Bilinear modelling of cellulosic orthotropic nonlinear materials

Abstract

The proposed method of modelling orthotropic solids that have a nonlinear constitutive material relationship affords several advantages. The first advantage is the application of a simple bilinear stress-strain curve to represent the material response on two orthogonal axes as well as in shear, even for markedly nonlinear materials. The second advantage is that this method correlates yield strengths in the orthogonal directions, which is necessitated by some finite-element programs. Herein, we provide an algorithm for fitting bilinear stress versus strain curves to data, such that the derived stress-strain law on each orthogonal axis is coupled by means of a common strain energy density function. Nonlinear stress-strain data for paper and paperboard illustrate the procedure. This method can be readily implemented in finite element applications.

Citation

Saliklis, E.P.; Urbanik, T. J.; Tokyay, B. 2003. Bilinear modelling of cellulosic orthotropic nonlinear materials. Journal of pulp and paper science. Vol. 29, no. 12 (Dec. 2003): Pages 407-411