In this work , we construct a new model for the collisional evolution of the main asteroid belt .
Our goals are to test the scaling law of and ascertain if it can be used for the whole belt .
We want to find initial size-frequency distributions ( SFDs ) for the considered six parts of the belt ( inner , middle , “ pristine ” , outer , Cybele zone , high-inclination region ) and to verify if the number of synthetic asteroid families created during the simulation matches the number of observed families as well .
We used new observational data from the WISE satellite ( ) to construct the observed SFDs .
We simulate mutual collisions of asteroids with a modified version of the Boulder code ( ) , where the results of hydrodynamic ( SPH ) simulations of and are included .
Because material characteristics can significantly affect breakups , we created two models — for monolithic asteroids and for rubble-piles .
To explain the observed SFDs in the size range D = 1 to 10 km we have to also account for dynamical depletion due to the Yarkovsky effect .
The assumption of ( purely ) rubble-pile asteroids leads to a significantly worse fit to the observed data , so that we can conclude that majority of main-belt asteroids are rather monolithic .
Our work may also serve as a motivation for further SPH simulations of disruptions of smaller targets ( with a parent body size of the order of 1 km ) .