2003 Volume 52 Issue 4 Pages 407-412
Fracture behavior under monotonic and cyclic loading in a glass fiber reinforced phenolic resin composite was experimentally characterized. First, monotonic tensile tests were conducted to measure stress-strain curves and acoustic emission (AE) behavior. Next, fatigue tests were performed to measure S-N curves for the virgin and after-cured specimens. Finally, fracture surfaces after both tests were observed by means of scanning electron microscopy (SEM). It is found that final failure abruptly takes place for both tests without showing visible damage on the surface of the specimens while permanent strain and cumulative AE events increase just before fracture. The after-cure process increases fatigue strength as well as monotonic tensile strength. Pull-out of fibers was observed on the fracture surfaces, however, it is difficult to determine the origin of fracture in both tests. The SEM fractography reveals that small resin particles are generated on the fiber surfaces in the case of a high cycle fatigue test.
