• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.377-384
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• 2008

In the bi-directional pile load test (BD PLT) for pile load test of Mega foundation, loading capacity specification were not specified exactly. Therefore there are so many confusions and variations of maximum 2 times in loading capacity are come out. In this study, specifications of bi-directional pile load test (BD PLT) were considered. Based on cases of the bi-directional pile load test performed in domestic areas, maximum equivalent test load, test load increasing ratio and sufficiency ratio of design load were analyzed. It can be known that the loading capacity specification of bi-directional pile load test must be defined as 1-directional test load that is established as more than 2 times of design load.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6C
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• pp.379-388
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• 2008

In the bi-directional pile load test (BD PLT) for pile load tests of Mega pile foundations, loading capacity standard is not specified exactly. Therefore there are so many confusions in performing the BD PLT and variations up to maximum 2 times in loading capacity are come out. In this study, standards of bi-directional pile load test (BD PLT) were considered. Based on cases of the bi-directional pile load test performed in domestic areas, maximum equivalent test load, test load increasing ratio, loading capacity increasing ratio and sufficiency ratio of design load were analyzed. It could be known that the loading capacity standard of bi-directional pile load test must be defined as 1-directional loading capacity and also must be established as more than 2 times of design load.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.1123-1134
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• 2020

The goal of this study was to develop an accelerated life test for an implement working pump for an agricultural tractor. The field experiments were conducted to measure the load of an implement working pump during major agricultural operations such as plow tillage, rotary tillage, baler operations, and wrapping operations. The measurement system for an implement working pump load was constructed using a pressure sensor, the engine rotational speed, and the hitch pump displacement. The measured implement working pump load was calculated as an equivalent load for each agricultural operation using the Palmgren-Miner rule, which is a cumulative damage method. The equivalent load was calculated using the total load data and peak load data when the total data included the operation of an implement working. The annual usage time of the agricultural tractor was applied to develop two integrated equivalent loads. The acceleration factor was calculated to develop an accelerated life test and was calculated from the two integrated equivalent loads, the maximum pressure, and the flow rate conditions of the hitch pump. In Korea, the warranty life of a tractor is 2,736 hours, and the time required for the test to guarantee the operational life of tractors was calculated as 7,561 hours. The acceleration factors were calculated as 453.6 and 38.3, respectively, from the total load data and peak load data. The fatigue test time can be shortened by 16.7 and 197.4 hours according to the result of the acceleration factors.

• Journal of the Korean Society for Advanced Composite Structures
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• v.4 no.1
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• pp.33-39
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• 2013

Structural insulated panels, structurally performed panels consisting of a plastic insulation bonded between two structural panel facings, are one of emerging products with a viewpoint of its energy and construction efficiencies. These components are applicable to fabricated wood structures. In Korea, there are few technical documents regulated structural performance and engineering criteria in domestic market. This study was conducted to identify fundamental performance of both monotonic load and quasi static cyclic load for SIPs in shear wall application. Static test results showed that maximum load was 44.3kN, allowable shear load was 6.1kN/m, shear stiffness was 1.23 M N/m, and ductility ratio was 3.6. Cyclic test was conducted by two kinds of specimens : single panel and double panels. Cyclic test results, which were equivalent to static test results, showed that maximum load was 45.42kN, allowable shear load was 6.3kN/m. Furthermore the accumulated energy dissipation capability for double panels was as 2.3 times as that for single panel. From performance of structural tests, it was recommended that the allowable shear load for panels was at least 6.1kN/m.

• Journal of Korean Association for Spatial Structures
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• v.6 no.1 s.19
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• pp.83-90
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• 2006

The GF(Gust Factor) method is usually used as a method to evaluate equivalent static wind loads for general structures. The GF method is performed on the assumption that the shape of the equivalent static wind load profile is typically similar to that of mean wind loads. The shape of fluctuating wind loads could be quite different with that of the mean wind loads in case of large-span structures. So, the effect of higher modes as well as first mode must be considered to evaluate the wind loads. In this study, the ACS (Advanced Conditional Sampling) method is suggested to evaluate of equivalent static wind loads after investigating about GF and LRC method. The An method ran derive effective static wind loads by combining wind pressures and inertia forces of a structure chosen at a maximum load effect. The maximum load effect is assessed with the time history analysis using pressure data measured in wind tunnel tests. Equivalent static wind loads evaluated using ACS, GF, and LRC methods are compared to verify the effectiveness of ACS method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.11 s.242
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• pp.1551-1559
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• 2005

This paper explains manufacturing process and experimental studies on a composite carbody of Korean tilting train. The composite carbody with length of 23m was manufactured as a sandwich structure composed of a 40mm-thick aluminium honeycomb core and 5mm-thick woven fabric carbon/epoxy face. In order to evaluate structural behavior and safety of the composite carbody, the static load tests such as vertical load, end compressive load, torsional load and 3-point support load tests have been conducted. These tests were performed under Japanese Industrial Standard (JIS) 17105 standard. From the tests, maximum deflection was 12.3mm and equivalent bending stiffness of the carbody was 0.81$\times$10$^{14}$ kgf$\cdot$mm$^{2}$ Maximum stress of the composite body was lower than 12.2$\%$ of strength of the carbon/epoxy. Therefore, the composite body satisfied the Japanese Industrial Standard.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.3 s.258
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• pp.304-312
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• 2007

The objective of this study is to develop a local failure criterion for a wall thinning defect of piping components. For this purpose, a series of tensile tests was performed using several types of simulated specimens with different stress states, including smooth round bar, notched round bar (five different notch radii), and grooved plate (three different groove radii). In addition, finite element (FE) simulations were performed on the simulated specimen tests and the results were compared with the test results. From the comparisons, the equivalent stress and strain corresponding to maximum load and final failure of notched specimens were proposed as failure criteria under tensile load. The criteria were verified by employing them to the estimation of failure of grooved plate specimens that simulate the wall thinning defect. It showed that the proposed criteria accurately estimate the maximum load and final failure of grooved plate specimen tests.

• Journal of the Korean Institute of Gas
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• v.12 no.1
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• pp.1-6
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• 2008

The notched Charpy impact test is one of the most prevalent techniques used to characterize the effect of high impulse loads on polymeric materials. In this study, a method of analysis in nylon plastic materials is suggested to evaluate the critical strain energy release rate for variation of notch angles from the Charpy impact energy measurement. Instrumented Charpy impact tester was used to extract ancillary information concerning fracture parameters in addition to total fracture properties and maximum critical load. The dynamic stress intensity factor of nylon plastic material was calculated for the ASTM Charpy specimen from the obtained maximum critical load. Also, the finite element model was developed to figure out the stress distributions for Charpy specimen with different notch angles subject to 3 point bending load which is equivalent to the load applied in the experiment.

• Computers and Concrete
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• v.20 no.6
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• pp.711-718
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• 2017

Nanotechnology is a new filed in concrete structures which can improve the mechanical properties of them in confronting to impact and blast. However, in this paper, a mathematical model is introduced for the concrete models subjected to impact load for wave propagation analysis. The structure is simulated by the sinusoidal shear deformation theory (SSDT) and the governing equations of the concrete model are derived by energy method and Hamilton's principle. The silicon dioxide ($SiO_2$) nanoparticles are used as reinforcement for the concrete model where the characteristics of the equivalent composite are determined using Mori-Tanaka approach. An exact solution is applied for obtaining the maximum velocity of the model. In order to validate the theoretical results, three square models with different impact point and Geophone situations are tested experimentally. The effect of different parameters such as $SiO_2$ nanoparticles volume percent, situation of the impact, length, width and thickness of the model as well as velocity, diameter and height of impactor are shown on the maximum velocity of the model. Results indicate that the theoretical and experimental dates are in a close agreement with each other. In addition, using from $SiO_2$ nanoparticles leads to increase in the stiffness and consequently maximum velocity of the model.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.1
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• pp.61-67
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• 2003

This paper presents a power transfer capability calculation algorithm considering initial maximum power transfer capability. In this method initial maximum power transfer capability is calculated first. Then, the initial value of active power outputs of generators is gotten for power transfer capability calculation. The proposed method is applied to IEEE-24 Reliability Test System and the results show the effectiveness of the method.