Please consider a 3 layered hybrid composite . With a Cu-Zn-Al thin film in the middle and carbon fiber - epoxy laminate on the top and bottom.
The point is that I have optimized the shape of Thin-film for damping issues , so the thin film does not go through all the composite structure , but only in some places.
Now I need to perform an analysis on the delamination between thin film lamina and Carbon-fiber laminate . I want to know what is the measure for delamination?
Is there any function which correlate the delamination with the interlaminar stresses?
Hi,
Try to insert cohesive element between the thin film and carbon fiber.
You have to check the literature for cohesive parameters.
Hello Pouya, taking into account the interlaminar SHEAR stress is the correct approach. The difficulty is to have the appropriate allowable stress which depends on the adhesion of the film to the carbon faces. If you feel that the adhesion of the resin system you are using is quite good you might take into account the shear stress allowable of the resin system and I would take a safety factor of 2.0. Kind Regards.
For you see and may be measure delamination you can use some NDT as ultrasound o digital radiography. This NDT will gives you a bidimensional image of what is hapen inside the material, As ultra-sound waves have diferents propagation velocities for diferents materials it will help you to see the diferents layers cohesion and to see if the composit is propelly bounded.
you can look at delamination from force-displacement perspective, or from energy perspective. On either case, you would need parameters for the common 3 modes of delamination: one normal separation, and two tangential separations (sliding and side-way separation). In ANSYS you can use cohesive zone elements or contact elements with cohesive zone material models, utilizing both types of models, either force-slip or fracture energy-slip parameters.
Delamination initiation can be characterized based on interlaminar stresses.
Delamination propagation can be characterized using strain energy release rate at delamination front.
Delamination location, size and shape would define possible reduction in mechanical properties of the laminated composite.
- Badges
- Science topic