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Accessing material properties for global parameter definition

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Dear community,

one of my geometric parameters which I define as "global parameters" depends on a material property. I have defined a material (mat7) in the global section with all necessary properties.

I have tried to access the material property to define the global parameter in a simmilar manner as in
www.comsol.de/community/forums/general/thread/5315, for me that would be

asin(mat7.CpCs.cs/c_a0)

The comsol tooltip when howering over the definition with the mouse says, "unknown parameter" and the expression shows in red indicating an error.

Should it be possible to access material properties to define parameters?
Thank you for your help.

Daniel

1 Reply Last Post 10 apr 2017, 08:34 GMT-4
Jeff Hiller COMSOL Employee

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Posted: 8 years ago 10 apr 2017, 08:34 GMT-4
Hello Daniel,

See Reference Manual, version 5.2a, page 225, for the list of the things a global parameter can depend on.

If mat7.CpCs.cs was going to be a true constant (i.e. not vary in space or time), you can create an additional global parameter and call it for instance "myparam", then set mat7.CpCs.cs to myparam and your other parameter to asin(myparam/c_a0).
If mat7.CpCs.cs was going to vary in space or time, it cannot enter into the definition of a global parameter.
Best,
Jeff
Hello Daniel, See Reference Manual, version 5.2a, page 225, for the list of the things a global parameter can depend on. If mat7.CpCs.cs was going to be a true constant (i.e. not vary in space or time), you can create an additional global parameter and call it for instance "myparam", then set mat7.CpCs.cs to myparam and your other parameter to asin(myparam/c_a0). If mat7.CpCs.cs was going to vary in space or time, it cannot enter into the definition of a global parameter. Best, Jeff

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