TY  - EJOU
AU  - Zhang, Yunfa  
AU  - Xia, Zihui  

TI  - Micromechanical Analysis of Interphase Damage for Fiber Reinforced Composite Laminates
T2  - Computers, Materials \& Continua

PY  - 2005
VL  - 2
IS  - 3
SN  - 1546-2226

AB  - In the present study, the initiation and evolution of the interphase damage and their influences on the global stress-strain relation of composite laminates are predicted by finite element analysis on a micromechanical unit cell model. A thin layer of interphase elements is introduced and its stress-strain relation is derived based on a cohesive law which describes both normal and tangential separations at the interface between the fiber and matrix. In addition, a viscous term is added to the cohesive law to overcome the convergence difficulty induced by the so-called snap-back instability in the numerical analysis. The matrix behavior is described by a recently developed nonlinear viscoelastic constitutive model. As application examples, glass fiber/epoxy unidirectional laminates under off-axis loadings are analyzed. One-quarter of the unit cell is used in the analysis accounting for the geometrical symmetry of the model, and the corresponding periodic boundary conditions for combined global shear and normal loading are derived. Results show that the initiation and evolution of the interphase damage can be well simulated and the predicted global stress-strain responses are in good agreement with the experimental results.
KW  - Interphase damage
KW  -  micromechanical modeling
KW  -  composite laminates
KW  -  off-axis loading
KW  -  finite element analysis
KW  -  viscoelastic analysis
KW  -  periodic boundary conditions

DO  - 10.3970/cmc.2005.002.213