Nonlinear Analysis of Space Trusses

Abstract

Nonlinear methods of analysis for space trusses are reviewed. Methods which do not require repeated reformation and reinversion of the stiffness matrix appear to give the greatest computational efficiency. A new method of analysis for static geometrically linear space trusses is presented. The method allows load increments and decrements, nonproportional loading and the simultaneous failure of several members, while retaining the computational efficiency of the “initial stress” method. In addition, the new formulation has the capability of including the computationally difficult internal instabilities caused by rupture of tension members and “chordal displacement snap through” of compression members in their postbuckling regime. The method can be used with both plane and space trusses in addition to geometrically linear fiber element structures. Because of the computational efficiency of the method, it is particularly useful for structural reliability analyses.