共查询到15条相似文献,搜索用时 62 毫秒
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本文针对马鞍面的力-位移分控多点成形的回弹进行了研究.采用数值模拟的方法,对不同曲率半径和不同板厚的鞍形面进行了成形过程的模拟和卸载回弹分析.结果表明,曲率半径越大,该方向的回弹越大;板厚越大,两个方向的回弹都变小,且起主导作用的方向对另一方向的影响越小. 相似文献
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圆柱面力—位移分控多点成形的数值模拟研究 总被引:1,自引:0,他引:1
针对多点成形厚向约束不足易产生成形缺陷的现状,论文研究了无模多点成形中提高成形质量的一种新的成形方法,提出了力—位移分控的多点成形模式.讨论了力—位移分控多点成形模式下提高成形质量的机理,给出了实现力—位移分控多点成形的方法.采用数值模拟的方法,对不同曲率半径、板厚、成形力条件下的柱面件成形过程及回弹进行了分析研究.结... 相似文献
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鞍面力-位移分控多点成形起皱的数值模拟研究 总被引:1,自引:0,他引:1
在多点成形中,起皱是影响板材成形质量的重要因素。针对鞍面在力-位移分控多点成形方式下的起皱,以ABAQUS为模拟分析平台,模拟了鞍面的成形过程,并分析了其起皱缺陷。研究结果表明:在鞍面力-位移分控多点成形过程中,当板厚较小(1和1.5 mm)时,板材中心区域发生了较为严重的起皱,且优先变形的方向发生的起皱现象更明显;随着板厚和曲率半径的增大,起皱趋势减小。针对起皱现象探明了起皱的原因,提出了鞍面起皱的抑制方法,并进行了模拟计算和成形试验,结果表明,增大成形力和错位都可以抑制起皱,错位并结合增大成形力可以显著改善板材成形质量。 相似文献
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压痕是板材多点成形中特有的成形缺陷,是多点成形必须解决的问题.通过ANSYS软件对板材进行球形面的多点成形仿真分析,并针对分析的结果提出了抑制压痕的方法,进一步数值模拟说明了一定厚度的弹性垫技术消除压痕缺陷的有效性. 相似文献
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基本体群成形面曲面造型是多点成形数值模拟中的关键问题之一。本文给出了基本体群成形面造型方法,并开发了相关程序。在此基础上,对多点成形中球面件的起皱缺陷及马鞍面的成形力进行了数值分析。 相似文献
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Q. Zhang T.A. Dean Z.R. Wang 《International Journal of Machine Tools and Manufacture》2006,46(7-8):699-707
Multi-Point Sandwich Forming (MPSF) is a new flexible forming technology. In this process, one half of a conventional die set is substituted by a discrete die with wide spaced pins plus deformable die sheet and a polyurethane upper die is used as the other half. FE simulation using this tool design reveals the effect of the shape of the upper die on workpiece deformation and the role played by the deformable interpolator and die sheet. It is shown that the deformed shape is a result not only of the reconfigurable die shape, but of the elastic die shape and elastic interpolator stiffness also. Using an interpolator enables smooth workpiece surfaces to be obtained, even when the die sheet is dimpled by the pins of the reconfigurable die. 相似文献
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Xue-peng Gong Ming-zhe LiQi-peng Lu Zhong-qi Peng 《Journal of Materials Processing Technology》2012,212(1):227-236
In order to realize high efficient and flexible manufacturing for 3-D surface, continuous multi-point forming (CMPF) is researched. Firstly, principle of CMPF is described, and its characteristics are analyzed by comparing with the conventional spinning methods. Secondly, FEA model of CMPF for disc-shape surface is established, forming load is analyzed theoretically, equivalent stress and plastic strain distributions of disc-shape surface are analyzed. Thirdly, wrinkling is analyzed through simulation results. Fourthly, forming process of tube-shape surface is studied. Finally, CMPF equipment is developed, and experiments are carried out. Results indicate: For disc-shape surface, equivalent stress in regions of center fixture and flexible roller exceeds yield stress; the maximum plastic strain is generated in center region; plastic strain in region of flexible roller takes the second place; shell elements in wrinkling region generate tangent direction compress deformation. For tube-shape surface, maximum value of equivalent stress appears in region of flexible roller; plastic strain field presents annular distribution, its maximum value appears in marginal region. Measure results of curvature radius of disc-shape surface and tube-shape surface almost accord with simulation results. Simulation results of stress field, strain field and wrinkling almost accord with practical situation. 相似文献
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Linfa Peng Xinmin Lai Mingzhe Li 《International Journal of Machine Tools and Manufacture》2006,46(12-13):1336-1342
During the last decades, the manufacturing mode and level of industry have been improving from mass production manufacturing to responsive and flexible manufacturing. Multi-point forming (MPF) is a flexible manufacturing technique, which is made up of a set of adjustable base elements controlled by MPF-CAD/CAM software. It uses discrete punches to express a continuous 3-D surface, by which the workpiece's surface under manufacturing is formed. With respect to the characteristics of MPF, two methods for NURBS surface extension are presented in this paper to design the blending surface between the surfaces of the blank holder and the workpiece. Two design approaches of transition surface are proposed: one is a flexible surface extension, and the other is a bridge surface extension. These two algorithms, through which the transition surface designed can reach G2 continuity, are both effective and reliable. Applications show that high-quality products are manufactured in MPF by this transition surface design. 相似文献
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板料冲压成形回弹的有限元数值模拟研究 总被引:10,自引:4,他引:6
随着对冲压件的尺寸精度要求的不断提高,精确预测给定冲压件的回弹量大小及分布显得非常重要。采用无模法模拟卸载回弹过程时,需要以加载成形后的应力为基础。本文给出了加载成形中的应力计算方法,并采用无模法建立了卸载回弹的计算模型。文中提出一种不同于传统的初始单元弹性化处理的方法,提高了回弹的计算精度。研究了卸载因子的取值规律对回弹计算的影响。利用自行开发的软件SheetForm模拟分析NUMISHEET’93标准考题中U型件深冲压的回弹情况,验证了该方法的有效性。 相似文献
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以盒形件多点成形过程为例,从拉深形状、板厚、材质等方面进行比较,针对多点成形过程中最主要的缺陷之一—压痕现象的产生原因及其抑制方法进行了数值模拟研究,并进行了实验验证。 相似文献