Introduction of the strain rate and cyclic loading effects on shape memory alloys constitutive law models

The superelasticity of shape memory alloys is a characteristic that permits to this smart material to dissipate significant energy during dynamic loads in addition to having the capacity to be used for seismic attenuation. Experimental studies have shown the strain rate and the cyclic loading caused by an earthquake influence on the residual strain and transformation stress of shape memory alloys. For this reason, this work consists of introducing the influence of the two latter parameters on constitutive laws of the most used shape memory alloy in the civil engineering field. A numerical model is then proposed and validated, and it represents residual strain–cyclic load and transformation stress–cyclic load relationships. A comparison between the original model, the built model and the experimental results is presented to show the consequence of taking into account the strain rate and cyclic loading effects. Finally, a parametric study is carried out to show cycles to be experimentally determined to get significant numerical results.