• Journal of the Korean Society for Precision Engineering
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• v.33 no.4
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• pp.317-324
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• 2016

Stress tests were conducted in the carbody of the railroad car to check the structural strength of the body of the railroad car. The objective of this study was to evaluate safety of the carbody of a railroad car under the maximal strength. The carbody of rolling stock is a principal structure that supports major equipment of the underframe and the freight. Therefore, the strength evaluation of this structure is important. This study was carried out to analyze the structure of carbody and evaluate safety under maximum vertical load, compressive load, and torsional load. Accordingly, stress tests were conducted on the carbody to measure the stress on each of their parts. Before the load test, a structural-analysis program was used for the stress distribution analysis of the body structure.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.209-214
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• 2001

Most reinforce concrete Columns of Building structure are subjected to both axial load and biaxial bending. However, It is hard to estimate the moment capacity of biaxial bending by exact solution. Thus, columns under biaxial bending are designed by approximate methods in practice. The purpose of this study is to compare experimental result with approximate methods and exact solution by computer. Parameters of the present test are compressive strength of concrete (350, 585, 650kgf/$\textrm{cm}^2$) and shape ratio of rectangular section. Ultimately, an experimental shape factor for rectangular RC column section is obtained through the test program. The shape of load contour is dominated by this shape factor obtained experimentally. So, reasonable design of RC columns subjected to both axial compression and biaxial bending depends on load contour.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.204-209
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• 2007

This study was carried out to analyze the effect of wind load on the structural stability of a container crane according to the increase of the lifting capacity using wind tunnel test and provided a container crane designer with data which can be used in a wind resistance design of a container crane assuming that a wind load at 75m/s wind velocity is applied on a container crane. Data acquisition conditions for this experiment were established in accordance with the similarity. The scale of a container crane dimension, wind velocity and time were chosen as 1/200, 1/13.3 and 1/15. And this experiment was implemented in an Eiffel type atmospheric boundary-layer wind tunnel with $11.52m^{2}$ cross-section area. Each directional drag and overturning moment coefficients were investigated.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.561-565
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• 2006

The paper presents a method of assessing the adequate tapaclty of photovoltaic generation systems for public buildings based on analysis of load variation patterns of customers. When PV systems are installed for supplying power for the customer load, reverse power relay is required by the guideline to be installed at the point of common coupling with the power network. The suggested method analyzes daily, weekly and monthly load demand of the customer that Irishes PV system installation, and determines the appropriate rating of the PV system for preventing PV generation from exceeding the customer demand. This work is expected to support renewable energy dissemination projects of public organizations.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.04a
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• pp.180-189
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• 1998

This paper was undertaken to do shape analysis of wear debris on oiliness agent and extreme pressure agent. The lubricating wear test was performed under different experimental conditions using the wear test device was made in our laboratory and were- specimens of the pin on disk type was rubbed in paraffine series base oil by materials, varying applied load, sliding distance, oil additives such as stearine acid, DBDS, TCP. The four shape parameters (50% volumetric diameter, aspect, roundness and reflectivity) on a kind of the additives are different on applied load and sliding distance and Its are affected by absorbed film and reaction film. DBDS and TCP have a role of extreme pressure agent but a role of absorbed film of stearic acid decrease in high load. The maximum wear volume on applied load be in existence in three kinds of the specimens because of reaction characteristics of the additives.

• International Journal of Concrete Structures and Materials
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• v.1 no.1
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• pp.45-55
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• 2007

Ten beams bonded with glass fiber reinforced polymer (GFRP) laminates were tested under cyclic loading with the load range and the FRP reinforcement ratio as test parameters. The maximum load level during cyclic loading was 55%, 65% and 75% of the static flexural strength while the minimum load level was kept constant at 35%. Deflections of the beams at the end of 525000 cycles were found to increase by 16% and 44% when the maximum load level was increased from 55% to 65% and 75% of the static flexural strength, respectively. Beams with FRP reinforcement ratios of 0.64% and 1.28% were found to exhibit lesser deflections of about 15% and 20%, respectively, compared to a similar beam without FRP reinforcement. An analytical approach based on cycle-dependent effective moduli of elasticity of concrete and FRP reinforcement is presented and found to predict the deflections of the test beams well.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.2
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• pp.121-128
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• 2004

This paper presents a new approach for determining an accurate incentive levels of Direct Load Control (DLC) program using sequential Monte Carlo Simulation (MCS) techniques. The economic analysis of DLC resources needs to identify the hourly-by-hourly expected energy-not-served resulting from the random outage characteristics of generators as well as to reflect the availability and duration of DLC resources, which results the computational explosion. Therefore, the conventional methods are based on the scenario approaches to reduce the computation time as well as to avoid the complexity of economic studies. In this paper, we have developed a new technique based on the sequential MCS to evaluate the required expected load control amount in each hour and to decide the incentive level satisfying the economic constraints. In addition, the mathematical formulation for DLC programs' economic evaluations are developed. To show the efficiency and effectiveness of the suggested method, the numerical studies have been performed for the modified IEEE reliability test system.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1212-1218
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• 2003

A novel loading mechanism of wedge roller type has been developed. This type traction drive has long system life and high efficiency by changing the pre-load on a contact point. And this loading mechanism does not need precision machining. So it has, as opposed to the conventional loading mechanism, an advantage in saving manufacturing cost. In this paper, by analyzing pre-load generating mechanism, spring pre-load and the roller size are defined and the stress on the contact point by pre-load is calculated. On the basis of this analysis, the model of wedge roller type traction drive for the test is made and was carried out its performance test. It can transmit input torque up to 1.5 N m, with high efficiency over 91% up to 98%, with slip rate under 2.5%.

• Journal of the Korean Society for Precision Engineering
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• v.6 no.3
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• pp.78-89
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• 1989

Applicability of tearing modulus based on J-integral proposed by Paris et al is investigated using compact tension specimens of strutural alloy steel (SCM4). Both general fracture test and instability fracture test are performed. The applied tearing modulus, ( $T_{j}$)app estimated from the real load vs. crack growth curve measured from experiments are compared with that estimated from the limit load vs. crack growth curve. The results are : (1) the $T_{j}$parameter could be applied to predict crack growth instability : (2) The use of ( $T_{j}$)app estimated from the load vs. crack growth curve, proposed in this study could be well predicted crack growth instability instead of that estimated form the limit load vs. crack growth curve.e.

• Journal of the Korean Society of Safety
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• v.10 no.4
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• pp.3-8
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• 1995

Anchors find their use in providing tie-back resistance for submerged footings, transmission towers, tunnels and ocean structures. Laboratory model teats were performed for the short-term net ultimate uplift capacity of a circular anchors with respect to various embedment depths and moisture content in saturated bentonite. The tests have been conducted with the anchor at two different moisture contents. Based an the model test results, empirical relationships between the net load, rate of strain, and time have been developed. Test results are as follows. 1) In creep tests for load versus ultimate uplift capacity, the displacement of plate anchors rapidly increases during the primary stage but thereafter becomes constant over a period of time. 2) Displacement increased with the increase of the sustain load and embedded ratio in soil. 3) If the load is less than or equal to 75% of the short-term ultimate uplift capacity, a complete pullout does not occur due to creep.