup experiment. The results show that the circular holes in the deformation region of the mesh plate become elliptical holes in the two progressive forming processes. Compared with hammer progressive forming, the forming angle of continuous contact incremental forming mesh plate is relatively large, and the mesh deformation is relatively small. The numerical simulation results show that the deformation of mesh plate belongs to plane strain, and the circular hole in the forming region is elliptical hole, which is consistent with the experiment, and the thickness of sheet metal varies according to the sine theorem. Compared with hammer progressive forming, the main strain fluctuation range, thickness and thinning rate fluctuation range of continuous contact incremental forming mesh plate are smaller. However, the equivalent stress fluctuation range of mesh plate is smaller and the forming force is smaller. Based on numerical simulation, the failure prediction of progressive forming failure of mesh plate is carried out by using CockcroftLatham criterion. The results show that the failure judgment results of hammer progressive forming failure of mesh plate are in agreement with the experimental results. However, there is a certain error in the judging result of continuous contact incremental forming. In addition, the influence of process parameters on the formability of mesh plate was studied by experiment and numerical simulation. The results show that the forming limit angle decreases with the increase of the feed rate of the mesh plate, while the diameter of the tool head and the feed speed have little effect on the forming limit angle. When the diameter of the mesh plate is constant, the forming limit angle does not increase when the diameter of the mesh plate is constant, and the forming limit angle is not increased, and the forming limit angle is increased when the diameter of the mesh hole is increased accordingly. In addition, with the increase of the forming depth, the mesh deformation in the continuous contact progressive forming region increases first and then decreases, and the whole deformation increases relatively with the increase of the feed rate and the feed rate of the layer.
【学位授予单位】：青岛理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG306

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