Hello everybody

By researching about what restrictions should be applied to the strain energy density function of a hyperelastic model, I found some very interesting papers about the Baker-Ericksen inequalities. Truesdell in 1956 had already set some restrictions about the positivity of the derivatives of the strain energy function but some authors later showed that they are overly restrictive.

My question is if have someone here already applied the BE inequalities to any model and how have you done this, because Im getting confuse about how can I apply them to my equation.

Thank you all,

regards

Felipe Stumpf, Brazil