A modelbased accelerationtracking approach is adopted to control the shake table, exhibiting good offline and online acceleration tracking performance. the proposed methods demonstrate that rths is an accurate and reliable means to investigate buildings with interstory isolation, including new configurations and supplemental control approaches.
A model‐based acceleration‐tracking approach is adopted to control the shake table, exhibiting good offline and online acceleration tracking performance. the proposed methods demonstrate that rths is an accurate and reliable means to investigate buildings with inter‐story isolation, including new configurations and supplemental control.
Abovementioned methods aim to improve control accuracy of shaking table acceleration tracking over a wide range of frequencies. assessment methods for shaking table performance are crucial in order to investigate the control efficiency of conventional andor new developed controllers. in this paper, the existing methods used to evaluate the.
Abstract. electrohydraulic shake tables (ehsts) are indispensable equipments in laboratory for evaluating structural performance subject to vibration environment. a novel feedforward inverse control with disturbance observer strategy is proposed in this paper in order to improve the acceleration tracking performance of the ehst system.
Acceleration tracking performance of the ucsdnees shake table j. e. luco1; o. ozcelik2; and j. p. conte3 abstract: the main objective of this paper is to investigate the tracking signal reproduction capability of the ucsdnees shake table system through a series of broadband and harmonic experiments with different tuning and test amplitudes.
Synchronous control of multiple shaking tables is challenging because of coupling between different shaking tables and complex dynamics of the testing systems. this article presents an adaptive waveform control for a twodegreeoffreedom dual electrohydraulic shaking tables testing system to improve the acceleration tracking performance.
Assessment of aseismic performance of ballasted track with largescale shaking table tests. this study uses fullscale models subjected to shaking table tests to evaluate the aseismic performance of ballasted track. the authors also tested for lateral ballast resistance force with the ballasted track model after shaking.
To study the seismic performance of hollow reinforced concrete piers under dynamic loads, nine hollow pier specimens with different stirrup ratios, reinforcement ratios, and axial compression ratios are designed and manufactured. the el centro wave, taft wave, and artificial lanzhou wave are selected as seismic excitation for the shaking table test.
The authors performed shaking table tests to evaluate the aseismic performance of ballasted track by using fullscale models. the test results showed that in the case of ballasted track with no countermeasures, the amplitude of lateral displacement and the residual displacement increased because the lateral resistance of ballasted track significantly decreased when the earthquake.
3.3. proposed acceleration reproduction controller3.3.1. design of the proposed controller. aimed at enhancing the acceleration tracking performance of the pfc controller for ehst systems, a flac controller capable of addressing the systems varying dynamics, inherent nonlinearities, external uncertainties and disturbances is combined to the pfc controller so as to constitute the.
Dense particle tracking (shakethebox) are compared according to their performance for velocity, vorticity acceleration and pressure (pressure from piv) measurement. different schemes for converting track data to a grid are examined: binning and finescalereconstruction using an advanced vortexincell approach (vic).
Dynamic simulations conducted on shake tables offer an economical means of examining the inelastic response of structures to earthquakes. however, past studies have shown the inability of shaketables to precisely simulate earthquake records (socalled acceleration tracking performance).
Electrohydraulic shake table (ehst), also known as earthquake simulator, is of considerable significance in civil engineering for evaluating structures or infrastructures subjected to earthquake ground motions. etc. for enhancing the acceleration tracking performance of ehst systems, an acceleration waveform reproduction strategy using.
Modulus, equivalent density, acceleration, and geometry, respectively. in the present case, three controllable similitude ratios should be determined in advance to obtain others. specically, s e, s ρ, and s l are chosen in this paper, and thus, s a can be calculated using equation (1). considering the shaking table size and the height re.
Figure 2. shake table with twostory structure a twostory steel frame structure is added to the shake table to study tracking performance in the presence of csi. the building consists of 1.27 cm thick steel plates connected by springsteel columns that constrain the motion to a single axis, minimizing torsion. to investigate controller.
Identiﬁcation of the mechanical subsystem of the neesucsd shake table by a leastsquares approach o. ozcelik1; j. e. luco2; and j. p. conte3 abstract: a leastsquares method is used to determine the fundamental parameters of a simple mathematical model for the mechanical subsystem of the neesucsd large high performance outdoor shaking table.
The interest in shake tables stems from a need to simulate earthquake behavior in laboratory settings. however, the inherent properties and nonlinearities associated with electromechanical and servohydraulic shake tables, combined with issues of table‐structure interaction, make accurate reproduction of earthquake acceleration time histories a challenging problem.
An electrohydraulic shaking table (ehst) is an essential experimental facility to simulate in realtime actual vibration situations. an adaptive controller combined with offline compensators is proposed to improve the acceleration frequency bandwidth and tracking accuracy of a sixdegreeoffreedom (6dof) ehst.
The results show a good acceleration tracking performance with respect to other conventional controllers. an important application in this field is the reproduction of seismic vibrations in smallscale structures. for example, in , tracking features of a shaking table of this type are presented. the actuator is a hydraulic servomechanism whose.
The main objective of this paper is to investigate the tracking (signal reproduction) capability of the ucsdnees shake table system through a series of broadband and harmonic experiments with diff.
These relations can be used as guidelines in planning of future seismic tests on the ucsdnees shake table or on large shake tables with similar controllers. the third objective is to evaluate the effectiveness of the existing iterative correctiontuning procedure for the.
Motion for hydraulic shaking tables 24. the three variables of tvc refer to displacement, velocity, and acceleration of the electrohydraulic shaking table. the feedback velocity is synthesized from the feedback displacement and acceleration. the tvc scheme can figure 1. the hydraulic shaking table system. figure 2. the block diagram of tvc.
Of transfer function) can be reduced, acceleration tracking in the time domain is either not achieved or limited within the low frequency range. this paper presents a method to improve the acceleration control performance for shake tables. the proposed method, called the acceleration trajectory tracking control (attc) method, combines an.
To verify the performance of the fpeea control, a shake table test was conducted for two types of earthquakes, namely the farfield 1994 northridge earthquake (hereafter northridge; pga 0.20 and 0.30 g) and the nearfault 1999 chichi earthquake as measured at station tcu102 (hereafter chichi tcu102ew; pga 0.08 and 0.10 g).
Electrohydraulic shake table (ehst) is vital seismic testing equipment in earthquake engineering for the assessment of structures subject to dynamic vibration excitations. the ehst system can be generally simplified as an electrohydraulic servo system with prominent acceleration replication requirement. in order to improve the acceleration tracking performance of a typical ehst system, a.
Therefore, a lowcost shake table named sarsar with arduino microcontroller boards has been developed for earthquake simulations. the horizontal components of the acceleration records obtained from past earthquakes are scaled and transferred to the shake table by developing software programs using an arduino due board.
Shake table acceleration tracking performance impact on dynamic similitude preliminary findings..11 mike mota, franklin moon, ahmet emin aktan proposing the optimized combination of different isolati on bearings subjected to nearfault shaking table tests of steel fiber re.
Shake table testing to date; thus in this dissertation, appropriate methods of addressing the boundary conditions between experimental and computational substructures are presented and evaluated. also, a novel strategy for acceleration control of shake tables is presented to enhance the acceleration tracking performance of shake tables ii.
Shake table training workshop 2015 – san diego, ca nheri ucsd workshop, 1415 december, 2015 1313 outline overview of nheriucsd shake table experimental facility •performance characteristics •capabilities and limitations largescale shake table tests performed on the nheriucsd shake table table acceleration tracking performance.
Shake tables are used to study the behavior of structures under earthquakes. however, the inherent dynamic properties of the shake tables add unwanted behaviors to the desired earthquake time history. an acceleration tracking numerical simulation is conducted and the superior performance and stability properties of the new controller are.