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将拉延筋模型引入到板料成形动力显式有限元分析中,并以汽车前照灯矩形反光镜为应用实例,对其拉延成形过程进行了模拟。 相似文献
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M.R. Morovvati B. Mollaei-DarianiM.H. Asadian-Ardakani 《Journal of Materials Processing Technology》2010,210(13):1738-1747
In this paper, the wrinkling of two-layer (aluminum-stainless steel) sheets in the deep drawing process, is investigated through an analytical method, numerical simulations, and experiments. In a deep drawing process, wrinkling can always be eliminated with an increase in the blank holder force (BHF). Thus, the aim of this study is to obtain the minimum required BHF to prevent wrinkling. In the analytical model, energy method is used to predict the wrinkling. Also, FE simulations were performed to study the effect of forming parameters on wrinkling. Experiments have been conducted to verify the analytical model and FE simulations. The effects of parameters such as the material properties of aluminum layer and lay-up on BHF and forming force are investigated. Results demonstrate that the optimum BHF is dependent on the blank geometry, material properties and lay-up. It is shown that BHF is greater when aluminum is in contact with the punch. Results show a good agreement between analytical, FE, and experimental results. 相似文献
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与传统的轧制板材相比,采用高压板料成形工艺加工的柔性辊压板坯可以实现工件的优化生产,使其应用于各种特殊场合。本文通过有限元法实现了对柔性辊压板坯加工过程中两个主要阶段(柔性轧制和高压板料成形)的数值模拟与优化。优化过程包括对板料加工链和载荷条件下工件性能两方面的优化。数值模拟与试验结果的对比表明,有限元方法与优化工具的组合成功实现了整个加工链和工件性能的数值模拟与优化。 相似文献
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Soo-Ik Oh Jong-Kil Lee Jeong-Jin Kang Joo-Pyo Hong 《Metals and Materials International》1998,4(4):583-592
Sheet metal forming is one of the most widely used processes in manufacturing. Traditional die design practice based on trial
and error method is time consuming and expensive. For this reason, the simulation technique based on Finite Element Method
(FEM) becomes more popular to develop and optimize die design. Two FE codes for the analysis of the sheet metal forming processes
are presented in this paper. The one is a two dimensional implicit code named KSHELL, and the other is a three dimensional
explicit code, ES-FORM. Draw bending, tube inversion and spring back processes were simulated by KSHELL. Three point bending,
automotive panel stamping and square cup drawing with Tailor Welded Blanks (TWB) were simulated by ESFORM. The simulation
results are discussed by comparing with experimental measurements. 相似文献
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选用非金属颗粒(NMG)作为研究对象,通过体积压缩试验和NMG在高应力水平下的物理性能试验,得到NMG体积压缩曲线和扩展的Drucker-Prager线性模型参数;通过摩擦强度试验,得到NMG的Mohr-Coulomb模型参数,并与扩展的Drucker-Prager线性模型参数比对基本吻合;测定了NMG与板材在不同正压力下的摩擦因数曲线。以材料性能试验为基础,对基于固体颗粒介质的板材软模成形工艺进行数值分析;设计制造固体颗粒介质板材成形试验模具,成功制出抛物线形零件。结果表明:固体颗粒介质与板材表面作用所表现出的显著摩擦性能,可以极大限度地发挥板料的成形性能;其工艺控制简便,模具结构简单;成形工件具有表面质量好、贴模性好、精度高等优点,为板材的加工和制备提供了新的方法和手段。 相似文献
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《Journal of Materials Processing Technology》2014,214(8):1769-1776
7000 series aluminium alloys have greater strength than conventional aluminium alloys used in the automotive industry, but little has been reported on their formability. In this paper the strength and formability of age-hardenable AW-7020 alloy sheet in the T6 temper condition was investigated at temperatures between 150 and 250 °C by warm tensile, Swift-cupping and cross-die deep-drawing tests. Differential scanning calorimetry (DSC) investigations were carried out to study the precipitation state of AW-7020 sheet in as-received, warm cross-die deep-drawn and post-paint-baked conditions. Formability was found to improve at temperatures above 150 °C and was sensitive to temperature and strain rate. There was also an onset of dynamic recovery from 150 °C. DSC results showed the presence of η′ precipitates in T6 temper and that these coarsen during the warm cross-die deep-drawing and paint baking processes with ∼30% drop in ultimate tensile and yield strengths. Dynamic recovery and coarsening of η′ precipitates were found to contribute to the increase in formability at elevated temperatures. 相似文献
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限制自由度单元及其在板料成形过程数值模拟中的应用 总被引:2,自引:0,他引:2
根据板料成形过程的特点,提出一种用于板料成形分析的新单元模型-三维限制自由度单元模型,这种单元既没有膜单元不能考虑横向剪应力的遗憾,也不受壳单元对于局部大的限制毛坯后机加工同时克服了体单元解决板结构问题时刚度矩阵奇异的缺点。 相似文献
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利用自主设计的模具结构在6300 kN液压机上对金属板材进行拉延极限性能测试,获得了不同材料、不同厚度、不同钢种下的拉延极限高度以及初始开裂部位,并对不同工艺下的材料极限性能及开裂部位进行了研究。结果表明:不同材料对拉延极限高度与材料初始开裂部位均有影响,拉延极限高度随着材料强度的增大而减小,且DC01钢的拉延开裂位置发生在半球根部,DP系列高强钢拉延开裂位置发生在半球上部;宝钢与唐钢所生产的同种材料的拉延极限性能相当;厚度只对材料的拉延极限高度有影响,而对材料初始开裂位置影响不大;DC01钢在不同工艺下的拉延极限性能与开裂位置均相差较大,而不同工艺对DP590高强钢的影响则相对较小。 相似文献
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钣金件多道次拉深中间构型的确定是塑性成形领域的一个难题.针对中间构型对多道次成形的影响,以轴对称盒形件为成形对象,采用试验方法进行了研究.试验设计了两种不同的中间构型,通过网格法研究在第1道次和第2道次中应变的分布规律;通过成形极限图研究两种中间构型第1道次和第2道次的成形性.试验结果表明,轴对称零件多道次成形在第2道次的成形中,底部成形近似为局部成形,容易在底部产生较大的拉伸应变,造成破裂缺陷,设计中间构型的底部应尽量与零件近似;第1道次和第2道次中沿母线方向的应变均为拉伸应变,自零件口部向零件底部周向的应变由压应变逐渐过渡到拉伸应变,以压应变为主,破裂一般发生在拉伸应变区. 相似文献
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各向异性屈服准则对铝合金板成形预测精度的影响 总被引:9,自引:0,他引:9
基于板料成形过程的数值模拟 ,研究了不同的各向异性屈服准则 (Hill194 8,BarlatYLD89,BarlatYLD91和BarlatYLD96 )对铝合金板成形过程的影响 ,模拟结果和实验结果进行比较 ,结果表明 ,采用屈服准则 (YLD96 )模拟结果和实验吻合较好 ,而Hill屈服准则的模拟结果和实验差别较大 ,故不适宜用于铝合金板的成形模拟。采用不同屈服准则模拟的应变分布有所不同 ,采用YLD89,YLD91和YLD 96屈服准则预测的起皱和断裂的趋势比Hill屈服准则预测的要高。 相似文献
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1 INTRODUCTIONTheanisotropyofsheetmetalexertsanevidentinfluenceontheformability .Itiswellknownthattheplasticanisotropyofsheetmetalisusuallycausedbycrystallographictexture ,whichisdevelopeddur ingmechanicaldeformationandheattreatment.Thereforethetextureshouldbetakenintoconsidera tioninthesheetmetalsimulationforahigheraccura cy .Inrecentyears ,greatprogresshasbeenmadeinthetechnologyofthecrystallineplasticityfiniteele mentanalysisofsheetmetalforming ,inwhichthetextureisintroducedthroughthem… 相似文献
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分析和论述了板料成形有限元模拟中网格重划技术,研究并建立了板料成形有限元网格重划算法,实现了状态参量在新旧网格中的传递,结合DYNAFORM有限元分析软件,对NUMISHEET’93设定的方盒标准考题进行了模拟,结果证实了该技术的可行性。 相似文献