In a bumper system, one end portion of a first tube is inserted into first beam holes, and the other end portion of the first tube is inserted into a first plate hole, one end portion of a second tube is inserted into second beam holes, and the other end portion of the second tube is inserted into a second plate hole. The bumper stay is joined to a bumper beam and a vehicle body plate by press-fitting in a state in which the first tube is expanded at the holes and the second tube is expanded at the holes. A first connection rib is in contact with the bumper beam, and a second connection rib is in contact with the vehicle body plate in the same direction as a direction in which the first connection rib is in contact with the bumper beam.

A bumper beam of a vehicle body structure (1) is provided with a laterally extending laterally middle part (55) and a pair of end parts (56) each extending from a corresponding lateral end of the middle part in an outboard direction with a certain inward slant with respect to a fore and aft direction, and each end part curves at a laterally middle point thereof so as to have a concave side facing outward with respect to the fore and aft direction.

A composite tie bar assembly for distributing loads to a support frame of an automotive vehicle. The tie bar assembly includes a pair of spaced apart. reinforcement bars extending longitudinally between opposing ends. A tie bar shell is supported by the reinforcement bars and extends between opposite first and second distal cods. The tie bar shell has a first support plate extending between the reinforcement bars adjacent the first distal end and a second support plate extending between the reinforcement bars adjacent the second distal end. Bach of the support plates includes a plurality of structural ribs formed Integral therewith for distributing loads from the reinforcement bars to the support frame of the vehicle.

A method for joining members according to an embodiment of the present invention includes: providing a bumper stay including two integrated pipe portions extending in an identical direction, the bumper stay including a recess provided between the pipe portions being adjacent to each other, the recess extending in a longitudinal direction of the pipe portions from end surfaces of the pipe portions, a part of the recess serving as a locking portion, and a bumper beam including a rear inclined wall formed with two hole portions into which the pipe portions of the bumper stay are insertable respectively; inserting the bumper stay into the hole portions of the bumper beam until the locking portion abuts on the rear inclined wall; and pipe-expanding an insertion portion of the bumper stay into the bumper beam to join the insertion portion to the bumper beam by press-fitting.

A bumper cross member designed as a hollow chamber profile for a motor vehicle having an upper component and a lower component joined to the upper component. Both components are each designed as a half shell having two legs spaced apart from one another and a web connecting the legs. An insert plate is joined to the legs of the half shells. The insert plate is arranged between the joints of the legs of the half shells facing toward one another and bridges the joint spacing between the legs of the two half shells.

A method of determining proof stress includes: calculating a needed load needed to completely crush a deformable impact absorption body of a barrier in a range that comes into contact with a rear bumper reinforcement, based on a load needed to completely crush the entire front surface of the impact absorption body, an area of the entire front surface of the impact absorption body, and an area of the front surface of the impact absorption body, which comes into contact with the rear bumper reinforcement; calculating a maximum bending moment acting on the rear bumper reinforcement in a case where the needed load is input; and determining proof stress of a pair of side members to be equal to or greater than the needed load and determining proof stress of the rear bumper reinforcement to be equal to or greater than the maximum bending moment.

A bumper reinforcement includes a bumper reinforcement body, a first extension portion, a second extension portion, and a weakened portion. The bumper reinforcement body is molded from a synthetic resin material, a length of the bumper reinforcement body extends in a vehicle width direction. The first extension portion is integrally molded with the bumper reinforcement body so as to extend from the bumper reinforcement body toward a vehicle rear side and oppose a vehicle structural member extending in the vehicle width direction from a vehicle front side. The first extension portion is provided within a range spanning from a vehicle width direction side end portion to a position at 40% of an overall vehicle width direction length of a vehicle front end section away from the vehicle width direction side end portion. The second extension portion is integrally molded with the bumper reinforcement body.

A beam assembly includes a first beam that has a first tubular portion and a first projecting portion that extends from the first tubular portion. A second beam has a second tubular portion and a second projecting portion that extends from the second tubular portion. The elongated interior of the first tubular portion defines a first hollow area and the elongated interior of the second tubular portion defines a second hollow area. The first beam is attached to the second beam with the first projecting portion attached to the second tubular portion and the second projecting portion attached to the first tubular portion to define a third hollow area between the first and second projecting portions.

An automobile structural member has a first wall part, a second wall part that faces the first wall part, and a third wall part that connects the first wall part and the second wall part. At least one of the first wall part and the second wall part has a main wall part in which two through-holes are formed, and at least two auxiliary wall parts that are provided so as to rise from the main wall part. Each auxiliary wall part is provided so as to rise in the thickness direction of the main wall part from an edge of a through-hole. The distance between two auxiliary wall parts in the longitudinal direction of the main wall part is 1.4 times or less the width of the main wall part at a portion between the two auxiliary wall parts.

A closed cross-sectional structure member includes a hollow member, the hollow member having a collision side wall part located on a collision side, an opposed collision side wall part opposing the collision side wall part, a pair of first side wall part and second side wall part connecting with end portions of the collision side wall part and end portions of the opposed collision side wall part, a first inner wall part extending from the first side wall part to an inside of the hollow member, a second inner wall part extending from the second side wall part to the inside of the hollow member, a third inner wall part connecting with the first inner wall part and the collision side wall part, and a fourth inner wall part connecting with the second inner wall part and the collision side wall part.