阅读说明：本技术 一种低密度条件下高比吸能点阵构型 (High-ratio energy-absorbing lattice structure under low-density condition ) 是由 刘文峰 宋宏伟 黄晨光 于 2021-01-04 设计创作，主要内容包括：本发明提供一种低密度条件下高比吸能点阵构型,包括由上面板和下面板构成的支撑板；点阵芯材,安装在上面板和下面板之间,包括两件结构一致的X形杆件,每件X形杆件包括两根正交连接的斜杆,和分别位于连接点两侧张开端内的支撑杆,斜杆的两端形成与上面板和下面板接触的固定端,两件X形杆件通过两根斜杆的连接点正交卡接。本发明在面外压缩载荷作用下,点阵杆件保持面内变形模式,中心节点处杆件密度逐渐增大,杆件之间的摩擦与挤压作用进一步的提升了点阵结构峰后的承载能力,避免了压缩过程中杆件变形带来的承载能力的快速下降,并能够以较高的平台载荷平稳的吸收冲击带来的动能。(The invention provides a high-specific energy-absorbing dot matrix configuration under a low-density condition, which comprises a support plate consisting of an upper panel and a lower panel; the lattice core material is arranged between the upper panel and the lower panel and comprises two X-shaped rod pieces with the same structure, each X-shaped rod piece comprises two oblique rods which are connected in an orthogonal mode and supporting rods which are respectively positioned in opening ends on two sides of a connecting point, fixed ends which are in contact with the upper panel and the lower panel are formed at two ends of each oblique rod, and the two X-shaped rod pieces are connected in an orthogonal mode through the connecting points of the two oblique rods. Under the action of an out-of-plane compression load, the lattice rod pieces keep an in-plane deformation mode, the density of the rod pieces at the central nodes is gradually increased, the friction and extrusion action between the rod pieces further improves the bearing capacity behind the peak of the lattice structure, the rapid reduction of the bearing capacity caused by the deformation of the rod pieces in the compression process is avoided, and the kinetic energy caused by impact can be stably absorbed by a higher platform load.)

1. A high-specific energy-absorbing lattice configuration under the condition of low density is characterized by comprising,

a support plate including an upper panel and a lower panel;

dot matrix core, install between top panel and lower panel, including two X shape member that the structure is unanimous, every X shape member includes the down tube that two orthogonals are connected, and be located the bracing piece in the tie point both sides open end respectively, the both ends of down tube are passed through arc bending section and are extended to the horizontal direction, form the stiff end with top panel and lower panel contact, and the junction of bracing piece and down tube is located arc bending section department, two X shape members are through the tie point quadrature joint of two down tubes, bracing piece perpendicular to top panel and lower panel.

2. The low density high specific energy absorbing lattice configuration of claim 1,

the supporting rods on the two sides of the X-shaped rod piece are symmetrical in position, and the inclined rod and the supporting rods are of an integrated structure.

3. The low density high specific energy absorbing lattice configuration of claim 1,

the wall thickness of the upper panel and the lower panel is 1/2 of the thickness of the X-shaped rod piece.

4. The low density high specific energy absorbing lattice configuration of claim 1,

the included angle between the fixed end and the supporting rod is an arc included angle.

5. The low density high specific energy absorbing lattice configuration of claim 1,

the length of the fixed section is twice the width of the diagonal rod.

6. The low density high specific energy absorbing lattice configuration of claim 1,

the cross sections of the inclined rod and the supporting rod are square with the same size.

7. The low density high specific energy absorbing lattice configuration of claim 1,

the included angle between the connecting point on the X-shaped rod piece and the supporting rod is a reinforced section parallel to the supporting rod.

8. The low density high specific energy absorbing lattice configuration of claim 1,

a groove with an upward opening is formed in the intersection point of one X-shaped rod piece, a groove with a downward opening is formed in the intersection point of the other X-shaped rod piece, and the two X-shaped rod pieces are connected together after being clamped and connected with each other through the two grooves.

9. The low density high specific energy absorbing lattice configuration of claim 1,

the X-shaped rod piece is fixedly connected with the upper panel and the lower panel in an adhesion mode.

10. The low density high specific energy absorbing lattice configuration of claim 1,

the density of the lattice core plate is 7.8 multiplied by 10^-5g/cm³。

Technical Field

The invention relates to the field of light energy-absorbing structures, in particular to a high-ratio energy-absorbing lattice structure which reduces the weakening phenomenon after a load peak by utilizing the interaction between lattice structure rod pieces in the compression process under the condition of low density.

Background

The light energy-absorbing structure can be applied to various protective structures such as automobiles, protective doors and the like, and the aim of realizing low-density and small-high-ratio energy absorption is always one of the aims sought by the light energy-absorbing structure. For the current high-ratio energy-absorbing lattice structure, for a tension-compression dominant lattice structure, a serious post-peak weakening phenomenon is a main reason which is not beneficial to energy absorption, and a main method for improving the energy absorption efficiency is to obviously reduce the post-peak weakening phenomenon on the premise of properly reducing peak load.

Disclosure of Invention

The invention aims to provide a high-ratio energy-absorbing lattice structure which reduces the weakening phenomenon after a load peak by utilizing the interaction between lattice structure rod pieces in the compression process under the condition of low density.

Specifically, the invention provides a high-specific energy-absorbing lattice configuration under a low-density condition, which comprises,

a support plate including an upper panel and a lower panel;

dot matrix core, install between top panel and lower panel, including two X shape member that the structure is unanimous, every X shape member includes the down tube that two orthogonals are connected, and be located the bracing piece in the tie point both sides open end respectively, the both ends of down tube are passed through arc bending section and are extended to the horizontal direction, form the stiff end with top panel and lower panel contact, and the junction of bracing piece and down tube is located arc bending section department, two X shape members are through the tie point quadrature joint of two down tubes, bracing piece perpendicular to top panel and lower panel.

Compared with the traditional lattice structure, the lattice structure has the advantages that the tensile and compression dominant deformation mode of the traditional lattice structure can be converted into the bending dominant deformation mode through the arc chamfer at the connecting part of the X-shaped rod piece and the upper and lower panels, under the action of an out-of-plane compression load, the lattice core material keeps the in-plane deformation mode, namely, the supporting rod is contacted with the inclined rod after being bent inwards, the density of the rod piece at the central node is gradually increased, the friction and extrusion between the rod pieces further improve the bearing capacity of the lattice structure after the peak, the problem of rapid reduction of the bearing capacity caused by the deformation of the rod piece in the compression process is solved, and the kinetic energy caused by impact can be stably absorbed by higher platform load.

Drawings

FIG. 1 is a schematic illustration of a lattice configuration according to one embodiment of the present invention;

FIG. 2 is a schematic view of the deformation process of one embodiment of the lattice configuration of the present invention under pressure;

FIG. 3 is an out-of-plane compressive experimental stress-strain plot of a lattice configuration of one embodiment of the present invention;

FIG. 4 is a schematic structural view of an X-shaped member according to an embodiment of the present invention.

Detailed Description

The detailed structure and implementation process of the present solution are described in detail below with reference to specific embodiments and the accompanying drawings.

In one embodiment of the present invention, as shown in fig. 1, a high specific energy absorbing lattice configuration at low density is disclosed, and the following description is given by taking one of the lattices as an example, and all lattice structures constituting the entire configuration are identical and independent of each other.

The specific lattice configuration includes a support plate 1 having upper and lower surfaces formed by an upper panel 11 and a lower panel 12, and a lattice core mounted between the upper panel 11 and the lower panel 12.

The support plate 1 is used as the inner surface and the outer surface of the lattice configuration, and can be a plane or an arc, and a plurality of mutually independent lattice core materials are arranged between the inner surface and the outer surface to form an energy absorption layer.

This dot matrix core is installed between top panel 11 and lower panel 12, including two X shape member 2 that the structure is unanimous, every X shape member 2 includes the down tube 21 of two quadrature connections, and be located the bracing piece 22 of tie point both sides open the end respectively, the both ends of down tube 21 extend to the horizontal direction through arc bending section, form the fixed section 23 with top panel 11 and lower panel 12 contact, and the junction of bracing piece 22 and down tube 21 is located arc bending section department, two X shape members 2 are through the tie point quadrature joint of two down tubes 21, form a support dot matrix that separates 90 degrees evenly distributed each other in space, bracing piece 22 perpendicular to top panel 11 and lower panel 12 after the connection.

As shown in fig. 2, the lattice configuration of the present embodiment, when a force is applied, firstly, plastic hinges are generated at the fixing sections 23 at the four ends of the X-shaped rod 2, and then the four support rods 22 are simultaneously bent inward and contacted with the inner sides of the two inclined rods 21 due to the influence of the arc-shaped bending sections, and a phenomenon similar to negative poisson ratio deformation occurs. The more significant the material aggregation at the cell center node with increasing deformation, a similar phenomenon of this lattice configuration occurs only within the lattice cell, unlike the overall shrinkage deformation during compression of negative poisson's ratio material. As can be seen from the compressive stress-strain curve of the bend dominated lattice configuration shown in fig. 3, the stress does not have a significant peak-to-peak weakening after reaching the peak value, and the platform stress remains relatively stable until the structure undergoes densification deformation.

Compare in traditional lattice structure, this embodiment sets up through the circular arc chamfer of X shape member and upper and lower panel junction, can draw traditional lattice structure and press the deformation mode that leads to change into the deformation mode that the bending is leading, under the effect of off-plane compression load, the lattice core keeps the deformation mode in the face, the bracing piece is the contact with the down tube after the incurving promptly, center node member density crescent, friction between the member and the further bearing capacity that has promoted behind the lattice structure peak of squeezing action, the bearing capacity fast decline problem that the member warp and bring in the compression process has been avoided, and can be with the kinetic energy that the steady absorption impact of higher platform load brought.

In one embodiment of the invention, the connecting point on the X-shaped bar member 2 is at an angle relative to the support bar 22 as a reinforcing section 24 parallel to the support bar 22. I.e. the angle between the two diagonal rods 21 is not acute but plane, which allows the diagonal rods 21 to be compressed while increasing the pressure resistance at the connecting point to avoid deformation prior to the support rods 22. In addition, after the reinforcing section 24 is adopted, the area of a connecting point is increased, and more conveniently, a clamping structure for connecting the two X-shaped rod pieces 2 is arranged at the connecting position.

Furthermore, the inclined rod 21 and the support rod 22 on the same X-shaped rod 2 are integrally formed, and the positions of the two support rods 22 are symmetrical. For example, the X-shaped bars 2 may be cut directly from the aluminum alloy sheet.

In order to make the supporting rod 22 deform toward the connecting point when being pressed, the included angle between the fixing section 23 and the supporting rod 22 is set to be an arc included angle, and when the fixing section 23 is pressed, the supporting rod 22 bears a lateral force toward the connecting point direction through the arc included angle in addition to a vertical pressure.

In one embodiment of the present invention, the cross-sectional shapes of the diagonal rods 21 and the support rods 22 are squares with the same diameter, and the structure can maintain the stress uniformity of the whole lattice and avoid local advanced deformation.

In the above embodiment, the radius of the arc-shaped curved section may be 3 times the radius of the arc-shaped included angle between the supporting rod 22 and the fixed section 23, such as: the radius of the arc-shaped bending section 212 is 6mm, and the radius of the arc-shaped included angle is 2 mm.

In order to improve the stress strength of the fixed section 23, the length of the fixed section 23 can be 1.5-2 times of the width of the diagonal rod 21. The length of the reinforcing section 24 at the corner between the two diagonal rods 21 can be 1/4-1/5 of the length of the supporting rod 22.

In the above embodiments, the X-shaped bar 2 is fixedly connected to the upper panel 11 and the lower panel 12 by adhesion.

The X-shaped bar 2 can also be formed by 3D printing, the printing material is PLA +, and the density is 1.24g/cm³The density of the finally formed bending dominant lattice structure is 7.8 multiplied by 10^-5g/cm³。

As shown in fig. 4, in one embodiment of the present invention, a groove 25 with an upward opening may be provided at the intersection of one of the X-shaped bar members 2, and a groove with a downward opening may be provided at the intersection of the other X-shaped bar member 2, and the two X-shaped bar members 2 are connected together after being snapped into each other through the two grooves 25.

Thus, it should be appreciated by those skilled in the art that while a number of exemplary embodiments of the invention have been illustrated and described in detail herein, many other variations or modifications consistent with the principles of the invention may be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Accordingly, the scope of the invention should be understood and interpreted to cover all such other variations or modifications.