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基于索鞍无预偏施工悬索桥的施工仿真 被引量:7
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作者 许世展 贺拴海 盖轶婷 《长安大学学报(自然科学版)》 EI CAS CSCD 北大核心 2007年第1期35-39,共5页
针对索鞍无预偏的悬索桥施工设计,通过基于悬索力学的解析迭代法与基于有限位移理论的有限元法相结合,系统地进行了施工中的主索下料长度、空缆状态及空缆标高、加劲梁吊装阶段的主塔受力和变形以及锚跨索股张拉时机与张拉量等控制参数... 针对索鞍无预偏的悬索桥施工设计,通过基于悬索力学的解析迭代法与基于有限位移理论的有限元法相结合,系统地进行了施工中的主索下料长度、空缆状态及空缆标高、加劲梁吊装阶段的主塔受力和变形以及锚跨索股张拉时机与张拉量等控制参数的仿真计算;并利用ANSYS程序和有限位移理论在悬索桥施工仿真应用时解的延续性和可逆性,从link10单元初应变调整入手,放弃初始状态试算的大循环迭代方法,建立了利用通用程序从结构成桥状态倒退到初始状态的有效方法。 展开更多
关键词 桥梁工程 悬索桥 索鞍无预偏 无应力长度 空缆状态 锚跨张拉 施工仿真
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索鞍无预偏施工悬索桥主缆的温度效应 被引量:12
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作者 刘来君 贺拴海 《长安大学学报(自然科学版)》 EI CAS CSCD 北大核心 2007年第1期40-44,共5页
针对索鞍无预偏施工悬索桥的几何形状对温度变化非常敏感等特点,研究了主缆架设过程中存在的温度效应问题。建立了主缆架设中索股、主缆横断面和纵断面的温度模型,根据无应力索索长恒定不变的原理求解温度作用下主缆中、边跨垂度,得出... 针对索鞍无预偏施工悬索桥的几何形状对温度变化非常敏感等特点,研究了主缆架设过程中存在的温度效应问题。建立了主缆架设中索股、主缆横断面和纵断面的温度模型,根据无应力索索长恒定不变的原理求解温度作用下主缆中、边跨垂度,得出了垂度计算公式,给出了有关主缆索股调整的具体方法。结果表明,该温度模型和计算公式是准确调整索股垂度的一种较简便可行的方法,为索鞍无预偏施工悬索桥的设计与施工提供了一定的理论依据。 展开更多
关键词 桥梁工程 悬索桥 索鞍无预偏 温度分布 温度模型 垂度调整
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大跨度悬索桥索鞍无预偏索塔张拉锚跨索股纠偏施工控制 被引量:4
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作者 徐勋 姜勇 +1 位作者 谢功元 强士中 《四川建筑科学研究》 北大核心 2008年第1期221-224,共4页
澜沧江悬索桥是国内首次采用索鞍无预偏索塔张拉锚跨索股纠偏方法施工的大跨度悬索桥。利用悬索桥结构理论和有限元非线性分析方法,分析结构在裸塔、主缆施工、主梁吊装到成桥不同阶段的控制参数,建立了张拉纠偏决策确定索塔纠偏量和主... 澜沧江悬索桥是国内首次采用索鞍无预偏索塔张拉锚跨索股纠偏方法施工的大跨度悬索桥。利用悬索桥结构理论和有限元非线性分析方法,分析结构在裸塔、主缆施工、主梁吊装到成桥不同阶段的控制参数,建立了张拉纠偏决策确定索塔纠偏量和主缆张拉量——参数测量、数值分析和有限元模型修正的非线性施工控制流程。有效地调整控制了桥梁内力和线型,确保桥梁施工安全和质量。 展开更多
关键词 悬索桥 索鞍无预偏 张拉索股纠 施工控制流程
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自锚式悬索桥索鞍无预偏施工吊杆张拉研究 被引量:2
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作者 张志伟 蔡金标 《低温建筑技术》 2010年第5期71-73,共3页
索鞍无预偏施工是现代悬索桥使用较少的一种施工方式,文章针对一座采用索鞍无预偏施工的自锚式悬索桥,先得出主缆吊点位移与主缆水平分力增量的近似线形关系,再采用有限元建模的方法计算出其主塔容许水平力,在吊杆张拉施工过程中以位移... 索鞍无预偏施工是现代悬索桥使用较少的一种施工方式,文章针对一座采用索鞍无预偏施工的自锚式悬索桥,先得出主缆吊点位移与主缆水平分力增量的近似线形关系,再采用有限元建模的方法计算出其主塔容许水平力,在吊杆张拉施工过程中以位移控制为主进行优化并制定合理的张拉顺序,最后通过有限元软件模拟真实的施工过程,研究了吊杆张拉过程中索鞍无预偏施工的一些基本理论方法和控制因素。结果表明优化后的吊杆张拉施工可以有效地控制主塔的内力和偏位,确保了桥梁施工安全和质量。 展开更多
关键词 自锚式悬索桥 索鞍无预偏 吊杆张拉 仿真计算 优化分析 施工监控
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自锚式悬索桥索鞍无预偏施工吊杆张拉的优化研究 被引量:4
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作者 张志伟 《世界桥梁》 北大核心 2011年第2期34-37,共4页
自锚式悬索桥吊杆张拉施工是一个重复性的过程,为了减少吊杆张拉的次数,基于优化原理,对某索鞍无预偏自锚式悬索桥吊杆张拉过程建立非线性规划的优化模型,提出考虑几何非线性影响的影响矩阵迭代方法,并采用通用编程软件MATLAB中的优化... 自锚式悬索桥吊杆张拉施工是一个重复性的过程,为了减少吊杆张拉的次数,基于优化原理,对某索鞍无预偏自锚式悬索桥吊杆张拉过程建立非线性规划的优化模型,提出考虑几何非线性影响的影响矩阵迭代方法,并采用通用编程软件MATLAB中的优化功能模块进行运算,最后将计算结果写入有限元软件模拟真实施工过程,证明该方法的有效性。结果表明:该方法减少了吊杆张拉施工时吊杆力施加的盲目性,优化后的吊杆张拉施工中,桥塔的偏位和应力得到了很好的控制,保证了施工过程中主梁和桥塔结构的安全。 展开更多
关键词 悬索桥 索鞍 无预偏 吊杆 张拉 优化 有限元法
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索鞍无预偏悬索桥索塔纠偏施工控制技术 被引量:1
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作者 徐永煌 《城市道桥与防洪》 2007年第10期43-45,共3页
索鞍无预偏悬索桥索塔纠偏是指张拉锚跨索股以平衡中、边跨的不平衡力,此施工工艺是国内首次采用,其施工和控制技术难度大。针对新工艺施工方法,利用现有悬索桥结构理论和施工控制理论,研究不同于常规索鞍预偏施工的张拉锚跨索股索塔纠... 索鞍无预偏悬索桥索塔纠偏是指张拉锚跨索股以平衡中、边跨的不平衡力,此施工工艺是国内首次采用,其施工和控制技术难度大。针对新工艺施工方法,利用现有悬索桥结构理论和施工控制理论,研究不同于常规索鞍预偏施工的张拉锚跨索股索塔纠偏的施工控制技术。可为今后同类型桥梁施工控制提供一定的借鉴价值。 展开更多
关键词 悬索桥 张拉锚跨索股 施工控制 张拉留量 索鞍无预偏
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基于无索鞍预偏的悬索桥施工控制计算分析
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作者 李盛洋 檀永刚 潘盛山 《武汉理工大学学报(交通科学与工程版)》 2013年第6期1296-1300,共5页
结合青龙山公园一号桥——地锚式空间索面悬索桥,介绍了该桥选用无索鞍预偏施工方法的特定背景,并论述了该种施工方法施工控制计算的特点.利用RM非线性有限元分析软件,建立有限元模型,进行施工阶段仿真分析,得出控制参数,并根据计算结果... 结合青龙山公园一号桥——地锚式空间索面悬索桥,介绍了该桥选用无索鞍预偏施工方法的特定背景,并论述了该种施工方法施工控制计算的特点.利用RM非线性有限元分析软件,建立有限元模型,进行施工阶段仿真分析,得出控制参数,并根据计算结果,分析该施工方法的控制特点. 展开更多
关键词 悬索桥 施工控制索鞍无预偏 非线性有限元分析 施工阶段模拟
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Analysis of phenotypic and genetic parameters for growth-related traits in the half smooth tongue sole,Cynoglossus semilaevis 被引量:2
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作者 刘峰 李仰真 +2 位作者 杜民 邵长伟 陈松林 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2016年第1期163-169,共7页
Phenotypic and genetic parameters for growth-related traits in the half-smooth tongue sole, Cynoglossus semilaevis, were estimated in 22 full-sib families produced by normal and neo-male breeding stocks. As phenotypic... Phenotypic and genetic parameters for growth-related traits in the half-smooth tongue sole, Cynoglossus semilaevis, were estimated in 22 full-sib families produced by normal and neo-male breeding stocks. As phenotypic males with female genotypes, neo-males are harmful in C. semilaevis aquaculture because they reduce overall production. The present study evaluated the difference in the growth-related traits: total length (TL), body weight (BW) and square root of body weight (SQ_BW) at the age of 570 days between normal and neo-male offspring (neo-males used as male parents). The difference in the proportion of females between normal and neo-male offspring was also assessed. Based on the linear mixed model, restricted maximum likelihood (REML) and best linear unbiased prediction (BLUP) were used to estimate various (co)variance components and estimated breeding values (EBVs) of growth-related traits. As a result, all the mean values of the three studied traits were significantly larger in normal offspring than in neo-male offspring. Additionally, the female proportion was significantly larger in normal offspring than in neo-male offspring. Heritability was 0.128+0.066 2 for TL, 0.128-4-0.065 5 for BW and 0.132~0.062 9 for SQBW, all of which were low level heritabilities. The correlation coefficients of EBVs and phenotypic values of the target traits were 0.516 for TL, 0.524 for BW and 0.506 for SQ_BW, all of which were highly significant (P〈0.01). Genetic correlations among TL, BW and SQ_BW were positive high (0.921-0.969) and higher than those of phenotype (0.711-0.748), both of which had low standard errors (0.063-0.123 for genotype, and 0.010-0.018 for phenotype). Compared with normal offspring, neo-male offspring have lower breeding values for each studied trait through EBVs comparison. Therefore, neo-male offspring should not be used as broodstock in a C. semilaevis breeding programs. 展开更多
关键词 Cynoglossus semilaevis estimated breeding value (EBV) HERITABILITY genetic correlation
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Phenotype Tendencies of Dam Populations in Genetic Evaluation of Pigs in Slovakia over 2000-2009
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作者 B. Bobcek O. Bucko A. Trakovicka J. Mrazova L. Gajdosova 《Journal of Agricultural Science and Technology(A)》 2011年第6期902-907,共6页
This paper makes an analysis of the phenotype tendencies of dam populations White Large (WL) and Landrace (L) over the years 2000-2009 after the introduction of Multivariate Best Linear Unbiased Prediction and ani... This paper makes an analysis of the phenotype tendencies of dam populations White Large (WL) and Landrace (L) over the years 2000-2009 after the introduction of Multivariate Best Linear Unbiased Prediction and animal model into the genetic evaluation of pigs in the Slovak Republic. The analysis of slaughter parameters over the years 2000-2009 showed a decreasing tendency concerning the fat thickness in WL from 18.30 (2000) to 12.40 mm (2009), which represents the reduction by 5.9 mm; in L from 16.40 mm (2000) to 12.10 mm (2009), which means the reduction by 4.30 mm. There was also observed a positive tendency in the percentage of carcass lean meat in a slaughter body. The overall population average for the years 2000-2009 was as follows: WL 54.36% and L 54.61%. The highest values of meatiness in 2000-2009 were achieved in WL + 1.59% and L + 2.92%. Apart from the daily gains in all parameters, there were also found both highly significant statistical differences and interactions between a period and a breed. 展开更多
关键词 PIGS dam populations M BLUP-AM fattening and carcass value pig.
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A comparison of genomic selection methods for breeding value prediction 被引量:8
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作者 王欣 杨泽峰 徐辰武 《Science Bulletin》 SCIE EI CAS CSCD 2015年第10期925-935,I0007,共12页
Recent advances in molecular genetics techniques have made dense marker maps available, and the prediction of breeding value at the genome level has been employed in genetics research. However, an increasingly large n... Recent advances in molecular genetics techniques have made dense marker maps available, and the prediction of breeding value at the genome level has been employed in genetics research. However, an increasingly large number of markers raise both statistical and computational issues in genomic selection (GS), and many methods have been developed for genomic prediction to address these problems, including ridge regression-best linear unbiased prediction (RR-BLUP), genomic best linear unbiased prediction, BayesA, BayesB, BayesCπ, and Bayesian LASSO. In this paper, these methods were compared regarding inference under different conditions, using real data from a wheat data set and simulated scenarios with a small number of quantitative trait loci (QTL) (20), a moderate number of QTL (60, 180) and an extreme number of QTL (540). This study showed that the genetic architecture of a trait should be fully considered when a GS method is chosen. If a small amount of loci had a large effect on a trait, great differences were found between the predictive ability of various methods and BayesCπ was recommended. Although there was almost no significant difference between the predictive ability of BayesCπ andBayesB, BayesCπ is more feasible than BayesB for real data analysis. If a trait was controlled by a moderate number of genes, the absolute differences between the various methods were small, but BayesA was also found to be the most accurate method. Furthermore, BayesA was widely adaptable and could perform well with different numbers of QTL. If a trait was controlled by an extreme number of minor genes, almost no significant differences were detected between the predictive ability of various methods, but RR-BLUP slightly outperformed the others in both simulated scenarios and real data analysis, thus demonstrating its robustness and indicating that it was quite effective in this case. 展开更多
关键词 Prediction Genomic selection Breeding value Comparison Predictive ability
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