共查询到18条相似文献，搜索用时 421 毫秒
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基于OpenSees-OpenFresco-MTS混合试验系统，选取关键构件底层中柱，进行大空间地下结构地震响应混合试验研究。在混合试验过程中，取结构底层中柱为试验子结构，取结构剩余部分与土体为数值子结构。为了满足试验要求，开发了一种专用于混合试验的可变刚度钢构件。通过更换柱脚螺杆改变试验装置侧向刚度。在混合试验前，根据数值模型中对应单元侧向刚度确定钢构件侧向刚度；根据幅值比和相位差等频域指标评价混合试验结果。试验结果显示:在上海人工波工况、El Centro波工况和Kobe波工况中，理论结果与试验结果匹配良好。在以大空间地下结构地震响应为研究对象时，基于OpenSees-OpenFresco-MTS的混合试验系统具有良好的稳定性与精确性。 相似文献
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作为一种集计算机模拟和物理试验于一体的新型混合试验方法,实时子结构试验在过去20年得到迅速发展.该试验方法的关键在于如何保证数值子结构和试验子结构的实时耦联.对于复杂结构来说,更需要高效的数值积分方法以确保每步计算在一个采样步长内完成.鉴于此,本文在Rosenbrock实时积分方法的基础上,提出了一种具有完全并行计算格式的耦合积分方法,并基于单自由度分离质量模型分析了该方法的收敛性;再通过对三自由度分离质量模型的数值模拟,验证了该方法的收敛性;最后,在多自由度试验平台上完成了两自由度结构的实时子结构试验.理论分析、数值模拟及实时子结构试验表明,该方法具有良好的稳定性和2阶精度,与直接积分方法相比更适用于复杂结构的实时子结构试验. 相似文献
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子结构地震模拟振动台混合试验原理与实现 总被引：2，自引：0，他引：2
为了解决地震模拟振动台承载能力及台面尺寸对大型结构试验的限制,扩展振动台的功能,本文提出了子结构地震模拟振动台混合试验方法、试验过程及实时数值积分方法,并给出了试验子结构边界条件的两种模拟形式.通过一个简单框架结构的地震模拟振动台试验和子结构混合加载试验验证了该方法的可行性,并指出了该试验方法的主要技术问题.混合试验方法通过子结构技术和振动台试验相结合,解决了目前的地震模拟振动台试验和拟动力试验在设备规模和加载速度上的局限性. 相似文献
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振动台子结构试验是一种有效的实时结构混合试验方法，持续受到国内外学者的关注。利用振动台和其它加载装置进行联合加载，从而提升和扩展振动台的加载能力，实现大比例甚至足尺结构试验的目的。基于主动质量驱动器(AMD)加载方法的振动台子结构试验中，在试验子结构和数值子结构完全拆分的情况下，无论采用位移PID还是三参量控制，在界面加速度输入情况下AMD系统在3～5 min后会产生失稳现象，通过调整控制增益、对加速度反馈信号进行滤波无法消除这种现象。在加速度传感器噪声的影响下，子结构试验系统无法保持长期稳定，通过数值仿真表明现有的时滞补偿算法也无法消除这种失稳现象。考虑这种情况，将卡尔曼滤波引入界面加速度的量测环节，通过整体结构模型求得的界面加速度对实测界面加速度进行修正，从而提升了振动台子结构试验的系统稳定性和试验精度。数值仿真结果表明，通过设置合理的卡尔曼滤波参数，可以抑制加速度传感器随机噪声对子结构试验精度的影响，系统时滞稳定性也得到显著改善。文中的研究结果为振动台子结构试验的成功实施提供了一种可行的解决方案。 相似文献
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西安建筑科技大学结构与抗震实验室和新疆大学结构实验室合作,以一个两层三跨钢框架结构为试验对象,进行了国内首例跨省远程协同子结构混合仿真拟动力试验。试验结果表明:OpenFresco网络平台通讯性能良好,数据远程传输消耗时间可忽略;通过两所大学实验室测得的力、位移、加速度等试验数据的对比分析,表明该试验系统具有良好的精确性及稳定性;通过OpenFresco网络平台,能够准确远程控制异地实验室的MTS试验系统进行协同工作,从而完成结构简单的子结构混合仿真拟动力试验,为下一步进行大型、复杂结构的子结构混合仿真拟动力试验提供了必要的理论和实践基础。 相似文献
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基于振动台的动力子结构试验界面反力获取方法 总被引：2，自引：0，他引：2
基于振动台的实时子结构动力试验是一种新型的结构动力试验方法.该试验方法引入了“子结构”这一概念,不仅减小了常规振动台试验对于试验规模的限制,而且克服了拟动力子结构试验中无法考虑加载速率影响的问题.由于该试验方法将整体结构拆分为数值子结构和物理子结构两部分,二者之间通过交界面相互作用力实现实时数据交互,以保证子结构体系与... 相似文献
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对于大型复杂结构的实时(拟动力)子结构试验,更适宜用无条件稳定的逐步积分方法。隐式逐步积分方法通常是无条件稳定的,然而需要复杂耗时的迭代求解非线性方法。为了避免迭代过程,等效力控制方法用反馈控制求解非线性方程,使隐式逐步积分方法在实时子结构试验中的应用成为可能。本文首先以平均加速度法为例介绍等效力控制方法的原理、关键参数的选取;然后介绍基于等效力控制的能量守恒子结构试验方法和隐式中点法;最后介绍这些方法在以防屈曲支撑阻尼器为试件的单自由度简化结构、以磁流变阻尼器为试件的海洋平台结构的实时子结构试验,以及装配式钢筋混凝土剪力墙结构和框支配筋砌块短肢剪力墙结构拟动力试验中的应用。研究结果表明:这三种等效力控制方法都具有很好的精度,等效力控制方法相对于中心差分法具有更好的稳定性。 相似文献
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离线模型更新混合试验对构件拟静力数据进行恢复力模型参数识别,并更新数值子结构中相应构件的模型参数来提高混合试验精度,但该方法尚缺少真实试验的验证。本文基于课题组开展的足尺RC柱拟静力试验,取恢复力模型为集中塑性铰Ibarra-Medina-Krawinkler（IMK）模型,进行框架结构离线模型更新混合试验研究。结果表明,当物理子结构取为RC足尺柱时,离线模型更新混合试验能获得接近于真实试验情况下结构的地震响应,从而对该方法的有效性进行了试验验证。利用IMK经验公式,将真实试验模型参数识别值按轴压比进行对照修正,应用于不同层数的框架结构地震响应模拟,实现了试验数据的重复利用。 相似文献
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SATMD与消能减震相结合的混合控制研究 总被引：1，自引：0，他引：1
根据模糊控制理论及抗震结构混合控制理论，利用自行设计的模糊控制器对波动调谐质量阻尼器（PTMD）子结构进行调谐控制以实现半自动化，同时在主结构上进行粘弹性阻尼器的优化设置，从而实现结构体系的多模态优化混合控制，最后提出半主动调谐质量阻尼器（SATMD）与消能减震相结合的混合控制实用设计方法。本文对推动结构混合控制理论的发展具有重要意义。 相似文献
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本研究运用DSP高速数字信号处理器的实时信号处理与控制技术,研究了基于速度控制法、OS数值积分法和相应的实验误差控制法的子结构拟动力实验系统。该试验系统对动力加载装置采用速度控制,在加载过程中考虑了加载速率对实验结果的影响,使隔震橡胶支座的速度相关性能在试验中得到充分体现,同时采用OS数值积分法,充分地减少了试验的时滞误差,提高了试验精度。并通过不同加载速率的子结构拟动力实验研究了天然橡胶支座、高阻尼橡胶隔震支座和超高阻尼橡胶隔震支座对桥梁的隔震效果,在对实验结果进行分析对比后,定量地研究了不同的加载速率对隔震桥梁子结构拟动力实验结果的影响。 相似文献
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Real‐time pseudodynamic (PSD) and hybrid PSD test methods are experimental techniques to obtain the response of structures, where restoring force feedback is used by an integration algorithm to generate command displacements. Time delays in the restoring force feedback from the physical test structure and/or the analytical substructure cause inaccuracies and can potentially destabilize the system. In this paper a method for investigating the stability of structural systems involved in real‐time PSD and hybrid PSD tests with multiple sources of delay is presented. The method involves the use of the pseudodelay technique to perform an exact mapping of fixed delay terms to determine the stability boundary. The approach described here is intended to be a practical one that enables the requirements for a real‐time testing system to be established in terms of system parameters when multiple sources of delay exist. Several real‐time testing scenarios with delay that include single degree of freedom (SDOF) and multi‐degree of freedom (MDOF) real‐time PSD/hybrid PSD tests are analyzed to illustrate the method. From the stability analysis of the real‐time hybrid testing of an SDOF test structure, delay‐independent stability with respect to either experimental or analytical substructure delay is shown to exist. The conditions that the structural properties must satisfy in order for delay‐independent stability to exist are derived. Real‐time hybrid PSD testing of an MDOF structure equipped with a passive damper is also investigated, where observations from six different cases related to the stability plane behavior are summarized. Throughout this study, root locus plots are used to provide insight and explanation of the behavior of the stability boundaries. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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A hybrid numerical and experimental simulation to collapse was conducted on a one‐half scale moment‐resisting frame building with two experimental substructures at different locations. An extensible hybrid test framework was used that adopts a generalized interface to encapsulate each numerical or tested substructure, through which only boundary displacements and forces are exchanged. Equilibrium and compatibility between substructures are enforced by an iterative quasi‐Newton procedure, while adopting a predictor‐and‐corrector method to avoid loading reversals on physically tested substructures. To overcome difficulties in controlling stiff axial and rotational deformations at the boundaries, the flexible test scheme employs either open‐loop or closed‐loop control at the boundaries: enforcing either compatibility or equilibrium, or both requirements at critical boundaries. The effectiveness of the extensible framework and its capability to simulate structural behavior through collapse is demonstrated by a geographically distributed test that reproduced the collapse behavior of a four‐story, two‐bay, steel moment frame previously tested on an earthquake simulator. A comparison of both experiments highlights the viability of the hybrid test as an effective tool for the performance evaluation of structural systems from the onset of damage through collapse. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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Scientific research proposing any type of device/technique for seismic protection of buildings is generally based on numerical models that adopt simplifications to make possible extensive analyses. This means that important details of the inelastic response could be neglected. Following this consideration, regardless of the device/technique invented, before it could be put into practice, an experimental verification of the actual structural performance should be conducted by full-scale tests at building level. This issue is investigated in the paper considering seismic retrofit of reinforced concrete (RC) framed structures by buckling-restrained braces (BRBs) as technique to be validated, while hybrid test is selected as tool for experimental validation at building level. The analysed seismic upgrading technique consists in the insertion of BRBs into the RC frame. The upgrading intervention is designed by a method developed in previous studies. This technique responds to an important need of the society. Indeed, existing RC frames showed high vulnerability in occurrence of past earthquakes when they were not originally conceived to sustain horizontal forces. The hybrid test is selected among the available experimental techniques because it allows the experimentation on full-scale specimens with reasonable cost. In this study, a substructure hybrid test was conducted and the results are here presented to (a) evaluate the effectiveness of the design method of BRBs for seismic upgrading, (b) investigate the integration of BRBs in existing RC frame, and (c) show the potentiality of the substructure hybrid test for the experimental verification of innovative techniques for seismic protection of buildings. 相似文献
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This paper presents a substructure online hybrid test system that is extensible for geographically distributed tests.This system consists of a set of devices conventionally used for cyclic tests to load the tested substructures onto the target displacement or the target force.Due to their robustness and portability,individual sets of conventional loading devices can be transported and reconfigured to realize physical loading in geographically remote laboratories.Another appealing feature is the flexible displacement-force mixed control that is particularly suitable for specimens having large disparities in stiffness during various performance stages.To conduct a substructure online hybrid test,an extensible framework is developed,which is equipped with a generalized interface to encapsulate each substructure.Multiple tested substructures and analyzed substructures using various structural program codes can be accommodated within the single framework,simply interfaced with the boundary displacements and forces.A coordinator program is developed to keep the boundaries among all substructures compatible and equilibrated.An Internet-based data exchange scheme is also devised to transfer data among computers equipped with different software environments.A series of online hybrid tests are introduced,and the portability,flexibility,and extensibility of the online hybrid test system are demonstrated. 相似文献
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Real‐time hybrid testing is a method that combines experimental substructure(s) representing component(s) of a structure with a numerical model of the remaining part of the structure. These substructures are combined with the integration algorithm for the test and the servo‐hydraulic actuator to form the real‐time hybrid testing system. The inherent dynamics of the servo‐hydraulic actuator used in real‐time hybrid testing will give rise to a time delay, which may result in a degradation of accuracy of the test, and possibly render the system to become unstable. To acquire a better understanding of the stability of a real‐time hybrid test with actuator delay, a stability analysis procedure for single‐degree‐of‐freedom structures is presented that includes both the actuator delay and an explicit integration algorithm. The actuator delay is modeled by a discrete transfer function and combined with a discrete transfer function representing the integration algorithm to form a closed‐loop transfer function for the real‐time hybrid testing system. The stability of the system is investigated by examining the poles of the closed‐loop transfer function. The effect of actuator delay on the stability of a real‐time hybrid test is shown to be dependent on the structural parameters as well as the form of the integration algorithm. The stability analysis results can have a significant difference compared with the solution from the delay differential equation, thereby illustrating the need to include the integration algorithm in the stability analysis of a real‐time hybrid testing system. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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采用子结构混合实验方法进行复杂结构的地震响应模拟。在混合实验中,根据结构的特征划分为多个子结构,每个子结构被封装起来,只有边界上的力和位移作为子结构间相互作用的变量,利用拟牛顿法保持整体结构的平衡和协调。目标结构为SRC框架剪力墙结构体系,结构顶部设置11层高的钢塔。在混合实验中,该结构被分为3个子结构,SRC部分为第一个子结构,采用OpenSees进行模拟;钢塔的第1层比较薄弱,是变形集中区域,采用实验进行模拟;钢塔其余部分采用ABAQUS有限元程序进行模拟。实验得到准确的地震响应,表明本文提出的混合实验方法可有效地结合多个有限元程序,充分利用各个有限元程序的优点进行复杂结构的地震响应模拟。 相似文献
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Peng Pan Hiroshi Tomofuji Tao Wang Masayoshi Nakashima Makoto Ohsaki Khalid M. Mosalam 《地震工程与结构动力学》2006,35(7):867-890
A new Internet online hybrid test system, designated the ‘peer‐to‐peer (P2P) Internet online hybrid test system’, is proposed. In the system, the simulated structure is divided into multiple substructures, and each substructure is analysed numerically or tested physically in parallel at geographically distributed locations. The equations of motion are not formulated for the entire structure but for each substructure separately. Substructures are treated as highly independent systems, and only standard I/O, i.e. displacements and forces at the boundaries, are used as interfaces. A ‘Coordinator’ equipped with an iterative algorithm based on quasi‐Newton iterations is developed to achieve compatibility and equilibrium at boundaries. A test procedure, featuring two rounds of quasi‐Newton iterations and using assumed elastic stiffness, is adopted to avoid iteration for the substructure being tested physically. A fast and stable solution using a socket mechanism is developed for data exchange over the Internet. Demonstration tests applied to a base‐isolated structure was conducted, and the results are compared with an online hybrid test using the conventional test method. The results obtained from the P2P Internet hybrid test match very closely those obtained from the conventional tests. Investigations are also carried out on time consumption and control accuracy. The results show that the Internet data exchange solution using the socket mechanism is fast, and tests were completed successfully under the constructed Internet online hybrid test environment. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献