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Query regarding Multiscale Modelling in COMSOL
Posted 2025/06/16 8:58 GMT-4 Structural Mechanics, Modeling Workflow, Material Models 1 Reply
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Hello,
I have looked into the Multiscale Model example provided by COMSOL "https://www.comsol.com/model/micromechanics-of-failure-multiscale-analysis-of-a-composite-structure-107951". The following model allows a 1-way communication where homogenized properties are transferred to the Macro-scale structure. Is it possible to expand this implementation to allow a 2-way communication where strains from macro-scale are transferred to the RVE to compute the stresses and upscaled to the Macro-structure?
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The problem with a general 2-way approach is that you would need the RVE attached to every Gauss point at the macro level. Since the global strain field varies, so does the local stresses.
To summarize, the best we can do is
* Use the micro-scale model to get global constitutive properties
* Using the global strain field, map it back to the micro-scale model in a few points to check the local stress state.
However, it would be interesting to know why you want to get the micro-scale stresses back to the global model.
One scenario that I can think of is that there is some kind of critical stress at the micro-scale level. This could for example cause debonding between two constituents. What you can do then, is to subject the micro-scale model to a large set of different strain states, and then develop a function f(e_x, e_y, e_z, e_xy, e_xz. e_yz) describing a safety factor or failure surface. You can then add this function at the global level, so that it can be evaluated or plotted for the entire structure.
-------------------Henrik Sönnerlind
COMSOL