Adhesives are commonly used to bond structural components into assemblies or to bond layers of material into composite laminates. Simulations often assume the bonding layer to be of infinite strength, but you may want to model the progressive separation of the adhesive as it reaches some known criteria, such as a stress limit. Of the existing theories that define these failure criteria, Mechanical supports the Cohesive-Zone Model (CZM) method and the Virtual Crack Closure Technique (VCCT) method. (See the Cohesive Zone Material (CZM) Model in the Theory Reference and VCCT-Based Crack-Growth Simulation in the Fracture Analysis Guide for more information about these methods.) In either case, the separation occurs along a predefined interface and cannot propagate in an arbitrary direction
Mechanical supports the following features for modeling interface delamination and debonding:
Interface Delamination – utilizes Mechanical APDL interface elements (INTER202 through INTER205) and supports the CZM and VCCT methods. Neither method supports interfaces with lower order triangle faces. Specifically, a prism with a triangle face on the interface or a tetrahedral element with a face on the interface. And, the VCCT does not support higher order elements.
Contact Debonding utilizes Mechanical APDL contact elements (CONTA171 through CONTA177) and supports the CZM method.
For additional technical information about Interface Delamination, see Modeling Interface Delamination with Interface Elements in the Fracture Analysis Guide. For more information about Contact Debonding, see Modeling Interface Delamination with Contact Elements (Debonding) in the Fracture Analysis Guide.
See the Interface Delamination Application and Contact Debonding Application sections for the steps to specify and configure these features. In addition, if you are using the Ansys Composite PrepPost (ACP) application in combination with the Interface Delamination feature, see the steps in the Interface Delamination and Ansys Composite PrepPost (ACP) section.
Analysis Type Requirements
Interface Delamination is supported by Static Structural and Transient Structural analyses only.
Any analysis type may contain a Contact Debonding object, but only the Static Structural and Transient Structural analyses support the progressive separation of an interface. Contact Debonding also supports linear perturbation, which allows you to simulate the vibration (Pre-stressed Modal) or stability (Eigenvalue Buckling) characteristics of a partially delaminated structure. You can also use the modes extracted in the Pre-stressed model to perform Mode Superposition analyses such as Harmonic Response, Response Spectrum, and Random Vibration.