共查询到19条相似文献,搜索用时 125 毫秒
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提出了一种基于数值模拟的板料弯曲回弹控制方法.以弧形件弯曲件为研究对象,在ABAQUS软件中进行弯曲成形过程和回弹过程模拟,得出预测回弹值,并结合回弹补偿原理进行模具型面的修正.实例结果表明,该方法可以有效地实现板料弯曲回弹控制,具有工程和科研实用价值. 相似文献
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利用激光作为热源使金属板料在无模具下发生热塑性变形是一种新的成形方法。文章分析了板料激光弯曲的基本原理,通过试验对影响板料激光弯曲的主要因素的变化规律作了系统的研究,对试验曲线做了定性分析,其结果可以为工程应用提供依据。 相似文献
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应用渐进成形技术,采用交叉分割材料法,提升材料成形特性,避免了板料在成形过程中被拉裂的现象,实现快速精准地滚塑模具制作;采用模具结构简化法,将复杂滚塑模具结构分解为若干简单几何体,便于板料渐进成形;成功解决了手工制作滚塑模具的弊端。试验结果表明:采用渐进成形技术制作给排水管道检查井滚塑模具的方法适用有效,该工艺的制造成本低、周期短、精度高,对板料渐进成形技术在滚塑模具中广泛应用具有一定的应用价值。 相似文献
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基于ANSYS/LS-DYNA的板料弯曲成形数值模拟 总被引:3,自引:1,他引:2
根据动力显式有限元理论,利用ANSYS/LS-DYNA软件对TZM合金板料的弯曲冲压过程进行模拟;分析了板料弯曲变形过程,预测了板料在冲压过程中容易产生缺陷的部位,检验了模具结构设计及冲压工艺是否合理,讨论了摩擦因数对成形质量的影响. 相似文献
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基于BP神经网络的板料折弯件下料尺寸的计算方法 总被引:1,自引:0,他引:1
在板料成形工艺中 ,弯曲成形是一种主要的工艺方法。而板料下料尺寸将直接影响到零件的成形精度以及后续工序的成败。针对工厂积累的大量生产和实验数据 ,提出一种基于人工神经网络计算弯曲件板料展开长度的方法。在概述解析法确定板料展开长度的基础上 ,建立了计算展开长度的人工神经网络模型。以板料厚度、成形半径及成形角度作为输入参数 ,中性层位移系数作为输出参数 ,用已积累的大量数据作为训练样本 ,对神经网络进行训练 ,得到这些参数和中性层位移系数的隐性规律 ,实现了弯曲成形板料展开长度的快速计算。实验结果表明 ,利用人工神经网络能够快速准确地计算出板料展开长度。 相似文献
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《Journal of Materials Processing Technology》2014,214(9):1820-1827
Continuous roll forming (CRF) is an effective process to manufacture swept surface parts of sheet metal. The forming tool in CRF is a pair of small-diameter bendable forming rolls, a swept surface is formed continuously after the rotating rolls sweep out the whole sheet metal blank. The two bent rolls and the non-uniformly distributed roll gap along the rolls’ length make the sheet metal bent in longitudinal and transverse directions simultaneously, the cross-section curve of the formed swept surface is controlled by the curved profile of the forming rolls and the spine curve is controlled by the differential elongations of sheet metal generated by roll gap. In this paper, a necessary condition for the formation of a swept surface is proposed and analyzed, the parametric equations of the formed surface in CRF are derived and the method to determine the roll gap for forming a given swept surface is presented. The numerical simulations and analyses on the CRF processes demonstrate the validity of the presented theoretical models. The experimental and measured results show that the formed surfaces are in good agreement with the desired surfaces, and swept surface parts with good forming precision can be obtained by CRF process. 相似文献
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Advanced polymers offer at the present time concrete possibilities in reducing the product development time and production
of prototypes and small series of sheet metal parts. However, the applicability of such materials requires different approaches
in comparison to conventional materials for sheet metal forming dies. This paper presents investigation results dealing with
tribological and tool design aspects for the use of polymeric materials in sheet metal forming. Friction and wear of sheets
with different surface topologies have been investigated. A new test method for measuring polymer/sheet wear is presented.
A coupled simulation model for the production of a test geometry aimed specifically at the investigation of die deformations
and loads is presented. The behaviour of two polymeric materials by forming the test geometry has been simulated and the maximal
loads and deformations during the process have been quantified. Simulation results have been subsequently validated in experimental
testing. 相似文献
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《Journal of Materials Processing Technology》2014,214(8):1673-1685
In this paper, an enhanced numerical method for forming tool design optimisation in three-dimensional (3D) sheet metal forming applications is presented. The applied procedure enables a determination of appropriate forming tool geometry so that the manufacture of a sheet metal product inside specified tolerances would be ensured. In addition to the springback that occurs in the formed part after removal of the forming tools, the impact of the thinning of the sheet metal during the forming process is considered in the method, and both effects are correspondingly compensated for an iterative procedure. Computational efficiency in the E-DA-3D method is achieved mainly because the improved accuracy of the communicated data established corresponding interrelations between the discretised topologies used in the definition of the prescribed product geometry, the current tool geometry, and on this basis actually computed product geometry which is achieved by means of additional point topology mappings. The potential and effectiveness of the method is demonstrated by considering two cases of the forming tool design optimisation that are also experimentally validated. 相似文献
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以基于法向量展开的射线法为基础,针对框肋类零件中的扣边板件和带缺口板件展开过程中所遇到的问题,采用借鉴前截切网格单元法向量的方法,并加入虚拟网格,得到了此类零件的合理毛坯形状.通过测试计算,改进后的算法快速高效,得到的零件毛坯形状合理准确.为进一步优化提供了良好的初始值. 相似文献
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Mrio Pinto Abel D. Santos Pedro Teixeira P.J. Bolt 《Journal of Materials Processing Technology》2008,202(1-3):47-53
The traditional market of sheet metal parts is based in high production volumes normally greater than 10.000 parts by using high-speed presses and highly automated operations, being the tooling usually made from steel or cast iron, which ensures the needed robustness for such production volumes. Current trends in stamping industries can be characterized by the increasing demand for individualization of products which leads to a growing development towards an increasing number of product variants, lower production volumes and shorter innovation cycles. These trends have triggered research in the development of faster and cost-effective tool manufacturing techniques suitable for low production volumes, since high investments in steel tools can only be compensated by huge volume series of one and the same part during long life cycles. A promising approach for production of small series of complex sheet metal parts is the use of non-conventional tooling materials such as polymers, wood and low melting point metals. The usage of these alternative materials in tooling is still looked with some suspicion, due to the lack of know-how on its processing and also on its wear durability, influenced by the required product geometry, blank material and expected production volume.
In this paper a study on the use of non conventional materials for tooling, to be used for producing a complex sheet metal part, is performed. The evolution of tool wear, roughness and geometrical changes in punch and die radius were measured and its influence in the stamped part geometry evaluated, for an imposed production volume target of 500 parts. Also a comparative study of the tooling costs is presented in order to assess the aptitude and economical feasibility of the use of these tooling materials for low production series. 相似文献
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Tailor die quenching in hot stamping for producing ultra-high strength steel formed parts having strength distribution 总被引:2,自引:0,他引:2
Tailor die quenching in the hot stamping of quenchable steel sheets was developed to produce ultra-high strength steel formed parts having strength distribution. Local portions of the heated sheet were quenched by holding grooved tools at the bottom dead centre during the stamping. Non-contact portions were generated in the sheet by grooving the tools, and thus the strength in the contact portions is high owing to the quenching and that in the non-contact portions is low owing to the lack of the quenching. Hat-shaped products having a tensile strength of approximately 1.5 GPa only at four corners were formed. 相似文献
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Technology of sheet hydroforming with a movable female die 总被引:2,自引:0,他引:2
Shi-Hong Zhang Li-Xin Zhou Zhong-Tang Wang Yi Xu 《International Journal of Machine Tools and Manufacture》2003,43(8):781-785
An improved sheet hydroforming process is proposed and investigated experimentally and numerically. A movable female die keeps in contact with the deformed area of the sheet blank so that further deformation of the deformed area is restricted. Under the sealing, the sheet blank under the flange can be drawn in. So the hydroformed part has less thinning than the hydrobulge formed part only, and the limit drawing ratio of the sheet can be remarkably improved. This process is especially suitable for forming of small batch production of sheet metal parts with complicated shapes. The female die can be replaced with other female die of various shapes, and can also be made of very cheap materials such as plaster and hard wood instead of metal when the part number is very small. Thus complex-shaped sheet parts can be formed with less expensive tool systems.In this paper, the hydroforming processes of part A (without a movable die) and part B (with a movable die) were investigated by experiment and by elastoplastic FEM. The effects of various process parameters on the deformation of the sheet blanks were investigated. The forming conditions affecting wrinkling and rupture have been analyzed. The effects of friction and contacting force acting on the experimental results are also discussed. 相似文献
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Strategies to improve the geometric accuracy in asymmetric single point incremental forming 总被引:2,自引:0,他引:2
Asymmetric incremental sheet forming (AISF) is a manufacturing process for the small batch production of sheet metal parts.
In AISF, a sheet metal part is formed by a forming tool that moves under CNC control. AISF currently has two dominant process
limits: sheet thinning and a limited geometric accuracy. This paper focuses on the latter limit. It is shown with a pyramidal
part that multi-stage forming can yield an increased accuracy compared to single-stage forming. However, due to residual stresses
induced during forming, the accuracy of the as-formed part can be lost if the part is trimmed after forming. A case study
with a car fender section shows that the geometric accuracy of the final part can be improved compared to single-stage forming
by a combination of multi-stage forming and stress-relief annealing before trimming. 相似文献
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金属板材数控渐进成形技术及加工轨迹坐标对位研究 总被引:1,自引:0,他引:1
金属板材数控渐进成形技术,是一种通过三轴数控成形机对金属板材进行逐层辗压而成形工件的柔性加工技术。本文探讨了金属板材数控渐进成形技术的过程、原理,同时,为了有效地排除成形过程中坐标对位对零件上出现的拉裂、材料堆积、材料硬化等现象的影响,本文提出了一种基于机器视觉的非接触式加工轨迹坐标对位方法,完成了金属板料数字化渐进成形中支撑模型的非接触式高精度快速定位。 相似文献