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板料卷圆回弹分析及数值模拟 总被引:2,自引:1,他引:1
回弹是板料冲压成形中普遍存在的现象,它的存在影响了零件成形的质量.本文探讨了板料弯曲回弹产生的力学机理及回弹产生的原因;分析了有限元方法计算回弹的特点;采用显示和隐式相结合的方法模拟了板料卷圆的成形及回弹过程;实现了对板料卷圆回弹的预测.通过调整有限元方法的计算参数,提高了模拟回弹的精度. 相似文献
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铟镍合金用于核燃料组件中定位格架特种条带的制造。针对铟镍合金材料价格昂贵、厚度较薄以及特种条带本身窄长等特点,利用CAE软件模拟冲压成形过程,快速预测冲制过程中条带的回弹、破裂、起皱等变化,为条带冲制用模具的设计提供参考依据。首先研究材料冲压特性;然后分析条带特征,确定冲制工艺方案;最后进行条带冲压成形有限元仿真分析,根据仿真结果优化模具的结构设计。结果表明:厚度为0.2667 mm的铟镍合金料带的冲压适应性较好,仿真冲压件模型没有破裂和起皱的趋势,条带刚凸高度回弹量较大,经过回弹补偿后,最终成形高度接近公称尺寸。依据CAE分析结果优化设计出的模具调试情况良好,能够满足特种条带的冲制加工。 相似文献
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Part 1 of this two-part paper presents the laboratory experiments on straight flanging, in which the influence of process variables, such as die shoulder radius, punch-die clearance, punch nose radius, pad force and material properties were discussed. This second part summarizes the FEM predictions for flanging and compares these results with some experimental data. Furthermore, flanging with coining to reduce springback has been investigated and evaluated by FEM for better dimensional control in flanging and hemming processes. 相似文献
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Sergey F. Golovashchenko Alan J. Gillard Alexander V. Mamutov Ramy Ibrahim 《Journal of Materials Processing Technology》2014,214(11):2796-2810
Electrohydraulic calibration (EHC) of springback is a novel method of removing springback from stamped sheet metal panels and is based upon the electro-hydraulic effect: a complex phenomenon related to the discharge of high voltage electrical current through a liquid. The EHC process involves clamping a stamped panel against a female die with the desired part shape and then applying several pulses of pressure onto and through the thickness of the sheet, in a process somewhat similar to conventional coining operations. However, in EHC the pressure is applied by a fluid and through the use of the electrohydraulic effect, and not with a matching hard tool as done in coining. In EHC, electrical energy is stored in a bank of capacitors and is converted into kinetic energy within the liquid by rapidly discharging the stored energy across a pair of electrodes submerged in a fluid. The objective of this paper is to describe the newly developed EHC process, to report the results of early proof-of-concept experiments, to present the results of more advanced experiments using a more industrial tool and actual part geometry, and to describe how numerical modeling techniques were used to optimize the design of the larger and more industrial tool. The developed concept of electrohydraulic stress relieving calibration is based upon clamping a stamped panel to the calibration die surface with the target shape and then applying pulses of pressure to eliminate internal stresses in the stamped panel. When a stamped blank is removed from a forming die, allowed to springback, and then clamped to a calibration die, the internal elastic stresses within the panel in such a configuration serve as a memory of the shape of the blank after springback, and it is these residual stresses that EH calibration is intended to remove from the panel. The developed concept of stress relieving calibration was initially validated by a simple experiment consisting of submerging a bent strip of aluminum into the fluid within an EH chamber, so that both the outer and inner surfaces of the strip (where the internal stresses from bending are located) were exposed to the fluid and the pressure pulse. This experiment served as an initial confirmation that impact with the tool is not necessary to achieve the calibration effect. The sheet metal materials used in this study, and for which springback was eliminated after forming, include DP 980 at 1.0 mm and 1.4 mm thick, and also DP600 at 1.0 mm thick. 相似文献
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等效拉延筋模型是影响回弹预测结果的一个重要因素。结合拉延筋试验、拉延筋试验的仿真以及拉深的仿真,研究了等效拉延筋模型对回弹预测结果的影响。结果显示,板料经过拉延筋后,出现材料硬化、变薄,并且有因横截面应力形成的力矩;仿真中采用等效拉延筋模型时,对板料经过拉延筋后出现的这些现象都不能准确地模拟。板料的硬化、在板料横截面的力矩,对工件的回弹预测结果影响显著。板料的横截面力矩的准确描述,对回弹预测的精度尤其重要。为了提高回弹的预测精度,有必要提出修正的等效拉延筋模型。 相似文献
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模面几何修正的回弹补偿方向分析 总被引:3,自引:0,他引:3
精确回弹预测的目的是通过数值回弹模拟来修正模面,使得回弹后零件与设计的产品一致,因此,在回弹预测的基础上进行基于数值模拟或逆向工程的模面补偿和工艺调整,甚至修改成形方案和模具结构,仍然是当前降低回弹的主要措施。文章对模面几何补偿方法进行了阐述,对其应用特点、精度和效率进行了系统的对比分析,结果表明,在以转动为主导回弹的情况下,法向补偿具有很高的精度,但运行计算时间较长;在回弹存在大平移的情况下,连线方向补偿则精度较高,且算法简单;而Z向反向补偿法虽然具有算法简单、计算效率高的优点,却不能很好地对模面进行修正。 相似文献
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本文对径向挤压成形的汽轮机静叶片进行了精压工艺研究。设计、制作了一套热精压模具、进行了工艺试验,精压后的零件达到了预期的要求。 相似文献
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