期刊文献+
共找到10篇文章
< 1 >
每页显示 20 50 100
ANALYSIS OF THREE-DIMENSIONAL UPSETTING PROCESS BY THE RIGID-PLASTIC REPRODUCING KERNEL PARTICLE METHOD 被引量:2
1
作者 Y. H. Liu J. Chen S. Yu X. W. Chen 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2006年第5期371-378,共8页
A meshless approach, called the rigid-plastic reproducing kernel particle method (RKPM), is presented for three-dimensional (3D) bulk metal forming simulation. The approach is a combination of RKPM with the flow t... A meshless approach, called the rigid-plastic reproducing kernel particle method (RKPM), is presented for three-dimensional (3D) bulk metal forming simulation. The approach is a combination of RKPM with the flow theory of 3D rigid-plastic mechanics. For the treatments of essential boundary conditions and incompressibility constraint, the boundary singular kernel method and the modified penalty method are utilized, respectively. The arc-tangential friction model is employed to treat the contact conditions. The compression of rectangular blocks, a typical 3D upsetting operation, is analyzed for different friction conditions and the numerical results are compared with those obtained using commercial rigid-plastic FEM (finite element method) software Deform^3D. As results show, when handling 3D plastic deformations, the proposed approach eliminates the need of expensive meshing and remeshing procedures which are unavoidable in conventional FEM and can provide results that are in good agreement with finite element predictions. 展开更多
关键词 MESHLESS reproducing kernel particle method(RKPM) three-dimensional upsetting INCOMPRESSIBILITY modified penalty method
下载PDF
Neutron-induced single event upset simulation in Geant4 for three-dimensional die-stacked SRAM
2
作者 Li-Hua Mo Bing Ye +6 位作者 Jie Liu Jie Luo You-Mei Sun Chang Cai Dong-Qing Li Pei-Xiong Zhao Ze He 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第3期394-401,共8页
Three-dimensional integrated circuits(3D ICs)have entered into the mainstream due to their high performance,high integration,and low power consumption.When used in atmospheric environments,3D ICs are irradiated inevit... Three-dimensional integrated circuits(3D ICs)have entered into the mainstream due to their high performance,high integration,and low power consumption.When used in atmospheric environments,3D ICs are irradiated inevitably by neutrons.In this paper,a 3D die-stacked SRAM device is constructed based on a real planar SRAM device.Then,the single event upsets(SEUs)caused by neutrons with different energies are studied by the Monte Carlo method.The SEU cross-sections for each die and for the whole three-layer die-stacked SRAM device is obtained for neutrons with energy ranging from 1 MeV to 1000 MeV.The results indicate that the variation trend of the SEU cross-section for every single die and for the entire die-stacked device is consistent,but the specific values are different.The SEU cross-section is shown to be dependent on the threshold of linear energy transfer(LETth)and thickness of the sensitive volume(Tsv).The secondary particle distribution and energy deposition are analyzed,and the internal mechanism that is responsible for this difference is illustrated.Besides,the ratio and patterns of multiple bit upset(MBU)caused by neutrons with different energies are also presented.This work is helpful for the aerospace IC designers to understand the SEU mechanism of 3D ICs caused by neutrons irradiation. 展开更多
关键词 NEUTRON three-dimension ICs single event upset multi-bit upset GEANT4
下载PDF
TC4-DT合金改锻工艺及超塑性变形行为 被引量:7
3
作者 喻淼真 王高潮 +2 位作者 郑漫庆 王志录 徐雪峰 《塑性工程学报》 CAS CSCD 北大核心 2013年第5期1-6,共6页
为研究TC4-DT钛合金的细化机理与超塑性变形行为,采用三维镦拔形变热处理改锻工艺对供货态的TC4-DT合金进行细晶化处理,并在电子拉伸实验机上采用最大m值法对细晶化和供应态的TC4DT进行拉伸实验。结果表明,采用三维镦拔工艺可简单有... 为研究TC4-DT钛合金的细化机理与超塑性变形行为,采用三维镦拔形变热处理改锻工艺对供货态的TC4-DT合金进行细晶化处理,并在电子拉伸实验机上采用最大m值法对细晶化和供应态的TC4DT进行拉伸实验。结果表明,采用三维镦拔工艺可简单有效的细化TC4-DT合金的原始组织,平均晶粒尺寸由原始组织的70μm细化至15μm;在变形温度850℃-900℃、最大m值法的试验条件下,处理后的TC4DT合金均表现出比供货态超塑性能好,最佳变形温度为870℃,最大延伸率可达到1233%。 展开更多
关键词 三维镦拔工艺 TC4-DT合金 细化晶粒 超塑性
下载PDF
基于三维镦拔工艺的TC4合金细晶超塑性 被引量:3
4
作者 梁军辉 王高潮 +1 位作者 马超 张杰刚 《热加工工艺》 CSCD 北大核心 2012年第23期1-4,共4页
钛合金的晶粒尺寸对其超塑性能有着显著影响。采用三维镦拔形变热处理工艺对供货态的TC4合金进行细晶化处理,然后采用恒应变速率法对细晶TC4合金的超塑性进行了研究。结果表明:采用三维镦拔工艺能简单、有效地细化TC4合金的原始组织,平... 钛合金的晶粒尺寸对其超塑性能有着显著影响。采用三维镦拔形变热处理工艺对供货态的TC4合金进行细晶化处理,然后采用恒应变速率法对细晶TC4合金的超塑性进行了研究。结果表明:采用三维镦拔工艺能简单、有效地细化TC4合金的原始组织,平均晶粒尺寸由原始组织的50μm细化至15μm。在变形温度800~950℃,应变速率为2.2×10-4s-1的试验条件下,处理后的TC4合金均表现出良好的超塑性能,最大伸长率达到747%。 展开更多
关键词 三维镦拔工艺 TC4合金 细化晶粒 超塑性
下载PDF
The Characteristics Analysis and Cogging Torque Optimization of a Surface-Interior Permanent Magnet Synchronous Motor 被引量:3
5
作者 Jikai Si Suzhen Zhao +2 位作者 Lufeng Zhang Ruiwu Cao Wenping Cao 《Chinese Journal of Electrical Engineering》 CSCD 2018年第4期41-47,共7页
This paper proposes optimal stator skewed slot analytical method for cogging torque reduction in surface-interior permanent magnet synchronous motor(SIPMSM)and analyzes the characteristics of SIPMSM.The series-paralle... This paper proposes optimal stator skewed slot analytical method for cogging torque reduction in surface-interior permanent magnet synchronous motor(SIPMSM)and analyzes the characteristics of SIPMSM.The series-parallel equivalent magnetic circuit models(EMCMs)of SIPMSM is built based on the characteristics of magnetic circuits,which is used to design the basic electromagnetic parameters of SIPMSM.Analytical expressions of cogging torque are derived from applying analytical techniques.Stator skewed slot for cogging torque minimum is adopted,and the stator skewed slot pitch is confirmed based on the analytical expressions of the resultant cogging torque.The cogging torque,torque ripple,back electromotive force(back-EMF),power-angle characteristics,efficiency and power factor of SIPMSM are analyzed by establishing 3-dimensional finite element model(3-D-FED)of SIPMSM with stator skewed slot and straight slot.It is shown that the comprehensive performance of optimized SIPMSM is improved as confirmed by finite element analysis and analytical calculation results. 展开更多
关键词 Surface-interior permanent magnet synchronous motor(SIPMSM) cogging torque stator skewed slot three-dimensional finite element model(3-D-FED)
原文传递
55NiCrMoV7钢锭热加工过程的微观组织与力学性能 被引量:1
6
作者 禹兴胜 武川 +1 位作者 石如星 汪雨昌 《热加工工艺》 北大核心 2021年第15期30-32,36,共4页
通过热加工试验(镦粗、拔长与热处理)结合扫描电子显微镜观察和力学性能测试,研究55NiCrMoV7钢锭的变形过程微观组织演化、断裂机制和力学性能变化。结果表明,随着镦拔变形量的增加,钢锭的铸态组织和缺陷可以逐步消除,材料的屈服强度、... 通过热加工试验(镦粗、拔长与热处理)结合扫描电子显微镜观察和力学性能测试,研究55NiCrMoV7钢锭的变形过程微观组织演化、断裂机制和力学性能变化。结果表明,随着镦拔变形量的增加,钢锭的铸态组织和缺陷可以逐步消除,材料的屈服强度、抗拉强度、伸长率和冲击韧性随着变形量增加而增加,断裂方式从铸态的完全脆性断裂逐渐过渡到脆性和韧性混合的断裂方式。调质热处理对马氏体形貌和碳化物的析出产生影响,进一步提高了材料的强度、塑性和韧性。 展开更多
关键词 镦拔变形 热作模具钢 微观组织演化 调质处理
下载PDF
Developing a 3D-FEM Model for Electromagnetic Analysis of an Axial Flux Permanent Magnet Machine
7
作者 Seyyed Mehdi Mirimani Abolfazl Vahedi 《Journal of Electromagnetic Analysis and Applications》 2010年第4期258-263,共6页
Recently, many optimal designs for axial flux permanent magnet (AFPM) motors were performed based on finite- element (FE) analysis. Most of the models are based on reduction of 3D problem to 2D problem which is not ac... Recently, many optimal designs for axial flux permanent magnet (AFPM) motors were performed based on finite- element (FE) analysis. Most of the models are based on reduction of 3D problem to 2D problem which is not accurate for design aspects. This paper describes an accurate electromagnetic analysis of a surface mounted, 28 pole AFPM with concentrated stator winding. The AFPM is modeled with three-dimensional finite-element method. This model in-cludes all geometrical and physical characteristics of the machine components. Using this accurate modeling makes it possible to obtain demanded signals for a very high precision analysis. Magnetic flux density, back-EMF, magnetic axial force and cogging torque of the motor are simulated using FLUX-3D V10.3.2. Meanwhile, the model is paramet-ric and can be used for design process and sensitivity analysis. 展开更多
关键词 AXIAL Flux PERMANENT MAGNET (AFPM) Motor three-dimensional FINITE-ELEMENT Method (3D-FEM) cogging TORQUE
下载PDF
优质GH4738合金棒材夹杂物研究 被引量:8
8
作者 郑宏波 杨树峰 +1 位作者 陈正阳 李京社 《中国冶金》 CAS 北大核心 2018年第S1期41-45,共5页
为了研究针对由三联工艺(真空感应熔炼+电渣重熔+真空自耗重熔)冶炼,经镦拔工艺开坯生产出的镍基高温合金优质GH4738棒材中夹杂物的类型与分布情况,通过扫描电镜和能谱仪分别对棒材横向和纵向的边缘、1/2半径处和中心处的夹杂物进行了检... 为了研究针对由三联工艺(真空感应熔炼+电渣重熔+真空自耗重熔)冶炼,经镦拔工艺开坯生产出的镍基高温合金优质GH4738棒材中夹杂物的类型与分布情况,通过扫描电镜和能谱仪分别对棒材横向和纵向的边缘、1/2半径处和中心处的夹杂物进行了检测,分析了夹杂物的成分、尺寸和数量。结果表明,优质GH4738合金棒材中的夹杂物主要为Ti(C,N)-MoS复合夹杂物、Ti(C,N)夹杂物、SiC夹杂物以及非常少量的Al2O3、MgO氧化物夹杂物,数量百分比分别为70%、20%、8%和2%。经镦拔开坯后,从中心到边缘处夹杂物总数递增,棒材横向上夹杂物尺寸呈降低趋势,但不同位置处夹杂物的平均尺寸差别不明显。 展开更多
关键词 GH4738 夹杂物 三联工艺 镦拔开坯
原文传递
铝合金锻造开坯变形均匀性数值模拟与实验验证 被引量:2
9
作者 李鹏伟 李翌瑞 +2 位作者 蔡安辉 王昕 周宏志 《锻压技术》 CAS CSCD 北大核心 2022年第8期1-6,28,共7页
锻造开坯变形均匀性是影响锻件质量的重要因素。以2A14铝合金为研究对象,利用Deform-3D有限元软件对锻坯应变场进行模拟,通过引入平均等效应变ε_(ave)、变形均匀系数a,结合晶粒形貌观察和拉伸力学性能测试,对“单向镦粗”和“多向镦粗... 锻造开坯变形均匀性是影响锻件质量的重要因素。以2A14铝合金为研究对象,利用Deform-3D有限元软件对锻坯应变场进行模拟,通过引入平均等效应变ε_(ave)、变形均匀系数a,结合晶粒形貌观察和拉伸力学性能测试,对“单向镦粗”和“多向镦粗”两种锻造开坯工艺的变形均匀性进行定量和定性分析。研究结果表明:“多向镦粗”锻造开坯工艺的变形均匀性较“单向镦粗”锻造开坯工艺好,且锻造累积应变量越大,变形均匀性越好,力学性能各向异性越弱。2A14铝合金在多向镦粗锻造开坯过程中,随着累积应变量的增加,晶粒细化机制由晶粒破碎机制逐渐转变为连续动态再结晶机制。 展开更多
关键词 锻造开坯 变形均匀性 多向镦粗 晶粒细化 2A14铝合金
原文传递
A New Technique:Research and industrial application of a novel compound permanent magnet synchronous machine
10
作者 Cheng-zhi FAN Ming-xing HUANG Yun-yue YE 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第4期471-477,共7页
We propose a novel kind of compound permanent magnet synchronous machine (CPMSM), which is applicable in low-speed and high-torque situations. We first explain the structure of the CPMSM. Based on theoretically deduci... We propose a novel kind of compound permanent magnet synchronous machine (CPMSM), which is applicable in low-speed and high-torque situations. We first explain the structure of the CPMSM. Based on theoretically deducing the calculation formulae of the CPMSM electromagnetic parameters, we analyze the operating characteristics of the CPMSM, and obtain the power-angle curves and working curves. The no-load magnetic field distribution and the cogging torque are analyzed by applying the finite element method of three-dimensional (3D) magnetic fields, to determine the no-load leakage coefficient and the waveform of the cogging torque. Furthermore, the optimal parameters of the permanent magnet for reducing the cogging torque are determined. An important application target of the CPMSM is in directdrive pumping units. We have installed and tested a direct- drive pumping unit in an existing oil well. Test results show that the power consumption of the direct-drive pumping unit driven by CPMSM is 61.1% of that of the beam-pumping unit, and that the floor space and weight are only 50% of those of a beam-pumping unit. The noise output does not exceed 58 dB in a range of 1 m around the machine when the machine is 1.5 m from the ground. 展开更多
关键词 Compound permanent magnet synchronous machine (CPMSM) Operating characteristic three-dimensional finite element analysis cogging torque Direct-drive pumping unit
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部