• International Journal of Automotive Technology
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• v.7 no.5
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• pp.565-570
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• 2006

The development of a light-weight vehicle is in great demand for enhancement of fule efficiency and dynamic performance. The vehicle weight can be reduced effectively by using lightweight materials such as aluminum and magnesium. However, if such materials are used in vehicles, there are often instances when different materials such as aluminum and steel need to be joined to each other. The conventional joining method, namely resistance spot welding, cannot be used in joining different materials. Self-piercing rivet(SPR) and adhesive bonding, however, are good alternatives to resistance spot welding. This paper is concerned with the crushing test of double hat-shaped member made by resistance spot welding, SPR and adhesive bonding. Various parameters of crashworthiness are analyzed and evaluated. Based on these results, the applicability of SPR and adhesive bonding are proposed as an alternative to resistance spot welding.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.142-147
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• 2004

The aluminum tube hydroforming is a manufacturing process which can provide lightweight components as automotive parts. In this paper, the hydroformability of aluminium tube in different condition of bending process is presented. An investigation has been conducted on how to control the deformed shape and its effect on thinning distribution after hydroforming by using finite element simulation. Finite element simulation of tube hydroforming for automotive trailing arm is carried out to explore the effect of 2-dimensional and 3-dimensional bending.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.4
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• pp.28-35
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• 2014

A composite honeycomb core is widely used for lightweight aircraft materials. However, the composite honeycomb core coupled with metal-cutting machining processes does not make a very good match. This paper describes an experimental study of the shape-machining characteristics of a composite honeycomb core, in which a five-axis gantry machine is used. The experimental conditions of the offset allowance, tooling condition and feed rate were applied. The shape machining characteristics of a flat surface, a vertical surface, and a concave surface are evaluated by comparing the machining shape and burr characteristics.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.6
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• pp.111-118
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• 2014

Aluminum lithium alloys are new materials developed for lightweight aircraft parts. However, as compared with conventional aluminum alloys in high-speed machining, problems such as tool wear, machining distortion, and cutting ability arise. This study presents the machining distortion characteristics of an Al-Li alloy wing tip in relation to the cutting heat in high-speed machining. A machining experiment was conducted with high-speed machining equipment for an evaluation of the machining distortion characteristics, with each machining stage temperature change of the workpiece machining surface, and the inside and outside temperature changes of the equipment measured. By measuring the amount of distortion of the workpiece before and after machining, the cutting heat was analyzed with regard to its effect on machining distortion in the product.

• Journal of Fashion Business
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• v.25 no.3
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• pp.51-70
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• 2021

The study aims to evaluate changes in textiles for automotive interior and suggest directions that the textile-development should take in order to achieve sustainability, and enter a circular economy system in the future. The main content and results of the study are as follows: First, we cover the overall sustainability study in the fashion and textile fields; in particular, the certification system is well established through the provision of information on the whereabouts of products to consumers and verification by external environmental auditors. Second, we considered the criteria of C2C in order to derive the necessary criteria for sustainability certification in the field of textiles. Third, we looked at the latest development trends of textile materials for automobile interiors which were divided into three categories: natural originated materials, circular economic consideration materials, and functional supplementary lightweight materials. In addition, we identified to what extent the trend of changes aggregated in the examples was satisfied and what was lacking when applied to the Basic criterion of C2C. As such, this study links and applies the sustainability criteria pursued in the fashion and textile fields to the textile for automotive interior materials, suggesting a direction for the textile field for automotive internal materials in the future. Based on the results of this study, it is hoped that studies on textiles for automotive interior considering the net economy will continue, and practical development in the industry will be realized.

• Composites Research
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• v.33 no.6
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• pp.383-389
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• 2020

Thermoplastic composite is introduced to design an automotive door impact beam, and the manufacturing process is demonstrated. The safety regulation for vehicles has been steadily tightened, and weight-reduction has become a mandatory factor in the automotive industry. Hence, both high-performance and lightweight are demanded for automotive components. The aim of the present study is to develop an automotive door impact beam using fiber-reinforced thermoplastic composites to reduce the weight of the impact beam while increasing its mechanical performance. A new production method which combines continuous fiber-reinforced composite and LFT(Long Fiber-reinforced Thermoplastic) is implemented by using insert injection molding process. The mechanical performance of the composite impact beam was evaluated using 3-point bending tests. Thermoplastic composite will expand its application range to various automotive components due to its light-weight design capability and high productivity.

• International Journal of Automotive Technology
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• v.7 no.4
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• pp.485-492
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• 2006

The AA5182/polypropylene/AA5182(AA/PP/AA) sandwich sheets have been developed for application to automotive body panels in future lightweight vehicles with significant weight reduction. It has been reported that the AA5182 aluminum sheet shows $L\"{u}ders$ band because of dissolved Mg atoms that cause fabrication process problem, especially surface roughness. The examination of serration behavior has been made after the tensile deformation of the AA/PP/AA sandwich sheets as well as that of the AA5182 aluminum skins at room and elevated temperatures. All sandwich sheets and the AA5182 aluminum skin showed serration behavior on their flow curves. However, the magnitude of serration was significantly diminished in the sandwich sheet with high volume fraction of the polypropylene core. According to the results of the analysis of the surface roughness following the tensile test, $L\"{u}ders$ band depth of the sandwich sheet evidently showed lower than that of the AA5182 aluminum skin. The strain rate sensitivity, m-value, of the AA5182 aluminum skin was -0.006. By attaching these skins to the polypropylene core, which has relatively large positive value of 0.050, m-value of the sandwich sheets changed to the positive value. The serration mechanism of the sandwich sheets was quantitatively investigated in the point of the effect on polypropylene thickness variation, that on the strain rate sensitivity and that on the localized stress state.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.4
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• pp.52-59
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• 2012

The subframe has been generally manufactured by using stamped steel material. Recently, automotive designers are considering aluminum as lightweight material. This paper describes the development process of an aluminum subframe which is made by high level vacuum die casting process, which is beneficial for minimizing gas contents and material properties. The weight of manufactured subframe is reduced by 4kg with the comparison of steel subframe. The aluminum subframe is packaged for the current vehicle layout and the imposed requirement is to attain a better structural performance that is evaluated in terms of mounting stiffness, noise and vibration, and endurance performance. The NVH evaluation results show that sound level is decreased by 8dB with the help of high roll-rod mounting stiffness as well as high structural modes.

• Journal of Adhesion and Interface
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• v.7 no.4
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• pp.60-64
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• 2006

In modern vehicle construction the search for means of weight reduction, improving durability, increasing comfort and raising body stiffness are issues of priority to the design engineer. The intelligent usage of many materials such as high strength steel, light-alloys and plastics enables a significant vehicle weight reduction to be achieved. The classical joining techniques used in the automobile industry need to be newly-evaluated since they often do not present workable solutions for such mixed-material connections, for example aluminium/steel. Calculation/simulation methods have made progress as a key factor for broader and more cost-effective implementation of structural bonding. This will lead to reduction of spotwelds and accelerate the car development. A special focus of the paper is the use of high strength steel grades. It will be shown that adhesive bonding is a key tool for yielding the potential of advanced high strength steel for low gauging without compromising the stiffness. The latest status of adhesive development has been described. Improvements with physical strength and glass temperature as well as of process relevant properties are shown. Also the situation regarding occupational hygiene is treated, showing that by further spotweld point reduction the emission around the working area can be even lowered against the current praxis. High performing lightweight design cannot longer do without high performing crash durable adhesives.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.1
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• pp.119-125
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• 2005

The current automotive is seeking the improvement of performance, the prevention of environmental pollution and the saving of energy resources according to miniaturization and lightweight of the components. And the variance analysis on the basis of structure analysis and DOE is applied to the lower control am. We have proposed a statistical design model to evaluate the effect of structural modification by performing the practical multi-objective optimization considering weight, stress and fatigue lift. The lower control arm is performed the fatigue analysis using the load history of real road test. The design model is determined using the optimization of acquired load history with the fatigue characteristic. The characteristic function is made use of the optimization according to fatigue characteristics to consider constrained function in the optimization of DOE. The structure optimization of a lower control arm according to fatigue characteristics is performed. And the optimized design variable is D=47 m, T=36mm, W=12 mm. In the real engineering problem of considering many objective functions, the multi-objective optimization process using the mathematical programming and the characteristic function is derived an useful design solution.