Results 11 to 20 of about 17,412 (176)

冲击荷载下焊接空心球节点的动力响应研究

open access: yesJianzhu Gangjiegou Jinzhan, 2021
为研究冲击荷载下节点刚度和冲击速度对焊接球节点动力响应的影响,对缩尺节点试件进行不同高度下的冲击试验;采用ANSYS/LS-DYNA软件中的Shell163壳单元模拟焊接球和杆件,采用Solid164实体单元模拟冲击物,建立焊接空心球节点精细化有限元模型。将试验结果和有限元分析结果进行对比,验证有限元模型的有效性。通过改变钢球冲击高度、球节点壁厚和直径,从节点的动应力、动应变、动位移、冲击力以及冲击能量5个方面,对焊接球节点开展动力响应分析。研究结果表明:动力响应随冲击能量的增加而增大 ...
吴长, 刘家乐, 王仁红
doaj  

Analytical solution for dynamic interaction of end-bearing pile groups subjected to horizontal dynamic loads [PDF]

open access: yes
An analytical model for the "pile-soil-pile" horizontal interaction in pile groups that accounts for the scattering effect of the receiver pile is presented in this study based on the plane strain model, to modify the calculating theory for closely ...
ZHENG Changjie1, 2 , CUI Yiqin1, 2, DING Xuanming3, LUAN Lubao4
core   +1 more source

SV波入射下饱和地层浅埋平行隧道动力响应机制

open access: yesDizhen xuebao, 2022
目前城市核心区交叠紧邻的隧道群大量涌现,其抗震安全性问题日益突出,但近邻隧道之间以及与地层的动力相互作用机制尚不清晰。本文针对饱和地层浅埋平行隧道,基于Biot两相介质理论,采用边界积分方程法分别建立了饱和地层水平和竖向双线隧道动力作用分析模型,并与典型算例精确解对比验证了本模型的有效性;在此基础上,研究了SV波入射频率变化和双线隧道间距变化对隧道结构及周围地层孔隙水压力的影响机制,并以单条隧道分析结果为参照进行对比分析。结果表明:相比单条隧道,相邻隧道的存在改变了既有隧道的动力响应特征 ...
Haitao Yu   +3 more
doaj   +1 more source

Analysis on the response of the dip slope with weak layer to earthquake [PDF]

open access: yes
Taking the down-slope with weak strata in the south of Fushun west open-pit mine as the reference prototype, numerical simulations of the down-slope with weak strata were conducted through FLAC3D software, which included the simulation of actual ground ...
Laigui WANG   +3 more
core   +1 more source

Dynamic Analysis of a High-rise-Building Structure during an Earthquake Considering Soil-Structure-Interaction [PDF]

open access: yes, 2017
土-结构体系有限元模拟计算分析的复杂性与计算成本,在一定程度上限制了土与结构相互作用分析在高层建筑结构设计中的应用。上部结构数值解与土解析解耦合的土-结构相互作用计算方法,为高层建筑结构提供了有效途径。利用作者提出的耦合算法,对一个钢框架-混凝土核心筒高层结构进行地震作用下的非线性动力分析,讨论了不同强度地震和不同种类地基土对结构地震反应的影响,得出了对实际工程具有指导性意义的结论。The conventional coupling analysis based on a comprehensive ...
卢佳盛, 孙宝印, 李勇
core   +1 more source

局部山体地形对断层动力学破裂过程的影响研究

open access: yesDizhen xuebao, 2018
基于曲线网格有限差分方法研究了垂直走滑断层在不同山体地形情况下的动力学破裂传播,分析并讨论了局部山体地形对断层破裂过程及相应地面地震动的影响,得到了各模型断层面的动力学破裂过程及相应的地表峰值速度特征。研究结果表明,山体地形尺度(山体高度及底部延展距离等)对断层动力学破裂过程影响较大,进而影响到相应的地面地震动分布。当山体地形处于自由地表上亚剪切向超剪切转换的位置附近时,山体地形会阻碍断层面上自由地表超剪切的产生。一般而言,对于具有一定埋深的断层,当山体地形底部延展距离一定时,山体高度越高 ...
Mingfeng Wang   +3 more
doaj   +1 more source

The Research on Wind-induced Vibration Control of Large Span Roof Structures with Different Damping Systems and Optimization of MTMD Damping System [PDF]

open access: yes, 2016
近年来,随着国内经济实力的增强和社会发展的需要,大跨空间结构在我国得到迅速发展,且跨度越来越大。由于大跨空间结构具有质量轻、阻尼小、柔性大、自振频率低等特点,因而对风荷载的作用很敏感。在风荷载的作用下,结构会产生较大的变形,严重降低结构的安全性和舒适性。为抑制结构的动力响应,学者们提出在结构适当位置处安装控制装置的概念。目前,高层建筑在风荷载作用下的振动控制研究已取得丰硕成果,并有大量的工程应用实例。然而,国内外学者对大跨空间结构的风振控制研究相对较少,因此有必要开展大跨空间结构的风振控制研究 ...
邵辉
core  

Scaling from microsite to landscape to resolve litter decomposition dynamics in globally extensive drylands

open access: yesFunctional Ecology, EarlyView.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Decomposition is the transformation of dead organic matter into its inorganic constituents. In most biomes, decomposition rates can be accurately predicted with simple mathematical models, but these models have long under‐predicted decomposition in globally extensive ...
Heather L. Throop   +8 more
wiley   +1 more source

Research on Influence of Drilling and Blasting Method on Structures Nearby During Tunnel Excavation [PDF]

open access: yes, 2017
采用钻爆法开挖隧道时,爆破振动将不可避免地对临近构筑物产生影响。文章以贵州盘兴高速上坡地隧道为研究背景,对该隧道施工方案及爆破振动计算原理进行了分析,通过LS-DYNA建立了该隧道的计算模型,模拟了隧道中药包爆炸过程,计算分析出岩体的受力及位移情况;研究爆炸产生的振动冲击波下输电塔的响应特征,提出隧道不同区段的爆破开挖优化设计方案,为类似工程提供参考和技术支撑。Drilling and blasting method are widely used in the excavation of tunnel,
冯恺, 张宁, 毛金龙, 洪阳洲
core  

From pollen provision to pollinator: Species‐specific sterol assimilation by wild bees in urban landscapes

open access: yesFunctional Ecology, EarlyView.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Human‐driven landscape change, particularly urbanization, is reshaping pollinator communities, yet the functional traits that mediate species persistence remain poorly understood. Dietary specialization is commonly used to predict species vulnerability.
Yan Yang   +5 more
wiley   +1 more source

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