共查询到18条相似文献,搜索用时 203 毫秒
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板料成形接触摩擦过程有限元模拟 总被引:1,自引:0,他引:1
在对板料成形过程中的接触摩擦进行有限元模拟时,为了取得可靠的计算结果,需要准确地描述模具与板料之间的动态接触状态。本文在全面分析成形中板料与模具接触边界动态变化的基础上,结合ABAQUS有限元分析软件给出了模型的几何描述、接触算法选择及应用VFRIC用户子程序来进行接触摩擦模型的建立等具体方法。并通过具体实例,证明了这些方法应用于板料成形过程的接触摩擦分析的可行性。 相似文献
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板料成形数值模拟进展 总被引:23,自引:5,他引:23
在给出板料成形的典型成形过程、物理过程与力学模型的基础上,评述了板料成形数值模拟的发展历史和最新进展,包括成形过程与成形缺陷模拟发展,常用材料模型与壳体模型,接触摩擦处理及汽车覆盖件成形应用,文末指出了该领域的发展趋势。 相似文献
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通过对Ti-50A板材拉深过程的数值模拟,研究了参数选择与状态控制的基本途径,建立了对拉深过程进行数值模拟所用的几何模型.选择了壳单元为离散模型,采用映射网格划分技术对几何模型进行了网格划分,并对板料拉深数值模拟过程采用了自适应网格划分.针对Ti-50A钛合金给出了合适的材料本构模型.解决了加载、边界约束及求解过程当中最佳的时间和步长问题.利用接触理论和经典的库仑摩擦定律处理了模拟过程当中板坯与模具的接触与摩擦问题,最终完整地建立了符合实际的Ti-50A拉深成形过程数值模拟的有限元模型.通过有限元模拟与实际情况对比,验证了所提出的技术方案. 相似文献
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本文分析了用有限元方法模拟板料三维塑性成形过程时所遇到的主要问题,提出了确定增量步长的一种新的算法和适用于三维板料计算的摩擦模型。 相似文献
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板料成形数值模拟的关键技术及难点 总被引:14,自引:4,他引:14
本文结合国内外板料成形数值模拟的最新研究动态,从关键算法、屈服函数、本构方程、有限元列式、接触问题、破裂准则、回弹计算、起皱分析八个方面叙述了板料成形有限元计算的关键技术及主要难点。 相似文献
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In this paper, a sheet metal forming simulator (SMFS) is used for evaluation of the frictional behaviour of AZ80 and ZE10 magnesium alloys under lubricated contact conditions. The results showed that the friction coefficient increases by increasing the contact pressure and decreasing the sliding velocity. A friction model is further developed for lubricated contact taking into account the surface roughness characteristics and the viscosity of lubricant. The proposed model showed very good agreement with the results of experiments. Finite element (FE) simulations were also carried out to investigate the effect of key process parameters on the results of SMFS. Based on the results of the FE model, the coefficient of friction increases by increasing the bending angle and pin diameter; however, these increases are not significant. 相似文献
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Xu Weili Yang Yuying Z. R. Wang Lin Zhongqin 《Journal of Materials Processing Technology》2000,100(1-3)
A new contact judgement method for sheet metal forming simulation is proposed. The method can overcome miss-judgement and error-judgement, and improve numerical stability and computational accuracy effectively. Based on the proposed contact judgement method, a static–implicit FE code is developed. Some typical sheet metal forming processes and the benchmark of NUMISHEET’93 are simulated, and satisfactory results being obtained. 相似文献
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有限元模拟成形仿真的结果,可以帮助设计开发者正确选择冲压工艺参数和模具形状及材料特性等。在对模拟进行后处理过程中,往往必须了解由有限元节点构成的参数曲面的性质,为后续回弹分析及毛坯设计提供重要支持。如何应用变形后的节点阵构成光顺的几何曲面是问题的关键。文章给出了由节点序列散点构成非均匀B样条光顺曲面的实际算法,并开发了应用程序。对散乱点数据构成曲面进行了系统的阐述,所开发的方法已经用于板料成形仿真中FE网格节点重构曲面。 相似文献
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The present paper describes the resolution of the numerical simulation of the sheet cutting problem by the large time increment method in the version applicable to non linear problems in large displacements with contact and friction. To modelize elastoplasticity and damage, we use the prandt-Reuss behaviour law and a new stable damage model standard generalized to metal forming in its exension to the non linear geometrical case. 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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Flexible forming technology provides significant application potential in various areas of manufacturing, particularly at a miniaturized level. Simplicity, versatility of process and feasibility of prototyping makes forming techniques by using flexible tools suitable for micro sheet metal forming. This paper reports the results of FE simulation and experimental research on micro deep drawing processes of stainless steel 304 sheets utilising a flexible die. The study presents a novel technique in which an initial gap (positive or negative) is adopted between an adjustment ring and a blank holder employed in the developed forming system. The blank holder is moveable part and supported by a particular spring that provides the required holding force. The forming parameters (anisotropy of SS 304 material, initial gap, friction conditions at various contact interfaces and initial sheet thickness) related with the forming process are in details investigated. The FE models are built using the commercial code Abaqus/Standard. The numerical predictions reveal the capability of the proposed technique on producing micro metallic cups with high quality and large aspect ratio. To verify these results, number of micro deep drawing experiments is conducted using a special set up developed for this purpose. As providing a fundamental understanding is required for the commercial development of this novel forming technique, hence the optimization of the initial gap in accordance with each sheet thickness, thickness distribution and punch force/stroke relationship are detected. 相似文献
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M. J. Finn P. C. Galbraith L. Wu J. O. Hallquist L. Lum T. -L. Lin 《Journal of Materials Processing Technology》1995,50(1-4):395-409
LS-DYNA3D, an explicit code, and LS-NIKE3D, an implicit code, have been coupled to facilitate the finite element (FE) modelling of sheet metal forming. The explicit FE code is used to model the forming process, in which the deformable blank contacts rigid tools. The implicit FE code is used to model the subsequent spring-back which occurs after the tooling is removed. In this way, the explicit code with its robust handling of contact during forming is combined with the implicit code and its large time steps during spring-back. The result is an efficient method for solving even very large (>20 000 deformable elements) sheet forming models. Three examples of the application of this method are given. 相似文献