Number Of integration point

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

Hello;

 

Could someone explain, what is number of integraion point throught thickness ? and how it effect the hourglass energy ?

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Answers

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited October 2018

    Hi,

     

    If only one integration point through thickness is used, a membrane only behavior will be obtained. In case of an elastic behavior, one gets the exact solution from three integration points – that is to say that the bending moments are exactly integrated through the thickness of the shell. In case of a plastic behavior, the bending moments are not integrated exactly. Using more integration points, the solution becomes more accurate; so it is recommended to use five integration points. It also controls hourglassing.

     

    Hourglass modes are element distortions that have zero strain energy. Hourglassing may easily lead to excessive distortions  To control hourglass assign Ishell-24 and N-5 for shell elements. And for solids use Isolid-14. For explicit structural analysis Ishell=24 formulation (QEPH shells) is recommended, due to balanced accuracy vs. speed. QEPH shells are more accurate for elastic or elasto-plastic loads, whatever the loading type - quasi-static or dynamic. Fully integrated 12 QBAT shells eliminate hourglassing, but are slower to compute.

     

    Try with different settings to study the hourglassing effect by postprocessing the hourglass energy in HG.

  • beytut
    beytut Altair Community Member
    edited October 2018

    thanks for your quick reply :))

  • Pranav Hari
    Pranav Hari Altair Community Member
    edited October 2020

    Hi beytut

     

    This forum post may also help you to relate integration point & hour glass. Have a look.

     

    https://community.altair.com/community?id=community_question&sys_id=1186c83a1b2bd0908017dc61ec4bcbec