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基于韧性准则的金属板料冲压成形断裂模拟 总被引:2,自引:0,他引:2
该文基于Rice-Tracey韧性失效准则,探索金属板料冲压成形的断裂数值模拟方法。首先设计两种试验,并结合有限元分析结果确定双相钢板料的材料失效参数;然后,基于Abaqus软件的显式模块Explicit,编写采用Rice-Tracey韧性失效准则的用户自定义材料子程序VUMAT;最后对双相钢薄板深拉成形过程中的断裂行为进行数值模拟,并进行了试验验证。结果表明,数值模拟结果与试验结果吻合较好。可见,Rice-Tracey韧性准则可用于金属板料冲压成形的断裂预测。 相似文献
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金属板料塑性成形过程中局部厚度和力学属性将发生变化,进而影响成形结构的最终物理性能。针对双相钢DP590材料,以点焊连接闭口帽型薄壁结构为例,利用落锤冲击试验装置研究了冲压成形条件对结构轴向冲击变形行为的影响,并对该成形—冲击过程进行了数值模拟。试验结果表明:冲压成形构件冲击变形模式为非稳定的混合渐进—欧拉屈曲模式,且随成形压边力增加,构件冲击失稳现象加剧。相应仿真过程发现,引入冲压成形历史信息后,冲击仿真可较为真实地复现物理测试结果,为确保前期冲压成形仿真结果的可靠性,宜采用能够反应三维应力状态的七参数壳单元。 相似文献
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研究渐进成形过程中板料减薄带的变化,可以提供合理的加工参数,提高板料的成形性能和加工利用率,减少零件破裂失效.基于渐进成形过程中金属板料轮廓的变化与理想情况下轮廓的区别,对渐进成形初始成形阶段A3003铝板减薄带的产生原因和剪切力的变化过程进行了理论分析,并通过有限元模拟分别从未变形区金属板料的长度和强度两个角度对板料渐进成形过程中未变形区下沉的影响,以及成形角度和杨氏模量对变形区回弹的影响两个方面,对减薄带的产生原因进行研究.结果表明:板料未变形区的下沉和变形区的回弹使板料在初始加工阶段形成一段平缓区域,工具头在平缓区域的变形性质发生了变化,平缓区域发生剪切变形导致了板料在初始加工阶段形成了减薄带;渐进成形时减小板料未变形区的长度,增大板料与垂直方向的角度可以一定程度上阻碍减薄带的产生,模拟结果与理论分析相符合. 相似文献
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在工业化水平日新月异的今天,对零件成形精度的要求越来越高,随着高强度金属板与合金板在许多行业领域里的广泛使用,使得由这些材料进行冲压成形的零件相对于传统的普通低碳钢板材零件,生产过程中的回弹问题比较突出,本文对市场上常用的弯曲回弹分析软件进行比较,分析优缺点,以期对相关工作者有所帮助。 相似文献
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目的研究热冲压过程中板料的温度变化及相变情况。方法采用Abaqus软件建立了热力耦合模型,对U形件热冲压成形及冷却淬火过程进行了数值模拟,分析了板料及模具的温度分布变化,并研究了板料不同区域的冷却速率,最后进行了热冲压试验。结果研究结果表明,板料经冷却淬火后,温度分布均匀,且冷却速率均大于临界冷却速率,板料可以发生完全马氏体相变。结论板料的底部冷却速率最快,淬火后为分布均匀的、细小的马氏体组织,最终通过热冲压试验验证了模拟结果的准确性。 相似文献
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采用了ANSYS有限元分析软件对圆锥形薄壁件成形过程进行了数值模拟,分析了冲压过程中两类失效形式产生的原因,并提出了相应的解决办法. 相似文献
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论述了椭圆花样冲压件的有限元模拟主要步骤,以椭圆花样冲压件为研究背景,采用Autoform软件对零件进行了冲压成形过程的有限元分析,完成了相关数值模拟,预测了板料成形过程中的缺陷,根据仿真结果对工艺方案再次CAE仿真优化,证明了前期数值分析对模具设计周期及成形质量具有重要意义。 相似文献
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SU Xiao-ping XU Lian School of Mechanical Power Engineering Nanjing University of Technology Nanjing P.R.China 《国际设备工程与管理》2008,13(3)
We point out that the finite element method offers a great functional improvement for analyzing the stamp forming process of an automobile panel. Using the finite element theory and the simulation method of sheet stamping forming, the element model of sheet forming is built based on software HyperMesh,and the simulation of the product′s sheet forming process is analyzed based on software Dynaform. A series of simulation results are obtained. It is clear that the simulation results from the theoretical basis... 相似文献
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Hydroforming is a manufacturing process that uses a fluid medium to form a component by using high internal pressure. Tube and sheet hydroforming has gained increasing interest in the automotive and aerospace industries because of its many advantages such as part consolidation, good quality of the formed parts etc. The main advantage is that the uniform pressure can be transferred to every where at the same time. Forming limit is the limit of the component up to that extent it can be formed safely. While analyzing hydroforming process, it is often assumed that the limit strains are identical as that of stamped sheet metal of equivalent material properties. It is not clear if such an assumption is valid. In this paper the forming limit strains during hydroforming is predicted. A series of tube bulge tests for tube hydroforming and limiting dome height test for sheet hydroforming and sheet stamping processes are simulated by a commercial finite element solver to predict the limit strains. Numerical simulation of forming limit strains in tube hydroforming with different internal pressure and different simulation set up with or without axial feeding, while in sheet hydroforming and sheet stamping, by changing the specimen geometry are considered to develop wide range of strain paths in the present work. The effects of process conditions on the forming limit strains are detailed. The comparison of limits strains during hydroforming and stamping processes is presented. Prediction of limits strains is based on a novel thickness based necking criterion. 相似文献
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为降低热冲压凹模的生产成本和使用成本,基于板料热冲压数值模拟对凹模结构进行了拓扑优化设计.运用有限元软件ABAQUS建立热力耦合有限元模型,对高强钢板U形件的热冲压成形和淬火过程进行了数值仿真.提取凹模与板料间关键工况下接触应力作为凹模拓扑优化的外在载荷,建立约束凹模结构关键区域节点位移的体积最小化拓扑模型,对热冲压凹模结构进行拓扑优化设计,最终实现结构减重20%,且优化后凹模的变形和应力与优化前的结果相差甚微.研究内容对热冲压过程数值模拟和模具结构拓扑优化研究具有一定参考价值. 相似文献
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目的研究复杂钣金零件充液拉深的成形性能,以代替传统的落压成形工艺。方法采用有限元方法对成形过程进行模拟,分析各工艺参数对零件成形质量的影响,以及起皱、破裂等缺陷出现的原因和避免方法,并获得合理的工艺参数范围。以仿真结果为依据,设置工艺试验的初始参数,对该复杂钣金零件进行充液成形试验,以验证工艺可行性。结果有限元仿真对成形过程中的起皱和破裂缺陷预测准确,并给出了可行的工艺参数范围;通过成形试验,验证了工艺参数的合理性,获得了合格零件。结论充液拉深工艺可以明显改进零件的成形性能,反胀压力、最大液室压力等是充液拉深工艺的重要参数,直接影响着充液拉深过程的成败。 相似文献
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This study examined the cooling channel design of hot stamping tools to provide an effective method for the cooling system design. A flat plate tool model was investigated to determine the effects of cooling channel and manufacturing parameters on the cooling rate and cooling uniformity of the sheet blank by conducting finite element analysis. The fractional factor method was also employed to establish empirical equations for describing the cooling performance of the flat plate model. The empirical equations established in the present study can efficiently predict the cooling rate and cooling uniformity of sheet blanks with various cooling channel designs, and are of much help in providing an initial cooling system design for hot stamping tools. To validate the accuracy of the finite element analysis, experiments on sheet blank cooling process were conducted using the proposed flat plate tool design. The cooling processes were cyclically repeated for the validation of blank temperature distribution. The temperature evolution of sheet blanks obtained from the finite element simulations agree well with the experimental results and the validity of the finite element model is confirmed, and thus the effectiveness of the empirical equations is established. 相似文献
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目的探究电流辅助高强钢板热成形工艺中坯料自阻加热的加热机理,揭示电一热一力三场耦合条件下金属板材的塑形变形规律,为工艺方案及工艺参数的制定提供理论依据。方法利用FEM软件对电流辅助高强钢板的热成形过程进行了数值模拟研究。结果获得了通电加热时坯料的温度场,并通过热一力耦合分析,得到了板材热成形时的应力及应变的分布规律。结论采用该加热方式可极大地提高加热速率,经过几十秒的加热即在变形坯料上获得了较均匀的温度场,满足板材热成形要求。应力、应变分析表明,加热时产生的压应力缓解了坯料变形时的应力集中,有助于板料塑性成形。 相似文献
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目的 解决冲压成形中工艺参数优化难的问题.方法 以一种深腔型零件的冲压成形为例.首先,借助灰度关联分析法对有限元中的工艺参数进行分析,获取该零件冲压成形中影响成形质量的2个主要因素——冲压速度和压边力.其次,借助拉丁超立方抽样法对上述2个因素进行随机取样,并借助DYNAFORM软件对其进行逐一模拟.再次,将冲压速度和压边力作为输入,最大减薄作为输出,训练在MATLAB中建立的BP神经网络,并借助遗传算法对其进行寻优.结果 最优成形压边力为1.372 MN,最优加载速度为1.5366 m/s.结论 与神经网络遗传算法预测相比,有限元结果的相对误差小于2%,零件试制结果的相对误差小于6%,该方法有较高的预测精度. 相似文献