• Structural Monitoring and Maintenance
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• v.11 no.3
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• pp.173-185
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• 2024

Currently, the electro-hydraulic servo loading control system manufactured by MTS, OpenFresco hybrid test interface software and OpenSees finite element software are widely used in structure laboratories to carry out hybrid test, but there is no relevant public information about full structure pseudo-dynamic test based on the above software and hardware. In order to study the feasibility of using the above software and hardware to carry out full structure pseudo-dynamic test, the full structure pseudo-dynamic virtual experiments of a single degree of freedom (SDOF) structure and a two degrees of freedom (2DOFs) structure are carried out based on the MTS 793 Demo Mode, and the results are respectively compared with the finite element analysis method. The results show that the finite element analysis results and full structure pseudo-dynamic virtual experiment results are highly consistent, which verifies the feasibility of carrying out the full structure pseudo-dynamic test based on the above software and hardware. Then, a three story steel frame full structure pseudo-dynamic test is conducted, and the smooth implementation of full structure pseudo-dynamic test of the three story steel frame further verifies the reliability of thistesting method. The implementation method of carrying out the full structure pseudo-dynamic tests are introduced in detail, which can provide some reference for relevant research.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.04a
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• pp.151-158
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• 2000

The use of unconditionally stable implicit time integration techniques for pseudo-dynamic tests has been recently proposed and advanced by several researchers such as Thewalt and Mahin Nakashima and Shing. The developed implicit algorithms are based on a-Method of Hugest et al. In this paper a concise summary and explanation of implicit method for Pseudo dynamic test is presented. Especially The a-C method developed by shing at al. has been in-depth evaluated for this study. Important parameters of the a-C method have been analyzed by the simulation test.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.617-622
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• 2000

The use of unconditionally stable implicit time integration techniques for pseudo-dynamic test has been recently proposed and advanced by several researchers such as Thewalt and Mahin, Nakashima and Shing, etc. The developed implicit algorithms are based on the $\alpha$-Method of Huges et al. In this paper, a concise summary and explanation of implicit method for Pseudo dynamic tese is presented. Especially, The $\alpha$-C method developed by shing et al. has been in-depth evaluated for this study. Important parameters of the $\alpha$-C method have been analyzed by the simulation test.

• Structural Engineering and Mechanics
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• v.24 no.1
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• pp.91-105
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• 2006

In this paper, post-earthquake capacity evaluation method of reinforced concrete buildings was studied. Substructure pseudo-dynamic test and static loading test of first story column in a four-story R/C building was carried out in order to investigate the validity of the evaluation method proposed in the Damage Assessment Guideline (JBDPA 2001). In pseudo-dynamic test, different levels of damage were induced in the specimens by pre-loading, and input levels of seismic motion, at which the specimens reached to the ultimate stage, were examined. From the experimental result, no significant difference in damage levels such as residual crack width between the specimens under static and pseudo-dynamic loading was found. It is shown that the seismic capacity reduction factors ${\eta}$ can provide a reasonable estimation of post-earthquake seismic capacity of R/C buildings suffered earthquakes.

• Geomechanics and Engineering
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• v.3 no.4
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• pp.255-266
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• 2011

Knowledge of seismic earth pressure against rigid retaining wall is very important. Mononobe-Okabe method is commonly used, which considers pseudo-static approach. In this paper, the pseudo-dynamic method is used to compute the distribution of seismic earth pressure on a rigid cantilever retaining wall supporting dry cohesionless backfill. Planar rupture surface is considered in the analysis. Effect of various parameters like wall friction angle, soil friction angle, shear wave velocity, primary wave velocity, horizontal and vertical seismic accelerations on seismic earth pressure have been studied. Results are presented in terms of tabular and graphical non-dimensional form.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.4_1
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• pp.77-85
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• 1992

The Pseudo-dynamic test is a new experimental technique for simulating the earthquake response of structures or structural components in the time domain. It is especially efficient for testing specimens that are too large, heavy or strong to be tested on a shaking table. But, in general, the responses obtained in the Pseudo-dynamic test can be distorted by the experimental errors inevitably during control and measurement procedures. The studies are to investigate the effects of the experimental errors on the Pseudo-dynamic responses and apply a correction method to the Pseudo-dynamic testing algorithm. It is shown that the corrected responses using the equivalent energy compensation method are in a good correlation with the theoretical ones. Thus, the corrected Pseudo-dynamic responses could be reliable for evaluating the seismic performance of structural systems.

• Geomechanics and Engineering
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• v.23 no.1
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• pp.1-13
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• 2020

To give a solution for seismic stability of tunnel faces subjected to earthquake ground shakings, the pseudo-dynamic approach is originally introduced to analyze tunnel face stability in this study. In the light of the upper-bound theorem of limit analysis, an advanced three-dimensional mechanism combined with pseudo-dynamic approach is proposed. Based on this mechanism, the required support pressure on tunnel face can be obtained by equaling external work rates to the internal energy dissipation and implementing an optimization searching procedure related to time. Both time and space feature of seismic waves are properly accounted for in the proposed mechanism. For this reason, the proposed mechanism can better represent the actual influence of seismic motion and has a remarkable advantage in evaluating the effects of vertical seismic acceleration, soil amplification factor, seismic wave period and initial phase difference on tunnel face stability. Furthermore, the pseudo-dynamic approach is compared with the pseudo-static approach. The difference between them is illustrated from a new but understandable perspective. The comparison demonstrates that the pseudo-static approach is a conservative method but still could provide precise enough results as the pseudo-dynamic approach if the value of seismic wavelengths is large or the height of soil structures is small.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.1
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• pp.111-120
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• 2015

HDR(High dynamic range) imaging is a technique to represent a dynamic range of real world. Exposure fusion is a method to obtain a pseudo-HDR image and it directly fuses multi-exposure images instead of generating the true-HDR image. However, it results ghost artifacts while fusing the multi-exposure images with moving objects. To solve this drawback, temporal consistency assessment is proposed to remove moving objects. Firstly, multi-level threshold bitmap and brightness bitmap are proposed. In addition, hue-angle constancy map between multi-exposure images is proposed for compensating a bitmap. Then, two bitmaps are combined as a temporal weight map. Spatial domain image quality assessment is used to generate a spatial weight map. Finally, two weight maps are applied at each multi-exposure image and combined to get the pseudo-HDR image. In experiments, the proposed method reduces ghost artifacts more than previous methods. The quantitative ghost-free evaluation of the proposed method is also less than others.

• Imaging Science in Dentistry
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• v.36 no.4
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• pp.199-206
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• 2006

Purpose: The purpose of this study was to evaluate comparison of static MRI and pseudo-dynamic (cine) MRI in temporomandibular joint (TMJ) disorder patients. Materials and Methods: In this investigation, 33 patients with TMJ disorders were examined using both conventional static MRI and pseudo-dynamic MRI. Multiple spoiled gradient recalled acquisition in the steady state (SPGR) images were obtained when mouth opened and closed. Proton density weighted images were obtained at the closed and open mouth position in static MRI. Two oral and maxillofacial radiologists evaluated location of the articular disk, movement of condyle and bony change respectively and the posterior boundary of articular disk was obtained. Results: No statistically significant difference was found in the observation of articular disk position, mandibular condylar movement and posterior boundary of articular disk using static MRI and pseudo-dynamic MRI (P<0.05). Statistically significant difference was noted in bony changes of condyle using static MRI and pseudo-dynamic MRI (P<0.05). Conclusion: This study showed that pseudo-dynamic MRI didn't make a difference in diagnosing internal derangement of TMJ in comparison with static MRI. But it was considered as an additional method to be supplemented in observing bony change.

• Smart Structures and Systems
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• v.26 no.1
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• pp.63-75
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• 2020

Substructure pseudo-dynamic hybrid simulation (SPDHS) combining the advantages of physical experiments and numerical simulation has become an important testing method for evaluating the dynamic responses of structures. Various parameter identification methods have been proposed for online model updating. However, if there is large model gap between the assumed numerical models and the real models, the parameter identification methods will cause large prediction errors. This study presents an ANN (artificial neural network) method based on forgetting factor. During the SPDHS of model updating, a dynamic sample window is formed in each loading step with forgetting factor to keep balance between the new samples and historical ones. The effectiveness and anti-noise ability of this method are evaluated by numerical analysis of a six-story frame structure with BRBs (Buckling Restrained Brace). One BRB is simulated in OpenFresco as the experimental substructure, while the rest is modeled in MATLAB. The results show that ANN is able to present more hysteresis behaviors that do not exist in the initial assumed numerical models. It is demonstrated that the proposed method has good adaptability and prediction accuracy of restoring force even under different loading histories.