Impact of shear and extensional stiffness on equilibrium configurations of elastic Cosserat rods

Nonlinear rods are functionally important components in many flexible multibody systems. In this contribution, the influence of the effective stiffness parameters [EA] and [GA] of a Cosserat rod that affect the extension of the centerline as well as trans verse shearing of cross sections is investigated in equilibrium configurations, also in comparison with the extensional strains of an extensible Kirchhoff rod. Besides rough order of magnitude estimates, quantitatively accurate bounds of the respective strains are derived theoretically and validated in numerical simulations. Keywords: Cosserat rods, effective stiffness parameters, extensional and shear strains