• Earthquakes and Structures
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• v.12 no.1
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• pp.23-34
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• 2017

Composite steel plate deep beam (CDB) is proposed as a lateral resisting member, which is constructed by steel plate and reinforced concrete (RC) panel, and it is connected with building frame through high-strength bolts. To investigate the seismic performance of the CDB, tests of two 1/3 scaled specimens with different length-to-height ratio were carried out under cyclic loads. The failure modes, load-carrying capacity, hysteretic behavior, ductility and energy dissipation were obtained and analyzed. In addition, the nonlinear finite element (FE) models of the specimens were established and verified by the test results. Besides, parametric analyses were performed to study the effect of length-to-height ratio, height-to-thickness ratio, material type and arrangement of RC panel. The experimental and numerical results showed that: the CDBs lost their load-carrying capacity because of the large out-of plane deformation and yield of the tension field formed on the steel plate. By increasing the length-to-height ratio of steel plate, the load-carrying capacity, elastic stiffness, ductility and energy dissipation capacity of the specimens were significantly enhanced. The ultimate loading capacity increased with increasing the length-to-height ratio of steel plate and yield strength of steel plate; and such capacity increased with decreasing of height-to-thickness ratio of steel plate and gap. Finally, a unified formula is proposed to calculate their ultimate loading capacity, and fitting formula on such indexes are provided for designation of the CDB.

• International journal of steel structures
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• v.18 no.4
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• pp.1210-1218
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• 2018

A new type of earthquake-resisting element that consists of a steel plate shear wall with slits is introduced. The infill steel plate is divided into a series of vertical flexural links with vertical links. The steel plate shear walls absorb energy by means of in-plane bending deformation of the flexural links and the energy dissipation capacity of the plastic hinges formed at both ends of the flexural links when under lateral loads. In this paper, finite element analysis and experimental studies at low cyclic loadings were conducted on specimens with steel plate shear walls with multilayer slits. The effects caused by varied slit pattern in terms of slit design parameters on lateral stiffness, ultimate bearing capacity and hysteretic behavior of the shear walls were analyzed. Results showed that the failure mode of steel plate shear walls with a single-layer slit was more likely to be out-of-plane buckling of the flexural links. As a result, the lateral stiffness and the ultimate bearing capacity were relatively lower when the precondition of the total height of the vertical slits remained the same. Differently, the failure mode of steel plate shear walls with multilayer slits was prone to global buckling of the infill steel plates; more obvious tensile fields provided evidence to the fact of higher lateral stiffness and excellent ultimate bearing capacity. It was also concluded that multilayer specimens exhibited better energy dissipation capacity compared with single-layer plate shear walls.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.3
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• pp.317-324
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• 2015

The design of anchorage zone in a post-tensioned member has been started from the evaluation of the ultimate resisting capacity as well as the maximum bursting stress developed, and a lot of design codes including AASHTO and PTI describe their design equations to determine the bearing strength of concrete at the anchorage zone. However, these equations usually give conservative results because their derivation is based on the simple anchorage with a wide bearing plate in the surface without any additional consideration for the load transfer mechanism through transverse ribs on the anchorage. To assess the influence of geometric parameters related to the transverse ribs on the resisting capacity of anchorage block, experiments and analysis are conducted. After verifying the validity of numerical model conducted through correlation studies between experimental and analytical results, parametric studies with changes in the transverse ribs are followed and design recommendations for the anchorage block are suggested from the numerical results obtained.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.295-298
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• 2005

Coupled shear wall(CSW) has been adopted as a lateral force resisting system in building frame structures. New Zealand code recommends the capacity design in designing the CSW. Capacity design based on using moment redistribution of member force may provide the economical benefit to designer. In this study, CSW's are designed by both capacity design and strength -based design. The design results and the seismic performance are compared by using nonlinear static analyses. The amount of reinforcement of shear wall and the section area of steel coupling beams by capacity design appear to be reduced by 19$\%$ and 17$\%$, respectively. Also CSW designed by capacity design shows good seismic performance at the ultimate state.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.5
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• pp.87-98
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• 2006

This paper is an experimental result of performing the prototype of anchor tests in field to investigate the ultimate uplifting capacity of permanent anchor embedded in weathered rock. For prototype of actual anchor test in situ, four grouted anchors having various anchor lengths were installed in field and their ultimate uplift capacities were obtained by analyzing test results of load-displacement curves obtained from field uplift tests. On the other hand, creep tests, applying pull-out loading at the stage of the maximum loading during 15 minutes, were performed to investigate ultimate resisting capacity of anchor so that the values of creep rate at the ultimate loading conditions were evaluated. Dial gauges were installed on the surface of ground to measure the vertical displacement distribution from the anchor so that the failure mechanism of permanent anchor embedded in weathered rock and failure boundary of ground during application of loading were evaluated.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.4
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• pp.187-194
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• 2005

The purpose of this study is to investigate experimentally the shear resisting behavior of the reinforced concrete beams strengthened with reinforcement materials. Seven specimens were manufactured and tested under static monotonic loading. The main variables in the test were the method and direction of reinforcement. This research is about the experiment of shear capacity of reinforced concrete beams strengthened with CFRP-rod, in the filling-up method. The test result indicated that the method of CFRP increase significantly the ultimate shear strength of a reinforced concrete beam.

• Computers and Concrete
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• v.33 no.2
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• pp.217-240
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• 2024

The purpose of this study is to propose new hysteretic characteristics of medium- to low-rise RC structures controlled by both shear and flexure. Through previous study, the dual lateral force-resisting system composed of shear and flexural failure members has a new failure mechanism that cooperates to enhance the flexural capacity of the flexural failure member even after the failure of the shear member, and the existing theoretical equation significantly underestimates the ultimate strength. In this study, the residual lateral strength mechanism of the dual lateral force-resisting system was analyzed, and, as a result, an equation for estimating the residual flexural strength of each shear-failure member was proposed. The residual flexural strength of each shear-failure member was verified in comparison with the structural testing results obtained in previous study, and the proposed residual flexural strength equation for shear-failure members was tested for reliability using FEA, and its applicable range was also determined. In addition, restoring-force characteristics for evaluating the seismic performance of the dual lateral force-resisting system (nonlinear dynamic analysis), reflecting the proposed residual flexural strength equation, were proposed. Finally, the validity of the restoring-force characteristics of RC buildings equipped with the dual lateral force-resisting system proposed in the present study was verified by performing pseudo-dynamic testing and nonlinear dynamic analysis based on the proposed restoring-force characteristics. Based on this comparative analysis, the applicability of the proposed restoring-force characteristics was verified.

• Journal of the Korea Concrete Institute
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• v.14 no.5
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• pp.645-652
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• 2002

This paper presents the flexural behavior and strengthening effect of reinforced concrete beams bonded with carbon FRP plate. Parameters involved in this experimental study were plate bond length and sheet web anchorage length. Test beams were strengthened with FRP plate on the soffit and anchored with FRP sheet on the web. In general, strengthened beams with no web anchorage were failed by concrete cover failure along the longitudinal reinforcement. On the other hand, strengthened beams with web anchorage were finally failed by delamination shear failure within concrete after breaking of CFRP sheet wrapping around web. The ultimate load and deflection of strengthened beams increased with an increased bond length of FRP plate. Also, the ultimate load and deflection increased with an increased anchorage length of FRP sheet. Particularly, the strengthened beams with web anchorage maintained high ultimate load resisting capacity until very large deflection. The shape of strain distribution of CFRP plate along beam was very similar to that of bending moment diagram. Therefore, an assumption of constant shear stress in shear span could be possible in the analysis of delamination shear stress of concrete. In the case of full bond length, the ultimate resisting shear stress provided by concrete and FRP sheet Increased with an increase of web anchorage length. In the resisting shear force, a portion of the shear force was provided by FRP anchorage sheet.

• Structural Engineering and Mechanics
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• v.37 no.1
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• pp.39-59
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• 2011

Results of an experimental investigation on the behavior and ultimate shear capacity of 27 reinforced concrete Transfer (deep) beams are summarized. The main variables were percent longitudinal(tension) steel (0.28 to 0.60%), percent horizontal web steel (0.60 to 2.40%), percent vertical steel (0.50to 2.25%), percent orthogonal web steel, shear span-to-depth ratio (1.10 to 3.20) and cube concrete compressive strength (32 MPa to 48 MPa).The span of the beam has been kept constant at 1000 mm with100 mm overhang on either side of the supports. The result of this study shows that the load transfer capacity of transfer (deep) beam with distributed longitudinal reinforcement is increased significantly. Also, the vertical shear reinforcement is more effective than the horizontal reinforcement in increasing the shear capacity as well as to transform the brittle mode of failure in to the ductile mode of failure. It has been observed that the orthogonal web reinforcement is highly influencing parameter to generate the shear capacity of transfer beams as well as its failure modes. Moreover, the results from the experiments have been processed suitably and presented an analytical model for design of transfer beams in high-rise buildings for estimating the shear capacity of beams.

• Journal of Korean Society of Steel Construction
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• v.9 no.1 s.30
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• pp.107-120
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• 1997

The purpose of this study is to develop composite structural system which is to have versatility in plan design and to improve economical efficieney, to maximise structural capacity than existing structural system. In this viewpoint, it was investigated to the properties of structural behaviors for i oint consisting of concrete filled steel square tube column and P.C reinforced concrete beam through a series of hysteretic behavior experiment. In the previous report, researched to the properties of joints with key parameters. such as Axial Force ratio and section types. From the based on previous results, this study investigated the properties of this joints with key parameters, such as strength of concrete, size of panel zone and Axial Force ratio. The obtained results are summarised as follows. (1) Investigating for the failure mode of the beam-to-column joint, the specimens of S,LL and LH series(except for L5H) presented flexural failure mode. (2) The initial stiffness of joint was increasd as the decrease of axial force ratio and increase of the concrete strength. (3) The rotation resisting capacity was effective as the increment of the concrete strength and decrement of the axial force ratio. (4) The emprical formula to predict the ultimate capacity of joint model to introduce decrease coefficient according to the axial force ratio to superimpose shearing strength of steel web(H section) and bending strength of reinforced concrete beam was expected.