• Proceedings of the KSR Conference
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• 2011.10a
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• pp.939-950
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• 2011

In this study, the load test of rubber tire bogie for monorail type LRT. Bogie for rolling stock in safety operation of the vehicle as an essential core unit before applying to the vehicle safety and reliability should be tested sufficiently. Rubber tire monorail type bogie compared to the traditional bogie wheel lots of formats, the complexity of the load acting static load test, the bogie of the vehicle operation conditions by structural analysis by considering the loading conditions was evaluated by calculating. Test methods and evaluation criteria based on urban rail vehicle performance testing by applying the test were welded parts and materials for the results leading to material fatigue endurance test by applying the result of evaluating the structure has been identified as safe.

• Journal of Biosystems Engineering
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• v.34 no.5
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• pp.325-330
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• 2009

This study was performed to develop accelerated life test methods for agricultural tractor transmission receiving variable load. To acquire parameters for calculation of accelerated life test, endurance tests were performed under different torque conditions. Test results showed that the shape factor of Weibull distribution was 1.5 and fatigue damage exponent was 5.4. The calculated test time was 5,877 hours under the conditions of average life (MTBF) 3,000 hours and 90% reliability for one test sample. According to the linear cumulative damage rule, test time could be reduced using increased test load. Test time could be reduced by 252 hours when 1.2 times of the rated load compared with 0.67 times of the rated equivalent load calculated by load spectrum of the agricultural tractor. Calculated acceleration coefficient was 23.3.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.68-73
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• 2002

It is necessary first to understand dynamic characteristics of bus full BIW assembly for fatigue endurance analysis. FE model has been used usually for analyzing the dynamic behavior of structures. A lot of experience and effort, however, is necessary to make the credible FE model. Experimental modal analysis of structures has been performed to verify the credibility of initial FE model and to update the model. In this work, experimental modal analysis was performed to understand dynamic characteristics of bus full BIW assembly in free-free boundary condition and the result was used to verify the initial FE model. In addition, some practical techniques, which were used in this experiment, were mentioned.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.2
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• pp.382-390
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• 1995

Failure of connecting rod in automotive engine may cause catastrophic situation. The corner radius at small end has an effect on stress raising. To investigate the stress distribution in connecting rod during operation, the finite element analysis was used by giving possible maximum tension and compression. Excessive sizing after forging connecting rod may result in the tensile residual stress which lower the fatigue life and cause premature failures. It was shown that when the sizing amount is too large, the location of high tensile residual stress coincide with that of high stress amplitude during operation through the elastic-plastic finite element analysis. The endurance limit moves down due to the surface finish and decarburization, which combines with the movement of resultant stress points to dangerous range. It was concluded that the precise control of sizing and enough corner radius are necessary to a reliability of connecting rod.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.314.2-314
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• 2002

It is necessary first to understand dynamic characteristics of a bus full BIW assembly for fatigue endurance analysis. FE model has been used usually for analyzing the dynamic behavior of structures. A lot of experience and effort, however, is necessary to make a credible FE model. Experimental modal analysis of structures has been performed to verify the credibility of initial FE model and to update the model. (omitted)

• Journal of the Korean Society of Physical Medicine
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• v.6 no.1
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• pp.81-92
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• 2011

Purpose : The purpose of this study was to compare combined exercise program group to conventional physiotherapy for patients with chronic neck pain. Methods : Participants were randomly allocated to two groups by experimental(n=17) and control(n=17). Combined exercise program group involved stretching, stability, strengthening and endurance, proprioceptive exercises along with an educational programme. Patient attended for 60min, three times a weeks. Control group was treated as conventional physiotherapy on 40 min, three times a weeks. Outcome variables included pain, disability, range of motion, fatigability at 0 and 6 weeks. Results : Pain, Disability Index, Fatigability significantly decreased(p<.05) and Range of motion improved significantly after active exercise program(p<.05). In conclusion. Combined exercise program improves pain and disability, range of motion, fatigability. Conclusion : These results suggest that combined exercise program is suitable for chronic neck pain.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.3
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• pp.110-116
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• 2002

Here are shown on stress and vibration evaluations and application of piping system in petrochemical plant with and actual example. While stress evaluation by thermal growth has no argument on the calculated results, vibrational evaluations have some different results in accordance with the evaluation methods. In case of the static stress evaluation the ASME B3l.3 code defines 7000 cycles of fatigue lift: in operating the piping system with a design condition. However, the method of vibrational evaluation on piping systems in petrochemical plants has not been established clearly, yet. In this stuffy, it is purposed to present the requirement of a vibrational evaluation method for petrochemical plant piping system, with an actual application.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.404-407
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• 2003

Among the ferroeletric thin films that have been widely investigated for ferroelectric random access memory (FRAM) applications, the $SrBi_2Ta_2O_9$ (SBT) thin film is appropriate as a memory capacitor material due to its excellent fatigue endurance. SBT thin films were etched in high-density $Cl_2/Ar$ in inductively coupled plasma. The maximum etch rate of SBT film is $1834\;{\AA}/min$ under $Cl_2/(Cl_2+Ar)$ of 30 %, rf power of 700 W, dc-bias voltage of -250 V, chamber pressure of 11 mTorr and gas flow rate of 20 sccm.

• Transactions of Materials Processing
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• v.19 no.4
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• pp.210-216
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• 2010

The importance and interests for saving of energy and cost in industry has grown up. Therefore, process optimization to reduce the process and energy become one of the most important things. The non-heat treated steel, post-heat-treated is no necessary, has attractive points as structural materials. However, establishment of mechanical properties is necessary to apply non-heat-treated steel to structural parts. In this study, for non-heat-treated steel and pre-heat-treated steel, we have investigated microstructure, hardness, the tensile strength, compressive strength. And the FE analysis technology to predict the hardness value of forged part is developed on micro-alloyed steel forged part.

• Journal of the Korea Concrete Institute
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• v.17 no.6 s.90
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• pp.1085-1090
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• 2005

Rod-type fiber reinforced polymer plastics(FRPs) similar to reinforcing steel bars have rarely been considered. In this study, an experiment was performed using beams strengthened with rod-type CFRPs and high-strength mortar overlay. The test results show that the strengthened beams not only had improved endurance limits but also improved load carrying capacities, stiffness values, and cracking loads as compared to a non-strengthened beam. Strengthened beams anchored with bolts throughout their entire span had more efficient structural behaviors, including composite behavior on the interface between the concrete and mortar, and load carrying capacity, than a strengthened beam anchored only on the end block.