Modal analysis of a gearbox-housing assembly using the area connector

DWerner
DWerner New Altair Community Member
edited October 2020 in Community Q&A

Dear Members,

 

my problem is the following:

 

I want to calculate the frequency modes of a gearbox-housing that consists of two parts screwed with a flange, using OptiStruct as solver.

 

A validated approach that I want to try is modelling the screws as a bar-element that connects two mpc-rigids, one in the thread-area an the other in the area of the screw-head. The problem that I have is the connection of the two meshes (3D-parabolic with tetra-elements) of the parts in the flange-area. Simply connecting the whole flange leads to unsatisfactory results so that I just want to connect the flange areas in a certain radius auround the axis of the screw.

 

My first idea was using the area-connector to create rigid-elements, but I still have problems to understand, how it works and if its even possible to do it in that manner.

 

When I select 'elems' in the location-botton of the area-panel and 'rigid' as type no area-connectors are created independent of every other option chosen.

 

Using 'node list' leads to really strange connections and its hardly possible to even achieve a creation of some connections.

 

Does anyone have an indea of a different approach connecting the flange-areas? As far as I know defining a contact is not possible for a modal analysis due to linearity.

 

Thank you very much in advance!!

 

 

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Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited April 2015

    Hi,

     

    Can you share a picture of the model?

     

    Contacts may not give a good result as they are non linear and will end up with worst frequency results.

     

    Maybe you should try with different options in area weld panel.

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  • DWerner
    DWerner New Altair Community Member
    edited April 2015

    Hi, thank you for your quick answer!

     

    I attached some pictures of the model, I hope that helps understanding my problem.

     

    I also made a Test-Model that originally served to check wether my modelling concept leads to reasonable results, I can be downloaded here:

     

    https://www.dropbox.com/s/dr9fjisk3m0g8p2/DWerner_Testmodell_AssemblyArea_Beam.hm?dl=0

     

    As the nets are quite simple, I had no problems creating an area-connector in this model, but when it came to adopting this to the gearbox-housing, I couldn't achieve creating this connector anymore. Are there some ways to remesh the flange area in a manner that creates a really flat and smooth mesh? Maybe this could help?

     

     

     

    Unable to find an attachment - read this blog

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