共查询到20条相似文献,搜索用时 62 毫秒
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对汽车车身铝合金板冲压成形进行有限元仿真与实验研究。结果表明,铝板整体分布较均匀,减薄率较小,可准确分析铝板在冲压成形过程中的冲压力分布、减薄程度、厚向异性。铝板具有较小的厚向异性系数,对其拉深性能影响小,沿轧制方向铝板厚度既有减薄也有增厚,且在成形部位的铝板厚度变化较大。与轧制方向成0°、45°、90°的铝板厚度变化量分别为0.27,0.27和0.26 mm。不同方向截面的铝板厚度变化也不同,铝板宽度变化量为2.8 mm,变化率为0.2%;冲压力随着凸模行程的增大不断增大,而后随着凸模行程增大,冲压力基本保持不变,并在凸模行程的最后阶段出现冲压力变小的趋势,且最大冲压力值为80 kN左右。 相似文献
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相对于汽车纵梁传统的整体折弯成形工艺,辊压成形工艺更加柔性化,其辊压柔性成形工艺将成为汽车纵梁成形工艺的发展趋势。一些商用车中卡汽车大梁的配件厂商提出先采用辊压成形然后再折弯的生产工艺,为此,中卡汽车大梁折弯机及折弯模具应运而生。建立折弯模具的数值模型并进行有限元计算,根据计算结果对模具结构进行改进,改善模具的受力状态,为进一步结构设计积累了经验,提高新产品研发成功的概率。 相似文献
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介绍了OLED背板内弯钩的折弯成形模具设计,极大地简化了模具结构,减少了模具制造成本,为折弯成形模具设计增加了一种新的选择(已申请了实用新型专利),通过实践证明,该模具结构设计合理、工作稳定、可靠,能完全保证制件质量,满足大批量生产的要求。 相似文献
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采用NUMISHEET'2002会议提出的铝合金板6111-T4大曲率半径纯弯曲回弹试验方案,在不同冲压行程下,对板料不同轧制方向的回弹角、成形力等进行试验研究.基于有限元软件eta/Dynaforrn,运用Hill'48屈服准则和Barlat'89屈服准则,模型分别采用指数强化模型和线性强化模型进行有限元仿真,与试验结果对比表明:随着凸模行程增加,冲压力增大,回弹后夹角增大;采用Barlat'89屈服准则和指数强化模型板料回弹值精度最高,误差为8.86%;采用Hill '48屈服准则和指数强化模型次之,误差为14.67%;屈服准则的选取对预测板料回弹量有较大影响,而强化模式的选取对回弹量的影响则不显著. 相似文献
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拉弯成形工艺具有成形精度高、回弹量小、生产效率高的优点,对轨道列车端顶弯梁进行拉弯数值模拟与成形实验。利用数学解析法计算得到了型材拉弯过程中夹钳的运动轨迹,并定义了型材拉弯过程中典型的成形缺陷。利用有限元模拟对比分析不同选材和工艺参数下成形后零件的应力分布、回弹、截面畸变和空间扭转。研究结果表明:选用ENAW-6005-T4材料可以避免型材拉弯过程中的断裂;采用预拉0.5%和补拉1.5%的加载组合时,型材的卸载回弹量最小;采用1.5 MPa的填充压强可以有效地抑制型材外壁的内凹;改善摩擦条件可以减小成形后的空间扭曲。采用优化后的工艺参数进行了实验验证,测量结果和数值分析规律相吻合。 相似文献
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Deformation behavior, temperature evolution and coupled effects have a significant influence on forming process and quality of component formed, which are very complex in forming process of aluminum alloy 7075 cross valve under multi-way loading due to the complexity of loading path and the multiplicity of associated processing parameters. A model of the process was developed under DFEORM-3D environment based on the coupled thermo-mechanical finite element method. The comparison between two process models, the conventional isothermal process model and the non-isothermal process model developed in this study, was carried out, and the results indicate that the thermal events play an important role in the aluminum alloy forming process under multi-way loading. The distributions and evolutions of the temperature field and strain filed are obtained by non-isothermal process simulation. The plastic zone and its extension in forming process of cross valve were analyzed. The results may provide guidelines for the determination of multi-way loading forming scheme and loading conditions of the forming cross valve components. 相似文献
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薄壁铝合金管小弯曲半径数控弯曲是个多因素耦合、多模具约束下的复杂过程。提出以有限元模拟为基础,基于显著性的工艺参数优化方法,即采用析因因子设计分析工艺参数对成形质量,即最大壁厚减薄率和最大截面畸变变化率影响的显著性,获得影响显著的参数,即管与防皱模间间隙的最优值,并确定其他影响不显著的参数值,包括管与模具间的间隙和摩擦、芯棒伸出量和助推速度。结果应用于规格为d50mm×1mm×75mm和d70mm×1.5mm×105mm(管外径D0×管壁厚t0×弯曲半径R)的铝合金管弯曲,获得了合格的管件。 相似文献
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In order to investigate the springback rules, the variation characteristics of physical property and microstructure in bending creep age forming process, a series of creep forming tests of 2124 aluminum alloy were conducted based on three kinds of single and double curvature forming tools. The results show that the spingback rate would be the minimum under the optimal coupling conditions among the temperature, aging time and internal stress state of material. Difference exists in the two directions of the formed sample with double curvature, but the curvature variation keeps the same. Yield strength, ultimate tensile strength and fracture toughness of the double curvature formed sample appear to be higher than those of the single curvature formed sample under the same aging condition, but the elongation and the anisotropy are opposite. 相似文献
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1 Introduction Warm forming of lightmass materials has been investigated as an alternative manufacturing process to achieve higher formability compared with forming at room temperature due to a substantial increase in material ductility[1?8]. SHEHATA et a… 相似文献
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A ductile fracture criterion is introduced into numerical simulation to predict viscous pressure forming limit of the automotive body aluminum alloy 6k2 l-T4. The material constant in the ductile fracture criterion is determined by the combination of the viscous pressure bulging (VPB) test with numerical simulation. VPB tests of the aluminum alloy sheet are carried out by using various elliptical dies with different ratios of major axis to minor axis(β), and the bugling processes are simulated by the aid of the finite element method software LS-DYNA3D. On the basis of the stress and strain calculated from numerical simulations, the forming limits of bulging specimens obtained are predicted by the ductile fracture criterion, and compared with experimental results. The fracture initiation site and the minimal thickness predicted by the ductile fracture criterion are in good agreement with the experimental results. 相似文献