• Journal of Korean Institute of Industrial Engineers
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• v.27 no.2
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• pp.197-202
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• 2001

The biomechanical analysis of the load carrying effect on different floor surfaces has been conducted. Four different floor surfaces were prepared for ten subjects with each walking at a fixed velocity(1.33 m/sec) while carrying five different loads. The results showed that because of the significant interaction effect between floor slipperiness and the load carrying task, the load carrying effect should be analyzed according to different levels of the floor slipperiness, especially contaminant floors. On oily surfaces, slip distance(SD) and heel velocity (HV) increased whereas stride length(SL) decreased as load increased. In other words, significantly longer SD, faster HV, and no normal gait were found as load increased. As a result, a different protocol should be applied to measure floor slipperiness on oily floors as compared to dry surfaces for tribological approach.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.273-274
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• 2002

In order to evaluate the flying characteristics of slider, the acoustic emission (AE) as well as friction signals are typically utilized. In this work the frequency spectrum analysis is performed using the AE signal obtained during the head/disk interaction such as load/unload mechanism using ramp, impact situation in the presence of a bump on disk surface and other contact phenomena including particle interaction. It was shown that the influence of impact can be characterized effectively in the AE frequency spectrum. As a result of this work, frequency spectrum analysis will be utilized with better understanding for studying the head/disk interface (HDI) characteristics and monitoring the particle interaction in HDI effectively.

• Nuclear Engineering and Technology
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• v.41 no.10
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• pp.1333-1346
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• 2009

To assure the reliability of cylinders or shells with fluid-filled annulus, it is necessary to investigate the modal characteristics considering fluid-structure interaction effect. In this study, theoretical background and several finite element models are developed for cylindrical shells with fluid-filled annulus considering fluid-structure interaction. The effect of the inclusion of the fluid-filled annulus on the natural frequencies is investigated, which frequencies are used for typical dynamic analyses such as responses spectrum, power spectral density and unit load excitation. Their response characteristics are addressed with respect to the various representations of the fluid-structure interaction effect.

• Structural Engineering and Mechanics
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• v.29 no.1
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• pp.1-16
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• 2008

Tunnels are generally constructed below the ground water table, which produces a long-term interaction between the tunnel lining and the surrounding geo-materials. Thus, in conjunction with tunnel design, the presence of water may require a number of considerations such as: leakage and water load. It has been reported that deterioration of a drainage system of tunnels is one of the main factors governing the long-term hydraulic and structural lining-ground interaction. Therefore, the design procedure of an underwater tunnel should address any detrimental effects associated with this interaction. In this paper an attempt to identify the coupled structural and hydraulic interaction between the lining and the ground was made using a numerical method. A main concern was given to local hindrance of flow into tunnels. Six cases of local deterioration of a drainage system were considered to investigate the effects of deterioration on tunnels. It is revealed that hindrance of flow increased pore-water pressure on the deteriorated areas, and caused detrimental effects on the lining structures. The analysis results were compared with those from fully permeable and impermeable linings.

• Steel and Composite Structures
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• v.47 no.3
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• pp.383-393
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• 2023

Conventional reinforced concrete design codes assume ideal strain evolution in semi-deep beams with externally bonded fiber-reinforced polymer (EB-FRP) web strips. However, there is a strain interaction between internal stirrups and web strips, leading to a notable difference between code-based and experimental shear strengths. Current study provides an experiment-verified detailed numerical framework to assess the potential strain interaction under quasi-static monotonic load. Based on the observations, steel stirrups are effective only for low EB-FRP amounts and the over-strengthening of semi-deep beams prevents the stirrups from yielding, reducing its shear strength contribution. A notable difference is detected between the code-based and the study-based EB-FRP strain values, which is a function of the normalized FRP stress parameter. Semi-analytical relations are proposed to estimate the effective strain and stress of the components considering the potential strain interaction. For the sake of simplification, a linearized correction factor is proposed for the EB-FRP web strip strain, assuming its restraining effect as constant for all steel stirrup amounts.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.7
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• pp.1270-1279
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• 2002

Residual stress is a dominant obstacle to efficient production and safe usage of device by deteriorating the mechanical strength and failure properties. Therefore, we proposed a new thin film stress-analyzing technique using a nanoindentation method. For this aim, the shape change in the indentation load-depth curve during the stress-relief in film was theoretically modeled. The change in indentation depth by load-controlled stress relaxation process was related to the increase or decrease in the applied load using the elastic flat punch theory. Finally, the residual stress in thin film was calculated from the changed applied load based on the equivalent stress interaction model. The evaluated stresses for diamond-like carbon films from this nanoindentation analysis were consistent with the results from the conventional curvature method.

• Geomechanics and Engineering
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• v.24 no.1
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• pp.15-28
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• 2021

Digging well foundation has been widely used in railway bridges due to its good economy and reliability. In other instances, bridges with digging well foundation still have damage risks during earthquakes. However, there is still a lack of knowledge of lateral behavior of digging well foundation considering the soil-foundation interaction. In this study, scaled models of bridge pier-digging well foundation system are constructed for quasi-static test to investigate their lateral behaviors. The failure mechanism and responses of the soil-foundation-pier interaction system are analyzed. The testing results indicate that the digging foundations tend to rotate as a rigid body under cyclic lateral load. Moreover, the depth-width ratio of digging well foundation has a significant influence on the failure mode of the interaction system, especially on the distribution of foundation displacement and the failure of pier. The energy dissipation capacity of the interaction system is discussed by using index of the equivalent viscous damping ratio. The damping varies with the depth-width ratio changing. The equivalent stiffness of soil-digging well foundation-pier interaction system decreases with the increase of loading displacement in a nonlinear manner. The absolute values of the interaction system stiffness are significantly influenced by the depth-width ratio of the foundation.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.1 s.16
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• pp.69-76
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• 2005

The pull-out capacity of expansion anchor(heavy duty anchor and wedge anchor) was studied experimentally in this paper. Loading conditions included tension, shear, and combined tension and shear. The heavy duty anchor and wedge anchor were manufactured in domestic and installed In plain concrete. The failure mode of steel and concrete were studied carefully for the analytical formula of the anchorage design and the experimental data were compared with different models for the interaction of tension and shear capacities. Based on the research, the following conclusion may be drawn : The interaction of forces is well-described by an elliptical interaction relationship.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.395-400
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• 2007

LRT(Light Railway Train), which is a intermediate system of train and bus, is arose for the solution of subway construction cost and the transportation capacity of bus. LRT was introduced in 1980's. About 30 local governments are plan to introduce LRT or constructing LRT, at present. AGT(Automated Guide-way Transit) system, which is a kind of LRT, is operated without driver. Rubber wheeled AGT system can reduce the noise and vibration compare to steel wheeled AGT, so it is estimated as ideal transportation system for urban area. And live loads at bridge are classified as the static load of vehicle and the dynamic wheel contact load which is occurred from the interaction of bridge and vehicle vibration, and the surface roughness. In the case of AGT system, the dynamic increment factor of bridge is greater than the normal train bridge and roadway bridge, because, the weight of AGT vehicle is more light that the train of truck. The exact method for dynamic increment factor is experiment. But this method is needed much money and time, moreover, this method cannot be adopted in design. Therefore, a simulation program for the interaction of AGT bridge, vehicle and surface roughness was developed, in this study. And the program was verified by experiment. As a result, the accuracy of the simulation program can be verified.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2000.09a
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• pp.211-222
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• 2000

The design values of rock socketed pile related with properties of rock mass are not clearly established. However, the drilled shafts socketed in rock are widely used as the foundation of large scaled structure. In this study, the characteristics of behavior of rock socketed pile is researched, and the properties of interface between pile and rock considering soil-structure interaction are evaluated for numerical modeling of rock socketed pile based on the previous researches. Based on the properties of interface and rock mass, the behaviors of rock socketed piles are numerically modeled and compared with field measurement. To verify the numerical analysis, a micro pile socketed in rock is modeled and the results of numerical analysis are compared with field measurement. The numerical results show a good agreement with field measured data, especially in terms of load transfer characteristics.