共查询到19条相似文献,搜索用时 421 毫秒
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充液拉深数值模拟流体力学模型的建立 总被引:2,自引:1,他引:1
充液拉深中的流体流动行为在充液拉深过程中起着重要的作用 ,但目前对流体的流动规律和如何把流体压力作用与板料的成形有效地结合起来缺乏深入的研究。有限元模拟是塑性成形中一个强有力的分析手段 ,但对流体压力行为缺乏研究 ,已成为充液拉深有限元模拟的瓶颈。本文通过对筒形件充液拉深工艺的分析 ,建立了接近实际的充液拉深流体力学模型。结合有限元数值模拟技术 ,提出了充液拉深流体压力行为在数值模拟分析中的实现方法 ,为充液拉深有限元数值模拟提供有效途径 相似文献
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正向充液变薄拉深工艺的研究 总被引:2,自引:0,他引:2
提出了一种称为正向充液变薄拉深的工艺方法。从理论上推导出变薄成形传力区拉应力计算式,并采用软铝车削毛坯进行了正向充液变薄拉深试验。当液压达到了120MPa时,车削铝毛坯的极限变薄拉深系数由0.5减小到0.3,说明正向充液变薄拉深工艺能有效地提高一次变薄拉深成形极限。 相似文献
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充液拉深对覆盖件成形性能影响的数值模拟 总被引:4,自引:0,他引:4
利用板料成形数值模拟技术比较覆盖件成形的常规拉深工艺和充液拉深工艺,得出了充液拉深的优势。提供了用商品化的板料成形有限元分析软件模拟充液拉深工艺的具体实施方法。 相似文献
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采用包含反胀、压平和拉深成形三个阶段的反胀充液拉深成形方法,得到不同反胀预变形时双相钢DP590的反胀预成形件和终成形件,研究了反胀对充液拉深成形件壁厚、应变的影响。结果表明:对于复杂曲面件反胀充液拉深,反胀高度存在极限值,当超过极限值时,试件出现折叠缺陷,限制了反胀量的提高;相对于普通充液拉深,反胀充液拉深对复杂曲面件底部有一定的强化效果,当相对反胀高度为16%时,可使底部壁厚减薄率增加2%、等效应变增大0.03,并且底部变形量随着反胀高度的增大而增加,而对直壁处变形基本无影响。 相似文献
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多点压边圈钣金充液拉深工艺是一种新制造技术。本文对形状复杂的某型号摩托车油箱充液拉深多点压边力控制进行了研究。通过有限元的模拟,优化了多点压边缸的配置和局部压边力的设置,分析了多点压边力对充液拉深工艺的影响,同时也预报了油箱充液拉深所需的反向液体压力和整体压边力。最后认为合理地配置多点压边缸和设置局部压边力,可以完全避免充液拉深过程中零件的起皱和破裂。 相似文献
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提出了种称为双向充液变薄拉深的工艺方法,从理论上推导出变薄成形极限计算式,并采用三种毛坯进行了双向充液变薄拉深度试验。当液压达120MPa时,车削软铝毛坯的极限变薄拉深系数由0.5减小到0.3;二次拉深毛坯的极限变薄拉深系数由0.6减小到0.45;二次拉深化退火毛坯的极限变薄拉深系数由0.6减小到0.4。 相似文献
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简要讨论了汽车车灯反光罩的常规拉深工艺和充液拉深工艺的特点及板料变形规律,说明充液拉深工艺是提高板料的变形程度、成形工件的尺寸精度、模具使用寿命的具有发展前景的一种先进方法,值得进一步研究和推广应用。 相似文献
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圆筒形件充液拉深成形精度 总被引:1,自引:1,他引:1
本文系统地研究了平底和球面圆筒形件充液拉深成形精度。充液拉深成形中,由于高压液体紧紧将毛坯贴向凸模表面,因而零件具有良好的贴模性并能获得很高的内径精度。同样,由于液压的施加在凸模圆角和压边圈之间产生与凸模运动方向相反的局部胀形,减小了凸模圆角处的弹复,提高了侧壁及球面件底部的形状冻结性。但是,平底零件的底面形状因液压的施加而使形状冻结性不好,平面度降低。 相似文献
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Hydromechanical deep drawing of cups with stepped geometries 总被引:1,自引:0,他引:1
This paper deals with the hydromechanical deep drawing of metal cups with complex stepped geometries. Two materials, a low-carbon steel (DC04) and stainless steel (DIN 1.4301), have been researched. A die set with a maximum possible deep drawing ratio β0,max = 3.0 for a punch diameter 100 mm has been designed and constructed. The die set is designed to withstand fluid counter pressures up to 200 MPa. Pressure control is achieved using a micro-metering pressure control valve. The process is initially simulated using the FEM solver LS-DYNA. Experiments have been conducted with two punch geometries. The punch geometries consist of cylindrical and conical wall segments. Complex positive and negative features are manufactured in the punch bottom face. The ability of transferring complex features from the punch onto the blank surface with high deep drawing ratios is investigated. Extended limiting deep drawing ratios of β0,max = 3.0 for DC04 and β0,max = 2.875 for DIN 1.4301 have been achieved. 相似文献
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在阐述板料液压拉深方法原理和分析国内外板料液压拉深典型装置的基础上,将板料液压拉深方法分为液压软凸模拉深、液压辅助压边拉深、对冲液压拉深、液压—机械拉深和内高压拉深等5种。对这些典型板料液压拉深装置及其工艺原理的发展及现状进行了详细的介绍和分析。最后对板料液压拉深工艺存在的问题作了阐述。 相似文献
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In order to make investigation into the tribological behaviors at the interface between tool and workpiece in the die corner of deep drawing, a tension-bending type test was used. A new tension-bending type test in which constant back tensions were applied and the deformation of specimen was plastic was developed. The workpiece used was an aluminum sheet with a smooth surface. The tests were carried out at a constant speed under various back tensions using a lubricant. The drawing force was measured during test and after tests the surface roughness of specimen was measured. In the lower average contact pressure, the surface roughening was predominant and the coefficient of friction was constant. On the other hand, in the higher average contact pressure, the flattening of surface asperities is predominant and the coefficient of friction decreased with increasing average contact pressure. 相似文献
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Sufficient data have now been generated to assess the influence of material, process, and tooling variables on the limiting
drawing ratio, when deep drawing cylindrical cups from circular blanks. The influence of these parameters is less well understood
in the deep drawing of nonaxisymmetric cups, and the data that exist have generally been collected from drawing tests. A theoretical
approach is presented for predicting the limiting drawing ratio when deep drawing prismatic cups. For a given blank geometry,
the drawing load is calculated to plastically deform the flange, overcome friction between the flange and the blank holder,
and to bend the material over the die radius. Deformation in the cup wall is ignored. The onset of yielding in the flange
is determined using a finite-element code. The calculated drawing load is compared to a theoretical maximum, and when the
two values coincide, this yields the limiting blank size under the assumed processing conditions, i.e., blank holder force,
die radius, blank shape, and coefficient of friction. The theoretical predictions were compared with experimental results
when deep drawing square cups from optimum blank shapes, and the correspondence was found to be acceptable. 相似文献
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矩形盒深拉深成形有限元模拟 总被引:1,自引:5,他引:1
针对矩形盒成形过程中各种形式的起皱和拉裂问题,采用MSC.Marc有限元分析软件对矩形盒深拉延成形过程进行模拟。建立了包括板料、凸模、凹模及压边圈在内的整体分析模型,通过对成形过程中拉深件的等效应力进行比较,分析了不同的凸模圆角半径、凹模圆角半径及凸模角半径对矩形盒拉深成形的影响。此外,还对模拟结果做了进一步的分析,得出了凸凹模圆角半径之间的相应关系,以便合理的确定矩形盒深拉延成形时二者的取值范围。考察了模拟方法的可行性和可靠性。 相似文献