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How to find out about the variable name phys.Solid.sl (in an error message)

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I get an error message:
"Tensor inner product failed. Tensor product must a least have rank equal to 2."
"phys.Solid.sl:item.alpha"

How can I find out where and how the variable "phys.Solid.sl:item.alpha" is defined?
Where is it set? What does it contain?

I checked "equation view" within the different knots .... but no variable name started with phys.
I inserted the variable name in the "search" of the help utility, but nothing was reported.

3 Replies Last Post Jan 24, 2014, 2:55 a.m. EST
Henrik Sönnerlind COMSOL Employee

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Posted: 1 decade ago Jan 23, 2014, 10:57 a.m. EST
Hi,

This sounds like it could be a bug, so I would recommend that you contact support.

The expression as such should be generated in the Thermal Expansion node under Multiphysics (it is the expression for the elastic contribution to the entropy). From the error message it seems like something is wrong with the thermal expansion alpha.

Regards,
Henrik
Hi, This sounds like it could be a bug, so I would recommend that you contact support. The expression as such should be generated in the Thermal Expansion node under Multiphysics (it is the expression for the elastic contribution to the entropy). From the error message it seems like something is wrong with the thermal expansion alpha. Regards, Henrik

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Posted: 1 decade ago Jan 23, 2014, 11:23 a.m. EST
Thank You, Henrik!


I would like to learn a bit more about the variable names.
Where can I find the following information?

When I decompose the name
"phys," I did not find anywhere in the variables. Where can it be found, what does it indicate?
"solid.sl" added by indices seems to indicate some stress tensor
: What kind of separation is it
"Item." what does this indicate
"alpha" You already mentioned the thermal expansion index.
Thank You, Henrik! I would like to learn a bit more about the variable names. Where can I find the following information? When I decompose the name "phys," I did not find anywhere in the variables. Where can it be found, what does it indicate? "solid.sl" added by indices seems to indicate some stress tensor : What kind of separation is it "Item." what does this indicate "alpha" You already mentioned the thermal expansion index.

Henrik Sönnerlind COMSOL Employee

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Posted: 1 decade ago Jan 24, 2014, 2:55 a.m. EST
Hi,

This is an error message which you as an end user should not see (it is an internal expression going wrong while generating the actual variable).

What you are supposed to see in Equation View is something like in the attached screenshot.

A variable has a 'scope' where it can be reached, similar to a variable in some programming languages. As an example (using the expression as it should have been generated):

- The variable ht.Ent belongs to the Heat Transfer in Solids interface with tag 'ht'.
- The stress components solid.sl11 etc belongs to the Solid Mechanics interface with tag 'solid'.
- The thermal expansion tensor te1.alpha11 etc belongs to the Thermal Expansion node with tag 'te1'.

If you look in Equation View under Linear Elastic in the Solid Mechanics interface, you will find the actual definition of solid.sl11.

If the tags are not visible in your model tree, select Model Builder Node Label-> Show Name and Tag.

Regards,
Henrik

Hi, This is an error message which you as an end user should not see (it is an internal expression going wrong while generating the actual variable). What you are supposed to see in Equation View is something like in the attached screenshot. A variable has a 'scope' where it can be reached, similar to a variable in some programming languages. As an example (using the expression as it should have been generated): - The variable ht.Ent belongs to the Heat Transfer in Solids interface with tag 'ht'. - The stress components solid.sl11 etc belongs to the Solid Mechanics interface with tag 'solid'. - The thermal expansion tensor te1.alpha11 etc belongs to the Thermal Expansion node with tag 'te1'. If you look in Equation View under Linear Elastic in the Solid Mechanics interface, you will find the actual definition of solid.sl11. If the tags are not visible in your model tree, select Model Builder Node Label-> Show Name and Tag. Regards, Henrik

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