Theoretic Analysis And Application Research On Energy Dissipating Restraint

Energy Dissipating Restraint (EDR) has some specialty which differs from normalenergy dissipating device. This device is able to provide several forms of hystereticcharacteristics. The triangular and double flag hysteretic modes have the capacity ofself-centering, that is to say, after totally unloaded to naught, the residual deformationof the device tends zero. In the addition, the element with triangular hystereticbehavior enables to provide AVS control by passive method. Some researches onseismic resistant performance of EDR with rectangular, triangular and double flaghysteretic behaviors are conducted in this paper. These related researches include:Introducing in detail how to yield the triangular, double flag, rectangular hystereticmodes; according static equilibrium of interior element of EDR, deducing someformulation to calculate the loading-stiffness and unloading-stiffness based on theconstitution models. These formulations provide help for designing and fabricatingEDR. On the basis of these formulations, the influence of model parameters onloading-stiffness and unloading-stiffness is studied; furthermore, the approach forimproving the max restore force of EDR is discussed. Quasi-static tests on an EDRare conducted in this dissertation, and all the three above hysteresis loops areobserved. The calculated stiffness is preliminary proved by the experimental results.The free vibration of single-degree-of-freedom (SDOF) system with rectangular,triangular hysteretic behaviors and the steady-state response of SDOF system withthree above hysteretic behaviors are studded, respectively. And equivalent parametersof three hysteretic modes are derived. These works provide some insight to these threehysteretic modes and their seismic resistant performance.To calculate the earthquake response of structures equipped hysteretic elements whosehysteretic modes are piece-wise, the algorithms conducting nonlinear dynamicanalysis are investigated, which include: Newton-raphson method, pseudo loadmethod, non-iterate approach in search of stiffness turn point by approximate oraccurate solution. The calculating precision and efficiency of these four methods arecompared. Besides, this paper emphasizes some problems which should be kept inmind when programming in accordance of these algorithms, and show the method ofhow to calculate the restore force for three hysteretic elements.Based on nonlinear response spectra analysis, parametric studies are preformed. Theimpact on structural earthquake response of six parameters are investigated, whichinclude loading-stiffness, unloading-stiffness, transition-stiffness of triangularhysteretic element, slip-force of double flag hysteretic element, and slip-force,transition-stiffness of rectangular hysteretic element. The results indicate that theparameter influence of the hysteretic modes on structural response is related to whatposition of linear structural period (T) is located on response spectra. If T closes to the － III －北京工业大学工学硕士学位论文period zone in which the gradient of certain response spectrum curve is positive, toincrease the equivalent stiffness of hysteretic element enables to decrease thisresponse, and otherwise, it will result in the response increasing.The comparisons of seismic resistant performance of the three hysteretic elements areconducted in two cases: one is that the intensity of earthquake is known, and the otheris that the intensity is unpredictable. The results show that: in the first case rectangularelement can get well control effect, but as the peak ground acceleration (PGA)increasing, the control effect decrease. But for triangular and double flag hystereticelement, the control effect has little change as PGA altering. So, when the intensity ofearthquake can't exactly forecast, the triangular and double flag element should beadopted.At the last part, this paper investigates the application of triangular...