How to perform a modal analysis from a nonlinear static analysis with PyAnsys?

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squaegeb
squaegeb Member Posts: 3
First Comment

Dear all,
I am trying to compute the eigenvalues of a mechanical system after a static analysis with "nlgeom,on" using PyAnsys.
I have run the following lines

static analysis

mapdl.run("/SOLU")
mapdl.run("antype,static")
mapdl.run("nlgeom,on")
mapdl.run("rescontrol,define,last,last")
mapdl.run("autots,on")
mapdl.run("nsub,1,10,1")
mapdl.run("time,1.")

etc outres commands

mapdl.run("solve")
mapdl.finish()

modal analysis

mapdl.solution()
mapdl.run("antype,,restart,,,perturbation")
mapdl.run("perturb,modal,,CURRENT,DZEROKEEP")
mapdl.run("solve,elform")
mapdl.run("modopt,lanb,6")
mapdl.run("solve")
mapdl.finish()

However the commands
mapdl.post1()
output = mapdl.set("LIST")
print(output)
do not give me the eigenvalues... I am wondering if the modal analysis is run properly. I note that no .Xnn files are created despite the rescontrol command line... Is the tangent matrix stiffness indeed taken into account,...
I have no clue what is wrong... I use 23R2
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