Space truss finite elements applied to actuated structures and origami – implementation and discussions

Resumo

In the various branches of engineering, dynamic analysis of structures is always a relevant topic and the training of future professionals and researchers in this area is always important. Nowadays, with the evolution of materials and topological dispositions, structural elements and structures are becoming increasingly lighter and slender, increasing the amplitude of movements in such a way that nonlinear geometric analysis is necessary. regarding actuated structures or origami mechanisms, there is a natural mobility between planes defined by the relative rotation in the creases that makes it possible to create foldable devices of great interest such as the production of retractable roofs, retractable antennas, wheels for light vehicles, biomechanical devices , among others. This work introduces the presence of actuators in spatial structures by directly controlling the initial length of truss elements (actuation). At the same time, to define origami or flat 3D structures, it is necessary to introduce the strain energy associated with the folds at the junction between flat panels (creases). To introduce this energy, vectors orthogonal to the adjacent origamic planes are defined and fictitious spring elements are introduced to oppose the change in the angle
between the planes. Illustrative examples and discussions of future work are presented.