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斜拉桥最优索力的探讨 被引量:56
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作者 陆楸 徐有光 《中国公路学报》 EI CAS CSCD 北大核心 1990年第1期38-48,共11页
斜拉桥作为高次超静定结构,其斜拉索力对梁的应力和变形起着决定性作用。按刚性支承连续梁法或零位移法确定的斜拉索力虽可达到梁内弯矩合理分布,但塔底弯矩往往得不到控制,且要达到这一索力状态,随施工方法不同而应有不同的初始张拉力... 斜拉桥作为高次超静定结构,其斜拉索力对梁的应力和变形起着决定性作用。按刚性支承连续梁法或零位移法确定的斜拉索力虽可达到梁内弯矩合理分布,但塔底弯矩往往得不到控制,且要达到这一索力状态,随施工方法不同而应有不同的初始张拉力和体系完成后的二次张拉力。本文提出了以斜拉索用量(索力×索长)最小为目标,任一受力阶段的梁、塔内力或位移满足容许值为约束条件来确定最优初始张拉力、二次张拉力以及恒载索力的方法。并通过计算实例论证了本文方法的正确性,通用性和合理性。 展开更多
关键词 斜拉桥 最优索 应力分析
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混凝土斜拉桥的最优索力调整
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作者 谢邦珠 《西南公路》 1996年第2期38-51,共14页
在斜拉桥施工中经常遇到两种误差;一是用千斤顶张拉索力的施力误差;一是控制梁标高的几何误差。通常通过调整索力把这两种误差保持在规定的容限内。然而,预应力混凝土斜拉桥徐变的影响不能忽略。如果不考虑徐变的影响,那么就可能在徐变... 在斜拉桥施工中经常遇到两种误差;一是用千斤顶张拉索力的施力误差;一是控制梁标高的几何误差。通常通过调整索力把这两种误差保持在规定的容限内。然而,预应力混凝土斜拉桥徐变的影响不能忽略。如果不考虑徐变的影响,那么就可能在徐变终止时超过容许的拉力幅度。本文提出可以考虑徐变影响的最优化施力方法。提出了若干最优化准则,然后通过使起因于索力的功量极小化,获得最优调整的索力。此外,还可使由施力误差引起的残余应力极小化。最后,引举若干例子说明本文提出的方法。 展开更多
关键词 混凝土桥 斜拉桥 最优索 调整 工程施工
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基于线性规划的某特大桥施工扣索索力优选分析 被引量:1
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作者 张耀庭 颜燕祥 +2 位作者 张正哲 李艳芳 张敏 《土木工程与管理学报》 2014年第3期12-16,共5页
随着斜拉桥等大跨度桥梁工程的发展,桥梁上部结构与桥墩(台)之间连接的钢索索力的确定已成为桥梁设计与施工过程中的关键技术问题,索力取值合理与否直接关系到结构施工及运营阶段的安全与正常使用问题。本文结合某特大桥的施工,将线性... 随着斜拉桥等大跨度桥梁工程的发展,桥梁上部结构与桥墩(台)之间连接的钢索索力的确定已成为桥梁设计与施工过程中的关键技术问题,索力取值合理与否直接关系到结构施工及运营阶段的安全与正常使用问题。本文结合某特大桥的施工,将线性规划原理引入到该桥的施工索力优化当中,以扣索用量最少为目标函数,以拉索索力大小为控制变量,以关键截面应力和悬臂端点挠度为约束条件;借助ANSYS软件和MATLAB工具,实现了结构线性工作阶段的施工(临时)扣索索力的优选分析。与已有的索力确定方法相比,本文提出的确定索力方法可减少施工过程中的调索次数,并提高设计索力的精度,为同类工程中钢索相对最优张拉力的确定提供了一种新的思路。 展开更多
关键词 施工扣 最优索 线性规划 目标函数
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斜拉桥成桥优化索力实用方法 被引量:1
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作者 牟严松 杨虎根 严允中 《贵州工业大学学报(自然科学版)》 CAS 2008年第6期147-150,共4页
斜拉桥的成桥状态的确定是斜拉桥设计工作中最重要的一个环节,成桥状态的合理性是保证斜拉桥结构安全、经济合理的重要前提。介绍了使用MIADS程序对斜拉桥成桥索力进行优化的方法,这个方法概念明确、简便易行、容易使设计者掌握和实际... 斜拉桥的成桥状态的确定是斜拉桥设计工作中最重要的一个环节,成桥状态的合理性是保证斜拉桥结构安全、经济合理的重要前提。介绍了使用MIADS程序对斜拉桥成桥索力进行优化的方法,这个方法概念明确、简便易行、容易使设计者掌握和实际应用。 展开更多
关键词 斜拉桥 成桥状态 最优索 最小弯曲能量法
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单面双空间索面部分斜拉桥关键技术分析——以什川黄河大桥为例
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作者 张春明 《工程技术研究》 2023年第3期18-20,共3页
什川黄河大桥为双塔三跨单面双空间索面预应力混凝土部分斜拉桥,文章以其为研究对象,分析其结构特征与设计经验,以期提供单面双空间索面部分斜拉桥关键技术参考。分析该桥主梁截面构造及基于索力与预应力优化的斜拉索合理成桥状态,发现... 什川黄河大桥为双塔三跨单面双空间索面预应力混凝土部分斜拉桥,文章以其为研究对象,分析其结构特征与设计经验,以期提供单面双空间索面部分斜拉桥关键技术参考。分析该桥主梁截面构造及基于索力与预应力优化的斜拉索合理成桥状态,发现该项目基于部分斜拉桥的力学特性,首次提出用钢-混斜撑杆解决单箱断面长悬臂设计问题。 展开更多
关键词 斜拉桥 单面双空间 最优索 筋用量比
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可重构柔索并联机器人协同避障方法研究 被引量:10
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作者 訾斌 王炳尧 +1 位作者 刘浩 钱森 《仪器仪表学报》 EI CAS CSCD 北大核心 2017年第3期593-601,共9页
针对可重构索驱动机器人自身结构与环境障碍物间高碰撞风险问题,设计了一种基于临界支撑线及多指抓握的可重构柔索机器人协同避障方法。通过简化环境障碍物与机器人结构得到一类可重构柔索机器人在复杂环境下的一般模型,在此模型基础上... 针对可重构索驱动机器人自身结构与环境障碍物间高碰撞风险问题,设计了一种基于临界支撑线及多指抓握的可重构柔索机器人协同避障方法。通过简化环境障碍物与机器人结构得到一类可重构柔索机器人在复杂环境下的一般模型,在此模型基础上利用其结构的拓扑约束及障碍物间的临界支撑线求取机器人的无碰撞运动区域;通过凸包算法及凸包映射算法求取不同构型及障碍物分布下可重构柔索并联机器人的力封闭工作空间,并分析不同构型及障碍物分布对机器人无碰撞力封闭工作空间的影响;随后,通过优化算法求取指定运动轨迹上最优索分布;最后在重构索驱动机器人实验平台对所得优化结果进行验证。实验结果显示,所设计的可重构柔索机器人协同避障方法能有效避免重构索驱动机器人运动过程中的碰撞。 展开更多
关键词 可重构柔并联机器人 协同避障 力封闭工作空间 多指抓握 最优索力分布
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系杆拱桥吊杆索力及施工张拉力确定方法 被引量:2
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作者 张传龙 虞建成 《山东交通科技》 2011年第6期51-53,56,共4页
结合工程实例,基于MIDAS软件平台就吊杆的成桥状态最优索力及施工张拉力的问题进行研究,通过对比分析不同计算方法所得的结果,得出了一些结论。
关键词 系杆拱桥 最优索 施工张拉力 MIDAS
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拱、弯梁与索空间组合桥梁的成桥调索方法 被引量:2
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作者 梁栋 马金龙 +1 位作者 刘志强 王云燕 《公路交通科技》 CAS CSCD 北大核心 2016年第8期86-91,105,共7页
利用修正的Ernst公式考虑吊索几何非线性,以影响矩阵法为理论基础,以目标索力差值和拱肋横向位移为双控制目标,采用以弯曲应变能最小为约束条件的最小能量法进行拱、弯梁与索空间组合结构的索力优化计算,约束最优方法求解出拱、弯梁与... 利用修正的Ernst公式考虑吊索几何非线性,以影响矩阵法为理论基础,以目标索力差值和拱肋横向位移为双控制目标,采用以弯曲应变能最小为约束条件的最小能量法进行拱、弯梁与索空间组合结构的索力优化计算,约束最优方法求解出拱、弯梁与索空间组合结构的施调索力、最优调索顺序以及调索过程索力控制终值。结合世界上跨度最大的拱、弯梁与索组合结构的工程调索实例,利用有限元法实现了调索计算。结果表明,该方法所确定的调索张拉顺序、施调索力能够满足调索施工控制要求,最终成桥状态亦达到设计要求,为今后类似结构的调索工程提供了重要参考。 展开更多
关键词 桥梁工程 力调整 影响矩阵理论 空间受力体系 最优顺序
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基于影响矩阵法的斜拉桥合理成桥索力确定
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作者 谢小辉 刘辉 《中国建材科技》 2014年第S1期240-241,共2页
斜拉桥是一种高次超静定的复杂结构体系,其拉索索力的大小对整个桥梁结构的内力分布好坏具有很大的影响,是全桥受力控制的关键因素之一,因此,对如何确定合理成桥索力将成为斜拉桥设计的关键问题。对此,本文以嘉绍大桥为工程背景,基于影... 斜拉桥是一种高次超静定的复杂结构体系,其拉索索力的大小对整个桥梁结构的内力分布好坏具有很大的影响,是全桥受力控制的关键因素之一,因此,对如何确定合理成桥索力将成为斜拉桥设计的关键问题。对此,本文以嘉绍大桥为工程背景,基于影响矩阵法,运用大型有限元软件ANSYS的二次开发技术,编制了合理成桥索力确定的优化程序,最终得到成桥状态下的一组最优索力。 展开更多
关键词 斜拉桥 合理成桥 影响矩陈法 二次开发技术 最优索
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一维优化的最优步长因子法
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作者 邹友金 《上海机械学院学报》 1989年第4期43-50,共8页
本文在分析一维优化方法的比例因子法的基础上,提出了一种直接调整步长的最优步长因子法并给出框图。该法较比例因子法理论上完善,迭代控制可靠。
关键词 最优 最优化算法 最优
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The optimal fractional Gabor transform based on the adaptive window function and its application 被引量:4
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作者 陈颖频 彭真明 +2 位作者 贺振华 田琳 张洞君 《Applied Geophysics》 SCIE CSCD 2013年第3期305-313,358,共10页
We designed the window function of the optimal Gabor transform based on the time-frequency rotation property of the fractional Fourier transform. Thus, we obtained the adaptive optimal Gabor transform in the fractiona... We designed the window function of the optimal Gabor transform based on the time-frequency rotation property of the fractional Fourier transform. Thus, we obtained the adaptive optimal Gabor transform in the fractional domain and improved the time-frequency concentration of the Gabor transform. The algorithm first searches for the optimal rotation factor, then performs the p-th FrFT of the signal and, finally, performs time and frequency analysis of the FrFT result. Finally, the algorithm rotates the plane in the fractional domain back to the normal time-frequency plane. This promotes the application of FrFT in the field of high-resolution reservoir prediction. Additionally, we proposed an adaptive search method for the optimal rotation factor using the Parseval principle in the fractional domain, which simplifies the algorithm. We carried out spectrum decomposition of the seismic signal, which showed that the instantaneous frequency slices obtained by the proposed algorithm are superior to the ones obtained by the traditional Gabor transform. The adaptive time frequency analysis is of great significance to seismic signal processing. 展开更多
关键词 FrFT generalized time bandwidth product optimal rotation factor search adaptive optimal Gabor transform spectral decomposition seismic signals
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A Modified Algorithm for Nonliear Integer Programming 被引量:2
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作者 孙会霞 《Chinese Quarterly Journal of Mathematics》 CSCD 2002年第3期24-29,共6页
Based on the analysis to the random sear ch algorithm of LUUS, a modified random directed integer search algorithm (MRDI SA) is given for first time. And a practical example is given to show that the adva ntage of th... Based on the analysis to the random sear ch algorithm of LUUS, a modified random directed integer search algorithm (MRDI SA) is given for first time. And a practical example is given to show that the adva ntage of this kind of algorithm is the reliability can’t be infuenced by the ini tial value X (0) and the start search domain R (0) . Besides, i t can be applied to solve the higher dimensional constrained nonlinear integer p rogramming problem. 展开更多
关键词 random search integer programming optimal soluti on RELIABILITY
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Niche Genetic Algorithm with Accurate Optimization Performance 被引量:2
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作者 LIUJian-hua YANDe-kun 《Journal of China University of Mining and Technology》 EI 2005年第2期100-104,共5页
Based on crowding mechanism, a novel niche genetic algorithm was proposed which can record evolution- ary direction dynamically during evolution. After evolution, the solutions’s precision can be greatly improved by ... Based on crowding mechanism, a novel niche genetic algorithm was proposed which can record evolution- ary direction dynamically during evolution. After evolution, the solutions’s precision can be greatly improved by means of the local searching along the recorded direction. Simulation shows that this algorithm can not only keep population diversity but also find accurate solutions. Although using this method has to take more time compared with the standard GA, it is really worth applying to some cases that have to meet a demand for high solution precision. 展开更多
关键词 NICHE genetic algorithm accurate optimization evolution direction
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DESIGN OF MAXIMALLY FLAT FIR FILTERS BASED ON EXPLICIT FORMULAS COMBINED WITH OPTIMIZATION 被引量:1
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作者 滕建辅 董健 +1 位作者 李锵 关欣 《Transactions of Tianjin University》 EI CAS 2006年第1期13-18,共6页
A maximally flat FIR filter design method based on explicit formulas combined with simulated annealing and random search was presented. Utilizing the explicit formulas to calculate the ini- tial values, the firate-wor... A maximally flat FIR filter design method based on explicit formulas combined with simulated annealing and random search was presented. Utilizing the explicit formulas to calculate the ini- tial values, the firate-word-length FIR filter design problem was converted into optimization of the filter coefficients, An optimization method combined with local discrete random search and simulated annealing was proposed, with the result of optimum solution in the sense of Chebyshev approximation. The proposed method can simplify the design process of FIR filter and reduce the calculation burden. The simulation result indicates that the proposed method is superior to the traditional round off method and can reduce the value of the objective function to 41%~74%. 展开更多
关键词 filter design MaxFlat filter simulated annealing random search
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A Biologic Behavior Simulation: Living Migration Algorithm (LMA)
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作者 李豆豆 邵世煌 齐金鹏 《Journal of Donghua University(English Edition)》 EI CAS 2008年第2期130-134,共5页
Biologic behaviors are the principal source for proposing new intelligent algorithms. Based on the mechanism of the bio-subsistence and the bio-migration, this paper proposes a novel algorithm—Living Migration Algori... Biologic behaviors are the principal source for proposing new intelligent algorithms. Based on the mechanism of the bio-subsistence and the bio-migration, this paper proposes a novel algorithm—Living Migration Algorithm (LMA). The original contributions of LMA are three essential attributes of each individual: the minimal life-needs which are the necessaries for survival, the migrating which is a basal action for searching new living space, and the judging which is an important ability of deciding whether to migrate or not. When living space of all individuals can satisfy the minimal life-needs at some generation, they are considered as the optimal living places where objective functions will obtain the optima. LMA may be employed in large-scale computation and engineering field. The paper mostly operates LMA to deal with four non-linear and heterogeneous optimizations, and experiments prove LMA has better performances than Free Search algorithm. 展开更多
关键词 bio-migration free search particle swarm optimization ant colony search
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Optimal searching for a Helix target motion 被引量:2
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作者 MOHAMED Abd Allah El-Hadidy 《Science China Mathematics》 SCIE CSCD 2015年第4期749-762,共14页
This paper discusses a search problem for a Helix target motion in which any information of the target position is not available to the searchers. There exist three searchers start searching for the target from the or... This paper discusses a search problem for a Helix target motion in which any information of the target position is not available to the searchers. There exist three searchers start searching for the target from the origin. The purpose of this paper is to formulate a search model and finds the conditions under which the expected value of the first meeting time between one of the searchers and the target is finite. Also, the existence of the optimal search plan that minimizes the expected value of the first meeting time is shown. Furthermore,this optimal search plan is found. The effectiveness of this method is illustrated by using an example with numerical results. 展开更多
关键词 Helix motion optimal search plan first meeting time probability measure multiobjective nonlinear programming problem
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T-QoS-aware based parallel ant colony algorithm for services composition 被引量:2
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作者 Lin Zhang Kaili Rao Ruchuan Wang 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2015年第5期1100-1106,共7页
In order to make cloud users get credible, high-quality composition of services, the trust quality of service aware(TQoS-aware) based parallel ant colony algorithm is proposed. Our approach takes the service credibili... In order to make cloud users get credible, high-quality composition of services, the trust quality of service aware(TQoS-aware) based parallel ant colony algorithm is proposed. Our approach takes the service credibility as the weight of the quality of service, then calculates the trust service quality T-QoS for each service, making the service composition situated in a credible environment. Through the establishment on a per-service T-QoS initialization pheromone matrix, we can reduce the colony's initial search time. By modifying the pheromone updating rules and introducing two ant colonies to search from different angles in parallel,we can avoid falling into the local optimal solution, and quickly find the optimal combination of global solutions. Experiments show that our approach can combine high-quality services and the improvement of the operational success rate. Also, the convergence rate and the accuracy of optimal combination are improved. 展开更多
关键词 services composition trust service quality ant colonyalgorithm PARALLEL
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A LINE SEARCH FILTER INEXACT SQP METHOD FOR NONLINEAR EQUALITY CONSTRAINED OPTIMIZATION
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作者 Li CAI Detong ZHU 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2012年第5期950-963,共14页
This paper proposes an inexact SQP method in association with line search filter technique for solving nonlinear equality constrained optimization. For large-scale applications, it is expensive to get an exact search ... This paper proposes an inexact SQP method in association with line search filter technique for solving nonlinear equality constrained optimization. For large-scale applications, it is expensive to get an exact search direction, and hence the authors use an inexact method that finds an approximate solution satisfying some appropriate conditions. The global convergence of the proposed algorithm is established by using line search filter technique. The second-order correction step is used to overcome the Maratos effect, while the line search filter inexact SQP method has q-superlinear local convergence rate. Finally, the results of numerical experiments indicate that the proposed method is efficient for the given test problems. 展开更多
关键词 Constrained optimization CONVERGENCE filter method inexact method maratos effect.
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Linear response eigenvalue problem solved by extended locally optimal preconditioned conjugate gradient methods
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作者 BAI ZhaoJun LI RenCang LIN WenWei 《Science China Mathematics》 SCIE CSCD 2016年第8期1443-1460,共18页
The locally optimal block preconditioned 4-d conjugate gradient method(LOBP4dC G) for the linear response eigenvalue problem was proposed by Bai and Li(2013) and later was extended to the generalized linear response e... The locally optimal block preconditioned 4-d conjugate gradient method(LOBP4dC G) for the linear response eigenvalue problem was proposed by Bai and Li(2013) and later was extended to the generalized linear response eigenvalue problem by Bai and Li(2014). We put forward two improvements to the method: A shifting deflation technique and an idea of extending the search subspace. The deflation technique is able to deflate away converged eigenpairs from future computation, and the idea of extending the search subspace increases convergence rate per iterative step. The resulting algorithm is called the extended LOBP4 dC G(ELOBP4dC G).Numerical results of the ELOBP4 dC G strongly demonstrate the capability of deflation technique and effectiveness the search space extension for solving linear response eigenvalue problems arising from linear response analysis of two molecule systems. 展开更多
关键词 eigenvalue problem linear response DEFLATION conjugate-gradient DEFLATION
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Derivation and Global Convergence for Memoryless Non-quasi-Newton Method
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作者 JIAO Bao Cong YU Jing Jing CHEN Lan Ping 《Journal of Mathematical Research and Exposition》 CSCD 2009年第3期423-433,共11页
In this paper, a new class of memoryless non-quasi-Newton method for solving unconstrained optimization problems is proposed, and the global convergence of this method with inexact line search is proved. Furthermore, ... In this paper, a new class of memoryless non-quasi-Newton method for solving unconstrained optimization problems is proposed, and the global convergence of this method with inexact line search is proved. Furthermore, we propose a hybrid method that mixes both the memoryless non-quasi-Newton method and the memoryless Perry-Shanno quasi-Newton method. The global convergence of this hybrid memoryless method is proved under mild assumptions. The initial results show that these new methods are efficient for the given test problems. Especially the memoryless non-quasi-Newton method requires little storage and computation, so it is able to efficiently solve large scale optimization problems. 展开更多
关键词 memoryless non-quasi-Newton method Wolfe line search global convergence.
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