Abaqus Explicit Abaqus Abaqus CAE 

 Hello community:
    I've recently been using the dynamics explicit in abaqus to perform a tensile simulation of a dog bone in metal, trying to match the simulated force-displacement curves to the experimental ones.
    The length of the model is 18mm, and when I simulated it, I found that with or without the addition of a damage model, the material necks (red circle) at a stretch distance of 2.8mm, and then the force starts to drop.
    But when I add a damage model, such as a ductile damage model, the control parameter will only control the necking of the material when it is less than 2.8mm (blue circle or before), and the control of the "fracture strain" and "displacement at failure" will only have an effect at a later time (green circle)
    But in fact, in my experiment, necking occurs at 3.5mm, but I can't move back the point where necking starts at 2.8mm with all the methods I've used. I want to increase the elongation of the material by controlling the onset of necking.Is there any way to do that?:(