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lshell，Derived Values,compute lshell.eXX

Posted Jul 7, 2020, 8:55 a.m. EDT Parameters, Variables, & Functions, Results & Visualization, Structural Mechanics Version 5.5 5 Replies

佳丽 毛
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For example, evaluate lshell.eXX in the Derived Value, but remind me not to define the expression, data set selection, multi-layer material.

5 Replies Last Post Jul 10, 2020, 4:03 a.m. EDT
Pawan Soami COMSOL Employee

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Posted: 4 years ago Jul 8, 2020, 12:48 p.m. EDT
Updated: 4 years ago Jul 8, 2020, 12:48 p.m. EDT

Hello,

Could you please clarify your question? I am not able to understand what exactly is the problem or what you are looking for.

Best regards,
Pawan Soami

Hello, Could you please clarify your question? I am not able to understand what exactly is the problem or what you are looking for. Best regards, Pawan Soami
佳丽 毛
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Posted: 4 years ago Jul 8, 2020, 11:16 p.m. EDT
Updated: 4 years ago Jul 8, 2020, 11:54 p.m. EDT

Thanks,

In the multi-layer shell module, the strain trend under tensile deformation is calculated. In the result , the derived value (line average) calculates the expression lshell.eXX, indicating that the variable is not defined. The following, the data set selects multi-layer material 1, selects an edge, the expression is lshell.eXX. Tips: The expression cannot be calculated and the variable is not defined. Isn't lshell.eXX a function expression that comes with the module? Is there something wrong with me, or which step is missing?

Jiali Mao

Thanks, In the multi-layer shell module, the strain trend under tensile deformation is calculated. In the result , the derived value (line average) calculates the expression lshell.eXX, indicating that the variable is not defined. The following, the data set selects multi-layer material 1, selects an edge, the expression is lshell.eXX. Tips: The expression cannot be calculated and the variable is not defined. Isn't lshell.eXX a function expression that comes with the module? Is there something wrong with me, or which step is missing? Jiali Mao
Pawan Soami COMSOL Employee

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Posted: 4 years ago Jul 9, 2020, 5:56 a.m. EDT

Dear Jiali,

In Layered Shell physics, whenever you are evaluating or plotting a quantity on lower dimensions (edges or points), you need to use mean() operator on the quantity for instance use mean() for edges and use mean(mean()) for points.

In your case, use mean(lshell.eXX) expression instead of just lshell.eXX and it should work. Let me know if you still face any issue here.

Best regards,
Pawan Soami

Dear Jiali, In Layered Shell physics, whenever you are evaluating or plotting a quantity on lower dimensions (edges or points), you need to use mean() operator on the quantity for instance use mean() for edges and use mean(mean()) for points. In your case, use mean(lshell.eXX) expression instead of just lshell.eXX and it should work. Let me know if you still face any issue here. Best regards, Pawan Soami
佳丽 毛
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Posted: 4 years ago Jul 9, 2020, 10:07 p.m. EDT
Updated: 4 years ago Jul 9, 2020, 11:41 p.m. EDT

Hi Pawan,

Thanks for your help. With your method, the problem is solved.

But I found that it can only be used in the line average. When I use this expression (1-amean(lshell.eXX))b/1e-3 in the line integration(a and b are variables defined in the model), I still get the prompt of undefined lshell.eXX. The variable b contains the parameter mean (lshell.eXX). Is it different in the integral operation?

I tried to find relevant knowledge, but I didn't find useful information. Do you have any relevant knowledge of recommend me to read, I am very lack of knowledge in this area.

Hi Pawan, Thanks for your help. With your method, the problem is solved. But I found that it can only be used in the line average. When I use this expression (1-a*mean(lshell.eXX))*b/1e-3 in the line integration(a and b are variables defined in the model), I still get the prompt of undefined lshell.eXX. The variable b contains the parameter mean (lshell.eXX). Is it different in the integral operation? I tried to find relevant knowledge, but I didn't find useful information. Do you have any relevant knowledge of recommend me to read, I am very lack of knowledge in this area.
Pawan Soami COMSOL Employee

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Posted: 4 years ago Jul 10, 2020, 4:03 a.m. EDT

Dear Jiali,

Its the same approach for line integral too and it should have worked. The way you have defined variable and used expression in line integral look correct to me. So I am afraid that its difficult to find out the problem without seeing the model. I would suggest you to contact COMSOL support for further help.

Best regards,
Pawan Soami

Dear Jiali, Its the same approach for line integral too and it should have worked. The way you have defined variable and used expression in line integral look correct to me. So I am afraid that its difficult to find out the problem without seeing the model. I would suggest you to contact COMSOL support for further help. Best regards, Pawan Soami

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