I have a composite material showing similar behavior along 0 & 90 deg in tensile test but exhibit anisotropic behavior in three point bend test. Can you please let me know the type of material card to be used to define such a material behavior.

Sudhir Hoskere
Sudhir Hoskere New Altair Community Member
edited September 2022 in Community Q&A
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Answers

  • PaulAltair
    PaulAltair
    Altair Employee
    edited September 2022

    This sounds like the type of behaviour you may see with a laminated composite, e.g. there are equal numbers of 0 and 90 degree plies in a stack, but their stiffness varies through thickness, the overall behaviour is a combination of the ply behaviours, typically in Radioss we would use /MAT/LAW25 to describe the material in each ply.

    But the answer to your query may be to use the correct /PROP card as it probably isn't possible to describe the behaviour in a single material), all prop options below can reference LAW25, you probably need TYPE11 or one of the PLY based composites (TYPE17 or TYPE51 or PCOMPP)

    For reference the Composite properties available (for shells) are listed below (in order of complexity/age): This might seem complicated, but I have explained it as simply as possible to provide a ready reckoner!

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    /PROP/TYPE9 (/PROP/SH_ORTH): Orthotropic Shell property (single layer), this allows a reference (0 degree) angle to be defined and an orthotropic material (e.g. /MAT/LAW25) to be referenced, integration points through thickness as per a ‘normal’ shell element.

     

    /PROP/TYPE10 (/PROP/SH_COMP): Property allowing multiple plies with different angles, all plies must have same thickness as each other and all must have same material (material is called from Material on Part card just like a ‘normal’ shell element) each ply has a single integration point through thickness.

     

    /PROP/TYPE11 (/PROP/SH_SANDW): Property allowing multiple plies with different angles. Thickness and material is referenced on the property card (so plies can have different thicknesses and materials to one another). The material law (not the specific material) used must be the same for all plies (e.g. all plies have to use a /MAT/LAW25). Each ply has 1 integration point through thickness. The material referenced on the /PART card is not used for the structural behaviour of the part, but is still used for contact stiffness with other parts, so should be representative.

     

    All above are ‘global’ laminate type models (not ply based), below are the ply based options

     

    /PROP/TYPE17 (/PROP/STACK) and /PROP/TYPE19 (/PROP/PLY): the /PART card references the /PROP/STACK and the /PROP/STACK then references multiple /PROP/PLY (which reference element sets for ply shapes). This is ply based but pretty much the same as /PROP/TYPE11 otherwise (i.e. only one material law may be used, single integration point through thickness per ply)

     

    /PROP/TYPE51 (no name for this!) and /PROP/TYPE19 (/PROP/PLY): pretty much as per /PROP/TYPE17 (/PROP/STACK), except with /PROP/TYPE51 you can use more than one material law (e.g. mixing LAW25 and LAW36). And you can specify multiple integration points through thickness per ply.

     

    /PROP/PCOMPP and /STACK and /PLY (note NOT ‘/PROP/STACK’ and ‘/PROP/PLY’): pretty much as per /PROP/TYPE51 functionally except that the new /STACK and /PLY entities are used (to avoid confusion of having 2 /PROP cards for a given component). The Part card references just the /PROP/PCOMPP, all elements in the part must be in a /PLY that is referenced by a /STACK.

     

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