저속충격에 의한 복합재료 적층판의 손상

Damage of Composite Laminates by Low-Velocity Impact

  • AHN SEOK-HWAN (College of Engineering, Pukyong National University) ;
  • KIM JIN-WOOK (Korea Institute of Machinery and Materials) ;
  • DO JAE-YOON (Busan Polytechnic college) ;
  • KIM HYUN-SOO (College of Engineering, Pukyong National University) ;
  • NAM KI-WOO (College of Engineering, Pukyong National University)
  • 발행 : 2005.02.01

초록

The study investigated the nondestructive characteristics of damage, caused by law-velocity impact, on symmetric cross-ply laminates, composed of [0o/90o]16s, 24s, 32s, 48s. The thickness of the laminates was 2, 3, 4 and 6 mm, respectively. The impact machine used, Model 8250 Dynatup Instron, was a drop-weight type that employed gravity. The impact velocities used in this experiment were 0.75, 0.90, 1.05, 1.20 and 1.35 m/sec, respectively. Both the load and the deformation increased when the impact velocity was increased. Further, when the load increased with the laminate thickness in the same impact velocity, the deformation still decreased. The extensional velocity was quick, as the laminate thickness increased in the same impact velocity and the impact velocity increased in the same laminate thickness. In the ultrasonic scans, the damaged area represented a dimmed zone. This is due to the fact that the wave, after the partial reflection by the deflects, does not have enough energy to touch the opposite side or to come back from it. The damaged laminate areas differed, according to the laminate thickness and the impact velocity. The extensional velocities are lower in the 0o direction and higher in the 90o direction, when the size of the defect increases. However, it was difficult to draw any conclusion for the extensional velocities in the 45o direction.

키워드

참고문헌

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