• Steel and Composite Structures
• /
• v.32 no.2
• /
• pp.265-279
• /
• 2019

The self-centering capacity and energy dissipation performance have been recognized critically for increasing the seismic performance of structures. This paper presents an innovative steel moment frame with self-centering steel reinforced concrete (SRC) wall panel incorporating replaceable energy dissipation devices (SF-SCWD). The self-centering mechanism and energy dissipation mechanism of the structure were validated by cyclic tests. The earthquake resilience of wall panel has the ability to limit structural damage and residual drift, while the energy dissipation devices located at wall toes are used to dissipate energy and reduce the seismic response. The oriented post-tensioned strands provide additional overturning force resistance and help to reduce residual drift. The main parameters were studied by numerical analysis to understand the complex structural behavior of this new system, such as initial stress of post-tensioning strands, yield strength of damper plates and height-width ratio of the wall panel. The static push-over analysis was conducted to investigate the failure process of the SF-SCWD. Moreover, nonlinear time history analysis of the 6-story frame was carried out, which confirmed the availability of the proposed structures in permanent drift mitigation.

• Journal of Haehwa Medicine
• /
• v.5 no.1
• /
• pp.215-231
• /
• 1996

In the literatual study on the hiccup, the results were as follows; 1. Hiccup is usually named as Hae yek, Hyel yek, Yel yek. 2. The cause of hiccup are stomach cold, rising of stomach fire, stagnation of vital energy and stagnation of phlegm, yang deficiency of spleen and kideny, deficiency of stomach-yin, or mental disorder due to the stagnation of phlegm, dyspepsia, depressed vital energy. 3. The treatment of hiccup are dispel cold by warming the middle warmer due to stomach cold, expel the heat-evil to loose hollow-organ due to rising up of stomach yin, regulate vital energy and dissipate phlegm due to stagnation of vital energy and stagnation of phlegm, warm and recuperate both of spleen and kidney due to spleen and kidney yang deficiency, nourish the stomach to promote the production of body fluid due to deficiency of stomach yin. 4. The prescription of hiccup are frequently used Gamchogungangtang Gangwhalbujatang Leejungtang Guelpigungang-tang due to stomach cold, Sosihotang Daesihotang Sojaganggitang due to rising up of stomach fire, Sunbokdaejasuktang due to stagnation of vital energy an dstagnation of phlegm, Bojungikgitang Goakhwanganwyisan Samsoeum due to spleen and kidney yang deficiency, Jaeumganghawtang Daebohoan due to deficiency of stomach yin, Hwanglyenjuklyetang Leejintang Guelpitang due to the stagnation of phlegm, Daewhajungeum due to dyspepsia, Mokhwangjogisan due to depressed vital energy.

• Structural Engineering and Mechanics
• /
• v.78 no.4
• /
• pp.387-401
• /
• 2021

This paper provides a methodology to analyze the seismic performance of different component designs in hybrid masonry structures (HMS). HMS, comprised of masonry panels, steel frames and plate connectors is a relatively new structural system with potential applications in high seismic areas. HMS dissipate earthquake energy through yielding in the steel components and damage in the masonry panels. Currently, there are no complete codes to assist with the design of the energy dissipation components of HMS and there have been no computational studies performed to aid in the understanding of the system energy dissipation mechanisms. This paper presents parametric studies based on calibrated computational models to extrapolate the test data to a wider range of connector strengths and more varied reinforcement patterns and reinforcement ratios of the masonry panels. The results of the numerical studies are used to provide a methodology to examine the effect of connector strength and masonry panel design on the energy dissipation in HMS systems. We use as test cases two story structures subjected to cyclic loading due to the availability of experimental data for these configurations. The methodology presented is however general and can be applied to arbitrary panel geometries, and column and story numbers.

• Structural Engineering and Mechanics
• /
• v.81 no.3
• /
• pp.317-333
• /
• 2022

Visco-Plastic Damper (VPD) as a passive energy dissipation device with dual behavior has been recently numerically studied. It consists of two bent steel plates and segments with a viscoelastic solid material in between, combining and improving characteristics of both displacement-dependent and velocity-dependent devices. In order to trust the performance of VPD, for the 1st time this paper experimentally investigates prototype damper behavior under a wide range of frequency and amplitude of dynamic loading. A high-axial damping rubber is innovatively proposed as the viscoelastic layer designed to withstand large axial strains and dissipate energy accordingly. Test results confirmed all assumptions about VPD. The behavior of VPD subjected to low levels of excitation is elastic while with increasing levels of excitation, a significant source of energy dissipation is provided through the yielding of the steel elements in addition to the viscoelastic energy dissipation. The results showed energy dissipation of 99.35 kN.m under a dynamic displacement with 14.095 mm amplitude and 0.333 Hz frequency. Lateral displacement at the middle of the device was created with an amplification factor obtained ranging from 2.108 to 3.242 in the rubber block. Therefore, the energy dissipation of viscoelastic material of VPD was calculated 18.6 times that of the ordinary viscoelastic damper.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.11b
• /
• pp.216-221
• /
• 2002

In this paper, the transmitted noise reduction of smart panels of which passive piezoelectric shunt damping is used, is experimentally studied. Shunt damping experiments are based on the measured electrical impedance model. A passive shunt circuit composed of inductors, and a load resistor is devised to dissipate the maximum energy into the joule heat energy. For multi-mode shunt damping, the shunt circuit is redesigned by adding a blocking circuit. Also the optimal location of the piezoelectric patch is studied by FEM in order to cause the maximum admittance from the patch for each mode of aluminum plate. In results, the transmitted sound pressure level of panels is efficiently reduced for multi-modes

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.30 no.3 s.246
• /
• pp.241-248
• /
• 2006

Shoe cushioning systems are important to prevent body injuries. This study developed and evaluated a cushioning system to reduce impact force on the heel. The cushioning system suggested consist of a polyurethane pocket, which contains water and porous grains of open cell to dissipate the energy effectively. Load-displacement curves fer the shoe cushioning system were obtained from an instrumented testing machine and the results were compared with various pockets with air, water or grains. Mechanical testings showed that the pocket with 5g porous grain was the best for the cushioning system. This system can be applied to the design of various kind of sport shoes.

• Journal of Korean Association for Spatial Structures
• /
• v.15 no.1
• /
• pp.85-94
• /
• 2015

SAFE damper is a hybrid damper which is comprised of a friction damper and a metallic damper. These two dampers combine to resist external energy in stages. Under minor earthquake loads, the friction damper operates alone. However, the friction damper and metallic damper dissipate the energy together when a severe earthquake occurs. In comparison with other methods for seismic retrofitting, the SAFE damper has many advantages. The SAFE damper doesn't cause damage to façade of the building, and the construction period can be reduced when retrofitting. This paper describes experiments evaluating the structural performance of the SAFE damper. From the results, it was found that the structural performance of a conventional RC bare frame can be significantly improved by the installation of the SAFE damper.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2004.11a
• /
• pp.85-89
• /
• 2004

The wave interactions with fully submerged and floating dual buoy/vertical porous membrane breakwaters has been investigated in experimentally to validate the developed theory and numerical method in the previous study, in which multi-domain hydro-elastic formulation was carried out in the context of linear wave-body interaction theory and Darcy's law. It is found that the experimental results agrees well with the numerical prediction. Transmission and reflection can be quite reduced simultaneously especially in the region of long waves. The properly tuned system to incoming waves can effectively dissipate wave energy and also offset each other between incident and scattered waves using its hydro-elasticity and geometry.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.3
• /
• pp.117-123
• /
• 2004

A brake disc with helical grooved vent in radial direction is proposed for the improvement of thermal dissipation. The heat transfer phenomenon is analyzed far both the proposed disc and the conventional one using finite element method. The thermal dissipation is considerably influenced by the geometrical differences of the brake discs. The results of the analysis show that the proposed brake disc with helical grooved vent has the improved performance to dissipate the thermal energy more effectively.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.10 no.3
• /
• pp.39-43
• /
• 2010

The main objective of this research is to develop a mechanistic performance predictive model for fatigue cracking of asphalt-aggregate mixtures. Controlled-stress diametral fatigue tests were performed to characterize fatigue cracking of asphalt-aggregate mixtures. Performance prediction model for fatigue cracking was developed using the internal damage ratio (IDR) growth method. In the IDR growth method, the general concepts of the dissipated energy, the reference tensile strain, the threshold tensile strain, and the strain shift factor were introduced. The source of the dissipated energy in the fatigue test is from the intrinsic viscoelastic material property of an asphalt concrete mixture and the damage growth within the asphalt concrete specimen. In controlled-stress mode test, the dissipated energy is gradually increased with an increasing number of load applications.