Abstract
Planetesimals were supposed to be porous bodies with homogenous internal structure. In their growth process, planetesimals collided each other to grow in their sizes and the thermal evolution of their interiors could cause pressure sintering, melting and gravity differentiation of the constituent materials. As a result, there could be a lot of growing bodies with heterogeneous internal structure such as silicate core-porous silicate mantle and rock mantle-metal core. So, we should consider a collisional phenomenon not only for homogenous bodies but also for layered bodies to study the planetary accretion process. A lot of experimental data (e.g. fragment velocity and largest fragment mass) on impact disruption have been presented by previous studies of homogeneous materials such as basalt and ice. But we do not have any experimental data on the collisional disruption of layered bodies. So, we investigate the collisional strength and fragment velocities of layered targets in order to clarify the difference of reaccumulation condition between homogenous targets and layered targets. In this study, we picked up a porous mantle-silicate core body as a layered body.
