• Journal of Applied Reliability
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• v.11 no.1
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• pp.31-41
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• 2011

A strut mount is an important part of vehicles which reduces the vibration and the impact transmitted from the wheels while supporting a shock absorber and a coil spring. Rubber compounding, shape design, and process design technologies are important components to improve the functionality of a strut mount such as durability, static, dynamic, and torsional characteristics. Among them the rubber compounding technology is the key technology which dominates the quality of a strut mount. In this study a strut mount with high reliability has been developed by adopting new rubber compounding and improving the shape of the inner plate and the isolator. Through the tests for prototypes it has been shown that the durability has been improved more than 2.5 times, from about 60,000 cycles to about 160,000 cycles.

• Journal of Sensor Science and Technology
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• v.31 no.4
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• pp.244-248
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• 2022

Recently, several studies on the development of superhydrophobic surfaces using various nano-sized carbon-based materials have been conducted. The superhydrophobic surfaces developed using carbon soot have advantages such as low processing cost and remarkable physical and chemical properties. However, their durability is low. To address this problem, in this study, a superhydrophobic surface with high durability and a multilayer structure was fabricated using ethanol vapor treatment. Candle soot was deposited on an aluminum substrate coated with paraffin wax, and a micro-nano multilayer structure with a size of several micrometers was fabricated via ethanol vapor treatment. The fabricated superhydrophobic surface was confirmed to have a contact angle of at least 156° and high durability. Finally, it was confirmed that ethanol vapor not only changed the nanostructure of carbon but also affected the durability of the structure.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.818-821
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• 2004

Generally, the high performance concrete of drying cracking and autogenous shrinkage are tend to be increased. In the previous study, it was found that the using method in combination with expansive additive and shrinkage reducing agent was more effective than the separtely using method of that. This study is to investigated the durability of high performance concrete using expansive additive and shrinkage reducing agent. Test results showed that the high performance concrete using expansive additive and shrinkage reducing agent had very good not only the durability performance such as salt injury, carbonation, resistance to freezing-thawing and permeability but also the resistance to shrinkage.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.215-216
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• 2010

This study investigated the development of high durability concrete under an oceanic region through the examination and comparison of the fundamental property and diffusion of chloride ion to apply a high durability admixture on the concrete.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.259-260
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• 2012

As RC structures in the marine environment rapidly increase, the interest and the importance of Chloride Penetration durable design have been growing. However, there is hardly any domestic Chloride Penetration durability of RC structures designed analysis programs. Currently, Chloride Penetration durable design method is studied and launched actively as a program in the United States, Europe, Japan and etc., but it is limited to Chloride Penetration durability of RC structures excluded from maintenance construction. Also, the level of dependence on the foreign technology is high; the foreign program is imported and used when needed. The main objective is to compare and to evaluate with the durability assessment program and several conditions when considering the design of Chloride Penetration durability through the programs developed abroad.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.269-272
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• 2006

The hydroforming processing is a relatively new technology in comparison with conventional stamping process. The hydroforming processing makes torsion beam in rear suspension of automobile. The durability of torsion beam is very important characteristic that operate in an automobile. In order to optimize the hydroforming process and satisfy the durability, the hydroforming simulation which could control an axial compression and high internal pressure with computer simulation has to be operated. This paper is about an optimum design to improve the kinematic and compliance characteristics of a torsion-beam of suspension system. The result from finite element analysis shows that the forming and the durability are optimized. If there is effect of First pressure in hydroforming processing that gap is in the die tool, the prototype of tube is not satisfied on the durability test.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.04a
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• pp.175-180
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• 1994

The purpose of this experimental study is to improve the workability and durability in high sulphated cement concrete with fly-ash. As a results, we can make high strength concrete by using only high sulphated cement but try to improve the workability and degree of strength by adding 10% fly-ash but the effect beyond my expectation to improve the workability and degree of strength does not show, and the improvable effect except the drying shrinkage of durability dose not show, either. So we must give attention to using fly-ash.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.3
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• pp.109-121
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• 2004

This paper presents an optimal design method for structure-borne durability of a vehicle body structure. Structure-borne durability design requires a new design that can increase fatigue lives of critical areas in a structure and must prohibit transition phenomenon of critical areas that results from modification of the structure at the same time. Therefore, the optimization problem fur structure-borne durability design are consists of an objective function and design constraints of 2 types; type 1-constraint that increases fatigue lives of the critical areas to the required design limits and type 2-constraint that prohibits transition phenomenon of critical areas. The durability design problem is generally dynamic because a designer must consider the dynamic behavior such as fatigue analyses according to the structure modification during the optimal design process. This design scheme, however, requires such high computational cost that the design method cannot be applicable. For the purpose of efficiency of the durability design, we presents a method which carry out the equivalent static design problem instead of the dynamic one. In the proposed method, dynamic design constraints for fatigue life, are replaced to the equivalent static design constraints for stress/strain coefficients. The equivalent static design constraints are computed from static or eigen-value analyses. We carry out an optimal design for structure-borne durability of the newly developed bus and verify the effectiveness of the proposed method by examination of the result.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.4796-4801
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• 2014

To increase the riding comfort and running stability of articulated type high speed railway vehicles(HSRV), it is important that the gangway connections for the passenger car satisfied fire safety, sound proof and durability under triaxial angular displacement (rolling/yawing/pitching) modes. On the other hand, a domestic test standard on the durability of the rubber components has not been determined. In this study, the fatigue life was predicted using the results of the nonlinear finite element analysis and the fatigue properties. Moreover, a fatigue rig test of the component was constructed to examine the durability.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.10
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• pp.1-8
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• 2021

Cylinder liners used in diesel engines of combat equipment are prone to cavitation due to wet cooling. The damage caused by erosion and corrosion due to cavitation has a fatal effect on the performance and lifespan of a diesel engine. Therefore, a study was conducted to improve the durability of cylinder liners. Two surface treatment techniques were proposed: nitriding and chrome plating. It was observed that the amount of erosion on the surface of nitride-treated cylinder liners was high because the surface-treated part eroded due to its weak impact resistance against the bubble explosion generated by cavitation. In contrast, the chrome-plated cylinder liner had a lower amount of erosion among the specimens subjected to the accelerated test. These results verified that the resistance of chrome-plated liners against cavitation is high. Therefore, it can withstand the impact of bubble explosion. If the chrome plating thickness is set with reference to the KS standard, an exceptional durability of abrasion, wear resistance, and corrosion resistance can be obtained. If the thickness is set between 120~250㎛, it is expected that the durability of the cylinder liner can be improved. Although a recovery method for corroded cylinder liners is suggested, the proposed method has an inherent risk of crack generation. Therefore, further research is required to solve this problem.