NONLINEAR ANALYSIS OF RETICULATED SPACE TRUSSES

Most existing methods of analyzing reticulated structures are either approximate or are applicable to only special cases. The present investigation studies the geometric nonlinear behavior and associated snap-through buckling of reticulated structures. The development is based on a large displacement finite element formulation, using bar elements, but may be expanded to include geometrically nonlinear behavior of more general elements. The formulation may be used to analyze space trusses that might undergo both large displacements and large member rotations. It is shown that upper and lower bounds are not always reliable, and that an approximate nonlinear analysis may be used to accurately determine the snap-through loads of large structures. Examples are presented to illustrate differences in results obtained through linear and nonlinear formulations.