• Journal of Ocean Engineering and Technology
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• v.24 no.1
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• pp.90-98
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• 2010

In this paper, vibration-based structural health monitoring methods that are suitable for caisson-type structures are examined by an experimental evaluation. To achieve the objective, four approaches are implemented. First, vibration-based structural health monitoring methods are selected to monitor the structural condition of caisson-type breakwaters. Second, a lab-scaled caisson structure is constructed to verify the selected monitoring methods. Third, the vibration characteristics are numerically analyzed using an FE model due to the change in the rubble mound condition. Finally, experimental vibration tests of the lab-scaled caisson structure are performed to monitor the vibration responses due to changes in rubble mound conditions and the performances of the selected methods are examined from the monitoring results.

• KIEAE Journal
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• v.12 no.2
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• pp.33-38
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• 2012

This study aims to evaluate the structural safety of the balcony photovoltaic systems easily installed or moved on the buildings. Also, the systems are controlled by solar altitudes focused on its mobility rather than high efficiency generation performance thereof. The results of the study are as follows. Two types of typical photovoltaic systems which can be mounted on the balcony are proposed, and, the sizes of the systems are designed to be adjusted within certain ranges of the frames in order to attach the various rail sizes. To evaluate the structural safety of the proposed systems, several simulation evaluations are performed on the safety evaluation standards by the Ministry of Construction-Transportation and KCI 2007. The results are that the proposed plans are reasonable in terms of stress and deflection in the structural aspects at the wind pressures of $1,907(N/m^2)$ of external wall surface under the condition of wind velocity higher than 25(m/s).

• KIEAE Journal
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• v.4 no.3
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• pp.45-52
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• 2004

The purpose of this research was to identify the structural characteristics of open housing typologically and systematically. The main method of this study was content analysis and literature review on open housing. This study found that the typological analysis on terminology and the details of the constituents concerning structural patterns in open housing indicated that the main approaches were classified into three criteria such as 'Organization Element', 'Construction Element', and 'Equipment Element'. Organization Element was classified into 'Main Dwelling Unit Area and its Form', 'Room Organization Method', 'Relationship with the Main Dwelling Unit's External Constituents', and 'Combination Method of Support and Infill'. Construction Element was classified into 'Method of Structure' and 'Structural Element Technology'. Equipment Element was classified into 'Method of Using Duct' and 'Wet Zone Method'. The attributes were determined based on these classifications. The results of this study can be used to construct an evaluation tool and further to develop a framework in understanding open housing. Technical research should be conducted on the variables that affect the flexibility of space.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.2
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• pp.154-161
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• 2014

This research presents results of structural designs and evaluations for 3MW Wind Turbine Blade by FEM analysis. After the GFRP model was designed as a baseline model, failure check by Puck's failure criterion and buckling analysis were accomplished to verify safety of wind turbine blade in the critical design load case. Moreover, applicability of two kinds of carbon spar cap model, was studied by comparing total mass, price and tip deflection to the GFRP model. The results showed that the GFRP model had sufficient structural integrity in the critical design load case, and the carbon spar cap model could be a reasonable solution to reduce weights, tip deflections.

• Journal of Mechanical Science and Technology
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• v.14 no.2
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• pp.215-225
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• 2000

The structural integrity of the fuel test loop (FTL) in a Korean experimental reactor is evaluated when the FTL, submerged in a water environment, is subjected to a postulated pipe rupture. The analyses are performed under static and dynamic conditions, imposing the thrust force history at each postulated pipe rupture section. Through analysis the following results are found: l) A double ended guillotine can not be expected based on the toughness of the material, 2) the structural integrity of the chimney surrounding the FTL would not impede the structural integrity by the pipe whip. All analyses are performed by finite element methods.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1389-1394
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• 2010

This paper describes the evaluation of structural integrity and dynamic characteristic of inertial load test equipments for performance test of railway vehicle propulsion control system. The propulsion control system of railway vehicle has to be confirmed of safety and reliability prior to it's application. Therefore, inertial load test equipments were designed through theoretical equation for performance test of propulsion control system. The structural analysis of inertial load test equipments was conducted using Ansys v11.0 and it's dynamic characteristic was evaluated the designed using Adams. The results showed that the structural integrity of inertial load test equipment was satisfied with a safety factor of 10.2. Also, the structural stability was proved by maximum dynamic displacement of 0.82mm.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.881-887
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• 2000

The interest in evaluation of structural intensity arises for practical reasons, because net energy flow distribution offers information of energy transmission path, positions of sources, and sinks of vibration energy. In this paper, structural intensity analysis of local ship structures using finite element method(FEM) is carried out. The purpose of this analysis is to evaluate the relative accuracy according to mesh fineness. The structural intensity of a stiffened plate varying their mesh fineness is analyzed and the results are compared with those obtained by the assumed made method. As results, the proper mesh size in qualitative/quantitative structural intensity analysis of plate structures is proposed. In addition, the propagation phenomenon of vibration energy is investigated for the L-type plate and box-girder structures.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.144-148
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• 2005

Cylinder frame manufactured by casting is assembled with the components such as cylinder head, cylinder liner and main bearing cap, etc. The mechanical contact between all of the neighboring components due to bolt tightening was taken into consideration. The loads used in structural analysis were the bolt tightening forces induced by hydraulic jack and the dynamic forces calculated from kinematic analysis. The difference of forces between the neighboring cylinders was taken into account. The maximum stress, stress amplitude and mean stress calculated from the results of structural analyses were used to evaluate the static and fatigue strength. Gray cast iron which is material of cylinder frame has the material characteristics of very small elongation and different strength in tension and compression. Based on such an material characteristics, the strength evaluation of cylinder frame was carried out with in-house program developed internally.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.4
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• pp.74-84
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• 2004

In this paper, a theoretical method was derived to redesign carbody members by substituting light-weight materials, and to estimate their structural characteristics. Some performance indices to estimate structural behaviors were derived in order to obtain equivalent designs in case of material substitutions under important design constraints of rolling stock, such as bending stiffness, natural frequency, bending and buckling strength. Validity of the theoretical method was evaluated by comparing its results with finite element results in some examples where the aluminium alloy was substituted for the structural steel. The numerical results of the examples show that the proposed method gives reasonable initial guesses for the material substitution designs.

• Smart Structures and Systems
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• v.5 no.4
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• pp.469-482
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• 2009

The emerging sensor-based structural health monitoring (SHM) technology has a potential for cost-effective maintenance of aging civil infrastructure systems. The author proposes to integrate continuous and global monitoring using on-structure sensors with targeted local non-destructive evaluation (NDE). Significant technical challenges arise, however, from the lack of cost-effective sensors for monitoring spatially large structures, as well as reliable methods for interpreting sensor data into structural health conditions. This paper reviews recent efforts and advances made in addressing these challenges, with example sensor hardware and health monitoring software developed in the author's research center. The hardware includes a novel fiber optic accelerometer, a vision-based displacement sensor, a distributed strain sensor, and a microwave imaging NDE device. The health monitoring software includes a number of system identification methods such as the neural networks, extended Kalman filter, and nonlinear damping identificaiton based on structural dynamic response measurement. These methods have been experimentally validated through seismic shaking table tests of a realistic bridge model and tested in a number of instrumented bridges and buildings.