충격손상을 받은 CFRP 적층판의 최적화 강도평가 법에 관한 연구

Abstract

In this paper, Formation of specimen is prepared using autoclave and impact test is utilized air gun apparatus.

The first, Fatigue bending strength and Strength bending strength of the CFRP laminates subjected to impact damage are estimated according to the orthotropic and quasi - isotropic composite laminates. When CFRP laminates are impacted by a steel sphere, the generated delamination is observed by the ultrasonic microscope. and the residual fatigue 3-point bending is tested by a three-point bending test. As a result, Fatigue bending strength of quasi - isotropic CFRP composite laminates with impact damage appear greater than that of orthotropic CFRP laminates. Also, in the case impacted side compression, Fracture of orthotropic CFRP composite laminates is propagated from the matrix crack generated near the impact point. in the case impacted side tension.

The second, the effects of specimen surface temperature change on the damages of CFRP laminates was experimentallay studided. Composite laminates used for this study are CFRP/EPOXY and CFRP/PEEK orthotropic laminated plate, which have two-interfaces. The relationship between the impact energy vs. delamination area, the impact energy versus residual bending strength of CFRP/EPOXY and CFRP/PEEK orthotropic laminated plates subjected to FOD under high temperatures were experimentally observed. As a result, When the impacted side is compressed, the residual bending strength of CFRP/PEEK laminates Op is greater than that of CFRP/EPOXY laminates O1. and when the impacted side is tension , the residual bending strength of CFRP/PEEK laminates Op is smaller than that of CFRP/EPOXY laminates O1.

The third, Composite laminates used for this study are CFRP/EPOXY orthotropic laminated plate, which have two-interfaces. and four-interface