Composite sandwich panel

AlessandroC
AlessandroC Altair Community Member
edited October 2020 in Community Q&A

Hi to everyone,

 

I would like to produce a crash between a composite sandwich panel and a fixed cylindrical rigid wall. The first one is made of three different materials defined as LAW25 (COMPSH), plies as Type19 and laminate panel as P17_stack.

 

Unfortunately something do not work properly. Can anyone help me to understand where I made mistakes?

<?xml version="1.0" encoding="UTF-8"?>2019-01-06.png

Unable to find an attachment - read this blog

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Answers

  • Pranav Hari
    Pranav Hari Altair Community Member
    edited January 2019

    Hi AlessandroC

     

    It seems that the Engine output requests have not been defined properly in your model.

    Instead of defining initial velocity and constrain at the rigid element, you can directly give it to the master node of the rigid.

    Check these Radioss tutorials from online help that is similar to your model and try making changes to your model accordingly.

     

    RDT: 3520

    RDT: 3530

     

    <?xml version="1.0" encoding="UTF-8"?>image.thumb.png.fa49bff51904f6af456fc77df125e022.png

     

    <?xml version="1.0" encoding="UTF-8"?>image.thumb.png.15083c87506471bdc27c9bd642ebf892.png

      

     

    Thanks

  • AlessandroC
    AlessandroC Altair Community Member
    edited January 2019

    Hi Pranav Hari

     

    thanks for your reply 

     

    I used hypercrash to set up loadcases and I got inspired by tutorial RD-T:3060. Could it be the problem?

     

  • AlessandroC
    AlessandroC Altair Community Member
    edited January 2019

    If I apply these fixes, I still have the follow result

     

    <?xml version="1.0" encoding="UTF-8"?>2019-01-06 (1).png

  • Pranav Hari
    Pranav Hari Altair Community Member
    edited January 2019

    Hi AlessandroC

     

    Can you please share both the OUT files

     

    Thanks

  • AlessandroC
    AlessandroC Altair Community Member
    edited January 2019

    Unable to find an attachment - read this blog

  • Pranav Hari
    Pranav Hari Altair Community Member
    edited January 2019

    Hi AlessandroC

     

     I meant the Radioss files; The starter & engine files.

    Sorry for the confusion:(/emoticons/default_sad.png' srcset='/emoticons/sad@2x.png 2x' title=':(' width='20' />

     

    Thanks

  • AlessandroC
    AlessandroC Altair Community Member
    edited January 2019

    I hope I shared with you all the files. By the way, if you want to calculate them again, remember that they take no more than 1 min each

    Unable to find an attachment - read this blog

  • AlessandroC
    AlessandroC Altair Community Member
    edited January 2019

    Any other suggestion?

     

    I am really trying everthing but nothing help me to understand what is the point

  • Pranav Hari
    Pranav Hari Altair Community Member
    edited January 2019

    Hi AlessandroC

     

    I could figure out some errors in your model. Try modifying these parameters are run the simulation.

     

    1. Check whether unit consistency is followed in your model. Check the units for Tstop, Tfreq and other time history files.

    2. Material is not defined for your shell component. Assign appropriate material to your component

    3. For the component Rigid, the card image assigned is PART. Change it to NONE.

     

    UNIT CONSISTENCY.png

     

    Try these changes and check whether its working

     

    Thanks

  • AlessandroC
    AlessandroC Altair Community Member
    edited January 2019
    Altair Forum User said:

     

    1. Check whether unit consistency is followed in your model. Check the units for Tstop, Tfreq and other time history files.

    2. Material is not defined for your shell component. Assign appropriate material to your component

    3. For the component Rigid, the card image assigned is PART. Change it to NONE.

     

     

    1. kN Kg mm ms is my global unit system. if you look at every single material I specified a local unit system kg/m/s in order to copy-paste faster fabric's properties: thas is very easy to do in hypercrash.

     

    2. I did not defined material for my shell because it is made of two fabrics and a single orthotropic core. All I have to do is define the type17_stack prop, right?

     

    3. if I use hypermesh, RBody is shown as a component, but not if I open it in hypercrash. I followed your advice by removing the card img Part, however solver still has the same issue

    <?xml version="1.0" encoding="UTF-8"?>2019-01-10 (1).png

    <?xml version="1.0" encoding="UTF-8"?>2019-01-10.png

  • AlessandroC
    AlessandroC Altair Community Member
    edited January 2019

    I tried to create again the same structure, I supposed there were some problems during mesh phase on the previous file, but it still has problems. anyone else has the same experience?  a specific tutorial for radioss and composites laminates?

  • Pranav Hari
    Pranav Hari Altair Community Member
    edited January 2019

    Hi AlessandroC

     

    Have a look at this exercise on composite modelling with Radioss

     

    Thanks

     

     

    Unable to find an attachment - read this blog

  • AlessandroC
    AlessandroC Altair Community Member
    edited January 2019

    Thank you 

    It will be very helpful. 

    Where can I find any other exercises on the same topic?

  • AlessandroC
    AlessandroC Altair Community Member
    edited January 2019

     

    Altair Forum User said:

    Hi AlessandroC

     

    Have a look at this exercise on composite modelling with Radioss

     

    Thanks

     

     

     

    According to your example, I tried to set up a sort of 3-points-bending test with two fixed rigid wall and another one that has a initial velocity.

     

    I used as much data as I could to define composites: the upper cylinder rigid wall impacts with the sandwich shell, but it bounces back instead of crashing the plate

     

    Unable to find an attachment - read this blog

  • Pranav Hari
    Pranav Hari Altair Community Member
    edited January 2019

    Hi AlessandroC

     

    Is this the correct file which you have shared. It seems like there is still inconsistency in the unit system.

    Please check the same

     

    Thanks

  • AlessandroC
    AlessandroC Altair Community Member
    edited January 2019

    Hi Pranav

     

    I already check, it should be ok

     

    Anyway, I made another problem inspired by your example 3.1: now the composite panel is a copy-pasted property and material data.

    However, It still has issues that I do not understand

     

    You could find all files attached there

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2019

    Hi 

    Please check the load  applied  i.e imposed velocity  ,for  any impact case recommended  load is the initial velocity

    and also apply the contact between the Rwall and plate 

     

     

  • AlessandroC
    AlessandroC Altair Community Member
    edited January 2019
    Altair Forum User said:

    Hi 

    Please check the load  applied  i.e imposed velocity  ,for  any impact case recommended  load is the initial velocity

    and also apply the contact between the Rwall and plate 

     

     

     

    Hi Pooja

     

    nothing is really changed

     

    here you are all the new files

     

    -

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