Diurnal temperature variation as the source of the preferential direction of fractures on asteroids: Theoretical model for the case of Bennu

It has been shown that temperature cycles on airless bodies of our Solar System can cause damaging surface materials. Nevertheless, propagation mechanisms in the case space objects are still poorly understood. Present work combines a thermoelasticity model together with linear elastic fracture mechanics theory to predict presence thermal gradients generated by diurnal cycling and under conditions similar those existing asteroid Bennu. The crack direction is computed using maximal strain energy release rate criterion, which implemented finite elements so-called G? method (Uribe-Suárez et al. 2020. Eng. Fracture Mech. 227:106918). Using methodology, for an initial tip different positions orientations computed. found cracks preferentially propagate North South (N-S), North-East South-West (NE-SW) North-West South-East (NW-SE) directions. Finally, fatigue analysis was performed order estimate growth rate. Computed value good agreement available experimental evidence.