• Steel and Composite Structures
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• 제34권1호
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• pp.107-122
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• 2020

Moment resisting stub columns (MRSCs) have increasingly adopted in special moment-resisting frame (SMF) systems in steel building structures, especially in Asian countries. The MRSCs typically provide a lower deformation capacity compared to shear-panel stub columns, a limited post-yield stiffness, and severe strength degradation as adopting slender webs. A new MRSC design with cored configuration, consisting of a core-segment and two side-segments using different steel grades, has been proposed in the study to improve the demerits mentioned above. Several full-scale components of the cored MRSC were experimentally investigated focusing on the hysteretic performance of plastic hinges at the ends. The effects of the depths of the core-segment and the adopted reduced column section details on the hysteretic behavior of the components were examined. The measured hysteretic responses verified that the cored MRSC enabled to provide early yielding, great ductility and energy dissipation, enhanced post-yield stiffness and limited strength degradation due to local buckling of flanges. A parametric study upon the dimensions of the cored MRSC was then conducted using numerical discrete model validated by the measured responses. Finally, a set of model equations were established based on the results of the parametric analysis to accurately estimate strength backbone curves of the cored MRSCs under increasing-amplitude cyclic loadings.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1993년도 가을 학술발표회 논문집
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• pp.261-266
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• 1993

This study was performed to evaluate the flexural behavior of polymer concrete sandwich panels which was made of unsaturated polymer resin. Bending tests under 4point loading was conducted for the 8 type of sandwich panel with different core and facing thickness. Results show that Load-Deflection, shearing force- shear strain, moment strength - strain relationships were effected by core and facing thickness.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 봄 학술발표회 논문집
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• pp.215-222
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• 2001

This study investigates the shear lag phenomenon existing in the shear wall of the wall-frame structure. Elastic analysis of such structures is carried out using a 3-D frame analysis program. The structural parameters governing the shear lag phenomenon are wall height and thickness. The analysis shows that the overturning moment due to external lateral load is resisted by both of the shear/core wall and the external frame. Severe unstable stresses are identified in height ratio of about 0.7 The taller or thinner wall shows the smaller shear lag phenomenon.

• 전기학회논문지
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• 제64권12호
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• pp.1695-1702
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• 2015

This paper presents the characteristic analysis and experiment of force characteristics in permanent magnet linear synchronous motor for accuracy prediction of linear motion machine tools. In particular, the pitching moment resulting from attraction force ripple has been analysed and tested. Firstly, we analysed the characteristics of detent force, attraction force, and pitching moment in permanent magnet linear synchronous motor according to the design techniques such as auxiliary teeth, chamfering, and permanent magnet skewing. In addition, we suggested the experimental set for measurement of pitching moment. Finally, the results from measurement shows the good agreement with those obtained from finite element analysis results.

• Steel and Composite Structures
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• 제46권5호
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• pp.621-635
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• 2023

The combination of replaceable and repairable properties in structures has introduced new approach called "Low Damage Design Structures". These structural systems are designed in such a way that through self-centering, primary members and specific connections neither suffer damage nor experience permanent deformations after being exposed to severe earthquakes. The purpose of this study is the seismic assessment of steel moment resisting frames with the aid of rigid rocking cores. To this end, three steel moment resisting frames of 4-, 8-, and 12-story buildings with and without rocking cores were developed. The nonlinear static analysis and incremental dynamic analysis were performed by considering the effects of the vertical and horizontal components of 16 strong ground motions, including far-fault and near-fault arrays. The results reveal that rocking systems benefit from better seismic performance and energy dissipation compared to moment resisting frames and thus structures experience a lower level of damage under higher intensity measures. The analyses show that the interstory drift in structures equipped with stiff rocking cores is more uniform in static and dynamic analyses. A uniform interstory drift distribution leads to a uniform distribution of the bending moment and a reduction in the structure's total weight and future maintenance costs.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.159-164
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• 2001

In this study, a polymer mortar sandwich panel (PMSP) was developed : Core was made with the polymer mortar whose compressive strength was about 840 kgf/$\textrm{cm}^2$, and both facings were made with the glass fiber reinforced plastics (GFRP). The results showed that the strain energies and the ductility indices increased 16-340 times and 2-8 times, respectively, as the thicknesses of facings increased from 0.6 to 3.0mm with fixing the core thickness to constants (12-36mm). On the other hand, these values showed a tendency of decrease as the core thickness increased regardless of thickness of facings. A set of basic data for the structural analysis could be provided by investigating the correlations, within the scope of this research, between the resisting moment and the thicknesses of core and facings.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.105-110
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• 2002

In this study, a MMA modified polymer mortal sandwich panels was developed : Core was made with the MMA modified polymer mortar whose compressive strength was about 1020 kgf/cm$^2$, and both facings were made with the glass fiber reinforced plastics (GFRP). The results showed that the strain energies increased 20-33 times, respectively, as the thicknesses of facings increased from 1.50 to 2.76 mm with fixing the core thickness to constants (30-50 mm). On the other hand, these values showed a tendency of decrease as the core thickness increased regardless of thickness of facings. A set of basic data for the structural analysis could be provided by investigating the correlations, within the scope of this research, between the resisting moment and the thicknesses of core and facings.

• 한국공간구조학회논문집
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• 제23권3호
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• pp.71-78
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• 2023

Recently, Free-Form and Irregular Shape high-rise buildings are constructed by IT technology development. Tilted shaped high-rise building which is one of Irregular shape high-rise buildings can cause lateral displacement by gravity load and lateral load due to tilted elevation shape. Therefore, it is necessary to review the behavior and structural aspects of the Tilted shape high-rise building by gravity load. In this paper, the dynamic characteristics of a tilted structure with a dual-core were analyzed with the core location as a design variable, and response behavior, vulnerable members, and vulnerable layers to earthquake loads were analyzed. As a result of the analysis, as the location of the core moved in an tilted direction, the eccentric distance and eccentric load decreased, reducing the axial force of the vertical members. However, the location of the core had little effect on the response.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.571-578
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• 2022

Modularization in a high-rise building is different from a small building, as it is exposed to more lateral forces like wind and earthquakes. The integrity, robustness, and overall stability of the modules and their performance is based on the joining techniques and strong structural systems. High lateral stiff construction structures like concrete shear walls and frames, braced steel frames, and steel moment frames are used for the stability of high-rise modular buildings. Similarly, high-rise stick-built buildings have concrete cores and perimeter frames for lateral load strength and stiffness. Methods for general steel-concrete connections are available in many works of literature. However, there are few modular-related papers describing this connection system in modular buildings. This paper aims to review the various research and practice adopted for steel-to-concrete connections in construction and compare the methods between stick-built buildings and modular buildings. The literature review shows that the practice of steel module-to-concrete core connection in high-rise modular buildings is like outrigger beams-to-concrete core connection in stick-built framed buildings. This paper concludes that further studies are needed in developing proper guidelines for a steel module-to-concrete core connection system in high-rise modular buildings.

• Steel and Composite Structures
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• 제25권4호
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• pp.457-472
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• 2017

The objective of this paper is to investigate the flexural behavior of concrete-filled round-ended steel tubes (CFRTs) under bending. Beam specimens were tested to investigate the mechanical behavior of the CFRTs, including four CFTs with different concrete strengths and steel ratios, and three CFRTs with varied aspect ratios. The load vs. deflection relationships and the failure modes for CFRTs were analyzed in detail. The composite action between the core concrete and steel tube was also discussed and examined based on the experimental results. In addition, ABAQUS program was used to develop the full-scale finite element model and analyze the effect of different parameters on the moment vs. curvature curves of the CFRTs bending about the major and minor axis, respectively. Furthermore, design formulas were proposed to estimate the ultimate moment and the flexural stiffness of the CFRTs, and the simplified theoretical model of the moment vs. curvature curves was also developed. The predicted results showed satisfactory agreement with the experimental and FE results. Finally, the differences of the experimental, FE and predicted results using the existing codes were illustrated.