By adding a Delamination node, you can model interfacial failure between the layers in a laminate.

If the same interface is selected in two Delamination nodes being active on the same boundary, the second definition will override the previous.

Select an initial state for the interface, Bonded or Delaminated. If the state is delaminated, the effect of this node is only to act as a contact condition between the two delaminated layers. In this case, only the Contact section of the settings is displayed.

The default is to set Adhesive stiffness to User defined. For this setting you enter each component of the stiffness vector kA individually.

When Adhesive stiffness is set to Use material data, the stiffness vector kA is computed from material data and layer thickness. From the Specify list, select a pair of elastic properties — Young’s modulus and Poisson’s ratio, Young’s modulus and shear modulus, or Bulk modulus and shear modulus. For the chosen properties, select from the applicable list to use the value From material or enter a User defined value or expression. In order to use From material, you must have assigned a material to the selected boundaries.

Enter a Thickness, ds, to specify the physical thickness of the adhesive layer.

Select a Cohesive zone model — Displacement based damage or Energy based damage to choose the type of variable that controls the damage process.

Select a Traction separation law — Linear, Exponential, Polynomial, or Multilinear. The definition of these differ between the two cohesive zone models, and the last option is available only for Displacement based damage.

For Multilinear separation, also enter the Shape factor, λ.

When the traction separation law is Linear, Exponential, or Polynomial select the Mixed mode criterion to be either Power law or Benzeggagh-Kenane. In either case, enter the Mode mixity exponent α. The mixed mode criterion determines how normal and shear components are combined into a single scalar failure criterion. For the Multilinear separation law, the mixed mode criterion is always linear (equivalent to a power law with  α= 1.)

In the Regularization drop-down menu it is possible to add a viscous delay to the damage growth for time dependent studies. Do this by selecting Delayed damage and enter a value for the Characteristic time, τ.

In this section you specify the Penalty factor used to minimize the overclosure of the two layers during compression in the normal direction. The default is to use From adhesive stiffness, in which case the normal component of the stiffness vector kA is used.

When Penalty factor is set to User defined, enter the Contact pressure penalty factor pn. The default value is <phys>.Eequ/<phys>.d_ad.

To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog box.

Maximum damage determines the residual stiffness of the adhesive layer after delamination. By default dmax = 1, which means that no residual stiffness remains. Enter a value smaller than 1 to introduce some residual stiffness.

Select Compute damage dissipation energy to compute and store to the energy dissipated by damage.

Physics tab with Layered Shell selected in the Model Builder tree: