• Journal of the Earthquake Engineering Society of Korea
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• v.2 no.4
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• pp.31-40
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• 1998

The purpose of this study is to investigate static elastoplastic behaviour and estimate ultimate resistance capacity of a high-rise apartment shear wall system subjected to a vertical distribution of lateral loading along the height. A typical 25-story two unit plan apartment is selected as a representive model. For the analysis, the pushover analysis is adopted to estimate initial elastic stiffness, post-yielding stiffness and story shear yield resistance level on each story of the structure through three-dimensional nonlinear analysis program-CANNY. In the result of elastoplastic analysis, it is observed that the yield strength of building structures is 1.6 times larger than required lateral design strength.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.673-679
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• 2005

Urban conditions such as underground facilities and ambient noises due to cultural activity restrict the application of conventional geophysical techniques in general. We used the linear array microtremor technique which uses these noises as strong energy source. The result parameter of the survey is shear wave velocity profile which had been applied as an fundamental information for the determination of the rock support type in tunnel design. This study was the first case in Korea which utilized a surface geophysical technique yielding successful result in urban area especially under the existing rail ways. The quantitative relation between the shear wave velocity from this method and the rock mass rating(RMR) determined from the inspection of the cores recovered from the same boreholes showed high statistical relationship. These correlations were then used to relate the shear-wave velocity to RMR along the entire profile.

• Transactions of Materials Processing
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• v.19 no.7
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• pp.411-415
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• 2010

A sandwich panel which is comprised of truss cores faced with solid face sheets is lightweight and multi-functional. So it is widely used to not only structural material but also heat transfer media in transportation field such as airplane, train and vessel. There are various core topologies such as pyramidal and tetrahedral truss, square honeycombs and kagome truss. The study focused on analytical approach to optimize compression and shear quality of the unit cell of PCM with pyramidal configuration. With various unit cell models which have the same core weight per unit area but different truss member angle, analytical solution for effective stress ($\bar{\sigma},\bar{\tau}$), peak stress ($\bar{\sigma}_{peak},\bar{\tau}_{peak}$) by yielding and buckling, relative density ($\bar{\rho}_c$) and effective stiffness ($\bar{E},\bar{G}$) have been computed and compared each other. With this approach, the most optimal core configuration was predicted. The result has become the efficient guidelines for the design of PCM core structure.

• Steel and Composite Structures
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• v.37 no.5
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• pp.517-532
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• 2020

This paper firstly developed a new type of Double Skin Composite (DSC) beams using novel enhanced C-channels (ECs). The shear behaviour of novel ECs was firstly studied through two push-out tests. Eleven full-scale DSC beams with ECs (DSCB-ECs) were tested under four-point loading to study their ultimate strength behaviours, and the studied parameters were thickness of steel faceplate, spacing of ECs, shear span, and strength of concrete core. Test results showed that all the DSCB-ECs failed in flexure-governed mode, which confirmed the effective bonding of ECs. The working mechanisms of DSCB-ECs with different parameters were reported, analysed and discussed. The load-deflection (or strain) behaviour of DSCB-ECs were also detailed reported. The effects of studied parameters on ultimate strength behaviour of DSCB-ECs have been discussed and analysed. Including the experimental studies, this paper also developed theoretical models to predict the initial stiffness, elastic stiffness, cracking, yielding, and ultimate loads of DSCB-ECs. Validations of predictions against 11 test results proved the reasonable estimations of the developed theoretical models on those stiffness and strength indexes. Finally, conclusions were given based on these tests and analysis.

• Steel and Composite Structures
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• v.33 no.5
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• pp.729-746
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• 2019

The nonlinear behavior of single- and multi-story steel plate shear walls (SPSWs) strengthened with three different patterns of fiber reinforced polymer (FRP) laminates (including single-strip, multi-strip and fully FRP-strengthened models) is studied using the finite element analysis. In the research, the effects of orientation, width, thickness and type (glass or carbon) of FRP sheets as well as the system aspect ratio and height are investigated. Results show that, despite an increase in the system strength using FRP sheets, ductility of reinforced SPSWs is decreased due to the delay in the initiation of yielding in the infill wall, while their initial stiffness does not change significantly. The content/type/reinforcement pattern of FRPs does affect the nonlinear behavior characteristics and also the mode and pattern of failure. In the case of multi-strip and fully FRP-strengthened models, the use of FPR sheets almost along the direction of the infill wall tension fields can maximize the effectiveness of reinforcement. In the case of single-strip pattern, the effectiveness of reinforcement is decreased for larger aspect ratios. Moreover, a relatively simplified and approximate theoretical procedure for estimating the strength of SPSWs reinforced with different patterns of FRP laminates is presented and compared with the analytical results.

• Earthquakes and Structures
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• v.10 no.1
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• pp.1-23
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• 2016

Steel plate shear walls (SPSWs) have been shown to be efficient lateral force-resisting systems, which are increasingly used in new and retrofit construction. These structural systems are designed with either stiffened and stocky or unstiffened and slender web plates based on disparate structural and economical considerations. Based on some limited reported studies, on the other hand, employment of low yield point (LYP) steel infill plates with extremely low yield strength, and high ductility as well as elongation properties is found to facilitate the design and improve the structural behavior and seismic performance of the SPSW systems. On this basis, this paper reports system-level investigations on the seismic response assessment of multi-story SPSW frames under the action of earthquake ground motions. The effectiveness of the strip model in representing the behaviors of SPSWs with different buckling and yielding properties is primarily verified. Subsequently, the structural and seismic performances of several code-designed and retrofitted SPSW frames with conventional and LYP steel infill plates are investigated through detailed modal and nonlinear time-history analyses. Evaluation of various seismic response parameters including drift, acceleration, base shear and moment, column axial load, and web-plate ductility demands, demonstrates the capabilities of SPSW systems in improving the seismic performance of structures and reveals various advantages of use of LYP steel material in seismic design and retrofit of SPSW systems, in particular, application of LYP steel infill plates of double thickness in seismic retrofit of conventional steel and code-designed SPSW frames.

• Steel and Composite Structures
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• v.11 no.3
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• pp.251-271
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• 2011

To make direct comparisons regarding the cyclic behavior of thin steel plate shear walls (TSPSWs) with different infill-to-boundary frame connections, two TSPSWs were tested under quasi-static conditions, one having the infill plate attached to the boundary frame members on all edges and the other having the infill plate connected only to the beams. Also, the bare frame that was used in the TSPSW specimens was tested to provide data for the calibration of numerical models. The connection of infill plates to surrounding frames was achieved through the use of self-drilling screws to fish plates that were welded to the frame members. The behavior of TSPSW specimens are compared and discussed with emphasis on the characteristics important in seismic response, including the initial stiffness, ultimate strength and deformation modes observed during the tests. It is shown that TSPSW specimens achieve significant ductility and energy dissipation while the ultimate failure mode resulted from infill plate fracture at the net section of the infill plate-to-boundary frame connection after substantial infill plate yielding. Experimental results are compared to monotonic pushover predictions from computer analysis using strip models and the models are found to be capable of approximating the monotonic behavior of the TSPSW specimens.

• Journal of the Earthquake Engineering Society of Korea
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• v.23 no.1
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• pp.31-42
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• 2019

In this study, the results of an analytical investigation on the seismic behavior of two residential 4-story bearing wall buildings with pilotis, each of which has symmetric or unsymmetric wall arrangement at their piloti level, are presented. The dynamic characteristics and lateral resistance of the piloti buildings were investigated through linear elastic and nonlinear static analyses. According to the results, the analytical natural period of vibration of the piloti buildings were significantly shorter than the fundamental period calculated in accordance with KBC 2016. In the initial elastic behavior, the walls resisting in-plane shear contributed to the lateral stiffness and strength, while the contribution of columns resisting flexural moments in double curvature was limited. However, after the shear cracking and yielding of the walls occurred, the columns significantly contributed to the residual strength and ductility. Based on those investigations, design recommendations of low-rise bearing wall buildings with piloti configuration are given.

• Steel and Composite Structures
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• v.44 no.3
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• pp.339-351
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• 2022

A mortar-filled rectangular hollow structural section (RHS) can increase a structural section property as well as a compressive buckling capacity of a RHS member. In this study, the tensile performance of newly developed mortar-filled RHS members was experimentally evaluated with various connection details. The major test parameters were the type of end connections, the thickness of cap plates and shear plates, the use of stud bolts, and penetrating bars. The test results showed that the welded T-end connection experienced a brittle weld fracture at the welded connection, whereas the tensile performance of the T-end connection was improved by additional stud bolts inserted into the mortar within the RHS tube. For the end connection using shear plates and penetrating stud bolts, ductile behavior of the RHS tube was achieved after yielding. The penetrating bars increased load carrying capacity of the RHS. Based on the analysis of the load transfer mechanism, the current design code and test results were compared to evaluate the tensile capacity of the RHS tube according to the connection details. Design considerations for the connections of the mortar-filled RHS tubes were also recommended.

• Journal of the Korea Concrete Institute
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• v.22 no.5
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• pp.675-684
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• 2010

The reinforced concrete members are designed to fail in flexural to lead ductile fracture. In the building structures, the failure is typically imposed on beams to prevent damages in columns. However, progression of plastic collapse mechanism may ultimately develop, a plastic hinge at the bottem end of the first floor column, which then can be subjected to shear or bond finally due to large axial force and small shear span-to-depth ratio. In this study, 10 RC column specimens failed in shear after flexural yielding was investigated to determine the factors affecting the plastic hinge length. The findings of this study showed that the most effective factor affecting the plastic hinge length was an axial force. As an axial force increase, an axial strain and a ductility ratio were decreased obviously. The test also shows the observed plastic hinge length was about 0.8~1.2d and the this result has difference compared with forward research.