Damage Growth in Interleaved CF/EP-Composites from Instrumented Impact Fatigue Data

[摘要] Impact fatigue behavior of cross-ply carbon fiber/epoxy (CF/EP) laminates of different lay-up containing adhesive interlayers (interleaves), as well, was studied in instrumented 3-point-bending (Charpy) and falling weight impact (IFWI) tests. It was established that due to low- energy repeated impact (impact fatigue) the maximum load (Fmax) decreases and the contact time with the projectile increases the appearance of which is a “flattening” of the force-time traces, at least above a critical number of impact (NOI) threshold. The absorbed proportion of the incident energy increases with NOI and thus with the damage growth. It was suggested that the change in the initial or secant slope of the load-deflection curves as a function of NOI reflects the damage growth more properly than the change in Fmax alone, as quoted previously.

[发布日期] 1994-07-01