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    Miller Axel ANSYS 2013 Detroit

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    Srashmi
    Miller axle

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    © All Rights Reserved
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    Miller Axel ANSYS 2013 Detroit

    Uploaded by

    Srashmi
    45 views26 pages
    Miller axle

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    Miller axle

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    45 views26 pages

    Miller Axel ANSYS 2013 Detroit

    Uploaded by

    Srashmi
    Miller axle

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    of 26

    2013 Regional Conference

    Testing of Elastomers and Plastics in


    Support of Analysis

    Kurt Miller, Axel Products, Inc.


    www.axelproducts.com

    1 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    axelproducts.com

    2 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Rubber Bands

    3 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Compression

    4 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Compression

    5 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    A Spring and a Dashpot?

    6 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    What does Incompressible Mean?

    7 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Volumetric Compression
    Poisson’s ratio approaching 0.5 means infinite bulk modulus, K
    For elastomer materials Poisson’s ratio is difficult or impossible to measure
    accurately. For plastic materials, it is hard to measure VC accurately. Measure
    Pressure-Volume directly, compute K (or D1 in ABAQUS)

    K/G Relationship to Poisson's Ratio

    100

    80
    K/G
    60
    K 2 1
    K/G

    G 3 1 2
    40

    20

    0
    0.3 0.32 0.34 0.36 0.38 0.4 0.42 0.44 0.46 0.48 0.5

    Poisson's Ratio
    8 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential
    Incompressibility

    Not a spring and dashpot

    9 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Confinement can be
    Significant

    10 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Hyperelastic Models Define a Surface

    11 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Rubber

    12 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Simple Tension
    •Uniaxial loading
    •Free of lateral constraint Gage Section:
    Length:Width
    >10:1

    13 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Planar Tension

    1. Uniaxial loading
    2. Perfect lateral constraint
    3. All thinning occurs in one direction

    14 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Equal Biaxial Extension

    Why?
    1. Same Strain State as
    Compression
    2. Can Not Do Pure Compression
    3. Can Do Pure Biaxial

    15 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Loading Conditions

    Some common Elastomers exhibit dramatic strain amplitude and


    cycling effects at moderate strain levels

    Conclusions:
    1. Test to Realistic Strain
    Levels
    2. Use Application
    Specific Loadings to
    Generate Material Data
    3. Need to load and unload
    to separate elastic from
    plastic

    16 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Loading Conditions

    Some common Elastomers exhibit dramatic strain amplitude and


    cycling effects at moderate strain levels

    Conclusions:
    1. Test to Realistic Strain
    Levels
    2. Use Application
    Specific Loadings to
    Generate Material Data
    3. Need to load and unload
    to separate elastic from
    plastic

    17 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Loading Conditions

    Some common Elastomers exhibit dramatic strain amplitude and


    cycling effects at moderate strain levels

    Conclusions:
    1. Test to Realistic Strain
    Levels
    2. Use Application
    Specific Loadings to
    Generate Material Data
    3. Need to load and unload
    to separate elastic from
    plastic

    18 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Loading Conditions
    Some common elastomers exhibit dramatic strain amplitude and
    cycling effects at moderate strain levels

    Conclusions:
    1. Pick one level
    2. Use Mullins Model
    3. Use FeFp
    4. Use large strain
    hysteresis model

    19 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Thermoplastic Elastomers
    Increasingly used to replace elastomers
    Rubber inside of plastic
    Plasticity and Flow

    Conclusions:
    1. Pick one level
    2. Use Mullins Model
    3. Use Viscoelastic
    4. Use large strain
    hysteresis model

    20 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Thermoplastic Elastomers

    21 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Teflon

    Conclusions:
    1. Pick one level
    2. Use FeFp

    22 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Hyperelastic Models
    • Material response is isotropic, isothermal, and
    elastic and is assumed fully or nearly
    incompressible.
    • There are many hyperelastic models available
    in ANSYS which can cover wide varieties of
    elastomers used in Industries.

    Available Hyperelastic models:


    • Arruda-Boyce Hyperelastic Material
    • Blatz-Ko Foam Hyperelastic Material
    • Extended Tube Material
    • Gent Hyperelastic Material
    • Mooney-Rivlin Hyperelastic Material
    • Neo-Hookean Hyperelastic Material
    Specialized Hyperelastic models:
    • Ogden Compressible Foam Hyperelastic Material
    • Ogden Hyperelastic Material • Anisotropic Hyperelastic Material
    • Polynomial Form Hyperelastic Material • Bergstrom-Boyce Material
    • Response Function Hyperelastic Material • Mullins effect
    • Yeoh Hyperelastic Material • User-Defined Hyperelastic Material
    23 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential
    Hyperelastic Models
    Curve Fitting feature
    • Material curve fitting allows you to derive coefficients from experimental data that
    you provide for your material.
    • With this capability, you compare experimental data versus program-calculated data
    for different nonlinear models and determine the best material model to use.
    • ANSYS provides curve-fitting, based on experimental data, for all of the available
    hyperelastic models. Any of the hyperelasticity models in ANSYS can be used.

    24 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    Experimental Elastomers Training at Axel
    Products
    ANSYS teams with Axel Product, Inc.
    (www.axelproducts.com) to offer this course that
    covers material testing, material modeling and
    finite element analysis of elastomers.

    25 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential


    A General Strategy

    1. Understand the loading conditions of the part


    2. Understand the general behavior of the materials
    involved
    3. Select the significant material behaviors
    4. Use existing or develop material models to describe the
    behavior
    5. Verify the performance of the material model

    26 © 2013 ANSYS, Inc. June 3, 2013 ANSYS Confidential

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