This paper presents the development of an orthotropic material model for the mechanical
analysis of wood in the plane perpendicular to the growth direction. It is based on an earlier
uniaxial development and experimental verification. The novel features are the biaxial
extension and the description of partially irrecoverable creep deformation by enhancing a
viscoelastic-mechanosorptive creep model by coupling it with orthotropic plasticity. The
mathematical description of both the equations of state and the evolution laws are …

This paper describes the development of an efficient numerical integration algorithm for an
orthotropic viscoelastic-mechanosorptive-plastic material model for wood, which was
presented in Part I of this serial. This development utilizes both a semianalytical algorithm for
the viscoelastic parts, and the return-mapping algorithm known from plasticity for the
mechanosorptive-plastic part of the model. This yields an easily computed, closed form
expression for the consistent tangent operator, and, as a consequence, a quadratic rate of …