🎉Community Raffle - Win $25

An exclusive raffle opportunity for active members like you! Complete your profile, answer questions and get your first accepted badge to enter the raffle.
Join and Win

Displacement load

User: "Amasker"
Altair Community Member
Updated by Amasker

Hi,I have a question,

 

In Optistruct, how to apply a displacement load on a cylindrical rigid wall to simulate a three-point bending test like following picture?

 

Thanks in advance。

 

 

<?xml version="1.0" encoding="UTF-8"?>三点弯.png

Find more posts tagged with

Sort by:
1 - 10 of 101
    User: "Rahul Rajan_21763"
    New Altair Community Member
    Updated by Rahul Rajan_21763

    You can refer attached OptiStruct example. For enforced displacement you can use SPCD card.

    Unable to find an attachment - read this blog

    User: "Amasker"
    Altair Community Member
    OP
    Updated by Amasker

    Rahul R

     

    I use SPCD card for a simple example,but it doesn't work, I am puzzled why?

     

     

    Unable to find an attachment - read this blog

    User: "Rahul Rajan_21763"
    New Altair Community Member
    Updated by Rahul Rajan_21763

    In loadstep subcase section , you checked IC condition as SPCD. Its not needed for static run. Just deactivate and run again.

    User: "Amasker"
    Altair Community Member
    OP
    Updated by Amasker

    Rahul R

     

    I am so sorry I don't express it clearly,I want to apply a uniform displacement=80mm to the rigid cylinder in the Y—axis direction winthin 0.2s,like this

     

    but I don't know how to make it by Optistruct?

     

     

    image.png.79905d6cb6f3871f83bb5739381c5043.png

     

     

     

     

     

    User: "Simon Križnik"
    Altair Community Member
    Updated by Simon Križnik

    Hi @Amasker

     

    the B-pillar three-point bend problem would require non-linear quasistatic or dynamic analysis due to three major nonlinearities:

    -large displacements/rotations/deformations

    -material yielding

    -contacts

     

    In dynamic analysis, inertial effects and momentum are included (loading in 0.2s) while quasistatic simulates very slow movement.

     

    Please go through free eBook: Introduction to Nonlinear Finite Element Analysis using OptiStruct

     

    The following videos should help:

    69a0f69e1b1f01cd90ed17a531e1c6979ed2aeb1.jpg?image_play_button_size=2x&image_crop_resized=960x614&image_play_button=1&image_play_button_color=005596e0

    Learning Video: RADIOSS - Altair HyperWorks Insider

     

    41adadc6f1d0fee92622775413b90791a0e7a377.jpg?image_play_button_size=2x&image_crop_resized=960x614&image_play_button=1&image_play_button_color=54bbffe0

    OptiStruct Nonlinear Learning Center

     

    Try to replicate in your model the analysis setup from the example shared by @Rahul R 

    User: "Amasker"
    Altair Community Member
    OP
    Updated by Amasker

    Thank you@Ivan,

     

    There is still a problem here in the example shared by @Rahul RIn Optistruct, how to set a cylinder created by myself as a rigid body and apply speed, I want to extract the contact force generated during the collision, and the rigid wall inside Optistruct cannot extract the contact force.

    Or in an explicit nonlinear dynamics analysis, can RW in load steps use other geometry as a rigid wall?

     

    I did a simple example,but there is no contact force in .h3d file,can you check it?thanks in advance

     

    following is.fem file

     

    Unable to find an attachment - read this blog

    User: "Rahul Rajan_21763"
    New Altair Community Member
    Updated by Rahul Rajan_21763

    In your shared deck, you have loadstep set to linear static analysis. CONTF will not work for linear cases.

    Please refer OptiStruct nonlinear eBook for more information using below link.

    https://altairuniversity.com/free-ebook-introduction-to-nonlinear-finite-element-analysis-using-optistruct/

    User: "Simon Križnik"
    Altair Community Member
    Updated by Simon Križnik

    In Optistruct, how to set a cylinder created by myself as a rigid body and apply speed, I want to extract the contact force generated during the collision, and the rigid wall inside Optistruct cannot extract the contact force.

    2

    Create rigid body using 1D>rigids. Boundary conditions are applied on the master/independent node. Output requests like displacements, forces,... can be requested by Analysis>output block.



     

    User: "Amasker"
    Altair Community Member
    OP
    Updated by Amasker

    It‘s very grateful,your suggestion is helpful, IvanRahul R


    There is still a small problem here, which makes me very confused. I originally applied a forced displacement of 80mm in the direction of the dof2 y axis, but the analysis result is that the rigid body has a large displacement along the x-axis direction. I don’t understand what went wrong. here is .fem file , can you give me some suggestion?

     

     

    And how to extract the value of specific energy absorption instead of cloud image?

    Unable to find an attachment - read this blog

    User: "Simon Križnik"
    Altair Community Member
    Updated by Simon Križnik

    Create a rigid body on impactor cylinder and then constrain its independent/master node in all DOF and apply the SPCD on the same node. 

     

     

    Attached is the edited model. Check the modifications and compare to 3pt bend example. The analysis takes a lot of iterations to converge so perhaps there is a more efficient analysis setup. 

     

    ESE in the global output request will output strain energy and strain energy density.

     

    Unable to find an attachment - read this blog