Research associate, Massachusetts Institute of Technology, Cambridge, Mass.
Head, Swiss Federal Laboratories for Testing Materials and Research (EMPA), Dubendorf,
Pages: 17 Published: Jan 1975
The mode of fatigue crack growth is described for a 0/90° E-glass/epoxy laminate under cyclic tension-tension loading. Crack growth appears to occur in a stepwise fashion with the crack remaining stationary for many cycles before each step of growth, whereupon a ligament of longitudinal ply at the crack tip is broken. A simple theory is described which assumes that the ligament at the crack tip is fatigued according to the S-N curve of the unnotched material. Using an assumed stress field and cumulative damage law, the number of cycles for initial growth from a notch and the rate of crack growth thereafter are predicted, and good agreement is demonstrated with experimental data.
composite materials, fatigue (materials), cracking (fracturing), fiber reinforced plastics, crack propagation
Paper ID: STP33163S