Abstract: An automotive body design method causing a computer to execute each of following steps for designing an automotive body in which a resin material is patched or coated to surfaces of automotive parts constituting a body-in-white structure of the automotive body and vibration-damping properties of a vibration noise reduction target part, which is a reduction target of vibration noise in the body-in-white structure, are improved, the automotive body design method includes: an optimization analysis model generation step of generating an optimization analysis model of performing optimization analysis on an optimized shape of the resin material to be patched or coated to all or some of the automotive parts in the body-in-white structure; and a resin material optimization analysis step of performing the optimization analysis using the generated optimization analysis model.

Abstract: An automotive body design method designs an automotive body in which vibration-damping properties of a body-in-white structure of the automotive body is improved by bonding and joining a sheet-like part to a surface of an automotive part configuring the body-in-white structure. The automotive body design method is executed by a computer and includes: an automotive part selection step of performing sensitivity analysis of the automotive part with respect to vibration characteristics used for evaluation of the vibration-damping properties of the body-in-white structure, and selecting an automotive part to bond and join the sheet-like part; and a sheet-like part optimization analysis step of performing optimization analysis on a shape of the sheet-like part to be bonded and joined to the automotive part selected.

Abstract: An internal structure of a side sill includes: an outer member; an inner member; a closed cross-sectional structure formed by joining the outer member and the inner member; a connecting member connecting the outer member and the inner member; and a collision energy-absorbing member configured to absorb collision energy while transmitting a crashworthiness load input to the outer member to the inner member side. The collision energy-absorbing member includes: a pair of first collision energy-absorbing members configured to form a linear load transfer path inclined with respect to a horizontal plane of the automotive body to transmit the crashworthiness load input to the outer member toward a corner portion of the inner member; and a second collision energy-absorbing member disposed in the first collision energy-absorbing member and configured to connect the inner member and the connecting member or the end portion, and absorb the collision energy.

Abstract: A press forming tool is configured to form a press forming part including: a top portion; a side wall portion having a recessed portion in which a bottom edge is recessed toward the top portion; and a flange portion formed outward on a bottom edge of the side wall portion, the recessed portion including a first curved portion continuous with the bottom edge being a portion having a large wall depth, an inclined side portion continuous with the first curved portion, a second curved portion continuous with the inclined side portion, and a recessed side portion having a small wall depth, arranged in order from the bottom edge being a portion having a large wall depth, the flange portion being formed such that the flange portion formed in the first curved portion becomes a shrink flange while the flange portion formed in the second curved portion becomes a stretch flange.

Abstract: A press forming tool is configured to form a press forming part including: a top portion having a convex and concave outer edge part; and a flange portion. The press forming tool includes: an upper die and a lower die; and a lower pad and an upper pad, which sandwich a blank in cooperation with the upper die and the lower die, in which, during an initial stage of forming, the flange portion is formed on the convex outer edge part, and a torsional shape portion having a torsional shape toward the concave outer edge part is formed continuously from the flange portion, and during a late stage of forming, the torsional shape portion is formed into the flange portion, and the flange portion is formed in the concave outer edge part so as to achieve formation of a target shape.

Abstract: A press forming method forms a press forming part including: a top portion having a convex and concave outer edge part where a convex outer edge part protruding outward in an in-plane direction and a concave outer edge part recessed inward in the in-plane direction are continuous to each other via a connecting outer edge part; and a flange portion continuously formed on the convex and concave outer edge part, and includes: forming a preformed part including a flange portion formed in the convex outer edge part and including a torsional shape portion having a torsional shape toward the concave outer edge part so as to be formed in the connecting outer edge part continuous from the flange portion; and forming the preformed part into a target shape by forming the torsional shape portion into the flange portion and forming the flange portion in the concave outer edge part.

Abstract: A press forming method for forming a press forming part includes: a first forming step of forming a preformed part, the preformed part including a side wall portion, a flange portion formed in a bottom edge being a portion having a large wall depth and a torsional shape portion formed in an inclined side portion continuous from the flange portion to reach a second curved portion; and a second forming step of further processing the preformed part formed in the first forming step, including processes of forming the torsional shape portion into the flange portion and forming the flange portion in the second curved portion continuous from the inclined side portion and in a recessed side portion having a small wall depth so as to achieve formation of a target shape.

Abstract: A method of predicting a tension-compression reverse loading behavior predicted by determining a model constant of a material model expressing the tension-compression reverse loading behavior of a metal sheet includes acquiring a value of the model constant of a prediction metal sheet by inputting metal materials test data, including a factor related to a uniaxial tension behavior, of the prediction metal sheet to a learned model that has been caused to perform machine learning using, as an input variable, metal materials test data of a learning metal sheet and using, as an output variable, a value of the model constant, which has been determined based on a tension-compression test of the learning metal sheet. The factor related to a uniaxial tension behavior includes point sequence data obtained by discretizing a stress-strain curve of uniaxial tensile test obtained from a uniaxial tensile test.

Abstract: A press forming tool is configured to form a press forming part including: a top portion; a side wall portion having a recessed portion in which a bottom edge is recessed toward the top portion; and a flange portion formed outward on a bottom edge of the side wall portion, the recessed portion including a first curved portion continuous with the bottom edge being a portion having a large wall depth, an inclined side portion continuous with the first curved portion, a second curved portion continuous with the inclined side portion, and a recessed side portion having a small wall depth, arranged in order from the bottom edge being a portion having a large wall depth, the flange portion being formed such that the flange portion formed in the first curved portion becomes a shrink flange while the flange portion formed in the second curved portion becomes a stretch flange.

Abstract: A press forming method for forming a press forming part includes: a first forming step of forming a preformed part, the preformed part including a side wall portion, a flange portion formed in a bottom edge being a portion having a large wall depth and a torsional shape portion formed in an inclined side portion continuous from the flange portion to reach a second curved portion; and a second forming step of further processing the preformed part formed in the first forming step, including processes of forming the torsional shape portion into the flange portion and forming the flange portion in the second curved portion continuous from the inclined side portion and in a recessed side portion having a small wall depth so as to achieve formation of a target shape.

Abstract: A press forming tool is configured to form a press forming part including: a top portion having a convex and concave outer edge part; and a flange portion. The press forming tool includes: an upper die and a lower die; and a lower pad and an upper pad, which sandwich a blank in cooperation with the upper die and the lower die, in which, during an initial stage of forming, the flange portion is formed on the convex outer edge part, and a torsional shape portion having a torsional shape toward the concave outer edge part is formed continuously from the flange portion, and during a late stage of forming, the torsional shape portion is formed into the flange portion, and the flange portion is formed in the concave outer edge part so as to achieve formation of a target shape.

Abstract: A press forming method forms a press forming part including: a top portion having a convex and concave outer edge part where a convex outer edge part protruding outward in an in-plane direction and a concave outer edge part recessed inward in the in-plane direction are continuous to each other via a connecting outer edge part; and a flange portion continuously formed on the convex and concave outer edge part, and includes: forming a preformed part including a flange portion formed in the convex outer edge part and including a torsional shape portion having a torsional shape toward the concave outer edge part so as to be formed in the connecting outer edge part continuous from the flange portion; and forming the preformed part into a target shape by forming the torsional shape portion into the flange portion and forming the flange portion in the concave outer edge part.

Abstract: Provided is a sheet material press forming method of press forming a formed part including a top portion with a protrusion having a blockage protrusive shape, the method including: preforming a high-strength steel sheet; and then forming it into a target shape without fractures or wrinkles, which is achieved by determining a shape in the preforming by press forming analysis according to the following steps: S1: the region of the protrusion having the target shape is discretized into two-dimensional elements and nodes for finite element analysis; and S2: the discretized portion are applied with internal stress in the normal directions of the two-dimensional elements from the inside of the discretized portion and deformed under the following conditions: (a) the two-dimensional elements are deformed within an elastic deformation range; and (b) adjacent ones of the two-dimensional elements have an angle therebetween which is free to change.

Abstract: Provided is a sheet material press forming method of press forming a formed part including a top portion with a protrusion having a blockage protrusive shape, the method including: preforming a high-strength steel sheet; and then forming it into a target shape without fractures or wrinkles, which is achieved by determining a shape in the preforming by press forming analysis according to the following steps: S1: the region of the protrusion having the target shape is discretized into two-dimensional elements and nodes for finite element analysis; and S2: the discretized portion are applied with internal stress in the normal directions of the two-dimensional elements from the inside of the discretized portion and deformed under the following conditions: (a) the two-dimensional elements are deformed within an elastic deformation range; and (b) adjacent ones of the two-dimensional elements have an angle therebetween which is free to change.

Abstract: A press forming method for forming a press-formed product having no flange portion from a blank by performing a crash forming process while using a die and a punch, the press-formed product including at least a top portion and a side wall portion continued from the top portion via a connecting portion and being structured so that either all or a part of the side wall portion curves toward an outside of the press-formed product to form a convex shape in a planar view, the press forming method including forming the side wall portion while keeping a tip end portion of the blank in continuous contact with a side wall forming portion of the die and causing the die to impose no restraint on any part other than the tip end portion of the blank.

Abstract: A press forming method for forming a press-formed product having no flange portion from a blank by performing a crash forming process while using a die and a punch, the press-formed product including at least a top portion and a side wall portion continued from the top portion via a connecting portion and being structured so that either all or a part of the side wall portion curves toward an outside of the press-formed product to form a convex shape in a planar view, the press forming method including forming the side wall portion while keeping a tip end portion of the blank in continuous contact with a side wall forming portion of the die and causing the die to impose no restraint on any part other than the tip end portion of the blank.