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崖门大桥动力特性及抗风评估
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作者 刘子宏 方世乐 《广东公路交通》 2000年第C00期9-11,共3页
崖门大桥地处台风多发地区 ,风环境较为恶劣。结构设计中对主桥进行了深入的三维有限元分析 ,并对其动力特性及抗风进行评估。评估结果与风洞试验报告较吻合。
关键词 双塔单索面预应力砼斜拉桥 崖门大桥 动力特性 抗风评估 结构设计中 有限元分析
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基于风荷载数值模拟和抗风揭试验相结合的既有金属屋面抗风性能评估方法 被引量:9
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作者 姚志东 卢炜 刘明奇 《建筑结构》 CSCD 北大核心 2021年第S01期1738-1741,共4页
基于计算流体力学(CFD)的风荷载数值模拟技术已较为成熟,而抗风揭试验是目前较为常用的针对金属屋面抗风性能评估的方法。鉴于既有建筑存在设计及技术资料缺失的情况,以深圳市民中心为例,提出了一种将风荷载数值模拟的结果用于既有金属... 基于计算流体力学(CFD)的风荷载数值模拟技术已较为成熟,而抗风揭试验是目前较为常用的针对金属屋面抗风性能评估的方法。鉴于既有建筑存在设计及技术资料缺失的情况,以深圳市民中心为例,提出了一种将风荷载数值模拟的结果用于既有金属屋面抗风揭试验的验证和对比,以实现对抗风性能进行有效评估的方法。经过研究分析和对比,获得了不满足承载力要求的金属屋面范围,从而为后续加固处理提供了有效的依据,验证了方法的可靠性。 展开更多
关键词 风荷载数值模拟 抗风揭试验 验证和对比 抗风性能评估
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台风作用下输电线路风振系数及抗风性能研究 被引量:5
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作者 付兴 杜文龙 +1 位作者 郑帅 李宏男 《东北大学学报(自然科学版)》 EI CAS CSCD 北大核心 2022年第7期913-920,共8页
为研究良态风与台风作用下的输电线路风振系数,以广东省国古线一铁塔为原型建立了有限元模型,采用谐波叠加法模拟了台风风场,并开展了动力分析.首先,对比了5种国内外设计规范的风振系数计算方法,发现各规范均未单独考虑台风的强脉动特性... 为研究良态风与台风作用下的输电线路风振系数,以广东省国古线一铁塔为原型建立了有限元模型,采用谐波叠加法模拟了台风风场,并开展了动力分析.首先,对比了5种国内外设计规范的风振系数计算方法,发现各规范均未单独考虑台风的强脉动特性;然后,基于惯性力法获取了铁塔风振系数并揭示了塔线耦联效应的影响.最后,利用生死单元法定量评估了两种风场下输电线路的抗风性能.结果表明:台风的高湍流特性导致顺风向风振系数大于良态风对应值;导线可增大铁塔横风向基频,并使铁塔振型由单塔的弯曲型变为塔线体系的弯剪型,塔线体系横担处风振系数大于单塔;湍流度从0.14提高至0.20,临界倒塌风荷载降低约11%.因此,台风多发地区的输电塔设计应适当提高湍流度取值,必要时还应考虑塔线耦联效应. 展开更多
关键词 输电线路 风振系数 台风 塔线耦联效应 抗风性能评估
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220 kV双回路典型角钢输电塔动力特性及抗风性能评估
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作者 张佳毅 占鹭林 +2 位作者 曹枚根 张若愚 陈长龙 《钢结构(中英文)》 2023年第1期29-36,共8页
输电塔是一类风敏感结构,具有自重大、结构柔、小阻尼等特点,对风荷载激励较为敏感,在东南沿海台风多发地区,风荷载是导致输电塔倒塔和事故的重要原因。为保障我国东南沿海地区输电线路的安全运行,合理评估该地区输电塔的抗风性能尤为... 输电塔是一类风敏感结构,具有自重大、结构柔、小阻尼等特点,对风荷载激励较为敏感,在东南沿海台风多发地区,风荷载是导致输电塔倒塔和事故的重要原因。为保障我国东南沿海地区输电线路的安全运行,合理评估该地区输电塔的抗风性能尤为重要。以福建福鼎沿海地区新建的220 kV双回路线路的典型直线塔为研究对象,开展了输电塔的动力特性、风振响应及抗风性能评估研究。首先,对输电塔进行了现场动力特性测试,测试输电塔在自然激励下的响应,采用随机子空间法识别输电塔频率和阻尼比等动力特性参数;其次,采用ANSYS软件建立了该输电塔的有限元计算模型,通过对输电塔动力特性的理论分析和现场实测,进一步认识和掌握了该塔的振动特性同时验证有限元模型的正确性;最后,依据现有规范对输电塔进行0°、45°、60°、90°静力风荷载分析及风速重现期分别为30,50,100 a的风振响应分析,得到静力、脉动风荷载作用下输电塔的塔顶位移值及塔身主材最大压应力值。在此基础上,采用输电塔的塔顶偏移比、杆件压屈比等评估参数对输电塔抗风性能进行评估。结果表明:该方法有效评估了输电塔在风速重现期分别为30,50,100 a的抗风能力,得到该基输电塔的抗风性能设计较为安全的结论。 展开更多
关键词 双回路输电塔 动力特性 风振响应 抗风性能评估
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A poor performance in comprehensive geriatric assessment is associated with increased fall risk in elders with hypertension: a cross-sectional study 被引量:30
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作者 Jiao-Jiao CHU Xu-Jiao CHEN +5 位作者 Shan-Shan SHEN Xue-Feng ZHANG Ling-Yan CHEN Jing-Mei ZHANG Jing HE Jun-Feng ZHAO 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2015年第2期113-118,共6页
Background Fall and serious fall injuries have become a major health concern for elders. Many factors including blood pressure and anti-hypertensive medication application were reported as hazards of fall. The purpose... Background Fall and serious fall injuries have become a major health concern for elders. Many factors including blood pressure and anti-hypertensive medication application were reported as hazards of fall. The purpose of this study was to determine if age related systemic functional decline related with increased fall risks in elderly patients with hypertension. Methods A total of 342 elderly hypertension patients (age 79.5 + 6.7 years, male 63.8%) were recruited to the study. Comprehensive geriatric assessment (CGA), including measurements about activity of daily living (ADL), nutrition, cognition, depression, numbers of prescription medication and number of clinical diagnosis, was conducted to evaluate the physical and mental status of each participants. Fall risk was evaluated by Morse fall scale, Tinetti perform- ance oriented mobility assessment (POMA) and history of fall in the recent years. Participants were grouped into tertiles according to CGA score. Correlation between CGA and fall risk was analyzed through SPSS 18.0. Results Participants with higher CGA score were likely to be older, had a lower body mass index (BMI), and a higher prevalence of cardiovascular disease, chronic obstructive pulmonary disease (COPD), cerebrovascular disease and osteoarthropathia. Participants in higher tertile of CGA score got increased prevalence of fall risk than those in lower tertile (P 〈 0.01 T3 vs. T1, P 〈 0.01 T3 vs. T2). Correlation analysis and regression analysis showed significant association between CGA and Morse fall scale (P 〈 0.001), as well as CGA and POMA (P 〈 0.001). Meanwhile, CGA components also showed co-relationships with increase fall risks. After adjusting age, BMI, benzodiazepine use, cardiovascular disease, cerebrovascular disease, COPD and osteoarthropathia, both history of fall in the recent year and rising Morse fall scale were significantly associated with ADL im- pairment (OR: 2.748, 95%CI: 1.598-4.725), (OR: 3.310, 95%CI: 1.893-5.788). Decreased Tinetti POMA score was associated with Mini-Mental State Examination (MMSE) (OR: 4.035, 95%CI: 2.100-7.751), ADL (OR: 2.380, 95%CI: 1.357-4.175) and shortened MNA form (MNA-SF) impairment (OR: 2.692, 95%CI: 1.147-6.319). Conclusions In elderly adults with hypertension, impaired physical and mental function is associated with increased fall risk. Further study is required to investigate possible mediators for the association and effec- tive interventions. 展开更多
关键词 Comprehensive geriatric assessment Elderly patient Fall risk HYPERTENSION
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