Transportation machine manufacturers are putting in efforts on research based on weight reduction. One of the representative materials for weight reduction is Fiber Reinforced Plastic (FRP). Increased used of FRP, glass fiber and carbon fiber could be a way of weight reduction. It is almost unavoidable to generate holes or notches during structural design. Little research have been carried out based on cracks with respect to materials used for design. The utilization of finite element analysis and the reliability of the analysis methods are increasing in order to promptly cope with the damages in materials. In this study, Compact Tension (CT) model based on ASTM E647 was designed using SM45C, steel for structural use, short fiber Glass Fiber Reinforced Plastic (GFRP), and woven type Carbon Fiber Reinforced Plastic (CFRP). In addition, J-Integral, which is a factor for determination of growth of crack that appears in cracks, was applied to general structure analysis. J-Integral is an equation of the body force of the material and strain energy in accordance with the loading force, and illustrates the crack growth using energy release rate. J-Integral values of SM45C, short fiber GFRP and woven type CFRP were found to be approximately 74,978 mJ/mm², 7492.3 mJ/mm² and 6222.4 mJ/mm², respectively.

In this study, application study of the life cycle assessment (LCA) is conducted on a composite small craft for sustainable design and production according to ISO 14040-14044 series. Procedure of general LCA is reconstituted to apply to composite small craft, and life cycle inventory (LCI) analysis is conducted on principal structures of composite small craft by developing a process flow diagram for boat building. Also, this study leads LCA results of structures and materials into the environmental impact category such as carbon footprint, water eutrophication, air acidification, and energy consumption. Especially, LCA results about production methodologies that are hand lay-up and vacuum infusion of glass fiber reinforced plastic are quantitatively compared and analyzed.