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Modeling heat transfer involving a phase change (ice to water) using Abaqus

Submitted by Marcus Rademacher on
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heat transfer
latent heat
phase change

I'm modeling the transient heat transfer of a cooler with an ice pack in it. How does one accurately model the phase change of the water? Here's what I've tried so far:

 1. Added latent heat property to material card. Used Latent heat = 334 kJ/kg, Solidus Temp = 0, Liquidus Temp = 0

   Result: Error, Solidus and Liquidus temps cannot be equal

 2. Solidus temp = -0.01, Liquidus temp = 0.01

   Result: Analysis ran, but diverged very early in the analysis.

Material Properties on Different Elements with Common Node

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node material property common

Hi,

 

I am having a conceptual doubt regarding the following case. Any suggestions are appreciated. We are here assuming linear elastic material.

 

 Let's say I have two bodies with different properties, and they share a common node (as in the attachment). However, I want to perform an analysis without any coupling or contact phenomena. Let's say thermal expansion of the bodies.So while doing the FEA analysis, I can assign the material properties in the element stiffness according to the body elements and solve.

 

free autoCAD software compatible with Abaqus ?

Submitted by Yasheng Chen on
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Dear all,

 I need a free autoCAD software to model the complex 3D geometry of human brain.  It is desirable that this software should generate output files readable to Abaqus/CAE for mesh generation.  I wonder whether these is such a software available.  An alternative way is to handle the geometrical modeling myself but I need to know the details of the file format used by Abaqus/CAE.  Does anyone have a clue?

Thank you very much!

Yasheng

plate and Hierarchical Finite Element

Submitted by shstar_2008 on
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Hi All

I have problem in choosing shape funcction for modelling vibration of plate. Vibration mode of plate is not symmetric. Then I don't know that Can I suppose that plate deflection(for example W(x,y,t) ) is seperable? i.e. Can I Write W(x,y,t)=w(x,y)*u(t) where d2u/dt2=-a2*u where a is frequency of vibration.

Please Help....

Thanks

Integration over a Triangle

Submitted by danton on
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Integration Triangle

I am working on FEM and i need integration points with their weight coefficients for triangle. I have found tables consisting of 25 points but i need even more. Where can i find a Matlab routine for this.

If it is any help the tables and methods i use are from D.A.Dunavant, High degree efficient symmetrical Gaussian quadrature rules for the triangle. 

 

Any help?

 

UMAT subroutine- error:fix time increment too large

Submitted by afarin on
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I have written a umat subroutine for the example that is with usdfld subroutine analyzing damage in a composite lamina.

After checking and compiling the subroutine, this ERROR is shown: fix time increment is too large.

I changed the step madule data but the error still is here. What should I do to solve this problem?

Please help me with this problem

Thank you

Surface-based cohesive behavior in abaqus 6.9-1

Submitted by icetree on
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Hi,

   Can anyone explain the difference between  Surface-based cohesive behavior and cohesive element?And to the  Surface-based cohesive behavior,how to define the every parameters in it?if possible,please upload an example with the  Surface-based cohesive behavior method.

     please take  some valuable suggestions。

Regards 

 

What's the meaning of "the maximum dissipation principle"?

Submitted by Chao Du on
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Hi everyone

I am a graduate student.I am trying to formulate a constitutive equation for rock salt based on irreversible thermodynamics theory. Recently,I encounted two prolems:

（1）how to define the damage variable?

(2)what's the meaning of "the maximum dissipation principle"?

could everyone give me some advice?

thanks a lot.

Chao Du

ABAQUS and Constitutive equation

Submitted by attaran on
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maxwell stress
Constitutive modelling

Dear all,

 I'm new to ABAQUS and I was wondering if we could have access to any constitutive equation in ABAQUS and add another stress tensor to the Cauchy stress tensor?

 regards, 

-- Hamid Attaran 

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