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fea modeling of effect of axial feeding velocity on strain field of rotary swaging process of pure magnesium

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中国有色金属学会会刊：英文版 2006年第5期16卷 1015-1020页

作者：荣莉聂祚仁左铁镛 School of Material Science and Engineering Beijing University of Technology

A coupled thermal-mechanical model of the rotary swaging of pure magnesium was developed using the general finite-element software program MSC/Marc to visualize the effect of axial feeding velocity on the rotary swaging process. The radial displacement occurring in one pulse impact increases in proportion to axial feeding velocity (vax). When the other processing parameters are fixed, the surface roughness of the swaged bar increases with vax and is in parabolic relation with vax. There exists a minimum velocity vax, min below which the decrease of vax will no longer improve the surface roughness. Under the technological conditions of this simulation, when the finial diameter d=6.6 mm, vax, min=1.82 m/min, and when d=7.0 mm, vax, =1.83 m/min. If min Ra=3.2 is required for the end product, then vax, =6.02 m/min is gotten for d=6.6 mm and vax, max max =7.05 m/min for d=7.0mm. The increase of vax has no notable influence on strain distribution along radial direction. The errors between the experimental and simulated height of the spiral spine-like ridges are below 8.0%.

关键词：回转模锻镁应变工艺参数 fea

Reliability design optimization of composite structures based on PSO together with fea

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Chinese Journal of Aeronautics 2013年第2期26卷 343-349页

作者： Chen Jianqiao Tang Yuanfu Ge Rui An Qunli Guo Xiwei Department of Mechanics Huazhong University of Science and Technology Research and Development Center Wuhan Iron and Steel (Group) Corp.

The present work aims to develop a method for reliability-based optimum design of composite structures. A procedure combining particle swarm optimization （PSO） and finite element analysis （fea） has been proposed. Numerical examples for the reliability design optimization （RDO） of a laminate and a composite cylindrical shell are worked out to demonstrate the effectiveness of the method. Then a design for composite pressure vessels is studied. The advantages and necessity of RDO over the conventional equi-strength design are addressed. Examples show that the proposed method has good stability and is efficient in dealing with the probabilistic optimal design of composite structures. It may serve as an effective tool to optimize other complicated structures with uncertainties.

关键词： Composite structures fea PSO Reliability analysis Reliability design optimization

3D Two-way Coupled TEHD Analysis on the Lubricating Characteristics of Thrust Bearings in Pump-turbine Units by Combining CFD and fea

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Chinese Journal of Mechanical Engineering 2016年第1期29卷 112-123页

作者： ZHAI Liming LUO Yongyao WANG Zhengwei LIU Xin State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China Department of Thermal Engineering Tsinghua University Beijing 100084 China

The thermal elastic hydro dynamic （TEHD） lubrication analysis for the thrust bearing is usually conducted by combining Reynolds equation with finite element analysis （fea）. But it is still a problem to conduct the computation by combining computational fluid dynamics （CFD） and fea which can simulate the TEHD more accurately. In this paper, by using both direct and separate coupled solutions together, steady TEHD lubrication considering the viscosity-temperature effect for a bidirectional thrust bearing in a pump-turbine unit is simulated combining a 3D CFD model for the oil film with a 3D fea model for the pad and mirror plate. Cyclic symmetry condition is used in the oil film flow as more reasonable boundary conditions which avoids the oil temperature assumption at the leading and trailing edge. Deformations of the pad and mirror plate are predicted and discussed as well as the distributions of oil film thickness, pressure, temperature. The predicted temperature shows good agreement with measurements, while the pressure shows a reasonable distribution comparing with previous studies. Further analysis of the three-coupled-field reveals the reason of the high pressure and high temperature generated in the film. Finally, the influence of rotational speed of the mirror plate on the lubrication characteristics is illustrated which shows the thrust load should be balanced against the oil film temperature and pressure in optimized designs. This research proposes a thrust bearing computation method by combining CFD and fea which can do the TEHD analysis more accurately.

关键词： pump-turbine thrust bearing TEHD lubrication two-way coupled CFD fea

Parametric analysis of warm forming of aluminum blanks with fea and DOE

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中国有色金属学会会刊：英文版 2006年第2期16卷 267-273页

作者：陈鹏林忠钦陈关龙 K. Muammer School of Mechanical Engineering Shanghai Jiao Tong University Shanghai 200030 China Department of Mechanical Engineering Univ ersity of Michigan Ann Arbor Michigan USA

The effect of temperature distribution on warm forming performance was investigated for 5083-O (Al-Mg) sheet metal blanks. Combined isothermal/non-isothermal fea with design of experiments tools were used to predict appropriate warm forming temperature conditions for deep drawing and two-dimensional stamping cases. In the investigated temperature range of 25?250 ℃, the formability of Al-5083 alloy is found to be greatly dependent on the temperature distribution of the die and punch. To achieve increased degrees of forming, different temperature levels should be assigned to the corner and body of the die and punch. And the optimal temperature distributions for warm deep drawing and warm two-dimensional stamping are not identical.

关键词：热成型铝合金有限元 fea DOE

Effects of reduction of diameter on microstructure and surface roughness of rotary swaged magnesium by fea

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中国有色金属学会会刊：英文版 2008年第A1期18卷 263-268页

作者：荣莉聂祚仁左铁镛 College of Materials Science and Engineering Beijing University of Technology

Combining the processing maps with fea,the critical values of reduction of diameter(ΔR) for the appearance of as-cast microstructure,dynamic recrystallization grains and twins in the swaged magnesium were respectively studied,by which the rational range ofΔR was *** ensure that the as-cast microstructure wouldn't be retained in the rotary-swaged magnesium,ΔR should be larger than 0.25 *** avoid the appearance of twins in the microstructure of rotary-swaged magnesium,ΔR should be less than 1.0 mm.ΔR should be between 0.25 mm and 1.0 mm to ensure the appearance of recrystallized *** surface roughness of rotary-swaged magnesium increases with the increase ofΔR by quadratic *** simulated results accord well with the experimental *** the process control of rotary-swaging(RS),ΔR should be maximized between 0.25 mm and 1.0 mm on the precondition that the requests for surface roughness have been satisfied.

关键词：旋揉工艺金属成形工艺金属学 fea

Evaluation on prediction abilities of constitutive models considering fea application

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Journal of Central South University 2018年第6期25卷 1251-1262页

作者：温彤刘澜涛黄倩陈霞方继钊 College of Materials Science and Engineering Chongqing University

本构模型在金属塑性成形数值模拟中扮演着重要角色,然而其对计算的影响仍不明确。本文基于Al 7050和Ti–6Al–4V合金的等温压缩实验应力–应变曲线,对Johnson-Cook(JC)以及Arrhenius-type(A-type)双曲正弦模型进行了拟合并得到表达式;... 详细信息

本构模型在金属塑性成形数值模拟中扮演着重要角色,然而其对计算的影响仍不明确。本文基于Al 7050和Ti–6Al–4V合金的等温压缩实验应力–应变曲线,对Johnson-Cook(JC)以及Arrhenius-type(A-type)双曲正弦模型进行了拟合并得到表达式;将应用2个方程直接预测的流动应力与实验结果进行比较,同时利用刚塑性有限元数值方法对热压缩过程进行模拟,发现对于实验数据的直接预测,A-type模型的预测精度高于JC模型的,对拟合数据以外的实验数据也一样。从数值模拟结果来看,利用A-type模型的计算结果与实验更加吻合,但吻合程度受拟合所采用参考参数的影响;从模拟得到的整体变形和应变分布来看,利用2种模型的结果差别不大。

关键词：正弦模型预言组成 fea Arrhenius Ti-6A1-4V 评估能力

A Comparative Study on the Truck Frame Stiffness with Solid and Beam Element fea Models

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Modern Mechanical Engineering 2023年第3期13卷 55-61页

作者： Shengyong Zhang Zack Gertzen Adam Manering Cristian Jongkind Department of Mechanical and Civil Engineering College of Engineering and Sciences Purdue University Northwest Westville USA

Truck frames should be designed and fabricated with enough rigidity to avoid excessive deflections. Finite element analysis (fea) plays an important role in all stages of frame designs. While being accurate, 3D solid element fea models are built upon frame configuration details which are not feasible in the preliminary design stage, partially because of limited available design data of frames and heavy computation costs. This research develops 1D beam element fea models for simulating frame structures. In this paper, the CAD model of a truck frame is first created. The solid element fea analysis, which is adopted as the baseline in this study, is subsequently conducted for the stiffness of the frame, Next, beam element fea analysis is performed for validating the feasibility of the beam element fea model by comparing the results from the solid and beam element fea models. It is found that the beam element fea model can predict the frame stiffness with acceptable accuracy and reduce the computation cost significantly.

关键词： fea Truck Frame Structural Stiffness 3D Solid Element 1D Beam Element

Iterative fea Method for Load Distribution of Flexible Supporting Thin-section Ball Bearing

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Journal of Harbin Institute of Technology(New Series) 2015年第1期22卷 9-14页

作者： Ju Shu Liqin Wang Yuze Mao Yuting Ding School of Mechatronics Engineering Harbin Institute of Technology

To figure out the load distribution of thin-section rolling bearing supported by flexible structure with squirrel cage and the distribution's influence on bearing life,an iterative fea method is proposed to use the result calculated from the Quasi-Dynamic model based on the rigid support hypothesis. The contact angle,contact position and stiffness of equivalent spring are modified during the iterative fea to optimize the fea model,and then the bearings' life can be predicted when the error is below 0.5%. It can be concluded that from the analysis results the load distribution under flexible support is more uniform than that of the rigid support,while the maximum load decreases by 11.2% and bearing life increases by 14.7%. The analysis result of different values of thickness of bearing house,rings and hollow shaft demonstrates the thicknesses of bearing house and hollow shaft have a greater influence on the load's uniformity and bearing's life than those of the rings.

关键词： flexible support with squirrel cage iterative fea

Influence of Skewing Design for Reduction of Force Ripples in DSL-SynRM using 3D fea

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CES Transactions on Electrical Machines and Systems 2019年第4期3卷 397-402页

作者： Anusha Vadde Sudha B M.S.Ramaiah University of applied sciences. Ramaiah University of applied sciences

Double Sided Linear Synchronous Reluctance Motors(DSL-SynRM)are being increasingly used in high force density *** force ripples are one of the major issue in machine which is due to nonlinear nature of current in the *** paper focuses on the reduction of force ripples for increasing the force density of the *** order to reduce the force ripples,DSL-SynRM with a skewed translator is *** proposed structure is designed and developed by using computational magnetic *** concept is effective for reduction of the force ripples and improves the force density of the *** proposed design has been reduced the percentage of force ripples by 21.62%,improved the force density by 10.32 N/mm³and efficiency by 0.89%.

关键词： DSL-SynRM force density force force ripple skewing fea