The employment of shape memory alloys (SMA) in a large number of applications in the fields of aeronautical, biomedical and structural engineering constitutes the basis for an increasing interest of researchers in the direction of an exhaustive modeling of their macroscopic behaviour. However, many SMA models present in the literature consider a perfect pseudo-elastic behaviour (i.e. no residual strains), which is proved by experiments to be only an approximation. This work takes its basis from the one-dimensional version of a model proposed by Auricchio et al. [
] which is able to describe main SMA macroscopic effects as pseudo-elasticity and shape-memory effect as well as to include permanent inelasticity and degradation effects. Such a model is here improved with the introduction of an elastic modulus which depends on the reached transformation strain level. Finally, some numerical tests are presented in order to show the good performance of the obtained model.