Negative contact pressures. CPRESS negative in tension ?
Negative contact pressures. CPRESS negative in tension ?
(OP)
Hi,
I have a working model of 3 concentric cylinders with the cylinder in the middle being the master surface and the other two being the slave surfaces. I have a pic attached of the model , which would better represent my question.
A gap opens up between the middle cylinder and the outer cylinder due to the tensile stresses as evident from the radial stress plot in the pic. In view of this I was expecting to see positive contact pressures on the outer tube . However Abaqus tells me the CPRESS values on the outer tube are negative.
So is CPRESS negative in tension and positive in compression ? I'm just trying to confirm if the CPRESS behavior is consistent with my radial stress distribution results.
Thanks
I have a working model of 3 concentric cylinders with the cylinder in the middle being the master surface and the other two being the slave surfaces. I have a pic attached of the model , which would better represent my question.
A gap opens up between the middle cylinder and the outer cylinder due to the tensile stresses as evident from the radial stress plot in the pic. In view of this I was expecting to see positive contact pressures on the outer tube . However Abaqus tells me the CPRESS values on the outer tube are negative.
So is CPRESS negative in tension and positive in compression ? I'm just trying to confirm if the CPRESS behavior is consistent with my radial stress distribution results.
Thanks





RE: Negative contact pressures. CPRESS negative in tension ?
Tara
http://tinyurl.com/4ydjg7m
RE: Negative contact pressures. CPRESS negative in tension ?
I'm seeing contact pressures of the order of -4E06 Pa to -2E09 Pa
Thanks for your help.
RE: Negative contact pressures. CPRESS negative in tension ?
Tara
http://tinyurl.com/4ydjg7m
RE: Negative contact pressures. CPRESS negative in tension ?
Is this because , the value 2e-11 meters is so small that Abaqus still considers it to be in contact ? I could view the separation only when I used a deformation scale factor of 20 ( scale factor of 1 being normal ).
I've attached how my assembly is setup and a plot of COPEN and CPRESS plotted against the angle theta.
RE: Negative contact pressures. CPRESS negative in tension ?
Thanks
RE: Negative contact pressures. CPRESS negative in tension ?
Tara
http://tinyurl.com/4ydjg7m
RE: Negative contact pressures. CPRESS negative in tension ?
Also , I have this file attached that talks about the subroutine DLOAD and states that
" *DLOAD defines pressure (i.e. compressive normal stress)
to be positive, so we apply tensile loading by making the pressure negative."
Does this statement lend any validity to my results ? I mean , I'm seeing separation in most regions , which implies tension and my contact pressures turn out to be negative in the region of separation as well.
Thanks for all the help once again.
RE: Negative contact pressures. CPRESS negative in tension ?
RE: Negative contact pressures. CPRESS negative in tension ?
Tara
http://tinyurl.com/4ydjg7m
RE: Negative contact pressures. CPRESS negative in tension ?