• Aerospace Engineering and Technology
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• v.11 no.1
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• pp.7-18
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• 2012

Full-scale static test was introduced for the KC-100 aircraft which is domestic civil aircraft to be certified for the first time. Test requirement, test frame, and important test stystems such as loading system, counterbalance system, restraint system and jacking system are explained in detail. Especially, the way to satisfy compliance for the installation of test article and loading system is introduced by using check sheets for the installations. 15 Full-scale and 7 local test conditions were successfully completed and the test data was obtained.

• Aerospace Engineering and Technology
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• v.4 no.1
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• pp.129-142
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• 2005

A semi-monocoque truncated cone structure, which is a main structure for the payload adapter of KSLV-I, was designed. Static test was performed to confirm the reliability of the cone structure under the design loads. Strains and displacements are measured during four load cases; the compressive axial, pure bending, pure shear, and combined loading conditions. The results showed that the cone structure satisfies the design requirements. An equivalent axial load was applied to the cone structure so that the global buckling of the cone structure occurred. The measured buckling load was compared with the predicted one by finite element method. The results show a good agreement.

• Journal of the Korea Concrete Institute
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• v.26 no.5
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• pp.627-634
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• 2014

In this study, standoff detonation tests and static beam tests on $160{\times}290{\times}2200mm$ RC beams were conducted to investigate the effect of local damage on the flexural strength and ductility index. And also, blast resistance of RC beams strengthened with steel fiber and FRP sheet were evaluated by these tests. The standoff detonation tests were performed with charge weight of 1kg and standoff distance of 0.1m. After the tests, crater diameters and loss weights of specimens were measured to evaluate the local damage of specimens. Flexural strength and ductility index were measured by conducting the static beam tests on the damaged and undamaged specimens. As a test results, normal concrete specimen(NC) showed relatively large crater and spall diameters that caused weight loss of 23.5kg as a local damage. Whereas, steel fiber reinforced concrete specimen(SFRC) and FRP sheet retrofitted specimens(NC-F, NC-FS) showed higher blast resistance than NC by reducing crater size and weight loss. Flexural strength and ductility index were decreased in case of local damaged specimens by detonation. Especially, large decrease of flexural strength was shown in NC as compared with intact specimen and brittle failure was occurred due to buckling of compressive reinforcement. In case of specimens strengthened with steel fiber and FRP sheet, residual flexural strength and ductility index were increased as compared with NC. In these results, it is concluded that critical local damage can be occurred unless enough standoff distance can be assured even if the charge weight is small. and it is verified that strengthening method using steel fiber and FRP sheet can increase blast resistance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.4
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• pp.35-40
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• 2005

There are many methods to reinforce the cylindrical structure for light weight design like skin-stringer and semi-monocoque. Isogrid is one of the reinforced structures to improve buckling load. Isogrid has many advantages for complex load case, internal pressure and concentrated load.In this paper, compressive buckling test and non-linear FE analysis of the isogrid panel are described. Diameter of panel is 2.4m and thickness of plate is 11.43mm. The angle which the panel accomplish is about 70 degrees and, its height is about 660mm. Local buckling, global buckling and variation of stiffness after local buckling were observed during buckling test of the panel. MSC/MARC is used for non-linear FE analysis. When analysis, initial imperfection of panel which occurred during plastic forming is considered. The results of analysis for buckling mode and buckling load have good agreements with test.

• Journal of Korean Society of Steel Construction
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• v.24 no.6
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• pp.647-657
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• 2012

Although nuclear power plant piping system is designed conforming to design specifications, the piping systems are deteriorated with increase in service life. In this study, monotonic and cyclic loading tests were carried out on TP316 stainless steel pipe specimens, and the effect of local wall thinning and cracking on failure behavior was investigated. In the tests, 0%, 35% and 75% wall thinning and cracking of initial thickness were artificially introduced to inside elbow and straight pipe specimens, and internal pressures of 20MPa were applied to simulate real operation condition. From the test results, the effect of local wall thinning and cracking on failure mode, ultimate load, number of cycle and strain energy was presented, and maximum bending moment was compared with allowable bending moment calculated by ASME code.

• Journal of Navigation and Port Research
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• v.37 no.2
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• pp.143-148
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• 2013

The aim of this study is to investigate the characteristics on the profile of local ice load acting on side shell of port side in bow part due to broken ice during icebreaking of ships in ice covered waters. The first Korean icebreaking research vessel 'ARAON' had a sea ice field trial in the Arctic Sea during early August, 2010, and the signals due to local ice impact measured from several strain gauges installed at bow part were gathered. It is known that these data with structural response characteristics due to local ice impact have some different characteristics with a typical hydraulic impact pressure - time history. In this study, the time history on the measured signals was analyzed and the characteristic values were presented using non-dimensional parameters.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.1
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• pp.67-75
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• 2014

A full-scale static test for a composite structure small aircraft (KC-100) was conducted in the KARI. The test includes 15 full-scale test and 7 local test conditions. Test requirements with test schedule, test article with dummy structures, test load generation, test system, and equipment are introduced for the test. Test load data of the 1st test condition(U1) was analyzed to evaluate an accuracy of load control for the test. The analysis results show that load data obtained during test were within tolerance of Static Null Pacing Error(SNPE) and the error value of load control was 8.6N. The error of load controls for the full-scale static test using dozens of actuators was calculated by a method suggested by authors. Test data for all other test conditions is also shown in this paper. Finally, reactions measured from restraint system of the U1 test condition show that the reaction changes as load increment. The factors which may change the change of reactions for a full-scale static test are introduced in this study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2866-2871
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• 2011

In this study, computation method of tensile load which develops in tie-bar of reinforced earth, connection strength between tie-bar and eco-block and shear strength of the interface between two eco-blocks were verified by experiments. According to the test results of connection strength test, peak tensile load of D13 deformed bar were close to allowable tensile load of it for situation of infill with soil. Connection strengths of D10 and D13 deformed bars were greater than the allowable tensile load of those respectively for situation of infill with concrete. According to the test results of shear strength of the interface between two eco-blocks, shear resistance parameters, ${\alpha}_u$ and ��${\lambda}_u$ were evaluated as 1.7kN/m and 2$27.6^{\circ}$ respectively.

• Composites Research
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• v.15 no.5
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• pp.7-13
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• 2002

The piezoelectric thin film sensor has good characteristics to observe the impact responses of composite structures. The capabilities for monitoring impact behavior of Gr/Ep laminates subjected to damage-induced impact using the PVDF(polyvinylidene fluoride) film sensor were examined. For a series of low-velocity impact tests from low energy to damage-induced energy, simulated sensor signals were compared with measured signals and the PVDF film sensor. Local impact damages(matrix cracking and delamination) were found at three impact tests, but the measured signals agreed well with the simulated sensor signals based on the linear relationship between the impact forces and the PVDF film sensor signals. And the inverse technique was applied to reconstruct the impact forces using the PVDF film sensor signals. Most of reconstructed impact forces had good agreement with the measured forces. The comparison results showed that the local damage due. to low-velocity impact didn't disturb the global impact responses of composite laminates and the reconstruction of impact forces from PVDF sensor signals wasn't affected by the local damage.

• Journal of the Korea Concrete Institute
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• v.19 no.1
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• pp.11-18
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• 2007

Seismic performance evaluation for dam safety evaluation has been continually conducted. However the behavior analysis for the spillway pier which is known as the weak point of dam is seldom reported. Therefore, this study performed the static loading tests for a prototype structures as elementary tests for the final seismic performance evaluation of dam safety. The prototype of pier structure has 1/20 scale and it adopts to strength model. And cracking loads and ultimate loads of real structures are calculated through numerical analysis using commercial FEM program (ABAQUS). The results of this study show some difference between the results of prototype tests and the results of numerical analysis. Also, the ultimate and cracking loads can be estimated through the prototype loading test and numerical analysis.