共查询到18条相似文献,搜索用时 203 毫秒
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《模具工业》2016,(4):5-14
针对空心铝型材挤压件,采用传统分流组合模具和蝶形模2种设计方案,分别建立三维设计模型,结合常规等速挤压工艺参数,使用有限元数值分析软件Hyper Xtrude分别对2副模具的型材挤压过程进行有限元数值仿真模拟,同时运用软件的优化设计功能对2副模具的工作带分别进行优化设计。分析、比较铝合金金属在模具型腔内流动变形的形态、压力、速度以及模具结构内部应力、弹性变形等参数。结果表明:采用蝶形模挤压成形空心型材时,金属的流动及变形较传统模具挤压时更均匀,分流桥上端流动死区减小,挤压压力曲线平稳,模具的等效应力分布更均匀,延长了模具的使用寿命,提高了生产效率和合格率、降低了生产成本,提高了经济效益。 相似文献
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对镁合金薄壁空心型材在实际生产过程中出现壁厚减薄的缺陷,采用数值模拟方法进行研究,分析了挤压过程中金属流速和压力分布情况,模拟结果表明,焊合室内压力不均及出模口处沿挤压方向金属流动速度差异,是导致型材壁厚减薄的主要原因,且模拟得到的壁厚值与实际测量值基本吻合。提出了控制型材壁厚的改进方案,对型材挤压模具结构进行改进,即增加焊合室高度和修改分流孔尺寸。其中修改分流孔尺寸的方案能得到壁厚较均匀的型材,是可行的方案。研究结果表明,有限元方法对复杂型材挤压生产中挤压模具和挤压工艺的优化有直接的指导意义。 相似文献
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铝材长方形空心管挤压过程数值模拟与模具结构优化设计 总被引:3,自引:0,他引:3
对AA1100铝材长方形空心管的挤压过程使用数值分析软件SuperForge进行数值模拟。在挤压生产中,金属流出工作带时的流速均匀性是得到高质量型材的关键。在挤压生产中通常采用几种方法修改模具,消除流速不均,例如修改分流孔的大小、形状和位置分布,修改工作带长度和焊合室形状尺寸等。本文通过数值模拟发现在长方形空心管挤压的初始模具设计中型材截面流速不均匀,造成端面不平。对此,提出了三种模具修改方案,并分别对其进行了数值模拟,经过分析比较确定了最佳模具设计方案,由此方案可以生产出合格的挤压件。 相似文献
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According to the rigid-viscoplasticity finite element method, the porthole die extrusion process of an aluminum harmonica-shaped tube was successfully simulated based on software Deform-3D. The distribution of stress field, effective strain field, velocity field and temperature field during the extrusion process were discussed and the metal flow in welding extrusion was analyzed. The simulation results show that the material flow velocities in the bearing exit are non-uniform with the originally designed die and the forepart of the profile is not neat or even. Aiming at solving this problem, the modification method of die structure was improved. The result shows that the uniform material flow velocities in the die exit and a perfect extruded are obtained by modification bearing length. 相似文献
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In order to investigate the effects of pockets in the porthole die on the metal flow, temperature at the die bearing exit and the extrusion load were contrasted with the traditional die design without the pockets in the lower die. Two different multi-hole porthole dies with and without pockets in lower die were designed. And the extrusion process was simulated based on the commercial software DEFORM-3D. The simulation results show that the pockets could be used to effectively adjust the metal flow and especially benefit to the metal flow under the legs. In addition, the maximum temperature at the die bearing and the peak extrusion load decrease, which indicates the possibility of increasing the extrusion speed and productivity. 相似文献
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Optimal extrusion die design to achieve flow balance 总被引:1,自引:0,他引:1
The design of a plane strain two-hole extrusion die is presented. This design example can be considered as a test case to judge the usefulness of the present method in the design of extrusion dies for uniform exit flow. Bearings for this die are to be designed so that the material exits both holes with parallel balanced flow. The finite-element method combined with techniques of mathematical programming is adopted. Derivatives of the objective function used during the optimization phase are efficiently computed using analytical sensitivity analysis and an optimal bearing length is reached after few iterations of the optimization procedure. Available experimental data for a two-out extrusion die with bearings have been used to validate the numerical results. 相似文献
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Based on the finite element simulation of profile extrusion process, the effect of local extrusion ratio, die bearing area and the distance between extrusion cylindrical center and local die orfice center on mental flow velocity was investigated. The laws of deformed metal flow on profile extrusion process were obtained. The smaller the local extrusion ratio, the faster the metal flow velocity; the smaller the area of die bearing, the faster the metal flow velocity; the smaller the distance of position of local die orifice(the closer the distance of position of local die orifice from extrusion cylindrical axis), the faster the metal flow velocity. The effect of main parameters of die structure on metal flow velocity was integrated and the mathematical model of determination of die bearing length in design of aluminum profile extrusion die was proposed. The calculated results with proposed model were well compared withthe experimental results. The proposed model can be applied to determine die bearing length in design of aluminum profile extrusion die. 相似文献
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截面变形是复杂空心型材挤压过程中经常遇到的难题,实际生产中需通过反复试模、修模才能得到合格的产品。针对6063铝合金空心型材截面内凹问题,采用数值模拟方法获得了挤压过程中不同方向上的金属流速及模具焊合室内不同高度的压力分布,分析与讨论了产生缺陷的原因,并优化了模具结构。模拟仿真结果表明,添加阻流块后挤压过程中型材不同位置和不同方向上的流动速度更加均匀,挤出型材向内凹的现象得到改善。实测结果显示,采用改进后的模具结构,挤压型材最大内凹量减小为0.15 mm,可以满足实际应用要求。 相似文献
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采用有限体积法,对异形空心铝合金型材挤压过程进行数值模拟,得到了挤压过程中材料流动速度场、应力场、应变场、温度场和挤压力的分布规律。以数值模拟结果为依据,针对模具设计存在的问题提出了解决方案,并通过分析得到了模具的最佳设计方案。结果表明:对于薄壁、结构复杂的异型空心型材,挤压模具设计的关键是合理地分配金属流量和平衡金属的流动速度。 相似文献
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铝型材挤压模工作带优化 总被引:8,自引:0,他引:8
基于MATLAB平台,将BP神经网络、遗传算法和数值模拟技术应用于铝型材挤压模具参数优化设计。采用三层BP神经网络建立型材挤压模具的数学模型,由正交实验法安排模拟实验组合,采用有限元软件进行挤压过程的数值模拟,并以具有不同工作带尺寸的挤压模具中金属流出模口平面上的Z向质点流速均方差作为模型目标值,将模拟结果作为神经网络的输人样本对训练网络并建立网络知识源,通过遗传算法求得模型的全局优化解;最后通过有限元数值模拟技术验证并比较优化所得工作带与经验法确定的工作带对金属流动均匀性的影响。数值模拟结果表明,本研究对挤压模具工作带的优化是有效的。 相似文献