• Composites Research
• /
• v.22 no.2
• /
• pp.24-29
• /
• 2009

This study aims to investigate the residual strength of sandwich composites with Al honeycomb core and carbon fiber face sheets after the quasi-static indentation damage by the experimental investigation. The 3-point bending test and the edge-wise compressive strength test were used to find the mechanical properties, and the quasi-static point load was applied to introduce the simulated damage on the specimen. The damaged specimens were finally assessed by the 3-point bending test and the compressive strength test. The investigation results revealed the residual strength of the damaged specimens due to the quasi-static indentation. The both test results showed that the residual strength of the damaged specimen was decreased according to increases of the damaged depth.

• Composites Research
• /
• v.18 no.2
• /
• pp.20-29
• /
• 2005

To evaluate the flexural deformation and strength of composite motor case above the glass transition temperature$(T_g),\;170^{\circ}C$, of resin material, a finite element analysis(FEA) model in which material non-linearity and progressive failure mode were considered was proposed. The laminated flexural specimens which have the same lay-up and thickness as the composite motor case were tested by 4-point bending test to verify the validity of FEA model. Also. mechanical properties in high temperature were evaluated to obtain the input values for FEA. Because the material properties related to resin material were highly deteriorated in the temperature range beyond $T_g$, the flexural stiffness and strength of laminated flexural specimen in $200^{\circ}C$ were degraded by also $70\%\;and\;80\%$ in comparison with normal temperature results. Above $T_g$, the failure mode was changed from progressive failure mode initiated by matrix cracking at $90^{\circ}$ ply in bottom side and terminated by delamination at the center line of specimen to fiber compressive breakage mode at top side. From stress analysis, the progressive failure mechanism was well verified and the predicted bending stiffness and strength showed a good agreement with the test results.

• Proceedings of the KWS Conference
• /
• 1991.11a
• /
• pp.35-37
• /
• 1991

• Proceedings of the Korean Fiber Society Conference
• /
• 1995.04a
• /
• pp.62-62
• /
• 1995

• 대한치과보철학회:학술대회논문집
• /
• 1993.12a
• /
• pp.48-49
• /
• 1993

• Proceedings of the Korean Fiber Society Conference
• /
• 1994.10a
• /
• pp.80-80
• /
• 1994

• Proceedings of the Korean Fiber Society Conference
• /
• 1994.04a
• /
• pp.60-61
• /
• 1994

• Proceedings of the Korean Fiber Society Conference
• /
• 1994.04a
• /
• pp.62-63
• /
• 1994

• 대한치과보철학회:학술대회논문집
• /
• 2000.11a
• /
• pp.51-51
• /
• 2000

• Journal of Ocean Engineering and Technology
• /
• v.26 no.1
• /
• pp.1-8
• /
• 2012

To correctly estimate ice load and ice resistance for a ship's hull, it is essential to understand the material properties of sea ice during ice field trials and to use the proper experimental procedure for gathering ice strength data. The first Korean-made icebreaking research vessel (IBRV), ARAON, had her second sea ice trial in the Arctic Ocean during July and August of 2010. This paper describes the test procedures used to properly obtain sea ice strength data, which provides the basic information on the ship's performance in an ice-covered sea and can be used to estimate the correct ice load and ice resistance on the IBRV ARAON. The data gathered from three sea ice field trials during the Arctic voyage of the ARAON includes the ice compressive strength, flexural strength, and failure strain of sea ice. This paper analyzes the gathered sea ice data in comparison with data from the first voyage of the ARAON during her Antarctic Sea ice trial in January 2010.