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15CrMo实体膨胀管最优锥角有限元分析 被引量:6
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作者 姚津 何继宁 +1 位作者 任钦贵 宋开红 《石油矿场机械》 2014年第1期25-29,共5页
利用有限元分析软件,根据弹塑性有限元接触问题的相关理论建立了可膨胀管膨胀过程的力学模型。对壁厚6mm的ф108mm管进行膨胀过程的计算机模拟,着重研究在不同膨胀率下,膨胀锥角与锥体完成胀管所需的液压力的变化关系;确定不同膨胀率下... 利用有限元分析软件,根据弹塑性有限元接触问题的相关理论建立了可膨胀管膨胀过程的力学模型。对壁厚6mm的ф108mm管进行膨胀过程的计算机模拟,着重研究在不同膨胀率下,膨胀锥角与锥体完成胀管所需的液压力的变化关系;确定不同膨胀率下所需的液压力最小的锥角值,即获得最优的锥角;研究了最优锥角下膨胀管的力学性能,通过参数优化设置,为现场应用提供理论依据。 展开更多
关键词 膨胀 膨胀液压力 数值模拟 优锥
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锥形避雷针避雷效果最优锥角研究
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作者 郭春轶 张雪华 杨林峰 《重庆科技学院学报(自然科学版)》 CAS 2017年第2期113-114,124,共3页
对圆锥形避雷针的锥角进行模拟计算,在已求得尖端面电荷分布密度的基础上,提出圆锥形避雷针模型在雷电防护中的锥角最优化理论。研究结果表明,高度确定的避雷针,在不同的云层电压下都存在一个避雷效果最好的锥角。
关键词 形避雷针 有效电荷 避雷效果 优锥
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锥形砧镦粗工艺数值模拟及锥角优化研究 被引量:1
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作者 贺佳阳 吴吉文 《南方农机》 2020年第21期129-130,共2页
应用DEFORM-2D有限元软件建立了模拟锥形砧镦粗工艺数值模型,并通过Preform Optimization模块,基于梯度优化法以变形均匀性为目标,选取摩擦系数、坯料高径比、砧与坯料界面传热系数、压下量四个因素进行了正交试验,得出影响锥形砧最优... 应用DEFORM-2D有限元软件建立了模拟锥形砧镦粗工艺数值模型,并通过Preform Optimization模块,基于梯度优化法以变形均匀性为目标,选取摩擦系数、坯料高径比、砧与坯料界面传热系数、压下量四个因素进行了正交试验,得出影响锥形砧最优锥角因素主次顺序:下压量>高径比>摩擦系数>砧与坯料界面传热系数。在此基础上对试验结果进行方差分析,得出下压量因素对于最优锥角的影响极显著,此结论为锥形砧镦粗工艺设计锥形砧锥角提供参考。 展开更多
关键词 锻造 形砧 镦粗 优锥
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基于最优推力锥的级联推力分配算法
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作者 朱孟萍 徐世杰 《航天控制》 CSCD 北大核心 2012年第5期48-54,共7页
推力分配是推力系统冗余配置时航天器姿态控制系统的必备组成单元。针对传统直接搜索法以及单纯形法在分配过程中在线计算量大、工程实现较难的不足,提出了一种基于最优推力锥的级联分配方法。该算法首先进行无约束分配,搜索出实现目标... 推力分配是推力系统冗余配置时航天器姿态控制系统的必备组成单元。针对传统直接搜索法以及单纯形法在分配过程中在线计算量大、工程实现较难的不足,提出了一种基于最优推力锥的级联分配方法。该算法首先进行无约束分配,搜索出实现目标控制量的准最优推力锥,然后用推力器喷气时间上限对无约束问题的最优推力组合进行饱和处理,更新推力器喷气时间上限,计算当前推力组合的控制误差,并作为下一步的目标控制量,更新推力锥,重复迭代,直至控制误差为0或当前目标量的可行锥不存在。文中以空间站核心舱为例进行了仿真,结果显示:与传统单纯形法相比,该方法能在保持计算量优势的前提下,在目标量可实现时能优化推力组合,精确实现目标量;目标量不可实现时,能在可达集内最大限度地实现目标控制量,充分利用了推力系统的控制能力。 展开更多
关键词 推力分配 航天器 推力 级联分配
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基于两阶段优化的主动配电网有功无功协调调度方法 被引量:11
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作者 杭晨辉 黄哲 +1 位作者 孟凡成 史佳琪 《可再生能源》 CAS 北大核心 2019年第1期71-78,共8页
分布式可再生能源出力的不确定性和主动配电网的有功、无功相互耦合,都会影响主动配电网的安全经济运行。文章提出了两阶段随机优化的主动配电网有功、无功协调调度方法,在考虑电力市场电价及保证配电网安全运行的前提下,最小化配电网... 分布式可再生能源出力的不确定性和主动配电网的有功、无功相互耦合,都会影响主动配电网的安全经济运行。文章提出了两阶段随机优化的主动配电网有功、无功协调调度方法,在考虑电力市场电价及保证配电网安全运行的前提下,最小化配电网主体的运行费用,采用二阶锥松弛和线性化技术将主动配电网的有功、无功优化转化为混合整数二阶锥凸优化,以快速求解。最后,以IEEE 33节点辐射型配电网为例,验证了所提模型能够有效处理风光随机性,通过有功无功的协调优化保证配电网的安全稳定运行。 展开更多
关键词 主动配电网 两阶段随机 分布式电源 混合整数二阶
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Z-C-X空间中一类随机方程解的存在性定理 被引量:3
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作者 程素丽 朱传喜 张旭慧 《纯粹数学与应用数学》 CSCD 2010年第2期335-338,352,共5页
在Z-C-X空间中利用优锥的概念,研究了随机半闭1-集压缩算子的若干问题.首先,证明了一个重要的不等式,其次,利用随机拓扑度理论证明了几个新的定理,从而得到一些新的结果.
关键词 Z-C-X空间 随机解 优锥 随机半闭1-集压缩算子
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大膨胀率实体膨胀管膨胀载荷的塑性力学计算 被引量:1
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作者 张丛雷 李春福 +3 位作者 张凤春 申文竹 宋开红 王燕群 《石油机械》 北大核心 2014年第7期1-6,共6页
已有的可膨胀管膨胀模型的力学分析和载荷计算多数建立在弹塑性力学基础上,忽略了套管材料在塑性阶段的应力强化效应,以及膨胀区向定径区过渡时的管体弯曲对轴向应力增量的影响。鉴于此,在已有模型的基础上,采用单一曲线假设和幂强化力... 已有的可膨胀管膨胀模型的力学分析和载荷计算多数建立在弹塑性力学基础上,忽略了套管材料在塑性阶段的应力强化效应,以及膨胀区向定径区过渡时的管体弯曲对轴向应力增量的影响。鉴于此,在已有模型的基础上,采用单一曲线假设和幂强化力学模型,建立了大膨胀率膨胀管膨胀载荷的力学模型,运用ANSYS Workbench14.5建立了膨胀管膨胀过程的三维轴对称模型,并进行了大膨胀率膨胀管膨胀载荷计算。研究结果表明,当膨胀率在15%~30%之间变化、膨胀力最优半锥角在12°~22°之间变化时,所需膨胀力最小;当其他参数恒定,摩擦因数、管半径、壁厚和膨胀率中任一个作为自变量时,膨胀力与该自变量呈线性递增关系。因此,选择合适的摩擦因数、膨胀率和壁厚对降低膨胀管施工难度相当重要;膨胀管应选择强化系数相对较小、硬化指数较大的管材,这样膨胀时所需膨胀力较小。 展开更多
关键词 大膨胀率 实体膨胀管 膨胀力 幂强化力学模型 膨胀
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Anti-interference beam pattern design based on second-order cone programming optimization 被引量:1
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作者 戴文舒 鲍凯凯 +1 位作者 王萍 王黎明 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2016年第3期255-260,共6页
When signal-to-interference ratio is low, the energy of strong interference leaked from the side lobe of beam pattern will infect the detection of weak target. Therefore, the beam pattern needs to be op... When signal-to-interference ratio is low, the energy of strong interference leaked from the side lobe of beam pattern will infect the detection of weak target. Therefore, the beam pattern needs to be optimized. The existing Dolph-Chebyshev weighting method can get the lowest side lobe level under given main lobe width, but for the other non-uniform circular array and nonlinear array, the low side lobe pattern needs to be designed specially. The second order cone programming optimization (SOCP) algorithm proposed in the paper transforms the optimization of the beam pattern into a standard convex optimization problem. Thus there is a paradigm to follow for any array formation, which not only achieves the purpose of Dolph-Chebyshev weighting, but also solves the problem of the increased side lobe when the signal is at end fire direction The simulation proves that the SOCP algorithm can detect the weak target better than the conventional beam forming. 展开更多
关键词 anti-interference beam pattern second-order cone programming optimization (SOCP) weak signal detection
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Improved design of reconfigurable frequency response masking filters based on second-order cone programming
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作者 吴尘 徐新洲 +1 位作者 黄程韦 赵力 《Journal of Southeast University(English Edition)》 EI CAS 2014年第4期422-427,共6页
In order to improve the design results for the reconfigurable frequency response masking FRM filters an improved design method based on second-order cone programming SOCP is proposed.Unlike traditional methods that se... In order to improve the design results for the reconfigurable frequency response masking FRM filters an improved design method based on second-order cone programming SOCP is proposed.Unlike traditional methods that separately design the proposed method takes all the desired designing modes into consideration when designing all the subfilters. First an initial solution is obtained by separately designing the subfilters and then the initial solution is updated by iteratively solving a SOCP problem. The proposed method is evaluated on a design example and simulation results demonstrate that jointly designing all the subfilters can obtain significantly lower minimax approximation errors compared to the conventional design method. 展开更多
关键词 frequency response masking FRM filter optimal design reconfigurability second-order cone programming SOCP
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Generalized cone-subconvexlike set-valued maps and applications to vector optimization 被引量:1
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作者 黄永伟 HUANG Yongwei 《Journal of Chongqing University》 CAS 2002年第2期67-71,共5页
The definitions of cone-subconvexlike set-valued maps and generalized cone-subconvexlike set-valued maps in topological vector spaces are defined by using the relative interiors of ordering cone. The relationships bet... The definitions of cone-subconvexlike set-valued maps and generalized cone-subconvexlike set-valued maps in topological vector spaces are defined by using the relative interiors of ordering cone. The relationships between the two classes of set-valued maps are investigated, and some properties of them are shown. A Gordan type alternative theorem under the assumption of generalized cone-subconvexlikeness of set-valued maps is proved by applying convex separation theorems involving the relative interiors in infinite dimensional spaces. Finally a necessary optimality condition theorem is shown for a general kind of set-valued vector optimization in a sense of weak E-minimizer. 展开更多
关键词 relative interiors generalized cone-subconvexlikeness set-valued vector optimization optimality conditions weak E-minimizer.
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Spacecraft Attitude Control with Saturation and Attitude Forbidden Constraints via Second⁃Order Cone Programming
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作者 CHEN Xi CAO Ruihao HU Qinglei 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2021年第2期237-248,共12页
This paper investigates the optimal control problem of spacecraft reorientation subject to attitude forbidden constraints,angular velocity saturation and actuator saturation simultaneously.A second-order cone programm... This paper investigates the optimal control problem of spacecraft reorientation subject to attitude forbidden constraints,angular velocity saturation and actuator saturation simultaneously.A second-order cone programming(SOCP)technology is developed to solve the strong nonlinear and non-convex control problem in real time.Specifically,the nonlinear attitude kinematic and dynamic are transformed and relaxed to a standard affine system,and linearization and L1 penalty technique are adopted to convexify non-convex inequality constraints.With the proposed quadratic performance index of angular velocity,the optimal control solution is obtained with high accuracy using the successive SOCP algorithm.Finally,the effectiveness of the algorithm is validated by numerical simulation. 展开更多
关键词 spacecraft reorientation attitude forbidden constraints actuator saturation velocity saturation secondorder cone programming(SOCP)
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KUHN-TUCKER NECESSARY CONDITIONS FOR (h, ψ)-MULTIOBJECTIVE OPTIMIZATION PROBLEMS 被引量:6
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作者 XUYihong LIUSanyang 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2004年第4期472-484,共13页
Five kinds of cones are introduced, which are used to establish the constraints qualifications, under which the generalized Kuhn-Tucker necessary conditions are developed for a class of generalized (h,φ)-differentiab... Five kinds of cones are introduced, which are used to establish the constraints qualifications, under which the generalized Kuhn-Tucker necessary conditions are developed for a class of generalized (h,φ)-differentiable single-objective and multiobjective programming problems by using Motzkin's alternative theorem and Ben-Tal generalized algebraic operations. 展开更多
关键词 CONES (h φ)-differentiable functions kuhn-tucker necessary conditions constraint qualifications optimal solutions efficient solutions
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TOPOLOGICAL STRUCTURE OF EFFICIENT SET OF OPTIMIZATION PROBLEM OF SET-VALUED MAPPING 被引量:7
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作者 LI YUANXI 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 1994年第1期115-122,共8页
This paper is concerned with the topological structure of efficient sets for optimizationproblem of set-valued mapping. It is proved that these sets are closed or. connected under someconditions on cone-continuity, co... This paper is concerned with the topological structure of efficient sets for optimizationproblem of set-valued mapping. It is proved that these sets are closed or. connected under someconditions on cone-continuity, cone-convexity and cone-quasiconvexity. 展开更多
关键词 Optimization of set-valued mapping Vector optimization Efficient solution Cone-convexity Cone-quasiconvexity Closedness Connectedness.
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EXTENSION OF SMOOTHING NEWTON ALGORITHMS TO SOLVE LINEAR PROGRAMMING OVER SYMMETRIC CONES 被引量:3
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作者 Zhenghai HUANG Xiaohong LIU 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2011年第1期195-206,共12页
There recently has been much interest in studying some optimization problems over symmetric cones. This paper deals with linear programming over symmetric cones (SCLP). The objective here is to extend the Qi-Sun-Zho... There recently has been much interest in studying some optimization problems over symmetric cones. This paper deals with linear programming over symmetric cones (SCLP). The objective here is to extend the Qi-Sun-Zhou's smoothing Newton algorithm to solve SCLP, where characterization of symmetric cones using Jordan algebras forms the fundamental basis for our analysis. By using the theory of Euclidean Jordan algebras, the authors show that the algorithm is globally and locally quadratically convergent under suitable assumptions. The preliminary numerical results for solving the second-order cone programming are also reported. 展开更多
关键词 Euclidean Jordan algebra linear programming smoothing algorithm symmetric cone.
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ON CONE D.C. OPTIMIZATION AND CONJUGATE DUALITY
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作者 M.SEMU 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2003年第4期521-528,共8页
This paper derives first order necessary and sufficient conditions for unconstrained coned.c. Programming problems where the underlined space is partially ordered with respect to acone. These conditions are given in t... This paper derives first order necessary and sufficient conditions for unconstrained coned.c. Programming problems where the underlined space is partially ordered with respect to acone. These conditions are given in terms of directional derivatives and subdifferentials of thecomponent functions. Moreover, conjugate duality for cone d.c. Optimization is discussed andweak duality theorem is proved in a more general partially ordered linear topological vectorspace (generalizing the results in [11]). 展开更多
关键词 Multi objective optimization Cone d.c. programming Optimality conditions Conjugate duality
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HENIG GLOBALLY EFFICIENCY FOR SET-VALUED OPTIMIZATION AND VECTOR VARIATIONAL INEQUALITY 被引量:6
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作者 YU Guolin 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2014年第2期338-349,共12页
This paper deals with Henig globally efficiency in vector optimization involving generalized cone-preinvex set-valued mapping. Some properties of generalized cone-preinvex set-valued map are derived. It also disclose ... This paper deals with Henig globally efficiency in vector optimization involving generalized cone-preinvex set-valued mapping. Some properties of generalized cone-preinvex set-valued map are derived. It also disclose the closed relationships between Henig globally efficiency of generalized conepreinvex set-valued optimization problem and Henig globally efficiency of a kind of vector variational inequality. 展开更多
关键词 Contingent epiderivative generalized cone-preinvex set-valued mapping Henig globallyefficiency set-valued optimization vector variational inequality.
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Optimization of Pyrolysis Properties using TGA and Cone Calorimeter Test
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作者 Won-Hee Park Kyung-Beom Yoon 《Journal of Thermal Science》 SCIE EI CAS CSCD 2013年第2期168-173,共6页
The present paper describes an optimization work to obtain the properties related to a pyrolysis process in the solid material such as density, specific heat, conductivity of virgin and char, heat of pyrolysis and kin... The present paper describes an optimization work to obtain the properties related to a pyrolysis process in the solid material such as density, specific heat, conductivity of virgin and char, heat of pyrolysis and kinetic parameters used for deciding pyrolysis rate. A repulsive particle swarm optimization algorithm is used to obtain the pyrolysis-related properties. In the previous study all properties obtained only using a cone calorimeter but in this paper both the cone calorimeter and thermo gravimetric analysis (TGA) are used for precisely optimizing the pyrolysis properties. In the TGA test a very small mass is heated up and conduction and heat capacity in the specimen is negligible so kinetic parameters can first be optimized. Other pyrolysis-related properties such as virgin/char specific heat and conductivity and char density are also optimized in the cone calorimeter test with the already decided parameters in the TGA test. 展开更多
关键词 Pyrolysis properties Thermogravimetric analysis Cone calorimeter Repulsive particle swarmoptimization
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