A structural panel for use with a gas turbine engine includes a first exterior wall, a second exterior wall, and interior walls. The first exterior wall includes a first exterior surface and a first interior surface parallel to the first exterior surface. The second exterior wall includes a second exterior surface and a second interior surface parallel to the second exterior surface. The interior walls extend from the first interior surface to the second interior surface. The interior walls are arranged to form a pattern of hexagonal cells. The pattern of hexagonal cells includes cell groups having a variation in structural strength such that at least one of the cell groups has a structural strength that is not the same as the remaining cell groups.