Unable to generate Spot weld connection between Solid elements

Altair Forum User
Altair Forum User
Altair Employee
edited June 2021 in Community Q&A

Hello Everyone,

 

I am trying to establish spot weld between Solid Hexa8N elements. I have tried to use 'plot', 'Type 2 spring' and 'HC Hexa' type. But in all the cases I am having following issues:

 

1) Type (Plot):   Simulation ran but solid elements were not connected

2) Type [Spring (Type 2)]:  Solver not able to identify the surface to create a spring elements.

3) Type HC Hexa: Contact interface defined by solver itself is not correct.


Apart from aforementioned problem I also want to give the max tensile strength of spot weld as as 40% of base material.

 

Thanks in advance.

Nitin Jain

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Answers

  • Pranav Hari
    Pranav Hari Altair Community Member
    edited February 2019

    Hi 

     

    Can you please share your model.

    You can use the secure drop box link https://ftin.india.altair.com:8443/filedrop/~Ma3TaE 

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2019

    Hello @Pranav Hari,

     

    I have uploaded the file on the shared link.

    But I have deleted some parts and Boundary conditions.

     

    Please assign boundary condition as per your convenience.

     

    Regards

    Nitin Jain

     

  • Pranav Hari
    Pranav Hari Altair Community Member
    edited February 2019

    Hi Nitin Jain

     

    I will check and update you.

  • Pranav Hari
    Pranav Hari Altair Community Member
    edited February 2019

    Hi Nitin Jain

     

    The recommended element types in Radioss for spot weld creation are shell element.

    Surface 1 and 2 for each solid spotweld should always connect with a shell element. If one surface of one solid spotweld is not connected with a shell element,

    then the stiffness will not be computed correctly and an error may occur

     

    Since you are having solid elements you have to create a shell coat and then connect using spots.

    There are three different ways of modeling spotweld:

    Node Connect
    Spring (/PROP/TYPE13) Connect
    Solid Connect

    When you create a spot weld using type 2 spring,  by default you will get the (TYPE13 spring property + TYPE2 contact). 

     

    In your case since you have to define max tensile strength of spot weld as 40% of the base material, then I recommend you use the solid connect method.

    Here you can specify separate failure criteria.

     

    This is explained in detail in the Radioss help documentation. Please have a look

    <?xml version="1.0" encoding="UTF-8"?>image.png

     

    Also, have a look at the Radioss example on solid spot weld creation.

     

    <?xml version="1.0" encoding="UTF-8"?>image.png

     

    I have shared the 2 example deck files, which is modeled using default spring contact and also solid connect. Check that too.

    Unable to find an attachment - read this blog

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited February 2019

    Since you are having solid elements you have to create a shell coat and then connect using spots.

     

    Contact surfaces can also be used.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited March 2019

    Thanks @Pranav Hari and @Ivan,

     

    I think making surface and then spot weld is time consuming process.

    Moreover I request you to please teach me, if I connect the extracted surface with connector: then solids will be connected as well or it will connect only extracted surfaces.

     

    Right now, I am trying to make the Seam weld connections (Hexa Tapered T type) but I am getting the distorted elements:

    <?xml version="1.0" encoding="UTF-8"?>image.thumb.png.48a899a842dc11bc3d428928b40074ac.png

     

    I am avoiding edge nodes for better results. But still some elements are not as desired.

     

    Regards

    Nitin Jain

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited March 2019

    Hello everyone,

     

    Does someone know how to solve the above mentioned problem??

     

    Thanks in advance.

     

    Regards

    Nitin Jain

  • tuan trinh
    tuan trinh Altair Community Member
    edited June 2021

    hi you

     

    i had refered the document, so i never make stiffness of spring, because the result also flying

     

    pelase show me

     

    thanks