load time history for fatigue analysis

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

sir , how can i generate load-time history for the fatigue analysis ?

Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2018

    Hi @yogeshchandra

     

    You can use MotionSolve:

    • Generating loads on a flexible body in MotionSolve via a transient MotionSolve analysis
    • Recovering stresses in OS
    • Running a fatigue analysis in OS to predict part failure

    Please refer to tutorials available on MV/MS on how to generate flexbodies and run a transient analysis with MotionSolve. 

  • yogeshchandra
    yogeshchandra Altair Community Member
    edited November 2018

    sir, can you provide the link for the said tutorial .

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2018

    Hi @yogeshchandra

     

    I have shared a file to your email ID.

     

    Please check the same. 

  • Subhu_21017
    Subhu_21017 Altair Community Member
    edited June 2019

    Hi @yogeshchandra

     

    You can use MotionSolve:

    • Generating loads on a flexible body in MotionSolve via a transient MotionSolve analysis
    • Recovering stresses in OS
    • Running a fatigue analysis in OS to predict part failure

    Please refer to tutorials available on MV/MS on how to generate flexbodies and run a transient analysis with MotionSolve. 

    Hello Gents,

     

    Is it possible to Extract Load with Rigidbody Analysis in Motionsolve?

    Thanks in Advance!

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited June 2019

    Hi,

     

    Load Extraction is also possible with rigid bodies.

    e09ea081464a457fa87766bb61fed5ed03fec5c3.jpg?image_play_button_size=2x&image_crop_resized=850x480&image_play_button=1&image_play_button_color=7b796ae0

    Keshav_Webinar_Load_Extraction - Altair

     

    Check tutorial: mv-3030: Load export:

    Unable to find an attachment - read this blog

  • Subhu_21017
    Subhu_21017 Altair Community Member
    edited June 2019

    Hi Hyperman and All,

     

    Actually I am working on an agri-equipment and planning to investigate on it's fatigue behavior.

    It is an assembly/mechanism operated around 1500 rpm.

    I am eager to know whether there will be difference in loads extracted between rigid body analysis and flexible body analysis?

     

     Regards,

    Subhu

     

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited June 2019

    It is impossible to answer without seeing the multibody system in question. Flexible bodies should be included to model links undergoing such severe deformations that joint locations are altered from rigid body kinematics.

     

    from free ebook: Practical Aspects of Multi-Body Simulation with HyperWorks

    Why Flexible Bodies?
    A traditional multi-body dynamic (MBD) analysis involves the simulation of a rigid body system under the application of forces
    and/or motions. In some cases, the flexibility of a body has a significant effect on the results of a simulation. Rigid body
    simulations do not capture such deformations and this may lead to inaccurate results. Inclusion of flexible bodies in MBD
    simulations accounts for flexibility.
    Simulation of flexible bodies in an MBD system has the following benefits:
    • Captures body deformation
    • Increases accuracy in load predictions
    • Determines the stress and/or strain distribution in a body
    • Helps generate loads needed for fatigue analysis
    However, flexible bodies introduce an additional set of equations in the system, and consequently, have a higher computational
    cost as compared to rigid body systems.

     

    from CAE and Multi Body Dynamics>Advanced Topics>Flexibility (attached bellow):

    High Speed Mechanisms
    At high speeds, the effects of inertial forces are large enough that the
    deformation of the links may be significan
    t. Neglecting these may well lead
    to failure of the mechanism: it may jam, vibrate too much, generate too
    much noise, and so on.

     

    Unable to find an attachment - read this blog

  • Subhu_21017
    Subhu_21017 Altair Community Member
    edited July 2019

    Hi Hyperman,

     

    How to extract/output modal participation factor from Motionsolve?

     

    TIA!

    Regards,

    Subhu

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited July 2019

    Modal participation factors are output by default from Motionsolve when flexible bodies are included. They can be plotted in HG using either mrf of abf files.

    <?xml version="1.0" encoding="UTF-8"?>flex_modal.jpg

    Unable to find an attachment - read this blog

  • Subhu_21017
    Subhu_21017 Altair Community Member
    edited July 2019

    Hi,

     

    I have a transient analysis in MBD with Flexible bodies.

     

    I want to evaluate the fatigue strength and damage of welds of the same in n-code.

    What are the possible ways to do it?

    Any Documents for reference would be very helpful.

     

    Thanks!

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited July 2019

    Hi,

     

    check the resource library

    Virtual Durability Process: Bringing Together MBD, FE and Fatigue is the most relevant to your query.

     

    You can request more e-learning material from nCode