GMT Sheet의 섬유배향상태에 따른 충격 특성

Abstract

섬유배향상태에 따라 두께와 섬유함유율에 변화를 주어 제작한 GMT-Sheet 시험편에 충격시험을 행하여 균열의 개시와 균열의 성장에 의한 파괴 에너지를 측정하여 충격과정 동안 흡수된 에너지를 통하여 섬유배향상태와 섬유함유율이 어떠한 상관관계를 갖는가에 대하여 고찰하였다. GMT-Sheet의 섬유배향상태에 따른 충격에 대한 연구를 수행한 결과 다음과 같은 결론을 얻었다. 1. GMT-Sheet는 섬유배함함수(J)가 증가함에 따라 강화재가 하중의 대부분을 담당하므로 충격 전·후에 측정된 운동 에너지 값은 섬유배향상태가 이방성이 될 수록 재료자체의 강도가 증가함으로 충격시 측정된 운동 에너지의 값도 증가한다. 또한, 섬유함유율의 증가로 강화재가 지지하는 하중이 늘어나므로 충격시 흡수되는 운동 에너지의 값도 증가하여 등방성에서 이방성으로 갈수록 충격에 대한 강도 및 강성이 더 좋아짐을 알 수 있다. 2. GMT-Sheet의 섬유배향상태가 등방성인 경우에서는 가해지는 하중에 의한 충격응력이 모든 방향으로 작용하지만 이방성이 될수록 강화된 특정방향으로 충격응력이 작용하므로 섬유의 강도지지 특성이 이방성에 비하여 향상되어 흡수되는 운동에너지 값이 섬유함유율의 증가에 따라 증가한다. 3. GMT-Sheet의 섬유배향상태가 등방성에 가까운 경우에서는 흡수된 충격 에너지의 값의 변화와 상관없이 강화된 방향으로의 섬유 지지력에 의해 인장강도의 변화량이 나타났고, 섬유배향상태가 이방성에 가까운 경우에서는 흡수된 운동 에너지의 증가와 더불어 인장강도 값의 변화량도 줄어들었다 4. GMT-Sheet의 섬유배향상태가 등방성에서 이방성으로 갈수록 섬유의 손상정도를 의미하는 흡수된 운동에너지의 변화보다는 하중을 지지하는 유리섬유의 지지력이 상승하여 섬유배향상태의 변화에 크게 영향을 받지 않고 일정한 상승폭을 나타였다.|Study of impact quality of plastic composite material is stopping to measure energy that have shortcoming that must give notch in test piece by existent study applies almost most Aijodeu impact test code and Syareupi impact test code and evaluates impact special quality, and is required in growth of crack than opening of essential crack thereby. Specially, plastic composite material can not consider fiber orientation state and effect of fiber inclusion rate etc.. that appear at factor and correction of deformities that is the material enemy who is consisted of reinforcement and base metal than metal, single material, strength decline of notch region has erratic special quality, but research material that measure this factor effectively in existent study is insufficient lowdown. Therefore, in this study, fiber orientation state and the fiber inclusion rate investigated if have some interrelation through absorbed energy impact process interval measuring fracture energy by growth of opening and crack of crack performing impact test in GMT-Sheet test piece that manufacture making change in fiber inclusion rate according to fiber orientation state. Got wave and following conclusion that achieve study about impact by GMT-Sheet's fiber orientation state. GMT-Sheet before because reinforcement takes charge of most of load according as island condemnation of a criminal to exile box stem increases impact kinetic energy value that is measured later increases cost of kinetic energy that is measured at impact that strength of material itself increases as fiber orientation function(J) state becomes aeolotropy. Also, can know that strength and hardness about impact improve better as value of kinetic energy that is absorbed at impact because load that reinforcement supports by augmentation of the fiber inclusion rate better increases and goes from isotropic to aeolotropy. Impact stress by load that is imposed in situation that GMT-Sheet's fiber orientation state is isotropic acts to all directions, but special quality is improved than aeolotropy it is load Approval of fiber because impact stress acts by specification direction that is solidified as become aeolotropy and absorbed kinetic energy value increases according to increase of the fiber inclusion rate. Change amount of tension strength appeared by fiber bearing value of direction that is solidified regardless of change of value of absorbed striking energy in occasion that GMT-Sheet's fiber orientation state is near in isotropic, and change amount of tension strength value decreased along with increase of absorbed kinetic energy in occasion that fiber orientation state is near in aeolotropy Because bearing value of glass fiber that support load than change of absorbed kinetic energy that mean damage degree of fiber as GMT-Sheet's fiber orientation state goes from isotropic to aeolotropy rises, fixed rise width was laziness without being influenced greatly in change of fiber orientation state.