Results of direct N-body simulations including fragmentation. Only two initial particles are considered, placed on the two arms of the V-shaped distribution so that their apoapsis and periapsis coincide at a_col. The simulations are stopped slightly after the first catastrophic impact between particles initially located on different arms (i.e., blue and red particles). Following the catastrophic collision, the post-impact orbital elements of fragments (a, e) shift to new positions that remain confined to the original constraint curves defined by a_col = a(1 ± e). This behavior is fully consistent with the analytical framework (Section 2; Figure 2). Although secondary collisions among fragments sometimes occur before the simulation is stopped, these fragment–fragment interactions involve significantly smaller relative velocities compared to the initial inter-arm catastrophic collision, and therefore do not substantially modify the a–e evolution. The numerical results demonstrate that, even when fragmentation and secondary impacts are included, the debris evolution remains governed by the same V-shaped dynamical constraint predicted analytically.