A study on fatigue crack propagation mechanism of GFRP in synthetic sea water

This paper evaluates the fatigue fracture behavior of a chopped strand glas s mat/polyester composite both in air and sea water. Bending fatigue(R=-1) was performed on dry and wet specimens, that is respectively in air and sea water. Where the pH concentration of sea water was controlled to 6.0, 8.2, 10.0 and the wet specimens were immersed in the sea waters for 4 months. T hroughout the tests, fatigue cracks both in the dry and wet specimens. test ed in the air or sea water. occurred at the beginning of the cycle, followe d by either of two regions : one decreasing and the other increasing as the crack growth rate increases.