• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.1049-1052
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• 2008

Coupling beams have been used in bearing wall system during last decades. Practically their sectional effects are fully considered in analysis stage to control lateral displacement because they have good contribution to the stiffness of bearing wall system. But the high resultant forces of coupling beam are not fully satisfied in design stage because coupling beams are restricted in sectional size. In this paper the performance of bearing wall system with coupling beam has been evaluated based on improved equivalent linearization procedure of FEMA 440. 15 storied building is selected for analysis. Variables for performance evaluation are natural period, degree of coupling and soil site. To evaluate performance, demand capacity spectrum is calculated based on KBC 2005. As a result, for the most of the cases the life safety limit of chord rotation of coupling beam is less than the performance point of system for soil site $S_D$. That means that the coupling beam can be severly damaged before the system reaches at performance point.

• Computers and Concrete
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• v.12 no.4
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• pp.565-583
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• 2013

Existing numerical models for strain-hardening cement-based composites (SHCC) are short of providing sufficiently accurate solutions to the failure patterns of coupling beams of different designs. The objective of this study is to develop an effective model that is capable of simulating the nonlinear behavior of SHCC coupling beams subjected to cyclic loading. The beam model proposed in this study is a macro-scale plane stress model. The effects of cracks on the macro-scale behavior of SHCC coupling beams are smeared in an anisotropic model. In particular, the influence of the defined crack orientations on the simulation accuracy is explored. Extensive experimental data from coupling beams with different failure patterns are employed to evaluate the validity of the proposed SHCC coupling beam models. The results show that the use of the suggested shear stiffness retention factor for damaged SHCC coupling beams is able to effectively enhance the simulation accuracy, especially for shear-critical SHCC coupling beams. In addition, the definition of crack orientation for damaged coupling beams is found to be a critical factor influencing the simulation accuracy.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1265-1267
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• 1995

In the fiber-photodiode(PD) coupling module using v-groove, the paraxial approximation is no longer valid because the beam enters obliquely the PD substrate with the angle of $20^{\circ}$ after being reflected from the $55^{\circ}$ mirror formed by anisotropically etching of the (100) silicon wafer. In this paper, we study the beam profile incident on the PD active area and fiber-PD coupling efficiency for this case.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.4 s.97
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• pp.445-451
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• 2005

This paper is the result of a experimental study about non-linear one to one modal coupling of a flexible circular cantilever beam which was transversely excited with harmonic excitation. It was proved that 2 order jumping in out of plane was caused by jump phenomenon in in-plane of flexible circular cantilever beam, because of non-linear coupling. In addition, cantilever beam showed hardening spring characteristics in in-plane and softening spring characteristics in out-of-plane.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.129-133
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• 2004

This paper is the result of a experimental study about non-linear one to one modal coupling of a flexible circular cantilever beam which was transversely excited with harmonic excitation. It was proved that 2 order jumping in out of plane was caused by jump phenomenon in in-plane of flexible circular cantilever beam, because of non-linear coupling. In addition, cantilever beam showed hardening spring characteristics in in-plane and softening spring characteristics in out-of-plane.

• Journal of the Korea Concrete Institute
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• v.27 no.6
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• pp.661-668
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• 2015

Coupled shear walls are effective lateral force resisting system in which coupling beams link individual walls. For improving the energy dissipation capacity of coupling beams, diagonal reinforcement details were developed. However, it is difficult to construct diagonal reinforced coupling beams due to the congestion of reinforcement in the beam. For resolving the problem, this study developed precast coupling beams with bundled diagonal reinforcement. To reduce the reinforcement congestion, bundled diagonal reinforcement were placed in the coupling beam. To evaluate the cyclic performance of coupling beams with bundled diagonal reinforcement, experimental test were conducted. For this purpose, two slender specimens with an aspect ratio of 3.5 were made and tested. It was observed that the cyclic performance of the coupling beam with bundled diagonal reinforcement was similar with that of the coupling beam with normal diagonal reinforcement placed according to design code to ACI 318-11.

• Journal of Power System Engineering
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• v.4 no.4
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• pp.65-69
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• 2000

On the dynamic behavior of a simple beam subjected to an uniformly distributed tangential follower force, the influences of the velocities and magnitudes of a moving mass have been studied by numerical method. The instant amplitude of a simple beam is calculated and analyzed for each position of the moving mass represented by the time functions. The uniformly distributed tangential follower force is considered within its critical value of a simple beam, and four values of velocity is also chosen. Their coupling effects on the deflections of a simple beam are inspected too. When a moving mass moves after middle zone of a simple beam at the low velocities, its deflection is increased by the coupling of an uniformly distributed tangential follower force and moving mass.

• Journal of the Earthquake Engineering Society of Korea
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• v.17 no.6
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• pp.271-278
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• 2013

The hysteretic behavior of diagonal reinforced coupling beams is excellent during earthquakes. However, construction of the diagonal reinforced coupling beams is difficult due to complex reinforcement details required by current code procedures (ACI 318-11). Due to the detail requirement, reinforcement congestion and interference among transverse reinforcement always occur during construction field. When the aspect ratio of the beam is large, the interference of reinforcement becomes more serious. The objective of this paper is to simplify the reinforcement details of slender coupling beams by reducing transverse reinforcement around the beam perimeter. For this purpose, high- performance fiber reinforced cementitious composites are used for making coupling beams. Experiments were conducted using three specimens having aspect ratio 3.5. Test results showed that HPFRCC coupling beams with half the transverse reinforcement required by ACI 318-11 provided identical seismic capacities to the corresponding coupling beams having requirement satisfying the requirement specified in ACI 318-11.

• Earthquakes and Structures
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• v.7 no.5
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• pp.817-842
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• 2014

ASCE/SEI 41-13 provides modeling parameters and numerical acceptance criteria for various types of members that are useful for evaluating the seismic performance of reinforced concrete (RC) building structures. To accurately evaluate the global performance of a coupled wall system, it is crucial to first properly define the component behaviors (i.e., force-displacement relationships of shear walls and coupling beams). However, only a few studies have investigated on the modeling of RC coupling beams subjected to earthquake loading to date. The main objective of this study is to assess the reliability of ASCE 41-13 modeling parameters specified for RC coupling beams with various design details, based on a database compiling almost all coupling beam tests available worldwide. Several recently developed coupling beam models are also reviewed. Finally, a rational method is proposed for determining the chord yield rotation of RC coupling beams.

• Steel and Composite Structures
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• v.7 no.4
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• pp.279-301
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• 2007

When coupling beams are proportioned appropriately in coupled core wall (CCW) systems, the input energy from ground motions is dissipated primarily through inelastic deformations in plastic hinge regions at the ends of the coupling beams. It is desirable that the plastic hinges form at the beam ends while the base wall piers remain elastic. The strength and stiffness of the coupling beams are, therefore, crucial if the desired global behavior of the CCW system is to be achieved. This paper presents the results of nonlinear response history analysis of two 20-story CCW buildings. Both buildings have the same geometric dimensions, and the components of the buildings are designed based on the equivalent lateral force procedure. However, one building is fitted with steel coupling beams while the other is fitted with diagonally reinforced concrete coupling beams. The force-deflection relationships of both beams are based on experimental data, while the moment-curvature and axial load-moment relationships of the wall piers are analytically generated from cross-sectional fiber analyses. Using the aforementioned beam and wall properties, nonlinear response history analyses are performed. Superiority of the steel coupling beams is demonstrated through detailed evaluations of local and global responses computed for a number of recorded and artificially generated ground motions.