Hi,

I want to simulate Laser Shock Peening Process in Abaqus. I want to apply a pressure of 6Gpa on a 4mm thick and 25mm square plate. I have partitioned the sutface into six 1mm squares and want to apply the load one after another. The pressure is not a constant one, it has to be applied with a frequency of 10^9 Hz for that I have attached periodic amplitude function with the load.

Now for the six different loads were defined in six different "steps" with a step time of 1 milli second as I want the load to be applied for 1 ms and then move to another square surface(as partitioned).

After running the program the animation which I got is resembling to the LSP process. But since I want the residual Stress induced I added one more "step" with step time 1 ms only without any load in this step.

Now when I see the result(Stress vs time curve) for an element, I can see that after fully unloading also Stress variation is taking place. In the seventh step no load is there but still stress variation can be seen. I was expecting it to be constant and that constant stress may be the residual stress but its not happening.

Anyone with a solution?