Abstract
This paper presents a total Lagrangian nonlinear formulation of elastic trusses, in which the governing stiffness equations are described as the relations between the overall forces and positions. With this selection of spatial positions as basic unknowns, the specification of the initial configuration becomes unnecessary and the separation of rigid body motion is automatically attained by an appropriate selection of local coordinates. A simple two bar truss and a reticulated truss are investigated as numerical examples. In the former, the characteristic of the present formulation and the convergence by the successive substitutions have been demonstrated. The latter example is chosen to show the effectiveness of the present formulation and simple systematic procedure to trace the finite displacement equilibrium paths including the main path and paths after bifurcations.
