Abstract: The invention relates to a motor vehicle underbody structure (1) which comprises a floor (3) delimited on each side by an underbody profiled section (5), there being at least one transverse partition (13) inside at least one of the two profiled sections (7). This partition (13) or at least one of the transverse partitions (13) also has an inner edge (13.1) and an outer edge (13.2), the outer edge (13.2) having a minimum height greater than a minimum height of the inner edge (13.1), so as to generate a bending torque at the floor (3) about a longitudinal direction in the event of a side impact.

Abstract: The invention relates to a motor vehicle chassis (3) comprising lateral side members (4), at least one of which is connected to at least one longitudinal frame element (5) via a crossmember (6), a first end (6a) of which is fixed to one of said lateral side members (4) and a second end (6b) of which is fixed to said longitudinal frame element (5). A part (7) jointly attached to the lateral side member (4) and to the crossmember (6) is provided with a support member (10) which is transversely (T1) interposed on the chassis (3) between a wall (4a) of the side member (4) and an end face (6c) of the first end (6a) of the crossmember (6), against which said support member (10) is antagonistically supported in a transverse manner (T1) under the effect of a lateral impact (C1) applied against the side member (4).

Abstract: The invention relates to a motor vehicle chassis (3), comprising an underbody frame covered by a floor (7) secured to the frame. The frame comprises side rails (4) and at least one longitudinal tube (5) placed at a transverse distance from one such rail (4) to which the tube (5) is connected via a crossmember (6) which is secured by one of the ends (6a) thereof to the tube (5) and by the other end (6b) thereof to the rail (4). The crossmember (6) forms a first member for transmitting to the tube (5) a first thrust force (EP1) generated by an impact applied laterally against the chassis (3). A strut (8) is jointly secured by the respective ends (8a, 8b) thereof to the crossmember (6) and to the tube (5), and is inclined with respect to the main direction in which they extend in a plane parallel to the floor (7). The strut (8) forms a second member for transmitting to the tube (5) a second thrust force (EP2) generated by said impact and transmitted to the strut (8) by the crossmember (6).