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Jianlei Yang Guofeng Wang Tao Zhao You Li Qing Liu 《JOM Journal of the Minerals, Metals and Materials Society》2018,70(7):1118-1123
Titanium alloy bellows possess significant features, such as light weight, excellent mechanical properties, and good corrosion resistance. In this study, current-assisted forming technology which was used to fabricate Ti31 alloy bellows showed a better response than existing forming processes. Moreover, the finite element method was also applied to simulate the current-assisted forming and optimize the forming parameters. The results show that the current-assisted heating curves can be divided into three stages, pre-heating, heating, and holding. The maximum thinning ratio of Ti31 alloy bellows is about 18% after current-assisted forming at 700°C, which corresponds to a current density of 11.0 A/mm2. The Ti31 alloy bellows formed by the current-assisted forming process exhibited superior quality with uniform wall thickness. 相似文献
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面对新能源汽车空调技术的需求,作为空调系统的核心部件电磁阀的性能是系统稳定的关键,而针对电磁阀尤其是其中波纹管结构优化与应力分析的研究甚少。采用有限元分析法,建立波纹管结构简化模型,分析波纹管的波高、壁厚对波纹管的刚度和等效应力的影响。结果表明:波纹管的波高与刚度、等效应力成负相关,壁厚与刚度、等效应力成正相关,设计波纹管结构时,需要综合考虑壁厚、波高、刚度与等效应力影响。以波纹管为研究对象,利用Ansoft Maxwell和ANSYS Workbench建立波纹管的电磁结构耦合有限元模型,通过Ansoft Maxwell电磁场有限元分析得到电磁阀电磁力分布情况,把电磁力作为载荷导入ANSYS Workbench中,对波纹管的主体结构进行动力学分析,得到结构的变形分布情况。 相似文献
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Mats Larsson 《Journal of Materials Processing Technology》2009,209(1):376-386
The purpose of this investigation is to better understand the behaviour and effects in modeling of drawbeads in sheet metal forming simulation. A finite element model is developed to examine how various modeling aspects, such as element size, number of integration points, material hardening, influence the results. Furthermore, some process parameters such as friction and tool geometry are also discussed.In the modeling of drawbeads in large-scale sheet metal forming analysis using finite element methods it is common to use an equivalent drawbead model. This is due to the need for very dense finite element meshes resulting in demands for extreme computer resources. Generation of input data for an equivalent drawbead model has to be reliable and simple. Herein one method is presented on how to use a plane strain model using actual bead geometry to derive data for the equivalent drawbead model as it is implemented in LS-DYNATM. 相似文献
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针对S形焊接金属波纹管密封的振动问题,选用面体代替波片实体单元进行数值建模和模态分析;研究了单元尺寸对波纹管振动频率的影响,提出了波片选用面体单元时的单元尺寸应小于0.5 mm,并验证了其有效性。利用电动振动试验平台进行振动试验测试,得到了波纹管的振动特性曲线。通过对比分析仿真结果和试验测试结果,确定了波纹管的前6阶振动固有频率和振型,揭示了波纹管的振动机制和影响因素,阐明了波纹管的数值建模方法和试验测试技术。研究结果对焊接金属波纹管密封的设计、制造和应用提供了参考。 相似文献
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Tom Gießgen Andreas Mittelbach Daniel Hche Mikhail Zheludkevich Karl U. Kainer 《工业材料与腐蚀》2019,70(12):2247-2255
An advanced mathematical approach to describe the influence of corrosion products on the corrosion rate is presented here. The related model can be used as input equation for numerical predictive corrosion simulations or simply as an empirical model, to extrapolate experimental data of corrosion tests to longer times and to interpret the physical parameters behind. This semiempirical model assumes that a constant share of the dissolved metal precipitates on the surface and hinders the diffusion processes. Hence, the effective corrosion rate decreases exponentially with increasing dissolution. The explicit corrosion progress over time is derived by time integration on a newly developed, time dependent corrosion rate equation. The derived expression can be effortlessly implemented in existing for example finite element method, which is demonstrated for the uniform corrosion of a zinc surface. Furthermore, this approach is qualitatively compared with other empirical models for corrosion products and the validity is demonstrated by fitting of experimental data. A very good agreement between experiment and theory can be achieved for various materials and environments considering no change of the driving corrosion mechanism. 相似文献
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FE simulation and process analysis on forming of aluminum alloy multi-layer cylinder parts with flow control forming 总被引:2,自引:0,他引:2
The aluminum alloy parts used in airbag of car were studied with flow control forming(FCF) method,which was a good way to low forming force and better mechanical properties. The key technology of FCF was the design of control chamber to divide metal flow. So, the design method of FCF was analyzed and two type of control chamber were put forward. According to divisional principle, calculation model of forming force and approximate formula were given. Then forming process of aluminum alloy multi-layer cylinder parts was simulated. The effect of friction factor, die radius and punch velocity on metal flow and forming force was obtained. Finally, the experiment was preformed under the direction of theory and finite element(FE) simulation results. And the qualified parts were manufactured. The simulation data and experimental results show that the forming sequence of inner wall and outer wall, and then the force step, can be controlled by adjusting the process parameters. And the FCF technology proposed has very important application value in precision forging. 相似文献
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颗粒增强金属基复合材料的屈服行为 总被引:10,自引:0,他引:10
运用空间轴对称弹塑性有限元方法和混合律模型,给出了应力应变分配系数与复合材料的弹性模量,屈服强度以及切线模量之间的定量关系式,并由此提出了一种新的定义颗粒增强金属基复合材料比例极限和屈服行为的方法,进而研究了颗粒形状(球体,正圆柱体以及椭球体)和材料结构参数(颗粒体积分数和颗粒根间距)对颗粒增强金属基复合材料拉伸变形行为的影响。研究表明,通过研究应力应变分析系数及其二阶导数来确定复合材料屈服行为的方法不仅适用于短纤维增强金属基复合材料,而且也适用于颗粒增强金属基复合材料。该方法可以较好地反映出颗粒形状和材料结构参数对复合材料屈服行为的影响,预测的比例极限与已发表的实验结果吻合较好。 相似文献
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一种微分型全量弹塑性有限元算法及其应用 总被引:6,自引:5,他引:1
推导了一种坐标更新的微分型全量弹塑性有限元算法,用它模拟金属的压缩失稳现象,计算结果同实测值非常接近,并优于增量算法和刚塑性算法的结果。表明这一算法用于模拟金属的压缩失稳现象非常有效。 相似文献
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Mechanical, thermal and physical coupling methods in FE analysis of metal forming processes 总被引:4,自引:0,他引:4
The thermal and mechanical equations for large deformations occuring in metal forming processes are recalled. The finite element approaches for viscoplastic or for elastic viscoplastic materials are presented briefly. The coupling of the previous equations with those describing the evolution of physical internal parameters is analysed. A compact form of the physical and mechanical equation is used to consider any time integration method. The micro-macro approach is an alternate way to introduce physical phenomena. This methodology is illustrated with the problem of texture evolution during forming of anisotropic materials. Finally the feasability of the inverse method for various types of coupling is investigated, with application to the computation of parameters defining the mechanical, thermal and physical behaviour of the material. 相似文献
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板料冲压过程是一个非常复杂的塑性成形过程,许多因素都直接或间接影响着成形的结果.以Forge2D软件为平台,采用弹塑性有限元法对某一汽车轮毂零件的成形过程进行数值模拟,揭示零件冲压过程中板料的变形行为,预测冲压过程中可能出现的各种工艺缺陷,例如坯料的局部减薄和破裂,并以模拟结果为依据提出改进工艺参数的办法,优化工艺参数,可以减少调试和修模的次数,以此实现降低模具费用、缩短制模时间、提高产品成品率和材料利用率,最终达到减少产品成本的目的.在此基础上,对3种冲压工艺方案分别进行了数值模拟,对比研究了各方案的成形特点,得出了较好的成形工艺参数方案. 相似文献
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Naksoo Kim Shiro Kobayashi Taylan Altan 《International Journal of Machine Tools and Manufacture》1991,31(4):553-563
In this study a new simplified 3-D numerical method and the associated computer program have been developed to simulate the shape rolling process. The 2-D rigid-plastic finite element method (FEM), used for the generalized plane-strain condition, is combined with the slab method. This method, called FSEM (finite and slab element method), reduces the computational effort without losing much accuracy obtained in the 3-D computer simulation of the shape rolling process. The FSEM has been used to develop a computer program, called TASKS for three-dimensional analysis of shape-rolling as a kinematically steady-state process. The program TASKS has been used to simulate the metal flow and the bulge profile in flat rolling of slabs, the shape rolling of a simple H section, and the rolling of a practical H-beam section. In flat rolling, predicted spreads agreed well with experimental results, given in the literature. The metal flow in rolling of a simple H section was compared with results of a full 3-D simulation, obtained by other investigators. The comparison indicated that the present predictions give quite good results. Finally, the predictions made for a practical pass, used in rolling H sections, also compared well with experimental data. 相似文献
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A suggestion of the strength analysis technique considering the interfacial bonding strength is very important for the design of parts and the estimation of fatigue behavior. In this paper three dimensional finite element analysis was performed during the elasto-plastic deformation of particulate reinforced metal matrix composites. Bonding strength, interface separation and matrix void growth between the matrix and reinforcements were predicted during deformation under tensile loading. The shape of the reinforcement was assumed to be a perfect sphere. The type of the reinforcement distribution was assumed as FCC array. The element birth and death method of the ANSYS program was used for estimating the interfacial bonding strength, void generation and propagation. The experimental data of the extruded SiCp/6061 AI composites were compared with the calculated results. 相似文献