Learning Forum

[emregungor]

I have been trying to simulate wrinkling and core failure under compressive loading and 3-point/4-point bending conditions. I guess, failed because of boundary conditions every time. Maybe anyone wants to help me about this problem. My analysis setup below, 

100x20 mm beam structure (long edge of beam along the x-direction and short edge along y-direction)

Geometry consist of 3 parts (bottom layer is surface as 3-layer CFRP-total thickness:0.375mm, middle layer is solid body as foam/honeycomb material-total thickness: 5mm, top layer is same bottom layer)

Short edge 'displacement conditions' x=y=z=0 for all face sheet and core

other short edge same conditions except top facesheet, this edge for free along the x-direction, line pressure loading on this edge and it will be 90 N/mm.

Both of long edges of facesheets and core faces free for x-direction (loading direction) and y=z=0 displacement.

all of them it's like that. But I never visualize the exact wrinkling and core failure types. 

P.s. :This boundary conditions and loading type for compressive loading. Yet I didn't prepare a simulation setup for 3-point or 4-point bending conditions, but I'm open to any suggestions.

[peteroznewman]

Please insert images to help us understand the model.

[emregungor]

Boundary conditions and results of first buckling mode images are below;

Thanks for your attention,

Emre

[emregungor]

Any of tips?

Best Regards,

Emre

[emregungor]

Hi,

I'm sharing new model that related to below article. My result nearly fit with article result. I guess, I can sure my boundary conditions and loading type. But still I have no idea, about how to predict to core crushing load or face wrinkling load? Please help me

 

Article : https://ieeexplore.ieee.org/document/4737987

[Wenlong]

Hi,

Very interesting simulation. Several of my thoughts:

• For a buckling & crushing simulation, it is probably necessary to use nonlinear stabilization, and for wrinkles(local buckling), energy-based nonlinear stabilization is necessary. But be careful your stabilization energy should be small compared to strain energy.


• You may introduce a geometry imperfection (results from the linear eigenvalue analysis). The amplitude should be small but it can help trigger the buckling shape. 

 

Bests,

Wenlong

[emregungor]

Thanks for your attention, I will try immediately your suggestions and I will write again. Many thanks.

Best regards,

Emre