• Journal of Mechanical Science and Technology
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• v.17 no.3
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• pp.343-349
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• 2003

The fuselage-wing intersection suffers from the cyclic bending moment of variable amplitude. Therefore, the influence of cyclic bending moment on the delamination and the fatigue crack propagation behavior in AFRP/Al laminate of fuselage-wing was investigated in this study. The cyclic bending moment fatigue test in AFRP/Al laminate was performed with five levels of bending moment. The shape and size of the delamination Lone formed along the fatigue crack between aluminum sheet and aramid fiber-adhesive layer were measured by an ultrasonic C-scan. The relationships between da/dN and ΔK, between the cyclic bending moment and the delamination zone size, and between the fiber bridging behavior and the delamination zone were studied. As results, fiber failures were not observed in the delamination zone in this study, the fiber bridging modification factor increases and the fatigue crack growth rate decrease and the shape of delamination zone is semi-elliptic with the contour decreasing non-linearly toward the crack tip.

• Korean Journal of Construction Engineering and Management
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• v.9 no.5
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• pp.75-85
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• 2008

The construction industry has been leading the growth of the nation's economy not only by providing with various infrastructure projects but also by positively impaction related industries such as crating numerous job opportunities. Relevant statistics show the production amount of construction taking about 17.5% of the GDP (Gross Domestic Product). In spite of its positive impacts on the economy, image of Korea construction industry is generally reflected as negative mainly because of its environmental disruption, low payment, bribe, fraudulent work and inefficiency. It brings students to be reluctant choosing the construction industry as their carrier path and governmental and principal research status. Therefore it has been difficult to recruit highly qualitied human resources to the industry while the morale of the whole industry has gradually become demoralized. To improve this stand, many domestic researchers carried out research projects for improving the image of Korea Construction Industry. This study also sympathizes with necessity of improving the negative image of construction industry to remain as one of the leading industry in the 21st century. Especially, this study focused on finding important factors which have significant influences on the image of the industry. Through out the research, image influence factors was identified by rigorous literature review and interviews as industrial and academic experts. Factors, then, categorized and used as the main framework for the survey which designed to fine the degree of impacts on the image of the construction industry. In analyzing the survey results, various statistical techniques was employed including factor analysis, Chi-Square-Test, Correlation Analysis and Multiple Linear Regression. Identified as the most influent factors to the image of the construction industry include morale of construction employee, and prospects the industry which of the judgement by payment, impacts on nation's economy, future of the industry, etc.