• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.4
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• pp.171-177
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• 2007

In this paper, an evaluation method of fracture toughness on interface cracks was investigated in friction welded dissimilar materials with interfacial edge cracks. To establish a reasonable strength evaluation method and fracture criterion, it is necessary to analyze stress intensity factor under the load and residual stress condition on friction welded interface between dissimilar materials. The friction welded specimens with an edged crack were prepared for analysis of stress intensity by using the boundary element method (BEM) and the fracture toughness. A quantitative fracture criterion for friction welded STS 304/SM 45C with interface crack is suggested by using stress intensity factor, F and the results of fracture toughness experiment.

• Journal of Aerospace System Engineering
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• v.6 no.2
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• pp.1-6
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• 2012

On this study, as a Human Factor(HF)'s point of view, typical PVI(Pilot Vehicle Interface) evaluation for small airplane cockpit design, PVI evaluation items and procedures to show compliance to KAS Part 23 "Airworthiness Standards : Normal, Utility, Acrobatic, And Commuter Category Airplanes" are introduced and reviewed. This study is based on the experience of Korean small civil airplane development and certification program.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.11
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• pp.2277-2286
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• 2002

The application of bonded dissimilar materials to industries as automobiles, aircraft, rolling stocks, electronic devices and engineering structures is increasing gradually because these materials, compared to the homogeneous materials, have many advantages for material properties. In spite of such wide applications of bonded dissimilar materials, the evaluation method of quantitative strength considering the stress singularities for its bonded interface has not been established clearly. In this paper, the stress singularity for Bctors and the stress intensity factors were analyzed by boundary element method(BEM) for the scarf joints of Al/Epoxy with and without a crack, respectively. From static fracture experiments of the bonded scarf joints, a fracture criterion and a evaluation method of interface strength in bonded dissimilar materials were proposed and discussed.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.4 no.4
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• pp.50-60
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• 1995

Recently advantages joining dissimiliar materials and light weight material techniques have led to increasing use of structural adhesives in the various industries. Stress singulartiy occurs at the interface edges of adhesively bonded dissimilar materials. So it is required to analyze its stress singularity at the interface edges of adhesively bonded joints indissimilar materials. In this paper, the analysis method of stress singularity is studied in detail. Also, effects of the stress singularity at the interface edge of adhesively bonded scarf joints in combinations of dissimilar materials are investigated by using 2-dimensional elastic program of boundary element method. As the results, the strength evaluation method of adhesively bonded dissimilar materials using the stress singularity factor, $\Gamma$,is very useful. The fracture criterion, method of strength evaluation and prediction of fracture strength by the stress singularity factor on the adhesively bonded dissimilar materials are proposed.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.3
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• pp.439-445
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• 2012

The stress singularity for the excess adhesive on interface of adhesively bonded joint was investigated by using the 2-dimensional elastic boundary element method (BEM). To establish a reasonable strength evaluation method and a fracture criterion for the excess adhesive of interface in adhesively bonded joint, it is necessary to evaluate fracture parameters with various bonding conditions. Under the variations of adhesively bonded thickness (h) and diameter (d) for the excess adhesive, a stress analysis was performed, and from the results, the stress singularity index (${\lambda}$) and the stress singularity factor (${\Gamma}$) were calculated. The variations have a great influences on the stress singularity for the excess adhesive of interface in adhesively bonded joint, and the ${\Gamma}$ is reduced as the "h" and "d" increase.

• Computational Structural Engineering
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• v.9 no.1
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• pp.85-91
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• 1996

The focus of the present work is on the computation of the stress intensity factor for the crack at the elastic-viscoelastic bimaterial interface. First, the stress intensity factor for an interface crack in dissimilar elastic and viscoelastic materials is dervied by applying the correspondence principle to associated elastic expression. Then the time-domain boundary element analysis is performed to calculate the stress intensity factor. Numerical results show that the proposed method is very useful for the analysis of the interface crack in elastic and viscoelastic materials.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.346-351
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• 2003

In this paper, an evaluation method of fracture toughness on interface cracks has been investigated under various mixed-mode conditions of the bonded scarf joints. Two types of the bonded scarf joints with an interface crack were prepared to analyze the stress intensity factors using boundary element method(BEM) and to perform the fracture toughness test. From the results of fracture toughness experiments and BEM analysis, an evaluation method of fracture toughness on interface cracks in the bonded components of dissimilar materials has been proposed and discussed.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.4
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• pp.110-116
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• 2003

In this paper, an evaluation method of fracture toughness on interface cracks has been investigated under various mixed-mode conditions of the bonded scarf joints. Two types of the bonded scarf joints with an interface crack were prepared to analyze the stress intensity factors using boundary element method(BEM) and to perform the fracture toughness test. From the results of fracture toughness experiments and BEM analysis, an evaluation method of fracture toughness on interface cracks in the bonded dissimilar materials has been proposed and discussed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.2
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• pp.140-146
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• 2009

Since the computer technology has been drastically developed and broadly employed for the design of human machine system, human system interface was somehow digitalized. Actually the operator's working environment employing the digital devices are not be fully digitalized due to its technical constraints so that it has been changed to the hybrid environment which has a combination of digital and analog elements. The hybrid environments need to study its characteristics and the guidelines for the proper design and evaluation purpose. This paper describes the human factor design elements of the console operated under hybrid environment through studying the characteristics of digital and analog environment based on the related human factor guidelines and literatures. The result of this paper implies the contribution to the evaluation of the generic human working environment which digital and analog elements are jointly used.

• Archives of design research
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• v.12 no.3
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• pp.105-114
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• 1999

As the microelectronics technology is developed, new types of smart intelligent products are being emerged. OSD user interface is one of the critical factor in this kind of product, especially brown goods and information devices, as it is responsible for imput and output function. OSD is being treated as accompaniment to hardware in spite of its importance, and therefore is developed from only simple and separate usability testing based on performance measurement. This study propose a usability evaluation method of OSD based on subjective preference to support existing usability testing. The purpose of this analysis is to make clear what is important factor and how its preference level is from the user's viewpoint. The various attributes of OSD are clarified from user's questionaire and interview, and orthogonal array is generated with specified factor levels. The prototypes are generated from rapid prototyping tool and tested in natural simulation environment. The preference data which collected in this usability testing is analyzed with conjoint analysis module. This usability evaluation is not the final stage in user interface design process but the early planned and circulated stage.