• Steel and Composite Structures
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• v.19 no.2
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• pp.277-292
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• 2015

Previous research has shown that steel plate shear walls (SPSWs) are efficient lateral force-resisting systems against both wind and seismic loads. A properly designed SPSW can have high initial stiffness, strength, and energy absorption capacity as well as superior ductility. SPSWs have been commonly designed with unstiffened and stiffened infill plates based on economical and performance considerations. Recent introduction and application of corrugated plates with advantageous structural features has motivated the researchers to consider the employment of such elements in stiffened SPSWs with the aim of lowering the high construction cost of such high-performing systems. On this basis, this paper presents results from a numerical investigation of the hysteretic performance of SPSWs with trapezoidally corrugated infill plates. Finite element cyclic analyses are conducted on a series of flat- and corrugated-web SPSWs to examine the effects of web-plate thickness, corrugation angle, and number of corrugation half-waves on the hysteretic performance of such structural systems. Results of the parametric studies are indicative of effectiveness of increasing of the three aforementioned web-plate geometrical and corrugation parameters in improving the cyclic response and energy absorption capacity of SPSWs with trapezoidally corrugated infill plates. Increasing of the web-plate thickness and number of corrugation half-waves are found to be the most and the least effective in adjusting the hysteretic performance of such promising lateral force-resisting systems, respectively. Findings of this study also show that optimal selection of the web-plate thickness, corrugation angle, and number of corrugation half-waves along with proper design of the boundary frame members can result in high stiffness, strength, and cyclic performances of such corrugated-web SPSWs.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.525-528
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• 1998

This paper reports on tests of reinforced concrete shear walls for wall-type apartment structure under axial loads and the cyclic reversal of lateral loads with different confinement of the boundary elements. Confinement of the extreme element by U-stirrups and tie hooks seems to be as effective as closed stirrups. The shear strength capacity seems not to be increased by the confinement but deformation capacity improved.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.419-422
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• 1999

This study was intended to investigate the cyclic behavior of high strength concrete beam-column connection. Four assemblies were designed 2/3 scale beam-column-slab joint and tested. The obtained results are follows. 1) The transverse beams increase the shear resistance and ductility of joint, 2) The slab was contributed to increase of the flexural capacity of the beam, but was not contributed to increase the joint ductility under lateral loads.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.469-474
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• 2002

This study was to define the strengthening effect of steel fibers in high strength RC columns. For this, ten specimens of columns were tested under cyclic lateral load and constant axial load. The testing parameters are steel fiber volume fraction of concrete and shear reinforcement ratio of hoop bars. Finally, the optimal content of steel fibers was evaluated as 1.0 - 1.5 % volume fraction of concrete.

• Structural Engineering and Mechanics
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• v.27 no.4
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• pp.439-456
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• 2007

Reinforced concrete (RC) joint shear strength models are constructed using an experimental database in conjunction with a Bayesian parameter estimation method. The experimental database consists of RC beam-column connection test subassemblies that maintained proper confinement within the joint panel. All included test subassemblies were subjected to quasi-static cyclic lateral loading and eventually experienced joint shear failure (either in conjunction with or without yielding of beam reinforcement); subassemblies with out-of-plane members and/or eccentricity between the beam(s) and the column are not included in this study. Three types of joint shear strength models are developed. The first model considers all possible influence parameters on joint shear strength. The second model contains those parameters left after a step-wise process that systematically identifies and removes the least important parameters affecting RC joint shear strength. The third model simplifies the second model for convenient application in practical design. All three models are unbiased and show similar levels of scatter. Finally, the improved performance of the simplified model for design is identified by comparison with the current ACI 352R-02 RC joint shear strength model.

• Geomechanics and Engineering
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• v.20 no.1
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• pp.29-41
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• 2020

It is extremely important to obtain rock strength parameters for geological engineering. In this paper, the evolution of sandstone cohesion and internal friction angle with plastic shear strain was obtained by simulating the cyclic loading and unloading tests under different confining pressures using Particle Flow Code software. By which and combined with the micro-crack propagation process, the mesoscopic mechanism of parameter evolution was studied. The results show that with the increase of plastic shear strain, the sandstone cohesion decreases first and then tends to be stable, while the internal friction angle increases first, then decreases, and finally maintains unchanged. The evolution of sandstone shear strength parameters is closely related to the whole process of crack formation, propagation and coalescence. When the internal micro-cracks are less and distributed randomly and dispersedly, and the rock shear strength parameters (cohesion, internal friction angle) are considered to have not been fully mobilized. As the directional development of the internal micro-fractures as well as the gradual formation of macroscopic shear plane, the rock cohesion reduces continuously and the internal friction angle is in the rise stage. As the formation of the macroscopic shear plane, both the rock cohesion and internal friction angle continuously decrease to a certain residual level.

• International journal of steel structures
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• v.18 no.4
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• pp.1297-1305
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• 2018

The corrugated steel plate shear walls have recently been proposed to address the seismic issues associated with simple steel plate shear walls; however, stiffness, strength, and ductility of the corrugated shear walls are significantly affected by varying the corrugation geometry under seismic loading. The present study investigates steel shear walls' models with corrugated or simple infill plates subjected to monotonic and cyclic loads. The performance of the corrugated steel plate is evaluated and then compared to that of the simple steel plates by evaluating the damping ratios and energy dissipation capability. The effect of corrugation profile angle, the existence of an opening, and the corrugation subpanel length are numerically investigated after validation of the finite element modeling methodology. The results demonstrate that incorporating corrugated plates would lead to better seismic damping ratios, specifically in the case of opening existence inside of the infill plate. Specifically, the corrugation angle of $30^{\circ}$ decreases the ultimate strength, while increasing the initial stiffness and ductility. In addition, the subpanel length of 100 mm is found to be able to improve the overall performance of shear wall by providing each subpanel appropriate support for the adjacent subpanel, leading to a sufficient buckling resistance performance.

• Nuclear Engineering and Technology
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• v.54 no.3
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• pp.1071-1084
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• 2022

The present study aims to investigate the dynamic properties of a novel isolation system composed of separate rubber and wire isolators. The testing program comprised pure compressive, pure-shear, compressive-stress dependence, and shear-strain dependence tests that used full-scale test specimens according to ISO 22762-1. A total of 22 test specimens were fabricated and investigated. Among the tests, the pure compressive test was a destructive test that reached up to the failure stage, whereas the others were nondestructive tests before the failure stage. Similar to the pure-shear test, at each compressive-stress level in the compressive dependence test or at each shear-strain level in the shear-strain dependence test, the cyclic loading was conducted for three cycles. In the nondestructive tests, examination of the dynamic shear properties in the X-direction was independent of the Y-direction. The test results revealed that the increase in the shear strain increased the energy dissipation but decreased the damping ratio, whereas the increase in the compressive stress increased the damping ratio. In addition, a macro model was developed to simulate the load-displacement response of the isolation systems, and the prediction results were consistent with the experimental results.

• Geotechnical Engineering
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• v.10 no.4
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• pp.119-132
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• 1994

Undrained cyclic triaxial tests were performed on silt contained in the sand in order to investigate the effect of silt contents on the liquefaction strength and shear characterist ifs of the sand. As the result of this experiment, the weakest percentage of silt contained in the sand was 30% for all the relative density considered in the test. Also, the same bests were performed to find the effect of cyclic speed applied ranging from 0.1Hz to 5Hz on the liquefaction strength. The more the silt is contained in the sand, the greater the liquefaction strength was affected by cyclic speed, While the silt -containing sand was far less influenced by the cyclic speed than clay containing sand. These results are believed to be caused by the change of pore water pressure of the effective stress path.

• Earthquakes and Structures
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• v.19 no.3
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• pp.189-196
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• 2020

The near-collapse performance limit is defined as the deformation at the 20% drop of maximum base shear in the decreasing region of the pushover curve for ductile framed buildings. Although monotonic pushover analysis is preferred due to the simple application procedure, this analysis gives rise to overestimated results by neglecting the cumulative damage effects. In the present study, the acceptabilities of monotonic and cyclic pushover analysis results for the near-collapse performance limit state are determined by comparing with Incremental Dynamic Analysis (IDA) results for a 5-story Reinforced Concrete framed building. IDA is performed to obtain the collapse point, and the near-collapse drift ratios for monotonic and cyclic pushover analysis methods are obtained separately. These two alternative drift ratios are compared with the collapse drift ratio. The correlations of the maximum tensile and compression strain at the base columns and beam plastic rotations with interstory drift ratios are acquired using the nonlinear time history analysis results by the simple linear regression analyses. It is seen that these parameters are highly correlated with the interstory drift ratios, and the results reveal that the near-collapse point acquired by monotonic pushover analysis causes unacceptably high tensile and compression strains at the base columns, as well as large plastic rotations at the beams. However, it is shown that the results of cyclic pushover analysis are acceptable for the near-collapse performance limit state.