Limit Load Analysis in Ansys
Limit Load Analysis in Ansys
(OP)
I'm new to using Ansys and trying to run a elastic perfectly plastic (EPP) limit load model. I'm coming from using Abaqus where a I would create a static structural run ramp the pressure have output written for each increment so I could visuals results up to failure. I'm trying to do the same in Ansys and having trouble. Any assistance would be appreciated. I've currently created and applied a material with bilinear isotropic hardening (yield strength set to strength limit and tangent modulus to 0), in a transient and static analysis. Both fail as expected but I can not visualize any results.





RE: Limit Load Analysis in Ansys
Rick Fischer
Principal Engineer
Argonne National Laboratory
RE: Limit Load Analysis in Ansys
why not "just" do a linear elastic analysis ?? I mean, you don't want to see any yielding ...
Quando Omni Flunkus Moritati
RE: Limit Load Analysis in Ansys
The three methods are listed in order of increasing complexity, increasing accuracy, and decreasing conservativeness. If the design doesnt pass with the elastic method, try the next one. I work on a device that only sees vacuum load, but we use BPVC anyway for lack anything better. If we use elastic method, the walls get too thick, and distortion occurs from welding heat. If we use limit load method, we can pass with a wall thickness that is easier to fabricate.
csbarone: in MAPDL use NSUBST or DELTIM commands to control substeps and determine where you will have results to save. Use the OUTRES command to odetermine which results get saved. Use the SET command on POST1 to load a result set for plotting. In Workbench go to Analysis Settings in the tree. set Auto Time Stepping to ON. Then set Define By to Time or Substeps (this is analagous to DELTIM and NSUBST in MAPDL). Then scroll down to Output Controls and use Store Results At to control which times to save.
Rick Fischer
Principal Engineer
Argonne National Laboratory
RE: Limit Load Analysis in Ansys
1) the structure doesn't go plastic (under anticipated loading), or
2) if it did go plastic (under some elevated loading), then it wouldn't collapse
Quando Omni Flunkus Moritati
RE: Limit Load Analysis in Ansys
The goal of protection against plastic collapse is #2.
Rick Fischer
Principal Engineer
Argonne National Laboratory
RE: Limit Load Analysis in Ansys
RE: Limit Load Analysis in Ansys
Rick Fischer
Principal Engineer
Argonne National Laboratory