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Undefined variable error message

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Hi, I am new to comsol.I have created a geometry which has 1[cm] width ,0.05cm depth and 0.5 cm height nickel alloy block on which there is a platinum strip of widht,0.05[cm].depth,0.005[cm],height,0.5[cm] to study the Joule heating due to current flow through platinum strip. On computing it shows the following error message: 'Undefined variable. -Variable:material.sigma13 -Geometry:geom1 -Domain:1-2 Failed to evaluate variable. -Variable:comp1.ec.sigmaaxz -Defined as:material.sigma13 Failed to evaluate variable. -Variable:comp1.ec.Jix -Defined as:(comp1.ec.Ezcomp1.ec.sigma Failed to evaluate variable. -Variable:comp1.ec.Jx -Defined as:comp1.ec.Jix Failed to evaluate expression. -Expression:d(((comp1.ec.Jxtest(comp1.V> Failed to evaluate Jacobian of expression. -Expression:((comp1.ec.Jx*(comp1.Vx)+

Please help me to find out what the error means and what should I do to compute the program.


3 Replies Last Post Nov 19, 2018, 5:30 p.m. EST
Mickaël Barsive COMSOL Employee

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Posted: 6 years ago Aug 29, 2018, 10:52 a.m. EDT
Updated: 6 years ago Aug 29, 2018, 10:53 a.m. EDT

Hello,

It seems that the electrical conductivity (more precisely the 13 component) is not defined. Please check in "Material" nodes if the material is well assigned to the domain 1 and 2.

For more help, please contact the COMSOL technical support.

Best regards,

Mickaël

Hello, It seems that the electrical conductivity (more precisely the 13 component) is not defined. Please check in "Material" nodes if the material is well assigned to the domain 1 and 2. For more help, please contact the COMSOL technical support. Best regards, Mickaël

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Posted: 6 years ago Aug 31, 2018, 1:01 a.m. EDT

Thank you. I was able to solve the issue.

With regards, Minna

Thank you. I was able to solve the issue. With regards, Minna

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Posted: 5 years ago Nov 19, 2018, 5:30 p.m. EST
Updated: 5 years ago Nov 19, 2018, 5:30 p.m. EST

Hi,

I am encountering a similar problem, I have a multiphysics analysis though - Heat Transfer and Solid Mechanics. I have defined the Young's Modulus as a piecewise function (pw1) under the global definitions with the variable 'p' as the vertical stress. When it is called for, under the 'Linear Elastic Strain' node of the Solid Mechanics Interface as pw1(p), I get an error saying that 'p' is an unknown variable.

Can you please help me regarding that? I have attached my file here.

Thanks, Simran

Hi, I am encountering a similar problem, I have a multiphysics analysis though - Heat Transfer and Solid Mechanics. I have defined the Young's Modulus as a piecewise function (pw1) under the global definitions with the variable 'p' as the vertical stress. When it is called for, under the 'Linear Elastic Strain' node of the Solid Mechanics Interface as pw1(p), I get an error saying that 'p' is an unknown variable. Can you please help me regarding that? I have attached my file here. Thanks, Simran

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