Products: ABAQUS/Standard ABAQUS/CAE
Benefits: This capability allows anisotropic damage in fiber-reinforced composite laminae to be modeled without the strong mesh dependency that is often characteristic of softening behavior.
Description: ABAQUS provides you with the capability to model anisotropic damage in fiber-reinforced composite laminae, such as depicted in Figure 7–4.
This damage model can be used only with elements that have a plane stress formulation (plane stress, membrane, shell, and continuum shell elements). It assumes that the material is elastic-brittle; that is, damage is initiated with a small amount of plastic deformation, so plasticity is neglected. It allows you to consider four different failure mechanisms (damage modes):fiber rupture,
fiber buckling and kinking,
matrix cracking under transverse tension and shear, and
matrix crushing under transverse compression and shearing.
The undamaged response of the material: in this case you must define a linear elastic material. Typically you will define the undamaged response of composite laminae using the elasticity model for orthotropic materials in plane stress.
A damage initiation criterion: the criterion defines the condition that must be satisfied at a material point prior to the onset of damage evolution. ABAQUS uses the well-established initiation criteria based on Hashin's analysis to model the anisotropic damage of fiber-reinforced materials. The failure surface for these criteria is expressed in the effective stress space (the stress acting over the damaged area that effectively resists the force).
A damage evolution law, including a choice of element removal: once the initiation criterion is met, the stiffness of the material will gradually degrade according to the evolution law specified. For this damage model ABAQUS offers an energy-based evolution law with linear softening and provides a choice of element deletion once all the material points in the element have been damaged. This damage evolution model alleviates the strong mesh dependency of the results due to strain localization effects. In addition, the viscous regularization technique is used to improve convergence behavior in ABAQUS/Standard for models with material softening behavior and stiffness degradation, such as occur when modeling material damage.
In addition, viscous regularization is also supported through the section controls for the element type.
Property module: Edit Material: MechanicalDamage for Fiber-Reinforced Composites
