• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.2
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• pp.86-93
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• 1999

Ceramic/metal bonded joints have led to increasing use of structural materials such as automobiles and heat engines. A method of strength evaluation focussing on fracture criterion of mixed mode was investigated in {{{{ {Si }_{3 } {N }_{4 } }}}}/metal bonded joint, Also Fracture toughness tests of {{{{ {Si }_{3 } {N }_{4 } }}}}/metal bonded joints with an interface crack were carried out and the stress intensity factors of these joints were analyzed by boundary element method. Form the results the fracture criterion and method of strength evaluation by the fracture toughness were proposed in {{{{ {Si }_{3 } {N }_{4 } }}}}/Metal bonded joints

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.7 s.262
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• pp.725-731
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• 2007

An air spring which is a part of the suspension system of automobiles is used to reduce and absorb the vibration and the noise. Main components of the air spring are a cord reinforced rubber bellows, a canister and a piston. The performance of the air spring are depended on configurations of rubber bellows, the angle and elastic modulus of cord. The finite element analysis are executed to predict and evaluate the load capacity and the stiffness. The design variables of air spring are determined to adjust the required specifications of the air spring. Several samples of the air spring are manufactured and experimented. It is shown that the results by finite element analysis are in close agreement with the test results.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.3
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• pp.241-247
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• 2009

It is important to satisfy the requirements and standards for the protections of passengers in a car accident. There are lots of studies on the crushing energy absorption of a structure members in automobiles. We have studied to investigate collapse characteristics and moisture absorption movements of CFRP(Carbon Fiber Reinforced Plastics) hat shaped sectional members when CFRP laminates are under the hygrothermal environment. In particular, the absorbed energy, mean collapse load and deformation mode were analyzed for side members which absorbed most of the collision energy. Variation of CFRP interlaminar numbers is important to increase the energy absorption capability. Therefore we have made a static collapse experiment to research into the difference of absorbed energy and deformation mode between moisture absorbed specimen and non-moisture absorbed.

• Journal of Sensor Science and Technology
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• v.16 no.1
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• pp.52-61
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• 2007

Networked embedded systems using the smart device and fieldbus technologies are now found in many industrial fields including process automation and automobiles. However the discrepancy between a node's view of current time and the rest of the system can cause many difficulties in the design and implementation of a networked system. To provide a networked system with a global reference time, the problem of clock synchronization has been intensively studied over the decades. However, many of the existing solutions, which are mainly developed for large scale distributed computer systems, cannot be directly applied to embedded systems. This paper presents a fault-tolerant clock synchronization technique that can be used for a low-cost embedded system using a CAN bus. The effectiveness of the proposed method is demonstrated with a set of microcontrollers and DC motor-based actuators.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.4
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• pp.120-127
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• 2013

Hybrid electric vehicles have applied electric parts for saving fuel consumption and reducing levels of environmental pollution. Electrification of automobiles is indispensable for entering into global market because of enhanced environment restriction. ISG (Integrated Starter & Generator) system is one of main electric parts and can improve fuel efficiency more than other components by using Idle Stop & Go function and regenerative braking system. However, if ISG motor and inverter work under the continuously high load condition, it will make them the decrease of performance and durability. So the ISG motor and inverter need to properly design the cooling system of them. In this study, we suggested the enhancement points by modifying the thermal design of ISG motor and then confirmed the improvement of the cooling performance.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.5
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• pp.469-474
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• 2010

Gasoline engines have proven their utility in light, medium and heavy duty vehicles. Concern about long term availability of petroleum and the environment norms by the increased vehicular emission have mandated the search for safe fuel. CNG is an environmentally clean alternative to the existing spark ignition engines with the advantages of minimum change. A higher octane number and a higher self ignition temperature make it an attractive gaseous fuel. The thermal efficiency is better than gasoline for the same engine. The reduced carbon mono oxide, carbon di-oxide, hydrocarbon emissions is a favorable outcome along with a slight increase in $NO_x$ emission when compared with gasoline fuel to a dual fuel mode in the existing spark ignition engines. The result from the experiment shows that CNG could be a potential substitute fuel that maintains performance and emissions characteristics in gasoline engines.

• International Journal of Automotive Technology
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• v.6 no.3
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• pp.293-303
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• 2005

Bonded dissimilar materials are being increasingly used in automobiles, aircraft, rolling stocks, electronic devices and engineering structures. Bonded dissimilar materials have several material advantages over homogeneous materials such as high strength, high reliability, light weight and vibration reduction. Due to their increased use it is necessary to understand how these materials behave under stress conditions. One important area is the analysis of the stress intensity factors for interface cracks emanating from circular holes in bonded dissimilar materials. In this study, the bonded scarf joint is selected for analysis using a model which has comprehensive mixed-mode components. The stress intensity factors were determined by using the boundary element method (BEM) on the interface cracks. Variations of scarf angles and crack lengths emanating from a centered circular hole and an edged semicircular hole in the Al/Epoxy bonded scarf joints of dissimilar materials are computed. From these results, the stress intensity factor calculations are verified. In addition, the relationship between scarf angle variation and the effect by crack length and holes are discussed.

• International Journal of Automotive Technology
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• v.6 no.4
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• pp.413-419
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• 2005

The United States automotive recycling infrastructure has successfully reduced the amount of automotive waste sent to landfills, especially since the introduction of shredders in the late 1950s. Shredders are necessary to process and recycle automotive hulks and other durable goods. However, this industry faces significant challenges as the automotive manufacturers are increasing the use of nonmetallic components which are difficult to recycle. Additionally, it is becoming obvious that automobiles contain hazardous materials which place heavy burdens on the environment. To address this growing concern, we propose a process planning model for automotive shredders to make tactical decisions regarding at what level to process and at what level to reprocess feed stock materials. The purpose of this paper is to test analytical models to help shredders improve the profitability and efficiency of the bulk recycling processes for end of life automobile returns. The work is motivated by an actual recycling problem that was observed at Capitol City Metals shredding facility in Indianapolis, Indiana.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.190-196
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• 2003

The load sharing and teeth deflection of helical gear system are analyzed to investigate the deformation overlap. The deformation overlap, which is calculated by the results of displacement analysis, is suggested as the basis for the tooth profile modification. Helical gear systems are formulated as contact problems, and solved by elastic contact theory and FEM. The developed computer program, which offers gear teeth deflection and deformation overlap, will be of much help to the improved design of manual transmissions for automobiles.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.2
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• pp.67-79
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• 1998

Inthe study, a method to evaluate the door closing sound has been developed. Based on the factor analysis, various adjective pairs which describe meaning of the door impact sound have been differentiated. This approach, called Semantic difference(SD) method, was originally developed in linguistics research on order to compare diverse mother tongue. This paper introduces at first how the door sound os generated and transmitted. After that, a factor analysis which is a tool of SD method is implemented to door closing sound for 12 domestic and 1 foreign car models. During investigation, the examined models are categorized into small, medium and luxurious size automobiles. The adjective pairs which attritbute to the door quality have been factorized into three group : expensive/ smooth, powerful/ heavy, and modern/dull. It turns out that the first factor : expensive/ smooth plays the most important role in door closing sound quality.