New modifying truss model and numerical simulation of steel fiber reinforced concrete under pure torsion

This paper presents a new strut-and-tie model on steel fiber reinforced concrete (SFRC) members under uniform (Saint Venant) torsion. This truss model is intended to reproduce the structural behavior in ultimate limit state, once concrete is cracked. The proposed model is based on previous formulations developed by other researchers; the main novelty is the use of average value linear interpolation methods. The developed model can be considered for constant section members; can be applied to rectangular, T, L, circular, thin-walled, and single-cell and multi-cell hollow sections, among other shapes. Comparison with experimental and numerical results (developed through accurate finite element analysis) shows that the proposed model is more accurate than the proposed formulations.