Curve fitting of hyperelastic materials
Curve fitting of hyperelastic materials
(OP)
ANSYS seems to curve fit biaxial stress-strain data very well up to 90% (and calculate representative coefficients for the Mooney Rivlin model).
Yet when I extract data from the equibiaxial region of my planar biaxial simulation, ANSYS estimates stresses not in line with the curve I used to generate the coefficients.
The extracted data looks more like the typical hyperelastic material (http://www.axelproducts.com/images/3_strains.gif) but as you can see in the attachment, the curve does not stiffen before 90%.
Yet when I extract data from the equibiaxial region of my planar biaxial simulation, ANSYS estimates stresses not in line with the curve I used to generate the coefficients.
The extracted data looks more like the typical hyperelastic material (http://www.axelproducts.com/images/3_strains.gif) but as you can see in the attachment, the curve does not stiffen before 90%.





RE: Curve fitting of hyperelastic materials
Also, when curve fitting stress-strain data, I believe it is better to use all your experimental data (uniaxial, biaxial, etc.) and find the best fit for all the curves combined.
Nagi Elabbasi
Veryst Engineering