Riks analysis, local buckling?
Riks analysis, local buckling?
(OP)
Hello,
I`m trying to do nonlinear analysis of a column.
I do linear buckling analysis to get the eigenvalues.
I use these material properties(steel):
*Elastic
2.09e+11, 0.3
*Plastic
200.2e+06, 0.0
246.0e+06, 0.0235
294.0e+06, 0.0474
374.0e+06, 0.0935
437.0e+06, 0.1377
480.0e+06, 0.18
Then I introduce imperfections and run static, riks:
*IMPERFECTION, FILE=buckle, STEP=1
1, 5.33
*Step, name=Step-1, nlgeom=YES, inc=40
*Static, riks
1, 1., 1e-05, , ,
But what I get with riks is local buckling(see picture).
It does not matter what BC or column shape i use, I always get local buckling or bending.
What I am doing wrong? Please give me any suggestions.
Thank you very much.
I`m trying to do nonlinear analysis of a column.
I do linear buckling analysis to get the eigenvalues.
I use these material properties(steel):
*Elastic
2.09e+11, 0.3
*Plastic
200.2e+06, 0.0
246.0e+06, 0.0235
294.0e+06, 0.0474
374.0e+06, 0.0935
437.0e+06, 0.1377
480.0e+06, 0.18
Then I introduce imperfections and run static, riks:
*IMPERFECTION, FILE=buckle, STEP=1
1, 5.33
*Step, name=Step-1, nlgeom=YES, inc=40
*Static, riks
1, 1., 1e-05, , ,
But what I get with riks is local buckling(see picture).
It does not matter what BC or column shape i use, I always get local buckling or bending.
What I am doing wrong? Please give me any suggestions.
Thank you very much.





RE: Riks analysis, local buckling?
RE: Riks analysis, local buckling?
I think that the shape should by similar in the riks analysis too.
RE: Riks analysis, local buckling?
RE: Riks analysis, local buckling?
Regards
Martin Stokes CEng MIMechE
RE: Riks analysis, local buckling?
The length of the column is 4000mm, so I get the imperfection of 5.33 milimeters.