Learning Forum

[dwidi]

Hello,

I am having a consistent error pop up when I try to run a DCB model for a hyperelastic material with separation distance-based debonding enabled. This model is currently in Static Structural. The error in the solution output is:

"More than one material option has been defined for material 1. Hyperelastic material (TB,HYPER) is not supported with other nonlinear models."

I've double checked my Engineering Data for the hyperelastic material and it doesn't seem like more than one material option has been defined (see below):

[Bhargava Sista]

The reason for the error is that you have both the hyperelastic and the cohesive zone models defined for the same material. Note that CZM does not represent the material but only the interface (imagine an adhesive holding the two parts, CZM represents the adhesive). Here are the steps that you need to follow:nDefine a new material and define separation based debonding under that materialnIn Mechanical define a bonded contact between the two parts, and set the formulation to either Augmented Lagrange or Pure Penalty (CZM uses penalty-based methods)nInsert Fracture object in the model tree, then drag and drop the bonded contact on to the Fracture object. This will introduce a debonding object.nIn the details of debonding object, select the CZM material defined earlier in Engineering Data as the CZM material.n

[dwidi]

THANK YOU SO MUCHArray! I didn't realize that we now have to create two completely new materials (one as the interface, one as the hyperelastic material) to get this to work. In 2019 both could be lumped together in one material, but I guess this new method can allow more flexibility in assigning interfacial properties separate from the geometric properties itself. Many thanks!!!n

[Bhargava Sista]

It should have been the same case in prior versions too. Theoretically, CZM cannot be assigned to continuum stress elements and hyperelastic material model cannot be assigned to interface (or contact) elements.n

[Facheng Zhao]

Hello, 

I have faced a similar problem. 

I apply displacement boundary condition(displacement 2 and fixed support), and CZM on the contact interface for a three-layered structure. The bonded connection is established between the top and middle layer interface (in red color line), as shown below 

The middle layer material is hyperelastic material properties, and the fracture of the bonded interface is defined as CZM, as shown below

After solving, where the detachment occurs, the elements of the middle layer are violated, as shown 

May I ask how to solve this kind of problem.

Thank you.