ABSTRACT
In hyperelasticity is typical to assume an explicit form of the stored energy density function for the material. This form is thereafter modulated through material parameters of the model as to fit some experimental data. On the contrary What-You-Prescribe-Is-What- You-Get (WYPIWYG) models consist of computational procedures which numerically obtain the stored energy function densities to a high precision without assuming their shape or employing material parameters. WYPIWYG procedures extract the necessary information from a complete set of experimental data. WYPIWYG procedures have been extended to compressible materials and also to transversely isotropic and orthotropic materials. We have also developed these type of procedures for modelling damage mechanics to capture the Mullins effect in soft materials. WYPIWYG stored energy functions have been used in anisotropic viscoelasticity to model the instantaneous (nonequilibrated) and relaxed (equilibrated) behaviors. WYPIWYG formulations are purely phenomenological and valid for most soft materials as rubber, foams or biological tissues. In this paper we show some of the advances on these type of formulations for soft materials.
