Structure made from composite materials for a carriage chassis

The invention relates to a structure made from composite materials for a vehicle chassis, said structure being configured to receive an undercarriage at each of its ends. This structure comprises at least one central beam (31) that comprises a median box (314) having a central part (311) and two ends (312, 313) with a reinforced structure, and the central part in turn comprises a reinforced part increasing the strength of the beam (11) with respect to the bending stresses imposed by the transported load. The median box (314) is reinforced by two lateral boxes (315, 316) extending over the entire length of the median box (314), assembled to said median box, the upper faces of which, together with the upper face of the median box, form the upper face of the beam. The structure also comprises a floor (32) that covers the upper faces of the median box (314) and the side boxes (315, 316). The elements making up the structure have shapes that are advantageously simple, easy to make from composite materials and easy to assemble.