抄録
This paper reports the results of impact tension of laminated plates reinforced with five harness satin of aramid roving cloth, glass roving cloth, glass chopped strand mat, glass mat and aramid cloth, and glass mat and glass roving cloth. Impact tensile tests of the matrix resin were also performed. The strain rare was within the range of 40sec-1. The stress-strain diagrams were prepared from the strain and load responses under impact. The results are summarized as follows:
The strong strain rate dependence on strength, elastic modulus, and absorbed energy was observed in the FRP laminates and matrix resin. The elongation to crack initiation was constant in GFRP when the strain rate was more than 5sec-1, but decreased with an increase of strain rate in AFRP. The breaking and crack initiation strength increased up to the critical strain rate, that is a strain rate of the maximum strength. The critical strain rate becomes a characteristic value by a kind of reinforcement, textile weave, laminate constitution, or matrix resin. The value is useful in evaluating impact resistance of different laminates. The impact fracture is caused by the embrittlement of the matrix resin, and notch sensitivity increases at the crossing points of roving cloth in impact tension.
