排序方式: 共有46条查询结果,搜索用时 15 毫秒
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Şaban S. Özsarıyıldız Ali Bozer 《The Structural Design of Tall and Special Buildings》2015,24(6):461-475
In this paper, optimum design of tuned mass damper for seismically excited structures is discussed. In the design process, a benchmark multi‐degree of freedom system is considered, and the performance measure of the optimization criterion is selected as the H2 and H∞ norms of the transfer function of the combined tuned mass damper and building system. Differential evolution algorithm is then utilized to minimize these objective functions. The objective function choice on performance and the effectiveness of differential evolution optimization algorithm in comparison with other algorithms in the literature are investigated through numerical simulations. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Lieping Ye Qianli Ma Zhiwei Miao Hong Guan Yan Zhuge 《The Structural Design of Tall and Special Buildings》2013,22(4):362-381
Elastoplastic and time‐dependent analysis of seismic structures has become a major analysis technique in popularly accepted performance‐based seismic design. However, the primary difficulty in using this technique is the lack of a unified criterion in the selection of various intensity indices of ground motions. Various earthquake factors influencing the elastoplastic response of seismic structures are highly sophisticated. Hence, it is vitally important to choose an appropriate and comprehensive earthquake intensity index to achieve an accurate correlation with the structural performance. In this study, a total of 30 earthquake intensity indices published in the literature are reviewed and are evaluated through correlation analysis based on 60 ground motion records. Examined herein is the correlation between existing earthquake intensity indices and the seismic responses of elastoplastic single degree‐of‐freedom and multi degree‐of‐freedom systems. The characteristics and applicability of such indices are also discussed in some detail, based on which appropriate earthquake intensity indices are recommended. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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试件特性对地震模拟振动台控制性能影响研究(Ⅱ)——对地震记录再现精度的影响及实时补偿 总被引:2,自引:0,他引:2
常规振动台系统共振频率为20 Hz,而试验试件1阶频率最大为8 Hz,在进行地震模拟振动台控制系统设计时将试件视为刚性体,二者存在较大差异.因此,振动控制系统控制频带窄、稳定性差,降低了地震记录再现精度.本文通过系统建模分析了试件质量、频率、阻尼等因素对振动台控制性能的影响.结果表明:试件各阶频率周围频带的输入波再现精度很低,出现不同程度的放大与削弱,最大可达3倍.针对这一问题设计了实时反力补偿算法以修正试件与台面相互作用对控制系统性能的影响,在保证系统稳定性的前提下提高了地震记录的再现精度. 相似文献
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The potential of digital twin technology is immense, specifically in the infrastructure, aerospace, and automotive sector. However, practical implementation of this technology is not at an expected speed, specifically because of lack of application-specific details. In this paper, we propose a novel digital twin framework for stochastic nonlinear multi-degree of freedom (MDOF) dynamical systems. The proposed digital twin has four modules — (a) a physics-based nominal model, (b) a data collection module, (c) algorithm for real-time update of the digital twin and (d) module for predicting future state. The modules for real-time update and prediction are based on the so-called gray-box modeling approach, and utilizes both physics based and data driven frameworks; this enables the proposed digital twin to generalize and predict future responses. The gray box modeling framework used within the digital twin is developed by coupling Bayesian filtering and machine learning algorithm. Although, the proposed digital twin can be used with any machine learning regression algorithm, we have used Gaussian process in this study. Performance of the proposed approach is illustrated using two examples. Results obtained indicate the applicability and excellent performance of the proposed digital twin framework. 相似文献
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MDOF子结构拟动力方法在复杂高层结构抗震试验中的应用研究 总被引:1,自引:0,他引:1
研究了实验子结构、计算子结构均为多自由度(MDOF)的子结构拟动力试验方法,并采用该方法对一种新型复杂高层结构——框支配筋砌体剪力墙结构进行了抗震试验研究。分析结果表明,当全结构的实验子结构采用多自由度后,不仅使实验能够得到全结构的地震反应,而且可以较好地反映实验子结构在真实地震作用下的力和位移的分布方式,并且可以得到不同性质楼层(如转换层结构的上部和下部楼层)在地震作用下的层位移-层剪力滞回耗能特性,而后两点是实验子结构采用单自由度的子结构拟动力试验做不到的。试验证明,采用实验子结构、计算子结构均为多自由度的子结构拟动力试验方法进行复杂高层结构的抗震试验能比目前常用的实验子结构采用单自由度的子结构拟动力试验获得更多有效而真实的数据。 相似文献
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对一般线性粘弹性阻尼器(含线性橡胶隔震支座)耗能结构的非正交振型叠加精确解法进行了系统研究。首先采用最一般的线性粘弹性阻尼器的积分型精确分析模型,用微分积分方程组实现一般粘弹性阻尼器耗能结构的时域非扩阶精确建模;然后采用传递矩阵法,直接在耗能结构原始空间上获得了一般线性粘弹性耗能变频结构在任意激励和非零初始条件下位移与速度时域瞬态响应的非正交振型叠加精确解;通过与3种典型结构的对比分析,验证了该精确解的正确性、简易性和普适性。该非扩阶精确解具有明确的物理意义,可视为现有比例粘滞阻尼定常结构的经典正交振型叠加精确解在一般线性粘弹性阻尼耗能变频结构的推广,能从本质上精确揭示耗能结构的振动机理,即尽管耗能结构的振型不具有正交性,但耗能结构响应仍然可精确分解为各振型响应的线性组合。此振动机理将为建立耗能结构精确的振型分解反应谱法提供分析路径,同时可将现有用于一般粘滞阻尼定常结构的参数识别、动力修改、最优控制及优化设计等方法推广到一般粘弹性阻尼变频非定常结构。 相似文献
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为了研究超高层建筑横风向气动刚度,进行了多自由度气弹模型试验,以直接测量模型在不同风速下的振动频率,用该频率相对于自振频率的改变量作为气动刚度的评估指标。分析了结构阻尼比、风场粗糙度、模型密度、折算风速、高宽比、涡振位移等因素对气动刚度的影响。结果表明:在共振临界风速附近,气动刚度造成风振频率改变量可达自振频率的10%;频率改变量随折算风速呈“V”字形变化,在折算风速小于8时,频率改变量通常为正,在共振临界风速附近频率改变量最大,折算风速大于12时,频率改变量保持稳定且略小于结构自振频率。由于涡振位移和气动刚度的相互作用,结构阻尼比越小、风场紊流度越小、模型高宽比越大、密度越小则频率改变量随风速变化的“V”字形越尖锐。最后提出了名义折算风速和实际折算风速的概念,并建立了气动刚度的简化估算模型。 相似文献
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多自由度无阻尼动力吸振器的理论研究 总被引:3,自引:0,他引:3
讨论了将简谐激振下无阻尼单自由度主系统的动力消振原理推广到多频谐波激励下无阻尼多自由度主系统的情况,通过选择一个合适的多自由度无阻尼动力吸振从系统。即从系统的固定频率正好是所有的激振力的频率,可以完全消除多频谐波激励下无阻尼多自由度主系统中某质点的振动响应。还讨论了根据给定弹簧-质量系统的特征值及对该系统进行小的、已知的修正后所得系统的特征值,来直接重构质量矩阵和刚度矩阵的方法。 相似文献