Equation Constraint - Thick Walled Pipe
Equation Constraint - Thick Walled Pipe
(OP)
Hi everyone,
I am quite new to Abaqus and FEM software in general. I am trying to model a thick walled pipe (closed) in Abaqus. The way I have been doing this is extruding a solid pipe section and constrain one end (BC) in the axial direction only (to allow for radial and hoop expansion). I have then applied a uniform internal pressure to the pipe and the associated axial pressure (calculated for a closed thick walled pipe).
The problem with the model is the way the pipe is deforming, it does not seem to make physical sense. I am expecting radial and hoop deformation to be uniform. I am unsure why this isnt working, could someone please outline how to fix this problem so i can have a well behaving closed thick walled pipe? (I am currently trying equation constraints)
Thank you! Please ask any questions and I will respond asap.
I am quite new to Abaqus and FEM software in general. I am trying to model a thick walled pipe (closed) in Abaqus. The way I have been doing this is extruding a solid pipe section and constrain one end (BC) in the axial direction only (to allow for radial and hoop expansion). I have then applied a uniform internal pressure to the pipe and the associated axial pressure (calculated for a closed thick walled pipe).
The problem with the model is the way the pipe is deforming, it does not seem to make physical sense. I am expecting radial and hoop deformation to be uniform. I am unsure why this isnt working, could someone please outline how to fix this problem so i can have a well behaving closed thick walled pipe? (I am currently trying equation constraints)
Thank you! Please ask any questions and I will respond asap.





RE: Equation Constraint - Thick Walled Pipe
You could try to make a cylindrical coordinate system (x in the radial direction of the pipe), then use a coupling to couple the end face of your pipe (free in x (radial) direction)). On the coupling's mater node you can apply a BC (DOF 123456). This should allow for radial expansion.
Hope it helps.
Br,
RE: Equation Constraint - Thick Walled Pipe
RE: Equation Constraint - Thick Walled Pipe
RE: Equation Constraint - Thick Walled Pipe
Thank you for your suggestions! I managed to get the pipe to behave as expected, this is what I did:
-> Assigned material orientation in the Parts Module to a cylindrical coord system
-> BCs: Constrained one face in the axial direction
-> Loads: Internal Pressure and Axial Pressure (calculated using closed thick walled pipe equations)
-> Constraints: Equation, I created two sets.
Set1: On the free face of the pipe I created a set consisting of ONE node in the I.D. of the pipe
Set2: On the free face of the pipe I created a set consisting of ALL the nodes , EXCLUDING the node I selected in Set1.
This worked using these sets in the equation constraint and in a cylindrical coord system (that was defined in the Assembly Module).
If this isn't clear and anyone wants me to explain in more detail just ask. Thanks All.