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Not able to obtain symmetric expansion

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Enggbot

Mechanical
Sep 16, 2021
1
IN
The purpose of my analysis is to obtain the expansion of a metal cylinder when it is heated to a higher temperature and use the deformed model as input model in another analysis.
The cylinder is modeled using brick elements. I have constrained the nodes on one flat surface of the cylinder to prevent any translation along the axial direction.
A higher temperature is provided to all the nodes as load and run a static analysis. Now the result does not show symmetric deformation. Why isn't it a symmetric expansion? I have attached a drawing just to give an idea about the model.
 
 https://files.engineering.com/getfile.aspx?folder=a6c5b7d9-278e-44cc-964d-81976f6f0b69&file=cyl1.JPG
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Hello!,
Without the model in hand is difficult to know the reason of the error, post your FEMAP model here and we will take a look to it, thanks!.

Make sure the mesh is exactly symmetric. Also, you can solve the problem fully in 3-D using CHEXA 8-nodes brick elements, or in 2-D using 2-D Solid axisymmetric CQUADX4 four-node elements, the results should be exactly the same, but at a reduced cost, see two examples in the next animations of the contact between two cylindrical solids of different materials under an expansive thermal load of nodal temperature:
• In the first example a 3-D surface-to-surface linear contact "no penentration" is used.
• In the second model a 2-D edge-to-edge axisymmetric linear contact "no penetration" is used.
• Both models are solved using Simcenter Nastran linear static (SOL101).

URES_CHEXA_nzi244.gif


URES_axi_2d_cuxcfg.gif


Best regards,
Blas.

~~~~~~~~~~~~~~~~~~~~~~
Blas Molero Hidalgo
Ingeniero Industrial
Director

IBERISA
48004 BILBAO (SPAIN)
WEB: Blog de FEMAP & NX Nastran:
 
"I have constrained the nodes on one flat surface of the cylinder to prevent any translation along the axial direction."

did you constrain every node on the face ? that'd over-constrain the face, preventing the nodes from moving apart as they would under temperature.

another day in paradise, or is paradise one day closer ?
 
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