A two-node superelement description for modelling of flexible complex-shared beam-like components

In this paper, a two-node superelement description is proposed for use in multibody models which is capable of modelling flexible complex-shaped beam-like components. Assuming that the deformations with respect to a co-rotational frame remain small, substructuring methods may be used to obtain a dynamical model with reduced mass and stiffness matrices from a linear finite element model. The development of a two-node superelement is established by linking a reduced linear finite element model with a non-linear finite beam element capable of describing large rigid body motion and small elastic deformations. This is achieved by equating their potential and kinetic energies. Two examples are included. A simulation of the spin-up motion of a flexible beam with uniform cross-section and a similar simulation in which the beam is simultaneously excited in the out-of-plane direction. Both examples show good agreement with simulations obtained using non-linear finite beam elements.