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Digital twin-driven shape-performance-control-application integrated design for unmanned underwater vehicles
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作者 Zhen WANG Ming YANG +2 位作者 Gongbo WANG Yexin LIAN Yunfan WANG 《Science China(Technological Sciences)》 2026年第3期394-396,共3页
As unmanned underwater vehicles (UUVs) are increasingly designed to perform long-duration missions in highly complex and often extreme environments, traditional design methods face significant and growing challenges^(... As unmanned underwater vehicles (UUVs) are increasingly designed to perform long-duration missions in highly complex and often extreme environments, traditional design methods face significant and growing challenges^([1,2]). 展开更多
关键词 integrated design extreme environments long duration missions traditional design methods digital twin unmanned underwater vehicles complex environments shape performance control
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A TRIBAND SWASTIKA SHAPED PATCH ANTENNA WITH REDUCED MUTUAL COUPLING FOR WIRELESS MIMO SYSTEMS 被引量:1
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作者 K Jagadeesh Babu K Sri Ramakrishna L Pratap Reddy 《Journal of Electronics(China)》 2011年第4期483-487,共5页
A novel compact Swastika shaped patch antenna is designed in the present work,which can be used for Multiple Input Multiple Output(MIMO) systems.The proposed two element MIMO system resonates at a triband of 3.3 GHz,5... A novel compact Swastika shaped patch antenna is designed in the present work,which can be used for Multiple Input Multiple Output(MIMO) systems.The proposed two element MIMO system resonates at a triband of 3.3 GHz,5.8 GHz,and 7.1 GHz with an improved impedance bandwidth of 37% and a reduced mutual coupling of-33 dB.These results are better compared to a normal E shaped patch antenna designed with same size and thickness,achieved without using any additional decoupling methods.A 2×2 MIMO system employing the Swastika shaped patch antennas is analyzed using computational electromagnetic ray tracing software for an indoor environment.The results show an improvement in the capacity compared to a 2×2 MIMO system developed with dipole antennas.The proposed antenna is a good choice for MIMO systems operating for several Ultra WideBand(UWB) applications. 展开更多
关键词 Swastika shaped patch antenna Multiple Input Multiple Output(MIMO) Impedance bandwidth Mutual coupling Capacity
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Isogeometric Analysis and Shape Optimization of Holed Structures via the Patch Removing Technique 被引量:1
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作者 Daoyuan Yu Shouyu Cai +1 位作者 Wenya Fan Lan Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第9期787-806,共20页
In this study,a patch removing based Isogeometric analysis(PR-IGA)method is proposed to conduct the holed structural analysis with only one parametric domain,in which there are also no trimmed elements.The theoretical... In this study,a patch removing based Isogeometric analysis(PR-IGA)method is proposed to conduct the holed structural analysis with only one parametric domain,in which there are also no trimmed elements.The theoretical foundation of this novel patch removing approach is that any holed structure can be obtained by removing sub-patches(i.e.,the holes)from an intact base patch.Since the parametric domains of these patches are all meshed by rectangular grids,the elements in the resulted holed structural parametric domain could all be untrimmed rectangles under certain mapping conditions.To achieve the special condition,a systematic technique consisting of T-spline local refinement and control points substitution/adjustment is provided.Due to the intactness of parametric elements,the analysis procedure of holed structures based on the proposed PRIGA is quite simplified and efficient compared to traditional multi-patch and trimming schemes.Moreover,after the deduction of analytical sensitivities related to structural mass and mechanical responses,the PR-IGA is directly employed in the holed structural shape optimization to successfully eliminate the need for model transformation during modeling,analysis and optimization processes.Numerical examples involving analysis and shape optimization of complex holed structures are presented to demonstrate the effectiveness of the proposed method. 展开更多
关键词 Isogeometric analysis patch removing shape optimization holed structure
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Double U-Shaped Slots Loaded Stacked Patch Antenna for Multiband Operation
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作者 Nagendra Prasad Yadav 《Open Journal of Antennas and Propagation》 2015年第2期9-17,共9页
The design of a seven-band stacked patch antenna for the C, X and Ku band is presented. The antenna consists of an H-slot loaded fed patch, stacked with dual U-slot loaded rectangular patch to generate the seven frequ... The design of a seven-band stacked patch antenna for the C, X and Ku band is presented. The antenna consists of an H-slot loaded fed patch, stacked with dual U-slot loaded rectangular patch to generate the seven frequency bands. The total size of the antenna is 39.25 × 29.25 mm2. The multiband stacked patch antenna is studied and designed using IE3D simulator. For verification of simulation results, the antenna is analyzed by circuit theory concept. The simulated return loss, radiation pattern and gain are presented. Simulated results show that the antenna can be designed to cover the frequency bands from (4.24 GHz to 4.50 GHz, 5.02 GHz to 5.25 GHz) in C-band application, (7.84 GHz to 8.23 GHz) in X-band and (12.16 GHz to 12.35 GHz, 14.25 GHz to 14.76 GHz, 15.25 GHz to 15.51 GHz, 17.52 GHz to 17.86 GHz) in Ku band applications. The bandwidths of each band of the proposed antenna are 5.9%, 4.5%, 4.83%, 2.36%, 3.53%, 1.68% and 1.91%. Similarly the gains of the proposed band are 2.80 dBi, 4.39 dBi, 4.54 dBi, 10.26 dBi, 8.36 dBi and 9.91 dBi, respectively. 展开更多
关键词 H-shape Fed patch Microstrip patch ANTENNA DOUBLE U-shape Slot Loaded Stacked patch Multiband ANTENNA
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Analysis and Design of Broadband Stacked Microstrip Patch Antennas 被引量:1
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作者 徐晓文 徐健 +2 位作者 刘章发 朱伯承 李世智 《Journal of Beijing Institute of Technology》 EI CAS 1997年第4期61-66,共6页
A broadband microstrip patch antenna was analyzed and designed.Full wave analysis method(FWAM) was employed to show that a stacked microstrip dual patch antenna(SMDPA) might have a much wider bandwidth than that of ... A broadband microstrip patch antenna was analyzed and designed.Full wave analysis method(FWAM) was employed to show that a stacked microstrip dual patch antenna(SMDPA) might have a much wider bandwidth than that of the ordinanry uni patch one.By means of discrete complex image theory(DCIT),the Sommerfeld integrals (SI) involved were accurately calculated at a speed several hundred times faster than numerical integration method(NIM).The feeding structure of the SMDPA was then improved and the bandwidth was extended to about 22% or more for voltage standing wave ratio (VSWR)s≤2 Finally,a matching network was constructed to obtain a bandwidth of about 25% for s≤1.5. 展开更多
关键词 broadband patch antennas full wave analysis complex image theory Sommerfeld integrals broadband matching
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一种新型宽频带微带贴片天线
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作者 李胜哲 武哲 +1 位作者 云宇 马令坤 《重庆大学学报》 北大核心 2026年第2期92-104,共13页
针对微带天线带宽有限的固有不足,提出一种基于L型寄生结构的宽频带微带贴片天线。采用主辐射贴片与L型寄生贴片组合设计,整体尺寸为0.83λ0×0.83λ0×0.083λ0(λ0为中心频率5 GHz对应的波长)。主辐射贴片工作在TM10模,通过L... 针对微带天线带宽有限的固有不足,提出一种基于L型寄生结构的宽频带微带贴片天线。采用主辐射贴片与L型寄生贴片组合设计,整体尺寸为0.83λ0×0.83λ0×0.083λ0(λ0为中心频率5 GHz对应的波长)。主辐射贴片工作在TM10模,通过L型寄生贴片电磁耦合激发多谐振点扩展带宽,选用介电常数2.2、损耗角正切0.000 9的Rogers5880介质基板降低Q值。采用180°反相差分馈电设计抑制方向图畸变。结果表明,天线在3.6~6.6 GHz频段内电压驻波比小于2,相对带宽达60%,是传统微带天线的6倍。在6.2 GHz峰值增益为9.8 dBi,远高于一般贴片单元,工作频段内增益波动小于1.5 dB。辐射方向图在3.6~6.3 GHz频段内主瓣指向偏差小于5°,交叉极化抑制优于-15 dB,中心频点达-38 dB。该设计通过单层寄生结构实现了宽带高增益特性,适用于5G和Wi-Fi等宽带无线通信系统。 展开更多
关键词 L型寄生结构 宽频带 差分馈电 微带贴片天线
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复杂截面直线导轨的三点弯曲矫直过程的数值模拟与试验验证
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作者 牛犇 张蕊华 +3 位作者 赵晨阳 王志龙 陈朝杰 叶秉良 《锻压技术》 北大核心 2026年第2期284-299,共16页
针对当前复杂截面直线导轨人工矫直精度与效率低的问题,提出了复杂截面直线导轨矫直算法模型。首先,通过预设参考简化截面,并基于线性硬化材料模型,分析了导轨矫直过程中的应力、应变和弯矩,构建了初始挠度与矫直载荷的预测模型。然后,... 针对当前复杂截面直线导轨人工矫直精度与效率低的问题,提出了复杂截面直线导轨矫直算法模型。首先,通过预设参考简化截面,并基于线性硬化材料模型,分析了导轨矫直过程中的应力、应变和弯矩,构建了初始挠度与矫直载荷的预测模型。然后,采用有限元对真实导轨进行矫直仿真,引入形状修正因子,并通过Active-Set最小二乘法对形状修正因子进行优化求解,确定了导轨最佳简化截面尺寸,从而显著提升了矫直精度。此外,通过调整预设参考截面尺寸和矫直跨距,验证了该算法的稳定性。最终,通过矫直试验表明,矫直模型与试验载荷误差控制在4.30%以内,精度较高,可为复杂截面导轨提供矫直参考。 展开更多
关键词 复杂截面直线导轨 三点矫直 矫直载荷 形状修正因子 简化截面尺寸
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一种用于空间要素几何特征度量的新型等效矩形EAPR指数集
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作者 肖天英 齐修东 葛小三 《测绘工程》 2026年第1期19-26,共8页
几何特征指数是量化图形几何特征的基本方法,其准确性和完整性直接影响空间数据处理的效率和成果质量。然而,现有的几何特征指数在实际应用中存在无法全面满足需求的问题。为此,文中提出一种与原始图形具有相同面积和周长的新型等效矩形... 几何特征指数是量化图形几何特征的基本方法,其准确性和完整性直接影响空间数据处理的效率和成果质量。然而,现有的几何特征指数在实际应用中存在无法全面满足需求的问题。为此,文中提出一种与原始图形具有相同面积和周长的新型等效矩形,基于此等效矩形构建几何特征指数集。实验结果表明,平均宽度是影响建筑物功能分类的重要特征;对于宽度均匀度的图形,可以利用等效矩形平均长度近似计算骨架线长度;通过与现有形状特征指数的相关性分析,验证了文中提出的3种矩形指数对图形形状刻画的有效性和独立性;结合理论分析和实际例证,文中提出的矩形指数在刻画图形复杂度方面相较于现有方法具有明显优势,有效提升空间要素几何特征的量化精度,为空间数据处理提供了新的工具和方法。 展开更多
关键词 等面积等周长矩形 平均宽度 骨架线长度 形状复杂度 建筑物形状特征
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复杂异形截面环件径向轧制孔型填充快速模拟
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作者 周黎 兰箭 郑继荣 《塑性工程学报》 北大核心 2026年第1期79-85,共7页
为保证复杂异形截面环件直径达到预计目标尺寸时其孔型填充情况同时符合实际工艺要求,建立了一种环件二维轴对称多步胀形有限元模型,综合运用二维上限元法与二维有限元方法提出了等效矩形截面环件的计算方法,并利用二维上限元法计算等... 为保证复杂异形截面环件直径达到预计目标尺寸时其孔型填充情况同时符合实际工艺要求,建立了一种环件二维轴对称多步胀形有限元模型,综合运用二维上限元法与二维有限元方法提出了等效矩形截面环件的计算方法,并利用二维上限元法计算等效矩形截面环件胀形过程速度场,然后通过二维轴对称有限元软件求解当前胀形步环件孔型填充情况。以钛合金机匣环件为例,采用二维轴对称有限元软件求解时间只需5~15 min,与三维有限元环件轧制模拟结果相比,环件截面填充率和内外径尺寸精度误差均在10%以内。通过环件二维轴对称多步胀形有限元模拟计算,可大幅减少环件轧制工艺设计与优化时间,提高生产效率。 展开更多
关键词 复杂异形截面环件 快速模拟 二维轴对称 有限元模拟
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Additive manufacturing techniques for WC−Co cemented carbides: Principle, progress, and perspective
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作者 Zhan-he LIU Ke-chao ZHOU +5 位作者 Kai-hua SHI Xiao-zan WU He XIAO Chao-qun PENG Ri-chu WANG Xiao-feng WANG 《Transactions of Nonferrous Metals Society of China》 2026年第1期1-24,共24页
Additive manufacturing(AM)technology has emerged as a viable solution for manufacturing complexshaped WC−Co cemented carbide products,thereby expanding their applications in industries such as resource mining,equipmen... Additive manufacturing(AM)technology has emerged as a viable solution for manufacturing complexshaped WC−Co cemented carbide products,thereby expanding their applications in industries such as resource mining,equipment manufacturing,and electronic information.This review provides a comprehensive summary of the progress of AM technology in WC−Co cemented carbides.The fundamental principles and classification of AM techniques are introduced,followed by a categorization and evaluation of the AM techniques for WC−Co cemented carbides.These techniques are classified as either direct AM technology(DAM)or indirect AM technology(IDAM),depending on their inclusion of post-processes like de-binding and sintering.Through an analysis of microstructure features,the most suitable AM route for WC−Co cemented carbide products with controllable microstructure is identified as the indirect AM technology,such as binder jet printing(BJP),which integrates AM with conventional powder metallurgy. 展开更多
关键词 cemented carbides additive manufacturing WC−Co direct additive manufacturing indirect additive manufacturing microstructure complex shapes
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面向大规模矩形相控阵的低复杂度波束赋形方法
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作者 魏文强 余显祥 +1 位作者 朱景晖 崔国龙 《雷达学报(中英文)》 北大核心 2026年第1期166-180,共15页
针对大规模矩形相控阵波束赋形面临的高计算复杂度瓶颈,该文提出一种基于维度解耦的波束加权向量快速设计方法,显著提升设计效率与波束调控灵活性。首先,充分利用矩形面阵的构型特性,推导方位维与俯仰维导向矢量解耦的波束形成表达式,... 针对大规模矩形相控阵波束赋形面临的高计算复杂度瓶颈,该文提出一种基于维度解耦的波束加权向量快速设计方法,显著提升设计效率与波束调控灵活性。首先,充分利用矩形面阵的构型特性,推导方位维与俯仰维导向矢量解耦的波束形成表达式,将传统高维加权向量设计问题高效转化为两个低维加权向量的联合优化问题,从根本上降低计算复杂度。在此基础上,构建以峰值旁瓣电平最小化为代价函数、波束电平与噪声输出功率为约束条件的优化模型,开发基于近端-交替方向乘子法的迭代求解算法,并严格推导算法收敛的充分条件,保障求解稳定性与可靠性。仿真结果验证,所提方法在大幅提升计算效率的同时,不仅能依据先验信息灵活调控主瓣宽度与零陷深度,还可通过调整信噪比损失实现峰值旁瓣抑制性能的精准权衡,展现出优异的工程实用性。 展开更多
关键词 大规模阵列 波束赋形 低复杂度算法 非凸优化 收敛性分析
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基于空间密度聚类和K-shape算法的城市综合体负荷模式聚类方法 被引量:15
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作者 魏勇 李学军 +4 位作者 李万伟 刘嘉明 王喻玺 李正辉 王飞 《电力系统保护与控制》 CSCD 北大核心 2021年第14期37-44,共8页
城市综合体作为新兴负荷种类,其负荷预测的精度直接影响电网的规划与安全运行。然而城市综合体负荷模式易受外部环境影响而出现异常变化,对其直接进行预测的精度不能满足实际运行的要求,需要对城市综合体负荷进行聚类以提取不同的负荷... 城市综合体作为新兴负荷种类,其负荷预测的精度直接影响电网的规划与安全运行。然而城市综合体负荷模式易受外部环境影响而出现异常变化,对其直接进行预测的精度不能满足实际运行的要求,需要对城市综合体负荷进行聚类以提取不同的负荷模式来提高预测的精度,因此提出了一种基于空间密度聚类和K-shape算法的城市综合体负荷模式聚类方法。首先利用自适应空间密度算法(DBSCAN)根据不同区域的密度大小来提取不同季节下综合体负荷的典型日负荷曲线。然后利用K-shape聚类算法在不同季节下对不同综合体的典型日负荷曲线进行聚类分析。最后将仿真结果与K-means、K-medoids的聚类结果进行对比。仿真结果表明,与其他两种方法相比,提出的DBSCAN-K-shape两阶段负荷模式聚类方法对城市综合体负荷进行聚类在不同的聚类指标下均具有较高的精度。 展开更多
关键词 城市综合体 负荷预测 日负荷模式 空间密度聚类 K-shape聚类
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Hydrodynamic Analysis and Shape Optimization for Vertical Axisymmetric Wave Energy Converters 被引量:9
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作者 张万超 刘恒序 +1 位作者 张亮 张学伟 《China Ocean Engineering》 SCIE EI CSCD 2016年第6期954-966,共13页
The absorber is known to be vertical axisymmetric for a single-point wave energy converter (WEC). The shape of the wetted surface usually has a great influence on the absorber's hydrodynamic characteristics which a... The absorber is known to be vertical axisymmetric for a single-point wave energy converter (WEC). The shape of the wetted surface usually has a great influence on the absorber's hydrodynamic characteristics which are closely linked with the wave power conversion ability. For complex wetted surface, the hydrodynamic coefficients have been predicted traditionally by hydrodynamic software based on the BEM. However, for a systematic study of various parameters and geometries, they are too multifarious to generate so many models and data grids. This paper examines a semi-analytical method of decomposing the complex axisyrnmetric boundary into several ring-shaped and stepped surfaces based on the boundary discretization method (BDM) which overcomes the previous difficulties. In such case, by using the linear wave theory based on eigenfunction expansion matching method, the expressions of velocity potential in each domain, the added mass, radiation damping and wave excitation forces of the oscillating absorbers are obtained. The good astringency of the hydrodynamic coefficients and wave forces are obtained for various geometries when the discrete number reaches a certain value. The captured wave power for a same given draught and displacement for various geometries are calculated and compared. Numerical results show that the geometrical shape has great effect on the wave conversion performance of the absorber. For absorbers with the same outer radius and draught or displacement, the cylindrical type shows fantastic wave energy conversion ability at some given frequencies, while in the random sea wave, the parabolic and conical ones have better stabilization and applicability in wave power conversion. 展开更多
关键词 vertical axisymmetric complex wetted surface semi-analytical method ASTRINGENCY geometrical shape
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Structural Dimension Optimization of Robotic Belt Grinding System for Grinding Workpieces with Complex Shaped Surfaces Based on Dexterity Grinding Space 被引量:9
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作者 GAO Zhihui LAN Xiaodong BIAN Yushu 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2011年第3期346-354,共9页
To improve the grinding quality of robotic belt grinding systems for the workpieces with complex shaped surfaces, new concepts of the dexterity grinding point and the dexterity grinding space are proposed and their ma... To improve the grinding quality of robotic belt grinding systems for the workpieces with complex shaped surfaces, new concepts of the dexterity grinding point and the dexterity grinding space are proposed and their mathematical descriptions are defined. Factors influencing the dexterity grinding space are analyzed. And a method to determine the necessary dexterity grinding space is suggested. Based on particle swarm optimization (PSO) method, a strategy to optimize the grinding robot structural dimensions and position with respect to the grinding wheel is put forward to obtain the necessary dexterity grinding space. Finally, to grind an aerial engine blade, a dedicated PPPRRR (P: prismatic R: rotary) grinding robot structural dimensions and position with respect to the grinding wheel are optimized using the above strategy. According to simulation results, if the blade is placed within the dexterity grinding space, only one gripper and one grinding machine are needed to grind its complex shaped surfaces. 展开更多
关键词 GRINDING ROBOTS complex shaped surface particle swarm optimization dexterity grinding space
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Influence of shape anisotropy on microwave complex permeability in carbonyl iron flakes/epoxy resin composites 被引量:8
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作者 温福昇 乔亮 +3 位作者 周栋 左文亮 伊海波 李发伸 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第6期2263-2267,共5页
To explore the mechanism of carbonyl iron flake composites for microwave complex permeability, this paper investigates the feature of the flakes. The shape anisotropy was certified by the results of the magnetization ... To explore the mechanism of carbonyl iron flake composites for microwave complex permeability, this paper investigates the feature of the flakes. The shape anisotropy was certified by the results of the magnetization hysteresis loops and the Mossbauer spectra. Furthermore, the shape anisotropy was used to explain the origin of composite microwave performance, and the calculated results agree with the experiment. It is believed that the shape anisotropy dominates microwave complex permeability, and the natural resonance plays main role in flake. 展开更多
关键词 carbonyl iron flake complex permeability shape anisotropy Mossbauer spectroscopy
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Collaborative manufacturing technologies of structure shape and surface integrity for complex thin-walled components of aero-engine:Status,challenge and tendency 被引量:13
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作者 Biao ZHAO Wenfeng DING +10 位作者 Zhongde SHAN Jun WANG Changfeng YAO Zhengcai ZHAO Jia LIU Shihong XIAO Yue DING Xiaowei TANG Xingchao WANG Yufeng WANG Xin WANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2023年第7期1-24,共24页
Presently,the service performance of new-generation high-tech equipment is directly affected by the manufacturing quality of complex thin-walled components.A high-efficiency and quality manufacturing of these complex ... Presently,the service performance of new-generation high-tech equipment is directly affected by the manufacturing quality of complex thin-walled components.A high-efficiency and quality manufacturing of these complex thin-walled components creates a bottleneck that needs to be solved urgently in machinery manufacturing.To address this problem,the collaborative manufacturing of structure shape and surface integrity has emerged as a new process that can shorten processing cycles,improve machining qualities,and reduce costs.This paper summarises the research status on the material removal mechanism,precision control of structure shape,machined surface integrity control and intelligent process control technology of complex thin-walled components.Numerous solutions and technical approaches are then put forward to solve the critical problems in the high-performance manufacturing of complex thin-wall components.The development status,challenge and tendency of collaborative manufacturing technologies in the high-efficiency and quality manufacturing of complex thin-wall components is also discussed. 展开更多
关键词 Collaborative manufacturing of shape and performance Complex thin-walled component Intelligent process control Material removal mechanism Surface integrity
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SOLUTION OF DIFFERENT HOLES SHAPE BORDERS OF FIBRE REINFORCED COMPOSITE PLATES BY INTEGRAL EQUATIONS 被引量:3
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作者 LI Cheng ZHENG Yanping CHEN Zhongzhong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2007年第5期23-27,共5页
Accurate boundary conditions of composite material plates with different holes are founded to settle boundary condition problems of complex holes by conformal mapping method upon the nonhomogeneous anisotropic elastic... Accurate boundary conditions of composite material plates with different holes are founded to settle boundary condition problems of complex holes by conformal mapping method upon the nonhomogeneous anisotropic elastic and complex function theory. And then the two stress functions required were founded on Cauchy integral by boundary conditions. The final stress distributions of opening structure and the analytical solution on composite material plate with rectangle hole and wing manholes were achieved. The influences on hole-edge stress concentration factors are discussed under different loads and fiber direction cases, and then contrast calculates are carried through FEM. 展开更多
关键词 Fibre reinforced composite Accurate boundary conditions Mapping functions Complex hole shape Integral equations
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Finite Element Modeling and Design of Rectangular Patch Antenna with Different Feeding Techniques 被引量:1
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作者 Rajat Arora Ajay Kumar +1 位作者 Saleem Khan Sandeep Arya 《Open Journal of Antennas and Propagation》 2013年第2期11-17,共7页
The finite element modeling of three dimensional structures is important for researchers especially in the field of antennas and other domains of electromagnetic waves. This paper presents a finite element calculation... The finite element modeling of three dimensional structures is important for researchers especially in the field of antennas and other domains of electromagnetic waves. This paper presents a finite element calculations and numerical analysis for the microstrip patch antennas. In this paper, two different designs have been modelled and analyzed and both designs are based on the rectangular patches. The feeding point of one design is inside the patch while the other design contains feeding point outside the patch is T shaped. The computational analysis showed some interesting results for radiation pattern and far field domain. For these designs, the characteristic impedance taken is 50 Ω and the operating frequency domain is 1.4 to 1.7 GHz. The microstrip patch antennas are encapsulated in the inert spherical atmosphere of 20 mm thickness containing air inside it. 展开更多
关键词 MICROSTRIP patch Antenna Finite Element Method T shapeD FEEDING Point FAR Field Domain
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Multiresolution method for bending of plates with complex shapes 被引量:1
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作者 Jizeng WANG Yonggu FENG +2 位作者 Cong XU Xiaojing LIU Youhe ZHOU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第4期561-582,共22页
A high-accuracy multiresolution method is proposed to solve mechanics problems subject to complex shapes or irregular domains.To realize this method,we design a new wavelet basis function,by which we construct a fifth... A high-accuracy multiresolution method is proposed to solve mechanics problems subject to complex shapes or irregular domains.To realize this method,we design a new wavelet basis function,by which we construct a fifth-order numerical scheme for the approximation of multi-dimensional functions and their multiple integrals defined in complex domains.In the solution of differential equations,various derivatives of the unknown function are denoted as new functions.Then,the integral relations between these functions are applied in terms of wavelet approximation of multiple integrals.Therefore,the original equation with derivatives of various orders can be converted to a system of algebraic equations with discrete nodal values of the highest-order derivative.During the application of the proposed method,boundary conditions can be automatically included in the integration operations,and relevant matrices can be assured to exhibit perfect sparse patterns.As examples,we consider several second-order mathematics problems defined on regular and irregular domains and the fourth-order bending problems of plates with various shapes.By comparing the solutions obtained by the proposed method with the exact solutions,the new multiresolution method is found to have a convergence rate of fifth order.The solution accuracy of this method with only a few hundreds of nodes can be much higher than that of the finite element method(FEM)with tens of thousands of elements.In addition,because the accuracy order for direct approximation of a function using the proposed basis function is also fifth order,we may conclude that the accuracy of the proposed method is almost independent of the equation order and domain complexity. 展开更多
关键词 MULTIRESOLUTION generalized Coiflet wavelet integral collocation method irregular domain complex shape high accuracy plate bending
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3D analysis of functionally graded material plates with complex shapes and various holes
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作者 曹志远 唐寿高 程国华 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2009年第1期13-18,共6页
In this paper, the basic formulae for the semi-analytical graded FEM on FGM members are derived. Since FGM parameters vary along three space coordinates, the parameters can be integrated in mechanical equations. There... In this paper, the basic formulae for the semi-analytical graded FEM on FGM members are derived. Since FGM parameters vary along three space coordinates, the parameters can be integrated in mechanical equations. Therefore with the parameters of a given FGM plate, problems of FGM plate under various conditions can be solved. The approach uses 1D discretization to obtain 3D solutions, which is proven to be an effective numerical method for the mechanical analyses of FGM structures. Examples of FGM plates with complex shapes and various holes are presented. 展开更多
关键词 functionally graded material semi-analytical method complex shape 3D analysis HOLE
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