Design non- design section problem

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

 I have applied forces on the face of gear and contraints at the centre, to run optimization I have created design part and and non-design part and then I meshed them together applied  forces and constarints on the non- design  part but when I ran the analysis there is no stress distribution in design part

I think the error is because my to mesh are not connected

How to solve this error

<?xml version="1.0" encoding="UTF-8"?>Screenshot (1).png

<?xml version="1.0" encoding="UTF-8"?>Screenshot (8).png

<?xml version="1.0" encoding="UTF-8"?>Screenshot (7).png

Tagged:

Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited April 2019
    Altair Forum User said:

     I have applied forces on the face of gear and contraints at the centre, to run optimization I have created design part and and non-design part and then I meshed them together applied  forces and constarints on the non- design  part but when I ran the analysis there is no stress distribution in design part

    I think the error is because my to mesh are not connected

    How to solve this error

    <?xml version="1.0" encoding="UTF-8"?>Screenshot (1).png

    <?xml version="1.0" encoding="UTF-8"?>Screenshot (8).png

    <?xml version="1.0" encoding="UTF-8"?>Screenshot (7).png

     

    1st photo is total load case with constarints

    2nd pic is design part

    3rd is non-design

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited April 2019

    Hi,

     

    • if nodes at the interface between design and non-design space are reasonably close together (matching) you can use tool>edges panel (shift+F3) and equivalence the nodes. 
    • If the nodes at the interface are not matching you can use tie contact to connect the components. 
    • If the above approaches fail, then you should remesh the components, making sure the mesh on the surface at the interface is used as a seed (Fixed trias/quads to tetra mesh) when tetrameshing both components. 
  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited April 2019

    How to connect by using  tie contact??

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited April 2019

    TIE contact can be automatically created using tools>contact browser>AutoContact 

    https://altairhyperworks.com/pdfs/tips/1095.pdf

     

    Tie contact can also be created manually by analysis>interfaces>create as type=TIE

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited April 2019
    Altair Forum User said:

    TIE contact can be automatically created using tools>contact browser>AutoContact 

    https://altairhyperworks.com/pdfs/tips/1095.pdf

     

    Tie contact can also be created manually by analysis>interfaces>create as type=TIE

    Thank you.

    I created the tie contact and the analysis was successful I got the stress distribution in both design and non-design components. But the problem is maximum stress value before splitting the whole component into design and non-design design part was less than the results that I got. According to me the stress values should be same before and after splitting component into design and non design space.

    Please comment on this..

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited April 2019

    Glad to help.

     

    Actually, the stress should be slightly higher in the localized area around the tied interface because of different load transfer mechanism (as moment loads due to misalignment between nodes, but I'm not sure).

    The difference between the effects of two different but statically equivalent loads becomes very small at sufficiently large distances from the load (Saint-Venant’s Principle).

    If you aren't specifically interested in localized stress around the interface tie can be used, otherwise proper node to node connectivity is preferred. 

Categories