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Time Dependent model

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Hello,

I m trying to run a simple time dependent model where i m streching a rectangular plate with an edge load defined as '800[N/m*s]*t[s]'. Unfortunately, i get this error:

Failed to evaluate operator Jacobian.
Failed to evaluate operator Jacobian.
- Operator: mean
- Geometry: 1
- Boundary: 1
Mean operator requires an adjacent domain of higher dimension.

Can anyone please help?

thx

1 Reply Last Post 2012年1月29日 GMT-5 14:01
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 2012年1月29日 GMT-5 14:01
Hi

without the odel it's difficult to tell, it has to do with the equation you have defined, that Comsol cannot derive to get a Jacobian, but the rest about "mean" (that is probably used internally to get some other COMSOL variable) could indicate a geoemtry coherence issue

by the way i suppose your eqution in the GUi is something like

800[N/m]*t[1/s] or 800[N/m/s]*t

as by default with a time dependent solver "t" is already defined with units of seconds so its not required in the equation field. But I agree its coherent to write it out like you did here on the FORUM to allow us to udnertand the true units of the variables

One point remains I would have expected N/m^2 for a boundary load (even in 2D as there its for 1[m] default depth for the 3rd implicit dimension

--
Good luck
Ivar
Hi without the odel it's difficult to tell, it has to do with the equation you have defined, that Comsol cannot derive to get a Jacobian, but the rest about "mean" (that is probably used internally to get some other COMSOL variable) could indicate a geoemtry coherence issue by the way i suppose your eqution in the GUi is something like 800[N/m]*t[1/s] or 800[N/m/s]*t as by default with a time dependent solver "t" is already defined with units of seconds so its not required in the equation field. But I agree its coherent to write it out like you did here on the FORUM to allow us to udnertand the true units of the variables One point remains I would have expected N/m^2 for a boundary load (even in 2D as there its for 1[m] default depth for the 3rd implicit dimension -- Good luck Ivar

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