The Statistics and Distribution of Helium in the Mantle

This paper deals with application of nonlinear analysis to study the systemʹs limit state behaviour of cable-tensioned steel structures. The cable tendon is modelled as an equivalent truss element with initial pretensioned force applied either as self-equilibrating axial load or as an equivalent thermal load. The modulus of elasticity of the cable material can be modified to account for the constructional stretch and sagging effects in the cables. Pinjointed space truss systems are modelled using a plastic-hinge nonlinear formulation, which implicitly satisfies the design specifications for ultimate strength of axially loaded members. Rigid space frame systems are modelled using an elasto-plastic nonlinear frame analysis program. The effectiveness of providing pretensioned cables in improving the limit state behaviour of pinand rigid-connected space frames is demonstrated through several examples.