Strain-rate dependence of interlaminar stress fields in the vicinity of free edges of AS4-PEEK composite laminates under uniaxial tension

Using finite element program generator (FEPG) of Beijing Feijian Software Corporation, a relative finite element procedure is developed for the three-dimensional viscoplasticity model which can characterize well the nonlinear behavior and strain-rate dependence behavior of thermoplastic composite, AS4-PEEK. Interlaminar stresses of angle-ply laminates [+/-theta](s) for different strain rates under uniaxial tension are calculated. The effects of the variation of strain rates on interlaminar stresses in the vicinity of free edges of AS4-PEEK composite laminates are investigated. From the three-dimensional plots of the interlaminar stresses, it can be seen that distant free-edge effects and end-edge effects exist in the angle-ply laminates [+/-theta](s). The interlaminar stresses in free-edges and two ends increase with increasing strain rates. The extents to which the strain rates affect interlaminar stresses are depicted.