Modal analysis with Ansys
Modal analysis with Ansys
(OP)
Hello,
This is my first question in the forum, sorry for my english.
I am involved in some modal correlation between test and numerical results with ansys. As a first step I have simulated weldings as a common nodes between the welded plates, and I have concluded that generally the local modes obtained by calculation are higher in frequency than the tested ones. So I understand this simulation is too stiff, and a better simulation of welding introducing some rotational stiffness should be necesssary. I have been looking for papers or reference documents talking about this problem but I have not succed.
Please, could anybody help me with this issue?
Thank you very much in advance for your collaboration
This is my first question in the forum, sorry for my english.
I am involved in some modal correlation between test and numerical results with ansys. As a first step I have simulated weldings as a common nodes between the welded plates, and I have concluded that generally the local modes obtained by calculation are higher in frequency than the tested ones. So I understand this simulation is too stiff, and a better simulation of welding introducing some rotational stiffness should be necesssary. I have been looking for papers or reference documents talking about this problem but I have not succed.
Please, could anybody help me with this issue?
Thank you very much in advance for your collaboration





RE: Modal analysis with Ansys
ex-corus (semi-detached)
RE: Modal analysis with Ansys
I have tried a finer mesh and the results were equivalent.
RE: Modal analysis with Ansys
RE: Modal analysis with Ansys
You are right, I knew that.
In fact I have used shell181 elements, and also I have tested hexas elements ( not tetrahedal) but the results remain similar.
Regards,
RE: Modal analysis with Ansys
Tobalcane
"If you avoid failure, you also avoid success."
RE: Modal analysis with Ansys
RE: Modal analysis with Ansys
As a first step I joined the plates with the cantlivers on their welding positions by common node, so coupling the six dof. After that I tried coupling just the translations and not the rotations, and the results on the local modes of the plates were better ( lower in frequency). So I think this the way to follow but I would like to know a little bit more why this is happenning and if somebody has experienced the same or knows about papers or bibliography talking about that.
Thanks.
RE: Modal analysis with Ansys
Tobalcane
"If you avoid failure, you also avoid success."
RE: Modal analysis with Ansys
RE: Modal analysis with Ansys
www.Roshaz.com
RE: Modal analysis with Ansys
My problem is depending on the type of welding you have the stiffness of the junction is different and this cause a different dynamic response of the structure ( basically on the local modes). What I would like to know if there is any book or paper talking about how to manage that in a similar problem.
RE: Modal analysis with Ansys
Tobalcane
"If you avoid failure, you also avoid success."
RE: Modal analysis with Ansys
Tobalcane
"If you avoid failure, you also avoid success."
RE: Modal analysis with Ansys
are you modeling the weldment? or just joining the plates?
the weldment is not a continuation of the plate, with some change in the elastic properties, and depending on the finishing, extra metal.
RE: Modal analysis with Ansys
https://bib.irb.hr/datoteka/83867.cim_999.doc
addresses some of the details of a weldment analysis
good luch