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Compression analysis of lattice structure

Posted Feb 17, 2023, 9:15 a.m. EST Simulation Apps, Materials, Structural Mechanics Version 5.5 2 Replies

Rahul Joshy
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Hi everyone, i am working on a compression analysis of gyroid. I applied the boundary conditions (with a fixed constraint on one side and boundary load on the other side). I did a time dependent study and wanted to generate a stress strain curve to observe the plastic deformation and the fracture afterwards. The graphs generated always displayed a linear curve wihhout any plastic deformation although the same study done on a simple cube showed plastic deformation (without the fracture point) for the same material propoerties (linear elasric material with plasticity). Can anyone assist me why COMSOL is not generating the desired stress strain curve?

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2 Replies Last Post Feb 22, 2023, 11:57 a.m. EST
Jeff Hiller COMSOL Employee

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Posted: 2 years ago Feb 17, 2023, 10:52 a.m. EST
Updated: 2 years ago Feb 17, 2023, 1:36 p.m. EST

Hello Rahul,

I'd suggest you post the two model files, so users of this Discussion Forum can look at the details of how you've set things up.

As a first guess: The cube is stiffer than the gyroid so for a given displacement of the top face the cube plastifies while a gyroid occupying the same volume does not. This guess does not hold if you are imposing the same load rather than the same displacement.

Jeff

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Jeff Hiller
Hello Rahul, I'd suggest you post the two model files, so users of this Discussion Forum can look at the details of how you've set things up. As a first guess: The cube is stiffer than the gyroid so for a given displacement of the top face the cube plastifies while a gyroid occupying the same volume does not. This guess does not hold if you are imposing the same load rather than the same displacement. Jeff
Rahul Joshy
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Posted: 2 years ago Feb 22, 2023, 11:57 a.m. EST
Updated: 2 years ago Feb 22, 2023, 11:57 a.m. EST

Hello Jeff, Sorry for the late reply. I made some tweaks to the model and fortunately i was able to get some part of the deformation curve. But, i am still struggling to get the densification region in the stress strain curve once the lattice has been compressed to 60 per cent of its length. Does COMSOL have this feature or am i doing anything wrong?

I am not able to upload the model because it exceeds the file size limit. i am attaching the screen captures of the boundary condition and material properties that i have defined for the model. Also the generated stress strain curve.

Hello Jeff, Sorry for the late reply. I made some tweaks to the model and fortunately i was able to get some part of the deformation curve. But, i am still struggling to get the densification region in the stress strain curve once the lattice has been compressed to 60 per cent of its length. Does COMSOL have this feature or am i doing anything wrong? I am not able to upload the model because it exceeds the file size limit. i am attaching the screen captures of the boundary condition and material properties that i have defined for the model. Also the generated stress strain curve.

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