Frame for an opening provided in an aircraft fuselage

A door frame provided at an opening made in a fuselage of an aircraft that is delimited by a skin, said door frame comprising:

• an upper longitudinal stiffener and a lower longitudinal stiffener;
• two vertical substructures connected by said upper and lower longitudinal stiffeners, each of said vertical substructures being arranged on a respective opposite side of the opening;
• and
• at least one stop provided at a level of the opening that uptakes radial forces exerted by the door;
• wherein each vertical substructure has a structure made of composite material with a first wall, a second wall that is connected to the first wall, and arranged essentially perpendicular to the first wall, and a third inclined wall that connects the first wall and the second wall in such a way as to obtain a box substructure having a closed and hollow cross-section in a sectional plane perpendicular to a vertical extent of the vertical substructure,
• wherein the first wall forms an edge of the opening, and the second wall is configured to be arranged in the plane of the skin of the fuselage.