hi! i am looking for a way to fracture the same geometry several times based on collisions inside a shredding machine. it should start off with big rocks that get crunched to smaller and smaller stones each time the machine chews on them. 
 
unfortunately if i start off with many little prefractured pieces only the outer pieces get corroded at first. but i want the pieces to crack properly through the middle!
 
is there any way to prefracture the rocks eg three times and deactivate one fracture per period? or is there even a way to set up truly dynamic fracturing?
 
example file attached.. hope someone can help  
 
rock_rbd_b.hipnc