Composite simulation - Curve fitting

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Hy,

 

I'm working at composite simulation and I need some help: I have to verify material card data give me by laboratory; with 0°/90° tensile test no problem but with +45°/-45° experimental curve and RADIOSS curve are totally different.

I try to eplain my problem better: material constants (by experimental Test) are E11=  20067 MPa, E22=23200 MPa, G12=1519 MPa, G23=1444 MPa and G31= 1444 MPa.

I have reproduced experimental test in RADIOSS and I have done card fitting. In 0°/90° tensile test curves were very different but after a little modification of elastic modulus, they fitt enought:

 

<?xml version="1.0" encoding="UTF-8"?>image.thumb.png.7ef447c00b5ad9ccf575e28f5fe53351.png

 

The problem is in +45°/-45° tensile test because curves are too different:

<?xml version="1.0" encoding="UTF-8"?>image.thumb.png.d1b68f96ba4dd02dc7463ff71e666f6b.png

 

Radioss curves are made in Hyperview, protting strain and stress of an element. 

What am I doing wrong? Could someone help me?

Thanks in advance.

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Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited December 2017

    Hi Marta,

    For the first curve we can observe that it is a linear curve but for second one (45 degree curve) it is not, that is it seems like entering into the plastic zone from the beginning.

    The values which you have provided constitute only the linear portion of the material card. Provide the material parameters that define the nonlinear behavior of the material and you can try running. The image below shows the parameters that define the linear and non linear part of the material curve.

     

     

    <?xml version="1.0" encoding="UTF-8"?>Law25.PNG

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