CN-122009363-A - Vehicle body spliced composite material frame based on skin-frame structure and reinforcing method

CN122009363ACN 122009363 ACN122009363 ACN 122009363ACN-122009363-A

Abstract

The invention provides a vehicle body spliced composite frame based on a skin-frame structure and a reinforcing method, and belongs to the technical field of composite structure design. The method comprises the steps of determining a load working condition of a vehicle body bearing frame, defining a main circumferential frame structure and a stiffening plate size parameter, carrying out statics analysis on the vehicle body bearing frame under the load working condition to obtain stress distribution under each working condition, carrying out safety constraint on a non-designed area according to the stress distribution, carrying out iterative solution with the minimum of a special working condition cost function as a target, determining the main circumferential frame based on a solving result, wherein the main circumferential frame comprises a composite bearing section formed by adopting a composite beam with a double C-shaped section and a square-shaped section which are coupled and connected through rivet bonding, and additionally arranging a corner piece stiffening layer in a high-stress area, determining an auxiliary frame based on the stress distribution, wherein the auxiliary frame comprises an orthogonal stiffening structure constructed by adopting a rectangular section rib interlocking process, and an auxiliary frame skin comprises an inner skin and an outer skin, wherein the inner skin and the ribs are bound, and the outer skin covers a splicing seam.

Inventors

ZHAO JIAN
WANG YANFU
LIU PENGBO
ZENG YAN
ZHAO GANG
GONG JUE

Assignees

大连理工大学

Dates

Publication Date: 20260512
Application Date: 20260312

Claims (9)

1. The utility model provides a car body spliced composite material frame based on covering-frame structure and reinforcement method which is characterized in that the method comprises the following steps: Determining the load working condition of a vehicle body bearing frame, and defining the size parameters of a main annular frame structure and a stiffening plate; Carrying out statics analysis on the vehicle body bearing frame under the load working condition to obtain stress distribution under each working condition; According to the stress distribution, presetting suspension mounting points, battery pack mounting points and longitudinal beam connecting points as non-design domains for safety constraint, and carrying out iterative solution with minimum cost function of special working conditions as a target; Determining a main circumferential frame based on the solving result, wherein the main circumferential frame comprises a composite bearing section formed by adopting a rivet bonding coupled and connected double C-shaped section and a square section composite material beam, and an angle sheet reinforcing layer is additionally arranged in a high stress area; determining an auxiliary frame based on the stress distribution, wherein the auxiliary frame comprises an orthogonal reinforcement structure constructed by adopting a rectangular section rib interlocking process; The auxiliary frame skin comprises an inner skin and an outer skin, wherein the inner skin is bound with the ribs, and the outer skin covers the splice seam.
2. The method of claim 1, wherein the security constraint comprises: the rigidity of the non-design domain is more than or equal to 8 multiplied by 106N/m, and the geometric tolerance is less than or equal to +/-0.5 mm.
3. The method of claim 1, wherein the load condition comprises: the load working conditions comprise a total load working condition and a local load working condition; the total load includes longitudinal stretching, transverse stretching, longitudinal compression, transverse compression, longitudinal bending, transverse bending, in-plane shearing, out-of-plane compressive load; The total load working condition is one or a combination of a plurality of total loads; the local load comprises equipment installation load, actuator cylinder load and hanging point load which are installed on one or a plurality of ribs; The local load condition is a single combination of the local loads.
4. The method of claim 1, wherein the special operating mode cost function comprises: Wherein, the The index is the index of the special working condition, and N is the total number of the special working conditions; M is a quality penalty term; The special working conditions comprise a frontal collision working condition, a side-tipping working condition and a ground impact working condition.
5. The method of claim 1, wherein the rivet bonding coupling has a glue line thickness of 0.2-0.3mm and a rivet spacing of 50mm or less.
6. The method of claim 1, wherein the rectangular cross-section ribs have an aspect ratio of 1.5:1-2:1 and a grooving depth of 30-40% of the rib height.
7. The method according to claim 1, characterized in that: the thickness of the inner layer skin is 1.0-1.5mm, and the inner layer skin is formed by compression molding of two-dimensional carbon fiber woven cloth; the inner skin is connected with the ribs through a cementing co-curing process.
8. The method according to claim 1, characterized in that: the thickness of the outer skin is 2.0-2.5mm, and the outer skin covers the surface of the splicing seam of the vehicle body; and the outer skin is covered on the splicing seam by adopting a hot press molding process.
9. A method according to claim 1, wherein triangular composite corner piece reinforcements are provided in the load concentrating area, the thickness being 120-150% of the thickness of the circumferential frame.

Description

Vehicle body spliced composite material frame based on skin-frame structure and reinforcing method Technical Field The invention relates to the technical field of composite material structure design, in particular to a car body spliced composite material frame based on a skin-frame structure and a reinforcing method. Background Along with the development of light weight of automobiles, carbon fiber composite materials are increasingly widely applied to automobile body frames, however, the problems of insufficient structural rigidity, easy failure of nodes and the like exist when large automobile body sections are spliced, and the prior art has obvious limitations. In the prior art, patent CN114357826a discloses a method for designing a layer of a composite material integral longitudinal and transverse reinforcement frame, and proposes a method for designing a layer of a composite material integral longitudinal and transverse reinforcement frame, but there is a contradiction between fiber continuity and process feasibility. Patent CN118761279A discloses a modeling method of a composite material ship body hat-shaped reinforced laminated plate acoustic vibration prediction model, solves the problem that modeling of a complex structure of a hat-shaped reinforced laminated plate in a ship body structure is difficult to effectively solve, and does not consider the balance problem of local reinforcement and overall light weight. Patent CN210553131U discloses a composite material longitudinal or transverse reinforced wall plate integral curing forming die, and does not consider the ply design problem of cross reinforced. Therefore, there is a need for a method of splicing and reinforcing composite frames that can achieve a combination of structural rigidity, connection reliability, and weight reduction requirements. Disclosure of Invention In view of the above, the invention provides a body spliced composite material frame based on a skin-frame structure and a reinforcing method, wherein the rigidity, the cost and the service life are cooperatively optimized through a composite section rivet bonding coupling frame, a rectangular rib interlocking process and a double-layer skin stress distribution system. For this purpose, the invention provides the following technical scheme: a car body spliced composite material frame based on a skin-frame structure and a reinforcing method thereof comprise the following steps: Determining the load working condition of a vehicle body bearing frame, and defining the size parameters of a main annular frame structure and a stiffening plate; Carrying out statics analysis on the vehicle body bearing frame under the load working condition to obtain stress distribution under each working condition; According to the stress distribution, presetting suspension mounting points, battery pack mounting points and longitudinal beam connecting points as non-design domains for safety constraint, and carrying out iterative solution with minimum cost function of special working conditions as a target; Determining a main circumferential frame based on the solving result, wherein the main circumferential frame comprises a composite bearing section formed by adopting a rivet bonding coupled and connected double C-shaped section and a square section composite material beam, and an angle sheet reinforcing layer is additionally arranged in a high stress area; determining an auxiliary frame based on the stress distribution, wherein the auxiliary frame comprises an orthogonal reinforcement structure constructed by adopting a rectangular section rib interlocking process; The auxiliary frame skin comprises an inner skin and an outer skin, wherein the inner skin is bound with the ribs, and the outer skin covers the splice seam. Further, the security constraint comprises: the rigidity of the non-design domain is more than or equal to 8 multiplied by 106N/m, and the geometric tolerance is less than or equal to +/-0.5 mm. Further, the load condition includes: the load working conditions comprise a total load working condition and a local load working condition; the total load includes longitudinal stretching, transverse stretching, longitudinal compression, transverse compression, longitudinal bending, transverse bending, in-plane shearing, out-of-plane compressive load; The total load working condition is one or a combination of a plurality of total loads; the local load comprises equipment installation load, actuator cylinder load and hanging point load which are installed on one or a plurality of ribs; The local load condition is a single combination of the local loads. Further, the special condition cost function includes: Wherein, the The index is the index of the special working condition, and N is the total number of the special working conditions; M is a quality penalty term; The special working conditions comprise a frontal collision working condition, a side-tipping working condition and a ground impa