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排序方式: 共有73条查询结果,搜索用时 15 毫秒
1.
钢支撑性能对高层钢结构动力反应的影响 总被引:1,自引:0,他引:1
钢框架-支撑结构体系是高层钢结构常用的结构体系。支撑的性能对高导钢框架-支撑体系的动力性能影响较大,其中支撑的工细比是关键的影响因素。文中通过大量的计算分析研究支撑长细比对高层钢框架-支撑体系弹塑性地震反应的影响,所得结论可供工程设计时参考。 相似文献
2.
This work proposes nonlinear parallel spring-damper scalar elements in series with a rigid beam element to represent drilling riser tensioner behavior during an emergency disconnection scenario in global riser analysis. The software package used was Orcaflex. This is a simpler approach than the more complex, full hydraulic-pneumatic-mechanic dynamic simulation modelling of the tensioning system, commonly used in literature, which can be time consuming and numerically more sensitive. The model can also be used to represent top tension variation in global riser analysis, allowing for more complex and precise simulations, especially for fatigue life and overpull estimations. The results show adequate agreement with the researched bibliography. 相似文献
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陆顺永 《地震工程与工程振动》1995,15(4):85-92
基于双线性和三线性的力-位移滞回线假设,导出了钢梁阻尼器隔震系统等效阻尼比与阻尼器延性率的关系;为了获得大阻尼比隔震系统,以尽量减小隔震系统的地震反应,求得了使系统阻尼比为最大的阻尼器相应延性率(即最佳延性率)所需满足的条件;给出了在给定地震地面运动输入条件下,使系统阻尼器变形位移达到最佳延性率的阻尼器初始刚度和屈服位移的确定方法。 相似文献
5.
The time series of the dynamic response of a slender marine structure was predicted in approximate sense using a truncated quadratic Volterra series. The wave-structure interaction system was identified using the NARX (Nonlinear Autoregressive with Exogenous Input) technique, and the network parameters were determined through supervised training using prepared datasets. The dataset used for network training was obtained by nonlinear finite element analysis of the slender marine structure under random ocean waves of white noise. The nonlinearities involved in the analysis were both large deformation of the structure under consideration and the quadratic term of the relative velocity between the water particle and structure in the Morison formula. The linear and quadratic frequency response functions of the given system were extracted using the multi-tone harmonic probing method and the time series of the response of the structure was predicted using the quadratic Volterra series. To check the applicability of the method, the response of a slender marine structure under a realistic ocean wave environment with a given significant wave height and modal period was predicted and compared with the nonlinear time domain simulation results. The predicted time series of the response of structure with quadratic Volterra series successfully captured the slowly varying response with reasonably good accuracy. This method can be used to predict the response of the slender offshore structure exposed to a Morison type load without relying on the computationally expensive time domain analysis, especially for screening purposes. 相似文献
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It is the purpose of this study to investigate the dynamic behaviour of catenary pipelines for marine applications, assuming the combined effect of harmonic motions imposed at the top, and the internal slug-flow. The analysis is based on the assumption of a steady slug-flow inside the pipe that results in a relatively simplified model for the formulation of the internal flow. The slug-flow model is described using several assumptions and empirical correlations which attempt to reveal the ill-understood and concealed properties of the slug-flow. The pipeline dynamics are investigated in the two dimensional space omitting the out-of-plane vibrations. The system of differential equations is generic and accounts for the steady effect of the internal liquid as is conveyed through the structure.The two models, those of the internal slug-flow and the pipeline’s dynamical model, are properly combined through the internal flow terms of the dynamic equilibrium system. The solution provided is achieved using a frequency domain technique which is applied to the linearized governing set. The effect of the slug-flow is assessed through comparative computations with and without internal flow effects. The conclusions are drawn having the structure excited under axial and normal motions paying particular attention to the variation of the dynamic components along the complete length of the pipeline. 相似文献
8.
During the past strong ground motions, chimneys constructed according to international standards are representative of similar structures at industrial areas throughout the world, including those collapsed or moderately damaged in earthquake-prone regions. This is due to the specialty of structural characteristics and the special loads acting on the structure such as earthquakes, wind and differences in the level of temperature, etc. In this context, the researchers and designers should focus on the dynamic behavior of chimneys especially under high temperature and seismic effects. For this purpose, the main focus of this study is to evaluate the dynamic response of a chimney under the above-mentioned effects considering soil-structure interaction (SSI). A 52 m steel chimney in Yeşilyurt township of Samsun City in Turkey was studied. The in-situ model testing and numerical models were compared. Before the commissioning of the chimney, a series of tests was realized to define its dynamic characteristics in case of no-heat and after the fabric got to work, the same tests were repeated for the same sensor locations to understand the heat effect on the dynamic response of the chimney. The ambient vibration tests are proven to be fast and practical procedures to identify the dynamic characteristics of those structures. The dynamic testing of the towers promises a widespread use, as the identification of seismic vulnerability of such structures becomes increasingly important. The data presented in this study are considered to be useful for the researchers and engineers, for whom the temperature and SSI effects on steel chimneys are a concern. Using the modal analysis techniques, presented finite element simulation for the soil/pile foundation-chimney interaction system is verified. The results of modal analyses using numerical solutions are shown to have acceptable accuracy compared with results obtained by in-situ test. The present study also aims to provide designers with material examples about the influence of these on the seismic performance of steel chimneys by means of reflecting the changes in the dynamic behavior. 相似文献
9.
选取已有钢筋混凝土柱—钢梁组合结构(RCS)框架的低周期反复试验数据,采用地震工程开源模拟软件OpenSees对其进行有限元模拟,对比骨架曲线与滞回曲线,试验结果与有限元结果吻合较好。随后考察弯矩放大系数(Mc/Mb=0.86、1.48、2.04)、柱轴压比(n=0.06、0.2、0.3、0.6、0.8)对抗震性能的影响,得到了各参数下框架的滞回曲线、骨架曲线和各特征阶段的荷载与位移值。分析了框架的破化过程、延性与强度退化。结果表明:RCS组合框架滞回曲线饱满,具有良好的变形及耗能能力;随着弯矩放大系数的减小、柱轴压比的增大,框架的水平极限承载力降低、屈服状态提前、位移延性降低。分析结果可供有关研究或工程应用参考。 相似文献
10.
《Geoforum》2017
Highly alkaline industrial residues (e.g., steel slag, bauxite processing residue (red mud) and ash from coal combustion) have been identified as stocks of potentially valuable metals. Technological change has created demand for metals, such as vanadium and certain rare earth elements, in electronics associated with renewable energy generation and storage. Current raw material and circular economy policy initiatives in the EU and industrial ecology research all promote resource recovery from residues, with research so far primarily from an environmental science perspective. This paper begins to address the deficit of research into the governance of resource recovery from a novel situation where re-use involves extraction of a component from a bulk residue that itself represents a risk to the environment. Taking a political industrial ecology approach, we briefly present emerging techniques for recovery and consider their regulatory implications in the light of potential environmental impacts. The paper draws on EU and UK regulatory framework for these residues along with semi-structured interviews with industry and regulatory bodies. A complex picture emerges of entwined ownerships and responsibilities for residues, with past practice and policy having a lasting impact on current possibilities for resource recovery. 相似文献