I am trying to modify a material in order to model its work hardening.
First, I will have to make a bilinear work hardening curve and then I will do the same to have a work hardening curve as close as possible to reality (using a "stress as a function of deformation" table).
You can create a new material like this: http://help.solidworks.com/2015/french/solidworks/cworks/t_custom_material_creating.htm
Then we can create deformation curves as shown here: http://help.solidworks.com/2015/french/SolidWorks/sldworks/HIDD_DLG_MATEDITTAB_TABLESCURVES.htm?id=55efda1884b941a7bd67da72be822bec#Pg0