共查询到18条相似文献,搜索用时 125 毫秒
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圆角半径的确定一直是冲压件工艺设计的关键技术,本文采用实验与理论模型相结合的手段,研究了凸模圆角半径对钢板冲压成形的影响。结果表明:冲压成形中的开裂位置和凸模圆角大小有关;圆角处的减薄率基本上与相对圆角半径R/t成反比;极限成形高度随凸模圆角半径的增大而增大。 相似文献
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基于有限元理论与选定的回弹角度判定标准,采用Dynaform软件探究了汽车U形件在弯曲成形过程中压边力、摩擦系数、板料厚度和凸模圆角半径对回弹的影响。研究结果表明:回弹角度随板料厚度增厚而降低,随凸模圆角半径增加而增加,随压边力增大先增大后减小,随摩擦系数增加先增大后减小。不同因素对回弹影响程度并不相同,在选定参数范围内板料厚度因素影响最明显,压边力次之,摩擦系数略低于压边力,凸模圆角半径影响最小。 相似文献
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本文运用探针测试法,测量拉深过程不同因子影响下的摩擦系数值,得出拉深摩擦系数受润滑剂,压边力,毛坯直径,凹模圆角半径、凸模圆角半径以及凸、凹模间隙影响的规律。 相似文献
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针对旋转挤压成形易产生裂纹的问题,利用Deform-3D有限元软件对AZ31镁合金旋转挤压过程进行了裂纹萌生的模拟,研究凸模在轴向-周向加载和径向-周向加载过程中,凸模圆角半径与摩擦系数对试样裂纹损伤分布的影响。结果显示,摩擦系数越大,裂纹损伤因子越大;凸模圆角半径越大,裂纹损伤因子越小,虽然凸模圆角半径R大于8 mm时裂纹损伤因子仍在减小,但是考虑工艺及材料利用,凸模圆角半径R为8 mm时最佳。通过单独径向、周向旋转挤压数值模拟,并与实验结果对比验证,得到轴向-周向加载下,筋部上区域损伤最大;径向-周向加载对试样的损伤影响较小。 相似文献
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工艺参数和材料性能对板料成形回弹的影响 总被引:1,自引:3,他引:1
分析总结了数值模拟中模拟参数(有限无算法、单元类型、材料模型、本构方程、积分点选取、接触和摩擦法则等)对回弹模拟精度的影响。对一细长支腿零件的工艺成形过程进行了数值模拟,研究了工艺参数及材料性能参数(压边力、凸模圆角半径、凸凹模间隙、板料厚度、摩擦系数、材料硬化指数)对工件回弹的影响。回弹角随凸模圆角半径和凸凹模间隙的增大而增大,随压边力、扳料厚度、摩擦系数和材料硬化指数的增大而减小。 相似文献
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在冲压带状板材时,如冲压工艺设计不合理,回弹会使冲压结果偏离图纸要求.用实验的方法探求无边压力情况下的板材回弹问题,分别就材料性能、板料厚度、凸模圆角半径、凸凹模间隙、凹模跨度、摩擦系数等诸多因素对板料回弹的影响做出了分析. 相似文献
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Kinji Sato Yoshiaki Sawa Yuhji Abe Toshio Yokoyama Hotsumi Kagawa 《Metals and Materials International》1998,4(6):1213-1218
The purpose of the present paper is to study methods to improve the stretching limit of metal sheet. The factors affecting
the stretching limit were sheet thickness, blank diameter, blank holding pressure, and forming rate. Punch radius, die radius,
and clearance between a punch and a die were retained constant. Tested materials were softened and half hardened types of
aluminum sheet. The effect of lubrication was also studied. Lubricants used were a press working oil and graphite. Stretching
by two types of punch shape, a spherical head punch and a truncated cone one, was tried in order to research the effect of
punch shape. The half hardened aluminium, which has a larger n-value, showed the larger stretching limit. The larger thickness
gave rise to the larger stretching limit. Flow characteristic of materials was poorer in larger diameter of a blank, so its
stretching limit was lower. A bit lower holding pressure, which allows drawing of materials to some extent, yielded larger
stretching limit than rigid holding. The forming rate did not so much affect stretching limit. Concerning the effect of lubrication,
applied position of lubricants was important. 相似文献
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This paper proposes an innovative incremental in-plane bending of thin metal sheets for manufacturing microscopic machine components. The unique feature of the process is that a tiltable punch having a beating face with trapezoidal profile is used. The beating face enables the punch to bend thin metal sheets in in-plane manner. Working conditions, including indentation and feeding pitch, can easily and flexibly control the bending radius and even the bending direction. The in-plane bent thin sheet products are expected to be used as springs, conical cylinders, bushes and other components of micro machines such as medical instruments. 相似文献
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铝合金板温成形过程中凸凹模圆角处摩擦的测量 总被引:3,自引:0,他引:3
在温成形过程中铝合金板与模具表面的接触和摩擦行为十分复杂,不同的接触区域摩擦状况不尽相同。本文分析了板料成形中摩擦测量的国内外发展状况,采用自行设计的新型摩擦测量装置完成了铝合金板温成形过程中凸凹模圆角处摩擦系数的测量。该测量装置的特点是可以模拟板料的真实变形过程,因而可以获得更为准确的测量结果。 相似文献
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The aim of this work is to identify the tribological size effects within sheet metal forming and to develop a size-dependent friction function for the integration in the FEM-simulation. A strip drawing test with deflection in combination with a numerical identification is used. The numerical identification is based on an analytical model for the punch force and an optimisation program, which identifies the friction coefficient in dependence on the contact pressure from the measured punch force vs. punch travel. Scaled experiments with sheet thicknesses from 0.02 mm to 2 mm were done to identify the tribological size effects. 相似文献
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《中国有色金属学会会刊》2010,(10)
Deep drawing is one of the most important processes for forming sheet metal parts.It is widely used for mass production of cup shapes in automobile,aerospace and packaging industries.Cup drawing,besides its importance as forming process,also serves as a basic test for the sheet metal formability.The effect of equipment and tooling parameters results in complex deformation mechanism.Existence of thickness variation in the formed part may cause stress concentration and may lead to acceleration of damage.Using TAGUCHI's signal-to-noise ratio,it is determined that the die shoulder radius has major influence followed by blank holder force and punch nose radius on the thickness distribution of the deep drawn cup of AA 6061 sheet.The optimum levels of the above three factors,for the most even wall thickness distribution,are found to be punch nose radius of 3 mm,die shoulder radius of 8 mm and blank holder force of 4 kN. 相似文献
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R. Srinivasan D. Vasudevan Palani Padmanabhan 《Journal of Materials Engineering and Performance》2012,21(7):1188-1192
This article deals with bend force behavior of electro-galvanized (EG) steel sheets in air bending process. A detailed experimental study was carried out on EG steel sheets of various coating thicknesses to investigate the influence of parameters such as coating thickness, orientation of the sheet, punch radius, die opening, die radius, and punch velocity on bend force behavior. From the results, it is found that zinc coating reduces the bend force and the increase in coating thickness reduces the bend force significantly. It is observed that the bend force is larger for larger punch radius, smaller die opening, and smaller die radius. It is also observed that the bend force is larger for 0° orientation than for 90° orientation. The bend force decreases with increase in punch velocity, and this influence is more prevailing in EG sheets than in plain sheets. 相似文献
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板成形数值模拟影响因素的正交试验分析 总被引:1,自引:0,他引:1
根据正交试验原理,应用板料成形软件对不同压边力、模具与板料间摩擦系数、凸凹模间隙和板料初始尺寸进行数值模拟,将数值模拟的厚度同实际成形件的厚度进行比较,得出上述因素对前翼子板成形结果的影响,并预测了前翼子板较优的理论成形条件。 相似文献