基于ANSYS软件benchmark模型耗能减振控制分析

本文系统介绍了当前国际结构振动控制的公共平台———Benchm ark模型,首次给出使用通用有限元软件ANSYS对第3阶段20层非线性钢框架抗震结构的有限元建模,结果表明,模态、无控地震反应分析结果和ASCE给出的MATLAB结果相同。利用粘滞阻尼器对此模型的耗能减振数值仿真分析的结果表明:粘滞阻尼器是一种性能很好的阻尼器,使用本文给出ANSYS的Benchm ark有限元模型来进行耗能减振控制分析是方便的、可行的。     

内藏X形软钢板铅复合耗能器的力学性能及减震分析

在内藏X形软钢板铅复合耗能器和软钢耗能器低周反复荷载试验研究基础上,进行了理论分析,理论计算滞回曲线与实测滞回曲线吻合较好。建议了恢复力模型。将内藏X形软钢板铅复合耗能器应用到了悬挂减震结构中,进行了地震反应时程计算分析,计算结果表明,装有内藏X形软钢板铅复合耗能器的结构具有良好的减震性能。     

消能减震高层方钢管混凝土框架结构振动台试验研究和弹塑性时程分析

本文首先介绍了一幢安装了粘滞阻尼器的复杂体型高层方钢管混凝土框架结构的1/15缩尺模型的模拟地震振动台试验结果;在此基础上,建立了梁、柱构件的多弹簧模型并组建了整体结构的计算分析模型,运用此计算模型首先对试验模型结构进行了动力弹塑性时程分析,计算结果和试验结果吻合较好,验证了计算模型的正确性;最后,以同样方法对原型结构进行了计算分析,并结合试验结果研究探讨了此结构的抗震性能和阻尼器的消能减震效果。结果表明:该结构未出现明显的薄弱层,能够满足规范的抗震设防要求,阻尼器发挥了一定的消能减震效果,进一步提高了结构的抗震性能。     

调质阻尼器地震反应控制应用研究

本文在结构地震反应时程分析基础上,研究调质阻尼器控制地震反应的最优参数设计方法,分析了多自由度体系的阻尼器设计以及调质阻尼器控制的失调效应．并用算例验证了该设计方法用于地震反应控制的可行性。     

半主动控制装置在受控结构中的优化设置

本文对振动控制系统中控制装置的优化设置方法进行了研究,并将其应用于基于磁流变阻尼器的半主动控制系统中,通过计算实例分析得出了关于控制装置优化设置问题的一些有意义的结论。     

500kN 足尺磁流变液阻尼器设计的关键技术

对我们制作的、目前出力居世界前列的500kN足尺MR阻尼器设计的关键技术、阻尼器的性能试验及力学模型的参数识别进行了研究。在对磁流变液材料的最大屈服剪应力、抗沉降稳定性以及磁滞响应时间等关键性能试验分析的基础上,确认该磁流变液的抗沉降稳定性和其他两项性能指标满足MR阻尼器的设计与工程应用要求。同时,对此500kN足尺MR阻尼器设计的关键技术,包括内置式碟型弹簧蓄能器、磁场防漏设计以及引线保护等进行了介绍;并通过对此MR阻尼器性能的试验,依据阻尼最小二乘法,对MR阻尼器采用的修正的B ingham模型的参数进行了识别,得到了与试验结果吻合的MR阻尼器的力学模型。通过研究可知,高性能磁流变液材料的制备以及MR阻尼器设计的关键技术是大吨位足尺MR阻尼器成功的关键。     

SMA复合摩擦阻尼器性能的试验研究

利用形状记忆合金(SMA)的超弹性效应及高阻尼性能,结合传统Pall摩擦型阻尼器的特点,提出了一种SMA复合摩擦阻尼器。在建立阻尼器力学分析模型的基础上,对SMA复合摩擦阻尼器的性能进行了试验研究,分析了位移幅值、加载频率等对阻尼器的等效刚度、单位循环耗能和等效阻尼比的影响,并与理论分析结果进行了对比。研究表明,SMA复合摩擦阻尼器在加卸载循环下会形成比较稳定的滞回曲线,表明这种阻尼器具有良好的耗能能力。     

大底盘多塔楼结构的混合隔震控制

结合某实际工程,针对大底盘多塔楼结构提出混合隔震的控制策略,即对大底盘上的一栋或多栋塔楼采用隔震技术,并在隔震层附设一定数量的被动、主动或半主动的减震控制装置。建立了这种大底盘多塔楼结构混合隔震控制体系的运动方程,方程中各塔楼与下部结构及隔震层之间的刚度解耦,并考虑了隔震层的非线性。研究中比较了被动非线性粘滞阻尼器,半主动变孔隙阻尼器与理想主动控制时的减震控制效果。结果表明,这种混合隔震体系可以有效地减小上部塔楼与下部结构的地震反应,提高大底盘多塔楼结构的抗震安全性,取得明显的经济和社会效益。半主动变孔隙阻尼器可以极好地追踪理想主动控制力,取得与理想主动控制相近的减震控制效果。被动非线性粘滞阻尼器也能取得较好的减震效果,且易于维护,经济性较好,从工程应用的角度来看更为现实可行,具有较好的应用推广价值。     

Semi‐active tuned mass damper building systems: Application

Seismic performance attributes of multi‐story passive and semi‐active tuned mass damper (PTMD and SATMD) building systems are investigated for 12‐story moment resisting frames modeled as ‘10+2’ stories and ‘8+4’ stories. Segmented upper portion of the stories are isolated as a tuned mass, and a passive viscous damper or semi‐active resetable device is adopted as energy dissipation strategy. The semi‐active approach uses feedback control to alter or manipulate the reaction forces, effectively re‐tuning the system depending on the structural response. Optimum tuned mass damper control parameters and appropriate matching SATMD configurations are adopted from a companion study on a simplified two‐degree‐of‐freedom system. Statistical performance metrics are presented for 30 probabilistically scaled earthquake records from the SAC project. Time history analyses are used to compute response reduction factors across a wide range of seismic hazard intensities. Results show that large SATMD systems can effectively manage seismic response for multi‐degree‐of freedom systems across a broad range of ground motions in comparison to passive solutions. Specific results include the identification of differences in the mechanisms by which SATMD and PTMD systems remove energy, based on the differences in the devices used. Additionally, variability is seen to be tighter for the SATMD systems across the suites of ground motions used, indicating a more robust control system. While the overall efficacy of the concept is shown the major issues, such as isolation layer displacement, are discussed in detail not available in simplified spectral analyses, providing further insight into the dynamics of these issues for these systems. Copyright © 2009 John Wiley & Sons, Ltd.     

Testing of dynamically substructured,base‐isolated systems using adaptive control techniques

Experimental techniques for testing dynamically substructured systems are currently receiving attention in a wide range of structural, aerospace and automotive engineering environments. Dynamic substructuring enables full‐size, critical components to be physically tested within a laboratory (as physical substructures), while the remaining parts are simulated in real‐time (as numerical substructures). High quality control is required to achieve synchronization of variables at the substructuring interfaces and to compensate for additional actuator system(s) dynamics, nonlinearities, uncertainties and time‐varying parameters within the physical substructures. This paper presents the substructuring approach and associated controller designs for performance testing of an aseismic, base‐isolation system, which is comprised of roller‐pendulum isolators and controllable, nonlinear magnetorheological dampers. Roller‐pendulum isolators are typically mounted between the protected structure and its foundation and have a fundamental period of oscillation far‐removed from the predominant periods of any earthquake. Such semi‐active damper systems can ensure safety and performance requirements, whereas the implementation of purely active systems can be problematic in this respect. A linear inverse dynamics compensation and an adaptive controller are tailored for the resulting nonlinear synchronization problem. Implementation results favourably compare the effectiveness of the adaptive substructuring method against a conventional shaking‐table technique. A 1.32% error resulted compared with the shaking‐table response. Ultimately, the accuracy of the substructuring method compared with the response of the shaking‐table is dependent upon the fidelity of the numerical substructure. Copyright © 2009 John Wiley & Sons, Ltd.