CFRPのモードII層間破壊じん性のひずみ速度依存性
1994 年 43 巻 487 号 p. 445-450
詳細
1994 年 43 巻 487 号 p. 445-450
The strain rate dependence of the Mode II interlaminar fracture toughness of unidirectional CF/epoxy composite laminates, Q-C133 (Besfight IM-600/Epoxy #133) and T300/2500 (Torayca T300/Epoxy #2500), was studied by the dynamic End Notch Flexure (ENF) test using a Split Hopkinson Pressure Bar (SHPB) system. The experimental technique using the ramped incident wave to avoid the high frequency vibration and the formula estimating energy release rate derived with aid of FEM analysis, both of which were obtained previously by the authors11), were used to carry out the high strain rate experiments. The results obtained are as follows:
In the range of shear strain rate γ of 10-5-102sec-1, the Mode II critical energy release rate GIIC tends to decrease with increasing γ. The value of GIIC at γ=102sec-1 is approximately 20% lower than the value at γ=10-5sec-1 on each specimen. This tendency is similar to the results reported in 10) and is considered to be caused by the fractographic difference between high and low strain rate loadings. That is, hackle-looking fracture surface due to the fracture of the matrix resin is observed at a low strain rate, but at a high strain rate, smooth fracture surface due to the debonding between the matrix resin and the reiforce fibers is observed.
