• Aerospace Engineering and Technology
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• v.1 no.2
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• pp.11-18
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• 2002

The structural load analysis of 50m class airship was performed. The airship maneuver condition for analysis was defined. Aerodynamic, inertia and buoyance models were built. Control surface motion to make defined maneuver condition were calculated. Load factors, load, shear and bending moment envelops were developed for full airship and tailwing. Gondola design loads were developed.

• Journal of Korean Association for Spatial Structures
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• v.4 no.3 s.13
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• pp.103-109
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• 2004

The lowest load when the equilibrium condition becomes to be unstable is defined as the buckling load. The primary objective of this paper is to be analyse stability boundaries for star dome under combined loads and is to investigate the iteration diagram under the independent loading parameter. In numerical procedure of the geometrically nonlinear problems, Arc Length Method and Newton-Raphson iteration method is used to find accurate critical point(bifurcation point and limit point). In this paper independent loading vector is combined as proportional value and star dome was used as numerical analysis model to find stability boundary among load parameters and many other models as multi-star dome and arch were studied. Through this study we can find the type of buckling mode and the value of buckling load.

• Computational Structural Engineering
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• v.3 no.1
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• pp.109-116
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• 1990

Live load data in domestic office buildings have been collected in a systematic manner. Based on surveyed data, equivalent uniformly distributed load intensities, which produce the same load effect as the actual spatially varying, live load, have been obtained for various structural members (such as slab, beam, column, etc. ). Influence surface method has been employed to compute load effects under real live load, including beam moment, slab moment as well as axial force in column. The results have been examined to find probabilistic characteristics and relationship between influence area and load intensity (or coefficient of variation). The results were also compared with other survey results and found to be reasonable. Based on the probabilistic load models obtained, the lifetime extreme values have been analyzed and compared with current design loads. Tentative equations applicable to decide more rational design loads are also suggested as functions of influence area.

• Journal of the Korean GEO-environmental Society
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• v.2 no.4
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• pp.51-61
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• 2001

A series of model tests and analyses by load transfer function were performed to study load-settlement behaviour with relative compaction ratio of soil and embeded depth of pile. In the model tests, embeded depth ratio(L/D) of pile were installed 15, 20, 25 and relative compaction of soil(RC) is 85%, 95% and then cement were injected at around perimeter of pile. For analysis of embedded pile, the paper were compared results of model tests with analysis results by Vijayvergiya model and Castelli model, Gwizdala model of elastic plasticity-perfect plastic model and then the fitness load transfer mechanism was proposed to predict load-settlement behaviour of embeded pile. The analysis results of predicted bearing capacity by load transfer function, ultimate bearing capacity of embeded pile were approached to measured value and behaviour of initial load-settlement curve were estimated that load transfer function by Castelli were similar to measured value. The result of axial load analysis of bored pile shows that skin friction estimated by load transfer mechanism is investigated more a little than that of measured values.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.2
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• pp.67-76
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• 1992

A procedure to determine the axle load limits of asphalt concrete pavements are proposed in this study. Axle load limits are determined by calculating maximum tensile strains at the bottom of the asphalt stabilized base layer and maximum vertical strains at the top of the subgrade. In order to investigate the efficiency of axle configuration, calculated influence line of wheel load on domestic expressway pavement system is used. Limiting strains are selected through the analysis of conventional failure criteria. From the analysis of axle load limits about axle composition(single-axle, tandem-axle, tridem-axle), it is found that the axle load limits of tandem-axle and tridem-axle can be calculated by muitipling the axle load limits of single-axle by axle numbers and that axle load limits are closely related to the thickness of each layer of pavement structure. It is also found that the axle load limits by tensile strains are more critical than those by vertical strains on asphalt concrete pavement models of YOUNG-DONG, KYONG-IN and KYONG-BU expressways.

• International Journal of Highway Engineering
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• v.14 no.2
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• pp.29-36
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• 2012

In this study, frequently passing vehicles with two, three, four, and five axles were chosen through traffic volume analysis in Kyung-In Expressway in order to analyze how the road roughness and vehicle speed affect on the dynamic loads for roads in various vehicle classes. Dynamic loads according to chosen vehicles are estimated by TruckSim program. Dynamic load amplification factor is ratio between dynamic and static loads, and it is also determined for each vehicle classes. From the result of dynamic loads estimated by the dynamic load amplification factor, it is shown that for three-axles vehicle, when IRI is 3.5 and vehicle speed is 100km/hr, asphalt pavements receive additional 36% of static loads in maximum. The analysis of the amplification factor according to each vehicle classes also indicates that the amplification factor increases as the distance between the axles becomes smaller and each axle receives more loads.

• Journal of Bio-Environment Control
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• v.17 no.3
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• pp.188-196
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• 2008

Single span pipe greenhouses (pipe houses) are widely used in Korea because these simple structures are suitable for construction by farmers thus reducing labor cost. However, these pipe houses are very weak and frequently damaged by heavy snow and strong wind. Pipe house is constructed by pipe fabricator, which is anchored to the ground by inserting each pipe end into ground to $30\sim40cm$, so the ground support condition of pipe end is not clear for theoretical analysis on greenhouse structure. This study was carried out to find out the suitable ground support condition needed f3r structural analysis when pipe house was designed. The snow and wind loading tests on the actual size pipe house were conducted to measure the collapsing shape, displacement and strain. The experimental results were compared with the structural analysis results for 4 different ground support conditions of pipe ends(fixed at ground surface, hinged at ground surface, fixed under ground and hinged under ground). The pipe house under snow load was collapsed at the eaves as predicted, and the actual strain at the windward eave and ground support under wind load was larger than that under snow load. The displacement was the largest at the hinged support under ground, followed by the hinged at ground surface, the fixed under ground and then the fixed at ground surface independent of displacement direction and experimental loading condition. The experimental results agreed most closely with the results of theoretical analysis at the fixed condition under ground among 4 different ground support conditions. As the results, it was recommended that the pipe end support condition of single span pipe greenhouse was the fixed under ground for structural analysis.

• Journal of Aerospace System Engineering
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• v.15 no.1
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• pp.80-85
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• 2021

In this study, for conducting a static load test of an external fuel tank used for an aircraft, the flight load acting on the external fuel tank was converted to the test load and the suitability of the converted test loads was confirmed. In order to calculate the test load from the flight load, the external fuel tank was divided into several sections. Shear load, moment by unit shear load, and unit moment were calculated for each section. Test loads for each section were then calculated by computing the shear load, the moment of each section, and flight load condition. In actual static load tests, it might not be possible to impose the test load in the calculated position due to physical constraints. Therefore, after determining positions in which the load could be imposed in the actual test, the test load calculated for each section was redistributed to selected positions. Finally, a test load plan was established by applying a whiffle tree to enhance the efficiency of the test performance while making it easier to operate the actuator. The reliability of the test load plan was verified by comparing it with flight load conditions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4C
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• pp.145-151
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• 2009

In general, a drilled shaft embedded in weathered rock has a large load bearing capacity. Therefore, most of the load tests are performed only up to the load level that confirms the pile design load capacity, and stopped much before the ultimate load of the pile is attained. If a reliable ultimate load value can be extracted from the premature load test data, it will be possible to greatly improve economic efficiency as well as pile design quality. The main purpose of this study is to propose a method for judging the reliability of the ultimate load of piles that is obtained from extrapolated load test data. To this aim, ten static load test data of load-displacement curves were obtained from testing of piles to their failures from 3 different field sites. For each load-displacement curve, loading was assumed as 25%, 50%, 60%, 70%, 80%, and 90% of the actual pile bearing capacity. The limited known data were then extrapolated using the hyperbolic function, and the ultimate capacity was re-determined for each extrapolated data by the Davisson method (1972). Statistical analysis was performed on the reliability of the re-evaluated ultimate loads. The results showed that if the ratio of the maximum-available displacement to the predicted displacement exceeds 0.6, the extrapolated ultimate load may be regarded as reliable, having less than a conservative 20% error on average. The applicability of the proposed method of judgment was also verified with static load test data of driven piles.

• The Journal of Engineering Geology
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• v.19 no.4
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• pp.441-457
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• 2009

This study estimated ultimate load by the determination methods based on ultimate load, yield load and settlement using experimental data from static load tests that applied load to driven piles used in sandy grounds at home and overseas until failure appeared markedly. Estimated ultimate load was normalized with actually measured failure load, and was compared among the determination methods according to the characteristics of pile. In addition, I have identified to the determination methods suitable for estimating ultimate load, and reevaluated the safety factor when determining allowable load. From the results of this study were drawn conclusions as follows. Among ultimate loads estimated by the ultimate-load-based determination methods, the value interpreted by Chin's method tended to overestimate actual measurements, and B. Hansen 80% standard and the stability plot method were considered most reliable as their results were closest to actual measurements. According to the results of this study, in calculating the allowable load, if the safety factor to be applied to failing load obtained by the method of determining extreme load is converted to the safety factor applied to the Standards for Structure Foundation Design, a value larger than 3.0 should be applied except the B. Hansen 90% method, and a value larger than 2.0 should be applied in the methods of determining yield load. In addition, if the safety factor to be applied to load obtained by the settlement standard is converted based on safety factor 3.0 for extreme load, a value smaller than 3.0 should be applied to the total settlement standard and the net settlement standard.