Steel4 – A Versatile Uniaxial Material Model for Cyclic Nonlinear Analysis of Steel-Based Elements

Steel4, a new material model for nonlinear dynamic analysis of steel-based anti-seismic solutions has been developed and implemented in the OpenSees environment. The paper highlights the main features of the highly customizable Steel4. It handles nonlinear kinematic and isotropic hardening and their combination; ultimate strength limit can be prescribed to provide more accurate material response at large deformations; it models asymmetric kinematic and isotropic hardening while preserving the Bauschinger effect in the material response; its memory of previous load history allows initial load cycles to influence future behaviour. The material has already been applied to modelling buckling restrained braces and conventional steel braces and showed promising results