Computational Methods for Debonding in Composites

Contents xi
5.4.2 AccumulationofPlasticStrain ......................111
5.5 Conclusions..............................................115
References.....................................................116
6 Study of Delamination in Composites by Using the Serial/Parallel
Mixing Theory and a Damage Formulation ...................... 119
Xavier Martínez, Sergio Oller, and Ever Barbero
6.1 Introduction . . ............................................120
6.2 Formulation..............................................121
6.2.1 Serial/ParallelMixingTheory .......................121
6.2.2 Tangent Constitutive Tensor . ........................124
6.2.3 Isotropic Continuum Damage Formulation . . . .........126
6.3 EndNotchFlexure(ENF)TestSimulation ....................131
6.3.1 ExperimentalTestDescription.......................131
6.3.2 NumericalModelDescription .......................132
6.3.3 Comparison Between the Numerical
andtheExperimentalResults........................133
6.3.4 DetailedStudyoftheNumericalResults ..............135
6.4 Conclusions..............................................138
References.....................................................139
7 Interaction Between Intraply and Interply Failure in Laminates .... 141
F.P. van der Meer and L.J. Sluys
7.1 Introduction . . ............................................141
7.2 SofteningOrthotropicPlasticity .............................142
7.2.1 ViscoplasticRegularization .........................144
7.2.2 StressEvaluation..................................145
7.2.3 ConsistentLinearization............................149
7.2.4 ConvergenceIssue.................................151
7.2.5 AssociativityVersusNon-associativity................152
7.3 Delamination.............................................154
7.4 NumericalExample .......................................156
7.5 Discussion...............................................158
References.....................................................159
8 A Numerical Material Model for Predicting the High Velocity
Impact Behaviour of Polymer Composites ....................... 161
Lucio Raimondo, Lorenzo Iannucci, Paul Robinson,
and Silvestre T. Pinho
8.1 Introduction . . ............................................161
8.2 A Phenomenological Model for Predicting
Material Non-linear Effects in UD Plies
UnderCompressive/ShearLoadingConditions.................162
8.2.1 Premise..........................................162
8.2.2 Outline of the Modelling Approach. ..................162
8.2.3 ShearNon-linearStress-StrainBehaviour .............163