  Rozitis et al. recently reported that near-Earth asteroid (29075) 1950 DA,
whose bulk density ranges from 1.0 g/cm3 to 2.4 g/cm3, is a rubble pile and
requires a cohesive strength of at least 44 Pa to 74 Pa to keep from failing
due to its fast spin period. Since their technique for giving failure
conditions required the averaged stress over the whole volume, it discarded
information about the asteroid's failure mode and internal stress condition.
This paper develops a finite element model and revisits the stress and failure
analysis of 1950 DA. For the modeling, we do not consider material-hardening
and softening. Under the assumption of an associated flow rule and uniform
material distribution, we identify the deformation process of 1950 DA when its
constant cohesion reaches the lowest value that keeps its current shape. The
results show that to avoid structural failure the internal core requires a
cohesive strength of at least 75 Pa - 85 Pa. It suggests that for the failure
mode of this body, the internal core first fails structurally, followed by the
surface region. This implies that if cohesion is constant over the whole
volume, the equatorial ridge of 1950 DA results from a material flow going
outward along the equatorial plane in the internal core, but not from a
landslide as has been hypothesized. This has additional implications for the
likely density of the interior of the body.
