JP7229616B1 - Structure - Google Patents

Abstract

Kind Code: A1 A structure is provided that causes out-of-plane deformation in response to tensile deformation or compressive deformation in a predetermined direction.
A plate-like structure having a first surface and a second surface opposite to the first surface, the first surface is tensile-deformed and deformed in a first direction of the extending direction of the structure. The second surface portion is formed to have a positive Poisson's ratio when compressively deformed, and the second surface portion is formed to have a negative Poisson's ratio when tensilely and compressively deformed in the first direction. Then, the structural body is subjected to tensile deformation in the first direction, whereby the end portion in the second direction orthogonal to the first direction among the extension directions is bent toward the first surface portion side with respect to the central portion, and the Along with the compressive deformation in one direction, the end portions in the second direction are bent toward the second surface portion with respect to the central portion.
[Selection drawing] Fig. 1

Description

The present disclosure relates to structures.

Conventionally, a planar structure having a shape in which a plurality of hexagonal unit units are connected has been proposed (see Patent Document 1). In Patent Document 1, examples of the unit include a first shape unit having a positive Poisson's ratio (honeycomb structure) and a second shape unit having a negative Poisson's ratio (reentrant honeycomb structure) when subjected to tensile deformation in the principal axis direction. . The planar structure of the first shape unit is deformed into a three-dimensional structure into a hyperbolic curved surface (saddle-shaped curved surface: Gaussian curvature <0) when a bending force rotating around the principal axis acts. The planar structure of the second shape unit deforms into a three-dimensional structure of an elliptical curved surface (dome-shaped curved surface: Gaussian curvature > 0) when a bending force rotating around the principal axis acts.

Patent No. 6817631

A planar structure (structure) formed by the first shape unit or the second shape unit described above is deformed into a three-dimensional structure by in-plane deformation accompanying the action of a bending force rotating around the main axis. In order to improve the technology, it is also required to devise a structure that causes out-of-plane deformation due to tensile deformation and compressive deformation in the principal axis direction.

A main object of the present disclosure is to provide a structure that causes out-of-plane deformation in response to tensile deformation or compressive deformation in a predetermined direction.

The structure of the present disclosure has taken the following measures to achieve the above main objectives.

The structure of the present disclosure is
A plate-shaped structure comprising a first surface portion and a second surface portion opposite to the first surface portion,
The first surface portion is formed to have a positive Poisson's ratio when tensilely deformed and compressively deformed in a first direction among the extending directions of the structure,
The second surface portion is formed to have a negative Poisson's ratio when subjected to tensile deformation and compression deformation in the first direction,
The structure is
Along with the tensile deformation in the first direction, an end portion in a second direction orthogonal to the first direction among the extending directions is bent toward the first surface portion with respect to the central portion,
Along with the compressive deformation in the first direction, the end portion in the second direction is bent toward the second surface portion with respect to the central portion.
This is the gist of it.

In the structure of the present disclosure, the first surface portion is formed such that the Poisson's ratio is positive when tensile deformation and compression deformation are performed in the first direction of the extending direction of the structure, and the second surface portion is: It is formed such that the Poisson's ratio is negative when tensile deformation and compression deformation are performed in the first direction. As a result, the structural body undergoes compressive deformation in the second direction and extensional deformation in the second direction along with the tensile deformation in the first direction. Bending deformation (out-of-plane deformation) occurs toward the first surface portion with respect to the central portion. Further, in the structure, the first surface portion is compressed and deformed in the second direction and the second surface portion is elongated and deformed in the second direction along with the compressive deformation in the first direction, so that the end portion in the second direction is centered. bending deformation (out-of-plane deformation) toward the second surface portion side with respect to the portion. That is, it is possible to provide a structure in which out-of-plane deformation occurs with respect to tensile deformation or compressive deformation in the first direction.

FIG. 3 is a perspective view of the structure 10 viewed from the upper right. It is the perspective view which looked at the structure 10 from the lower left. 4 is a top view showing an upper surface portion 20 of the structure 10; FIG. 3 is a bottom view showing a bottom surface portion 30 of the structure 10; FIG. FIG. 5 is an explanatory diagram showing a state when the structure 10 is pulled and deformed in the front-rear direction; FIG. 5 is an explanatory diagram showing a state when the structure 10 is compressed and deformed in the front-rear direction; FIG. 3 is a perspective view of the structure 110 viewed from the upper right. FIG. 3 is a perspective view of the structure 110 as seen from the lower left. 4 is a top view showing an upper surface portion 120 of the structure 110; FIG. 4 is a bottom view showing a bottom surface portion 130 of the structure 110; FIG. FIG. 3 is a perspective view of the structure 210 viewed from the upper right. FIG. 3 is a perspective view of the structure 210 as seen from the lower left. 3 is a top view showing an upper surface portion 220 of the structure 210; FIG. 3 is a bottom view showing a bottom surface portion 230 of the structure 210; FIG. 3 is a perspective view of the structure 310 viewed from the upper right. FIG. 3 is a perspective view of the structure 310 as seen from the lower left. FIG. 4 is a top view showing the top surface portion 320 of the structure 310. FIG. 4 is a bottom view showing a bottom surface portion 330 of the structure 310; FIG. 4 is a perspective view of the structure 410 viewed from the upper right. FIG. 4 is a top view of the structure 410 viewed from above; FIG. 4 is a bottom view of the structure 410 viewed from below; FIG.

Embodiments of the present disclosure will be described with reference to the drawings. 1 is a perspective view of the structure 10 of the present embodiment as seen from the upper right, FIG. 2 is a perspective view of the structure 10 as seen from the lower left, and FIG. 20 is a top view, and FIG. 4 is a bottom view showing a bottom surface portion 30 of the structure 10. FIG. The front-back direction (first direction), left-right direction (second direction), and up-down direction of the structure 10 are as shown in FIGS.

The structure 10 is an integrally molded product, for example, integrally molded by injection molding, blow molding, extrusion molding, or 3D printing of a resin material or rubber material, or by casting, forging, pressing, cutting, extrusion molding, or molding of a metal material. It is integrally molded by 3D printing or the like. As shown in FIGS. 1 to 4, the structural body 10 is formed in a net-like and plate-like shape as a whole.

As shown in FIGS. 1 to 4, the upper surface portion (first surface portion) 20 of the structural body 10 is formed in a honeycomb structure as a whole, and the lower surface portion (second surface portion) 30 is formed in a reentrant honeycomb structure as a whole. is formed in The upper surface portion 20 and the lower surface portion 30 are connected by a connecting portion 40 .

As shown in FIGS. 1 and 3, the upper surface portion 20 is specifically formed in a shape in which a plurality of hexagonal unit units 21 are connected. The unitary unit 21 has six sides 22a-22f and six vertices 23a-23f. The sides 22a and 22d extend in the front-rear direction on the right side and the left side, respectively, with a gap in the left-right direction. One ends of the sides 22b and 22c are connected to the front ends of the sides 22a and 22d respectively to form vertices 23a and 23c, and the other ends of the sides 22b and 22c extend in the horizontal direction through the vertices 23a and 23c. They are connected to each other on the front side of a straight line (not shown) to form a vertex 23b. One ends of the sides 22e and 22f are connected to the rear ends of the sides 22d and 22a to form vertices 23d and 23f, and the other ends of the sides 22e and 22f extend in the horizontal direction through the vertices 23d and 23f. They are connected to each other behind an existing straight line (not shown) to form a vertex 23e. Therefore, the interior angles of the vertices 23a to 23f are all minor angles. The lengths of the sides 22a and 22d are the same, the lengths of the sides 22b, 22c, 22e and 22f are the same, and the interior angles of the vertices 23a, 23c, 23d and 23f are the same. are formed identically. As a result, the unit 21 is formed symmetrically with respect to a straight line 24 extending in the front-rear direction through the vertices 23b and 23e. Note that the sides 22a, 22b, 22c, 22d, 22e, and 22f of a certain unit unit 21 are the sides 22d, 22e, and 22f of different unit units 21, respectively, except when they are the front, rear, left, and right ends of the upper surface portion 20. , 22a, 22b, and 22c.

As shown in FIGS. 2 and 4, the lower surface portion 30 is specifically formed in a shape in which a plurality of hexagonal unit units 31 are connected. The unitary unit 31 has six sides 32a-32f and six vertices 33a-33f. The sides 32a and 32d extend in the front-rear direction on the right side and the left side with a space therebetween in the left-right direction. One end of each side 32b, 32c is connected to the front end of each side 32a, 32d to form vertices 33a, 33c, and the other ends of sides 32b, 32c extend in the horizontal direction through the vertices 33a, 33c. They are connected to each other behind a straight line (not shown) to form a vertex 33b. One ends of the sides 32e and 32f are connected to rear ends of the sides 32d and 32a to form vertices 33d and 33f, and the other ends of the sides 32e and 32f extend in the horizontal direction through the vertices 33d and 33f. They are connected to each other on the front side of an existing straight line (not shown) to form a vertex 33e. Therefore, the interior angles of the vertices 33b and 33e are dominant angles, and the interior angles of the vertices 33a, 33c, 33d and 33f are minor angles. The lengths of the sides 32a and 32d are the same, the lengths of the sides 32b, 32c, 32e and 32f are the same, and the interior angles of the vertices 33a, 33c, 33d and 33f are the same. are formed identically. As a result, the unit 31 is formed symmetrically with respect to a straight line 34 extending in the front-rear direction through the vertices 33b and 33e. It should be noted that the sides 32a, 32b, 32c, 32d, 32e, and 32f of a unit unit 31 correspond to the sides 32d, 32e, and 32f of another unit 31, respectively, except for the front, rear, left, and right ends of the lower surface portion 30. , 32a, 32b, and 32c.

In this embodiment, as shown in FIGS. 1 and 2, in the structure 10, the lengths of the sides 22a and 22d of the unit units 21 of the upper surface portion 20 are equal to the lengths of the sides 32a and 32d of the unit units 31 of the lower surface portion 30. The sides 22a and 22d are formed to be shorter than the length, and the entire sides 22a and 22d and part of the sides 32a and 32d overlap each other when viewed in the vertical direction. The lengths of the sides 22b, 22c, 22e and 22f and the lengths of the sides 32b, 32c, 32e and 32f are formed to be the same. The midpoints of 32c, 32e, and 32f overlap each other when viewed in the vertical direction. Furthermore, the size of the unit unit 21 in the front-rear direction and the left-right direction is approximately the same as the size of the unit unit 31 in the front-rear direction and the left-right direction. are the same.

In the structure 10 of the present embodiment configured in this manner, the upper surface portion 20 has a positive Poisson's ratio when it is tensile-deformed and compressively deformed in the front-rear direction (first direction), and is deformed in the left-right direction (second direction). contraction deformation and extension deformation. On the other hand, the lower surface portion 30 has a negative Poisson's ratio when it is tensile-deformed and compressively deformed in the front-rear direction, and is stretch-deformed and contracted-deformed in the left-right direction, respectively. FIG. 5 is an explanatory view showing a state when the structure 10 is tensile-deformed in the longitudinal direction, and FIG. 6 is an explanatory view showing a state when the structure 10 is compressively deformed in the longitudinal direction. 5 and 6, like FIG. 1, correspond to perspective views of the structure 10 from the upper right. When the structural body 10 is pulled and deformed in the front-rear direction, the upper surface portion 20 is contracted and deformed in the left-right direction, and the lower surface portion 30 is elongated and deformed in the left-right direction. Therefore, as shown in FIG. 5, the structural body 10 as a whole undergoes bending deformation upward at both ends in the left-right direction with respect to the central portion. In other words, when the structure 10 is stretched and deformed in the front-rear direction, the structure 10 generates an upward load at both ends in the left-right direction. On the other hand, when the structure 10 is compressed and deformed in the front-rear direction, the upper surface portion 20 is stretched and deformed in the horizontal direction, and the lower surface portion 30 is compressed and deformed in the horizontal direction. Therefore, as shown in FIG. 6, the structural body 10 as a whole undergoes bending deformation downward at both ends in the left-right direction with respect to the central portion. In other words, when the structure 10 is compressed and deformed in the front-rear direction, the structure 10 generates an upward load at both ends in the left-right direction. As a result, it is possible to provide the structure 10 that causes out-of-plane deformation in response to longitudinal tensile deformation and compressive deformation. Such a structure 10 can be used, for example, for parts that require bending deformation, such as morphing wings and robot parts, or for mechanisms that require a change in load direction.

The connection portion 40 of the structure 10 is formed in a shape that is predetermined by analysis, experiment, or the like as a shape that can suppress such out-of-plane deformation of the structure 10 from being hindered. In addition, the inventors have found through analysis and experiments that when the structure 10 is subjected to tensile deformation or compression deformation in the front-rear direction, a first predetermined range from the upper surface side (at least 1/20 to the thickness of the structure 10) The Poisson's ratio is positive in a range of about 1/10), and the Poisson's ratio is negative in a second predetermined range from the lower surface side (a range of at least about 1/20 to 1/10 of the thickness of the structure 10). It was confirmed. Therefore, for example, the first predetermined range from the upper surface side can be considered as the upper surface portion 20 , and the second predetermined range from the lower surface side can be considered as the lower surface portion 30 .

The structure 10 of the present embodiment described above has a mesh-like and plate-like shape as a whole. The surface portion) 30 is formed in a reentrant honeycomb structure as a whole. As a result, when the upper surface portion 20 undergoes tensile deformation and compressive deformation in the front-rear direction, the Poisson's ratio becomes positive, and the lower surface portion 30 undergoes contraction deformation and extension deformation in the left-right direction, respectively. Then, the Poisson's ratio becomes negative, and the material expands and contracts in the horizontal direction. As a result, when the structure 10 is stretched and deformed in the front-rear direction, the structure 10 as a whole undergoes bending deformation upward at both ends in the left-right direction with respect to the central portion, and compressively deforms the structure 10 in the front-rear direction. As a whole, the structure 10 is bent downward at both ends in the left-right direction with respect to the central portion thereof. As a result, it is possible to provide the structure 10 that causes out-of-plane deformation in response to longitudinal tensile deformation and compressive deformation.

In the embodiment described above, the upper surface portion 20 of the structural body 10 is formed to have a honeycomb structure as a whole, and the lower surface portion 30 is formed to have a reentrant honeycomb structure as a whole. That is, the upper surface portion 20 and the lower surface portion 30 are each formed in a shape in which a plurality of hexagonal unit units 21 and 31 are connected. However, the shape of the unit units 21 and 31 is not limited to a hexagonal shape. For example, it may be formed like the structure 110 of FIGS. 7-10. It may be formed like the structure 210 of FIGS. 11-14. It may be formed like the structure 310 of FIGS. 15-18. It may be formed like the structure 410 of FIGS. 19-21. They will be described in order below.

First, the structure 110 will be described. 7 is a perspective view of the structure 110 viewed from the upper right, FIG. 8 is a perspective view of the structure 110 viewed from the lower left, and FIG. 10 is a bottom view showing the bottom surface portion 130 of the structure 110. FIG. The front-back direction (first direction), left-right direction (second direction), and up-down direction of the structure 110 are as shown in FIGS. As shown in FIGS. 7 to 10, the structural body 110 is formed in a mesh-like and plate-like shape as a whole. connected by

As shown in FIGS. 7 and 9, the upper surface portion 120 is formed in a shape in which a plurality of rectangular unit units 121 are connected. The unitary unit 121 has four sides 122a-122d and four vertices 123a-123d. One ends of sides 122a and 122d are connected to each other to form vertex 123d, and one ends of sides 122b and 122c are connected to each other to form vertex 123b. The other ends of sides 122a and 122b are connected to each other on the front side of a straight line (not shown) extending in the horizontal direction through vertices 123b and 123d to form apex 123a. The other ends of the sides 122c and 122d are connected to each other behind the straight line to form a vertex 123c. Therefore, the interior angles of the vertices 123a to 123d are all minor angles. The sides 122a to 122d have the same length, the interior angles of the vertices 123b and 123d are the same, and the interior angles of the vertices 123a and 123c are the same. As a result, the unit 131 is formed symmetrically with respect to a straight line 124 extending in the front-rear direction through the vertices 123a and 123c, and a straight line extending in the left-right direction through the vertices 123b and 123d. It is formed symmetrically with respect to the front and back. Note that the sides 122a, 122b, 122c, and 122d of a certain unit 121 become the sides 122c, 122d, 122a, and 122b of another unit 121, respectively, except when they are the front, rear, left, and right ends of the upper surface portion 120. .

As shown in FIGS. 8 and 10, the lower surface portion 130 is formed in a shape in which a plurality of rectangular unit units 131 are connected. The unitary unit 131 has four sides 132a-132d and four vertices 133a-133d. One ends of sides 132a and 132d are connected to each other to form vertex 133d, and one ends of sides 132b and 132c are connected to each other to form vertex 133b. The other ends of sides 132a and 132b are connected to each other on the front side of a straight line (not shown) extending in the horizontal direction through vertices 133b and 133d to form apex 133a. The other ends of the sides 132c and 132d are connected to each other on the front side of the straight line and on the rear side of the vertex 133a to form a vertex 133c. Therefore, the interior angle of vertex 133c is a dominant angle, and the interior angles of vertices 133a, 133b, and 133d are minor angles. Sides 132a and 132b have the same length, sides 132c and 132d have the same length, and vertices 133b and 133d have the same interior angle. As a result, the unit 131 is formed symmetrically with respect to a straight line 134 extending in the front-rear direction through the vertices 133a and 133c. Note that the vertices 133a, 133b, 133c, and 133d of a certain unit 131 become the vertices 133c, 133d, 133a, and 133b of another unit 131, respectively, except when they are the front, rear, left, and right ends of the lower surface portion 130. .

In the structure 110, the size of the unit 121 in the front-rear direction and the left-right direction is approximately the same as the size of the unit 131 in the front-rear direction and the left-right direction.

In the structure 110 configured in this way, similarly to the structure 10, the upper surface portion 120 has a positive Poisson's ratio when subjected to tensile deformation and compressive deformation in the front-rear direction (first direction), and the lower surface portion 130 has a positive ratio. Poisson's ratio becomes negative when tensile deformation and compression deformation are applied in the direction. Therefore, similarly to the structure 10, when the structure 110 is stretched and deformed in the front-rear direction, the structure 110 as a whole undergoes bending deformation upward at both ends in the left-right direction with respect to the central portion. is compressed and deformed in the front-rear direction, the structure 110 as a whole undergoes bending deformation downward at both ends in the left-right direction with respect to the central portion. As a result, it is possible to provide the structure 110 that causes out-of-plane deformation in response to longitudinal tensile deformation and compressive deformation. The inventors have confirmed these things through analysis and experiments. Note that the connection portion 140 of the structure 110 is formed in a shape predetermined by analysis, experiment, or the like as a shape capable of suppressing such out-of-plane deformation of the structure 110 .

Next, the structure 210 is described. 11 is a perspective view of the structure 210 viewed from the upper right, FIG. 12 is a perspective view of the structure 210 viewed from the lower left, and FIG. 14 is a bottom view showing the bottom surface portion 230 of the structure 210. FIG. The front-rear direction (first direction), left-right direction (second direction), and up-down direction of the structure 110 are as shown in FIGS. As shown in FIGS. 11 to 14, the structural body 210 is generally formed in a substantially mesh-like and plate-like shape, and an upper surface portion (first surface portion) 220 and a lower surface portion (second surface portion) 230 are connected. 240 are connected.

As shown in FIGS. 11 and 13, the upper surface portion 220 is formed in a shape in which a plurality of square unit units 221 are connected. The shape of the unit 221 is similar to that of the unit 121 of the upper surface portion 120 of the structure 110 . Therefore, detailed description of the unit 221 is omitted.

As shown in FIGS. 12 and 14 , the lower surface portion 230 is formed in a shape in which a plurality of octagonal unit units 231 are connected via connecting portions 235 . The unitary unit 231 has eight sides 232a-232h and eight vertices 233a-233h. One ends of sides 232a and 233h are connected to each other to form vertex 233h, one ends of sides 232b and 232c are connected to each other to form vertex 233b, and one ends of sides 232d and 232e are connected to each other. to form a vertex 233d, and one ends of the sides 232f and 232g are connected to each other to form a vertex 233f. The other ends of the sides 232a and 232b are connected to each other behind a straight line (not shown) extending in the horizontal direction through the vertices 233h and 233b (the center side of the octagon) to form a vertex 233a. . The other ends of the sides 232c and 232d are connected to each other on the right side (center side of the octagon) of a straight line (not shown) extending in the front-rear direction through the vertices 233b and 233d to form a vertex 233c. The other ends of the sides 232e and 232f are connected to each other on the front side (center side of the octagon) of a straight line (not shown) extending in the horizontal direction through the vertices 233d and 233f to form a vertex 233e. The other ends of the sides 232g and 232h are connected to each other on the left side (center side of the octagon) of a straight line (not shown) extending in the front-rear direction through the vertices 233f and 233h to form a vertex 233g. Therefore, the interior angles of vertices 233a, 233c, 233e, and 233g are dominant angles, and the interior angles of vertices 233b, 233d, 233f, and 233h are minor angles. The sides 232a to 232h have the same length, the vertices 233b, 233d, 233f and 233h have the same interior angles, and the vertices 233a, 233c, 233e and 233g have the same interior angles. is formed in As a result, the unit 221 is formed symmetrically with respect to a straight line 234 extending in the front-rear direction through the vertices 233a and 233e, and a straight line extending in the left-right direction through the vertices 233c and 233g. (not shown). Note that the vertices 233a, 233c, 233e, and 233g of a certain unit 221 are connected to the vertices 233e and 233g of another unit 221 via connecting portions 235, respectively, except when they are the front, rear, left, and right ends of the lower surface portion 230. , 233a and 233c.

In the structure 210, the size of the unit unit 221 in the front-rear direction and the left-right direction is approximately the same as the size of the unit unit 231 in the front-rear direction and the left-right direction.

In the structure 210 configured in this way, similarly to the structure 10, the upper surface portion 220 has a positive Poisson's ratio when subjected to tensile deformation and compression deformation in the front-rear direction (first direction), and the lower surface portion 230 has a positive ratio. Poisson's ratio becomes negative when tensile deformation and compression deformation are applied in the direction. Therefore, similarly to the structure 10, when the structure 210 is stretched and deformed in the front-rear direction, the structure 210 as a whole undergoes bending deformation upward at both ends in the left-right direction with respect to the central portion. is compressed and deformed in the front-rear direction, the structure 210 as a whole undergoes bending deformation downward at both ends in the left-right direction with respect to the central portion. As a result, it is possible to provide the structure 210 that causes out-of-plane deformation in response to longitudinal tensile deformation or compressive deformation. The inventors have confirmed these things through analysis and experiments. Note that the connection portion 240 of the structure 210 is formed in a shape predetermined by analysis, experiment, or the like as a shape capable of suppressing such out-of-plane deformation of the structure 210 .

Next, the structure 310 will be described. 15 is a perspective view of the structure 310 viewed from the upper right, FIG. 16 is a perspective view of the structure 310 viewed from the lower left, and FIG. 18 is a bottom view showing the bottom surface portion 330 of the structure 310. FIG. The front-rear direction (first direction), left-right direction (second direction), and up-down direction of the structure 310 are as shown in FIGS. As shown in FIGS. 15 to 18, the structural body 310 is formed in a plate shape as a whole, and a top surface portion (first surface portion) 320 and a bottom surface portion (second surface portion) 330 are connected by a connection portion 340. ing.

As shown in FIGS. 15 and 17, the upper surface portion 320 includes row units 320A in which a plurality of S-shaped unit units 321A are connected in the front-rear direction with the S-shaped vertical direction being the front-rear direction of the upper surface portion 320; Row units 320B in which a plurality of inverted S-shaped unit units 321B are connected in the front-rear direction of the upper surface portion 320 so that the up-down direction of the inverted S-shape is the front-rear direction of the upper surface portion 320 are alternately arranged in the left-right direction of the upper surface portion 320. It is formed in an arranged shape. The lower surface portion 330 includes row units 330A in which a plurality of inverted S-shaped unit units 331A are connected in the front-rear direction of the lower surface portion 330 with the left-right direction of the inverted S-shape as the front-rear direction of the lower surface portion 330, and S-shaped unit units 330B. A plurality of row units 330B connected in the front-rear direction of the lower surface portion 330 are arranged alternately in the left-right direction of the lower surface portion 330 and connected to each other.

In structure 310, unit units 330A and 330B of upper surface portion 320 overlap unit units 331A and 331B of lower surface portion 330, respectively, when viewed in the vertical direction. Further, in the structure 310, the size of the unit unit 321 in the front-rear direction and the left-right direction is approximately the same as the size of the unit unit 331 in the front-rear direction and the left-right direction. The number of unit units 331 is the same.

In the structure 310 configured in this way, similarly to the structure 10, the upper surface portion 320 has a positive Poisson's ratio when subjected to tensile deformation and compression deformation in the front-rear direction (first direction), and the lower surface portion 330 has a positive ratio. Poisson's ratio becomes negative when tensile deformation and compression deformation are applied in the direction. Therefore, similarly to the structure 10, when the structure 310 is stretched and deformed in the front-rear direction, the structure 310 as a whole bends and deforms both ends in the left-right direction upward with respect to the central portion. is compressed and deformed in the front-rear direction, the structure 310 as a whole undergoes bending deformation downward at both ends in the left-right direction with respect to the central portion. As a result, it is possible to provide the structure 310 that causes out-of-plane deformation in response to longitudinal tensile deformation and compressive deformation. The inventors have confirmed these things through analysis and experiments. Note that the connection portion 340 of the structure 310 is formed in a shape predetermined by analysis, experiment, or the like as a shape capable of suppressing such out-of-plane deformation of the structure 310 .

Next, the structure 410 is described. 19 is a perspective view of the structure 410 viewed from the upper right, FIG. 20 is a top view of the structure 410 viewed from above, and FIG. 21 is a bottom view of the structure 410 viewed from below. be. The front-back direction (first direction), left-right direction (second direction), and up-down direction of the structure 410 are as shown in FIGS. As shown in FIGS. 19 to 21, the structural body 410 is formed in a plate shape as a whole, and the upper surface portion (first surface portion) 420 and the lower surface portion (second surface portion) 430 are connected by the connecting portion 440. ing.

As shown in FIGS. 19 to 21, the structure 410 includes a through hole 411 whose diameter gradually increases from the upper surface portion 420 side to the lower surface portion 430 side, and a cross-shaped hole 411 that gradually increases in diameter from the lower surface portion 430 side to the upper surface portion side. through-holes 412 are formed alternately at intervals in the front-rear direction and the left-right direction.

In the structure 410 configured in this manner, the upper surface portion 420 has a positive Poisson's ratio when subjected to tensile deformation and compression deformation in the front-rear direction (first direction), and the lower surface portion 430 has a positive rearward-rearward direction. Poisson's ratio becomes negative when tensile deformation and compression deformation are applied in the direction. Therefore, similarly to the structure 10, when the structure 410 is stretched and deformed in the front-rear direction, the structure 410 as a whole undergoes bending deformation upward at both ends in the left-right direction with respect to the central portion. is compressed and deformed in the front-rear direction, the structure 410 as a whole undergoes bending deformation downward at both ends in the left-right direction with respect to the central portion. As a result, it is possible to provide the structure 410 that causes out-of-plane deformation in response to longitudinal tensile deformation and compressive deformation. The inventors have confirmed these things through analysis and experiments.

In the above-described embodiment, the unit 21 of the upper surface portion 20 of the structure 10 is formed in a hexagonal shape (hexagonal shape A type) in which the interior angles of all the vertices 23a to 23f are all minor angles, and the lower surface portion 30 The unit 31 has a hexagonal shape (hexagonal shape B type) in which the interior angles of the two vertices 33b and 33e are dominant angles and the interior angles of the four vertices 33a, 33c, 33d, and 33f are minor angles. formed. The unit 121 of the upper surface portion 120 of the structure 110 is formed in a quadrangular shape (square shape A type) with all minor angles 123a to 123d, and the unit 131 of the lower surface portion 130 has one vertex 133c. is a dominant angle and the three vertices 133a, 133b, and 133d are each formed in a quadrangular shape (quadrangular shape B type) with minor angles. The unit 221 of the upper surface portion 220 of the structure 210 is formed in a rectangular A type similar to the unit unit 121, and the unit unit 231 of the lower surface portion 230 has four vertices 233a, 233c, 233e, and 233g. The four vertices 233b, 233d, 233f, and 233h are formed in an octagonal shape (octagonal shape B type) with minor angles, respectively. However, the structure is formed so that the Poisson's ratio is positive when the upper surface is tensile-deformed and compressively deformed in the longitudinal direction, and the Poisson's ratio is positive when the lower surface is tensile-deformed and compressively deformed in the longitudinal direction. It is sufficient if it is formed so as to be negative. Therefore, the combination of the unit units of the upper surface portion and the unit units of the lower surface portion of the structure is not limited to these. For example, a combination of quadrangular shape A type and hexagonal shape B type, a combination of hexagonal shape A type and quadrangular shape B type or octagonal shape B type, all internal angles of all vertices are minor angles of 8 A combination of a square shape (octagonal shape A type) and any one of a square shape B type, a hexagonal shape B type, and an octagonal shape B type may be used. Moreover, the unitary units of the upper surface portion and/or the lower surface portion of the structure may have polygonal shapes other than quadrangular, hexagonal, and octagonal shapes, such as triangular and pentagonal shapes.

In the above-described embodiments, in the structures 10, 110, and 210, the unit units 21, 121, and 221 of the upper surface portions 20, 120, and 220 and the unit units 31, 131, and 231 of the lower surface portions 30, 130, and 230 are It is supposed to be formed in a polygonal shape. Further, in the structure 310, the unit units 321 of the upper surface portion 320 and the unit units 331 of the lower surface portion 330 are formed in an S shape or an inverted S shape. However, in the structure, one of the unit units on the upper surface portion and the unit units on the lower surface portion may be formed in a polygonal shape, and the other may be formed in an S shape or an inverted S shape.

In the above-described embodiment, the sizes of the unit units 21 of the upper surface portion 20 of the structure 10 in the front-rear direction and the left-right direction are approximately the same as the sizes of the unit units 31 of the lower surface portion 30 in the front-rear direction and the left-right direction. (See Figures 3 and 4). However, the size of the unit unit 21 in the front-rear direction and the left-right direction may be different from the size of the unit unit 31 of the lower surface portion 30 in the front-rear direction and the left-right direction. The same is true for structures 110, 210, 310, and 410.

In the embodiment described above, the structure 10 is assumed to be an integrally molded product. However, the structure 10 includes a plurality of members, for example, an upper surface member forming the upper surface portion 20, a lower surface member forming the lower surface portion 30, and a connecting portion member forming the connecting portion 40. It is good also as what is mutually joined and comprised. The same is true for structures 110, 210, 310, and 410.

In the embodiment described above, the structure 10 is configured by connecting the upper surface portion 20 and the lower surface portion 30 by the connection portion 40 . However, the structure 10 includes a main body portion in which the upper surface portion 20 and the lower surface portion 30 are connected by the connecting portion 40, a covering portion covering at least one of the upper surface portion 20 and the lower surface portion 30 of the main body portion, may be provided. In this case, for example, the covering portion may be made of a sheet material that is sufficiently thinner than the main body, or may be formed integrally with the main body. The same is true for structures 110, 210, 310, and 410.

The correspondence relationship between the main elements of the embodiments and the main elements of the invention described in the column of Means for Solving the Problems will be described. In the first to fifth embodiments, the structures 10, 110, 210, 310, and 410 correspond to the "structure", the upper surface portions 20, 120, 220, 320, and 420 correspond to the "first surface portion", The lower surface portions 30, 130, 230, 330, 430 correspond to the "second surface portion". Also, the unit units 21, 121, 221, 321, and 421 correspond to the "first unit unit", and the unit units 31, 131, 231, 331, and 431 correspond to the "second unit unit".

Note that the correspondence relationship between the main elements of the embodiment and the main elements of the invention described in the column of Means for Solving the Problem indicates that the embodiment implements the invention described in the column of Means to Solve the Problem. Since it is an example for specifically explaining the mode for solving the problem, it does not limit the elements of the invention described in the column of the means for solving the problem. That is, the interpretation of the invention described in the column of Means to Solve the Problem should be made based on the description in that column, and the embodiment should be based on the description of the invention described in the column of Means to Solve the Problem. This is only a specific example.

Although the embodiments for carrying out the present disclosure have been described above, the present disclosure is not limited to such embodiments in any way, and can be implemented in various forms without departing from the gist of the present disclosure. is of course.

[Appendix]
[1] A structure according to the present disclosure is a plate-like structure including a first surface portion and a second surface portion opposite to the first surface portion, wherein the first surface portion is an extension of the structure. The second surface portion is formed to have a positive Poisson's ratio when tensilely deformed and compressively deformed in a first direction among the existing directions, and the second surface portion has a Poisson's ratio when tensilely deformed and compressively deformed in the first direction. is negative, and in the structure, the ends in a second direction perpendicular to the first direction out of the extending directions become central portions as a result of tensile deformation in the first direction. and the end portion in the second direction is bent toward the second surface portion with respect to the central portion along with the compressive deformation in the first direction. This is the gist.

In the structure of the present disclosure, the first surface portion is formed such that the Poisson's ratio is positive when tensile deformation and compression deformation are performed in the first direction of the extending direction of the structure, and the second surface portion is: It is formed such that the Poisson's ratio is negative when tensile deformation and compression deformation are performed in the first direction. As a result, the structural body undergoes compressive deformation in the second direction and extensional deformation in the second direction along with the tensile deformation in the first direction. Bending deformation (out-of-plane deformation) occurs toward the first surface portion with respect to the central portion. Further, in the structure, the first surface portion is compressed and deformed in the second direction and the second surface portion is elongated and deformed in the second direction along with the compressive deformation in the first direction, so that the end portion in the second direction is centered. bending deformation (out-of-plane deformation) toward the second surface portion side with respect to the portion. That is, it is possible to provide a structure in which out-of-plane deformation occurs with respect to tensile deformation or compressive deformation in the first direction.

[2] In the structure of the present disclosure, the first and second surface portions are each formed into a shape in which a plurality of first and second unit units are connected, each having a polygonal shape, an S shape, or an inverted S shape. It may be

[3] In the structure in this case (the structure described in [2] above), the first and second unit units are first and second polygonal shapes, respectively, and the first and second polygonal Each shape has an even number of vertices, has both vertices at both ends of first and second diagonal lines parallel to the first direction, and is formed to be symmetrical with respect to the first and second diagonal lines. It may be

[4] In the structure in this case (the structure described in [3] above), the first polygonal shape is any one of a quadrangular shape, a hexagonal shape, and an octagonal shape, and all are all minor angles, and the second polygonal shape is any one of the quadrangular shape, the hexagonal shape, and the octagonal shape, and the 4 In the case of the angular shape, the interior angle of any one of the two vertices is a dominant angle, and the interior angles of the remaining three vertices are minor angles. The interior angles of both vertices are formed so as to be dominant angles and the interior angles of the remaining four vertices are minor angles. are dominant angles and the interior angles of the remaining four vertices are minor angles.

[5] In the structure of the present disclosure in which the first and second surface portions are formed in a shape in which a plurality of first and second unit units are connected (the structure described in [2] above), The first surface portion includes a first row unit in which a plurality of the S-shaped first unit units are connected in the first direction with the vertical direction of the S-shaped unit as the first direction, and the inverted S-shaped unit. A shape in which a plurality of first unit units are arranged alternately in the second direction with a plurality of second row units connected in the first direction with the vertical direction of the inverted S shape as the first direction. and the second surface portion includes a third row unit in which a plurality of the S-shaped second unit units are connected in the first direction with the horizontal direction of the S-shaped configuration as the first direction. , and fourth row units in which a plurality of the second unit units having the inverted S shape are connected in the first direction with the lateral direction of the inverted S shape as the first direction, alternately in the second direction. It is good also as what is formed in the shape arranged so that it may line up.

[6] In the structure of the present disclosure (the structure described in [1] above), the first surface portion is formed in a honeycomb structure as a whole, and the second surface portion is formed in a reentrant honeycomb structure as a whole. It is good also as what is formed in.

[7] In the structure of the present disclosure (the structure described in [1] above), a first through hole whose diameter gradually increases from the first surface portion toward the second surface portion, and the second surface portion and a second through hole that becomes larger in a cross shape as it goes from the first surface portion to the first surface portion.

[8] The structure of the present disclosure (the structure according to any one of [1] to [7] above) further includes a covering portion that covers at least one of the first and second surface portions. It can be a thing.

[9] In the structure of the present disclosure (the structure according to any one of [1] to [7] above), the structure may be an integrally molded product.

10,110,210,310,410 structure 20,120,220,320,420 upper surface portion 21,31,121,131,221,231,321,331,421,431 unit unit 30,130, 230, 330, 430 bottom surface.

Claims (9)

A plate-shaped structure comprising a first surface portion and a second surface portion opposite to the first surface portion,
The first surface portion is formed to have a positive Poisson's ratio when tensilely deformed and compressively deformed in a first direction among the extending directions of the structure,
The second surface portion is formed to have a negative Poisson's ratio when subjected to tensile deformation and compression deformation in the first direction,
The structure is
Along with the tensile deformation in the first direction, an end portion in a second direction orthogonal to the first direction among the extending directions is bent toward the first surface portion with respect to the central portion,
Along with the compressive deformation in the first direction, the end portion in the second direction is bent toward the second surface portion with respect to the central portion.
Structure. The structure of claim 1, wherein
The first and second surface portions are each formed in a shape in which a plurality of first and second unit units are connected, each being polygonal, S-shaped, or inverted S-shaped.
Structure. 3. The structure of claim 2, wherein
the first and second units are first and second polygonal shapes, respectively;
Each of the first and second polygonal shapes has an even number of vertices, has vertices at both ends of first and second diagonals parallel to the first direction, and are formed so as to be symmetrical at the
Structure. 4. The structure of claim 3, wherein
The first polygonal shape is any one of a tetragonal shape, a hexagonal shape, and an octagonal shape, and is formed so that all interior angles of all vertices are minor angles,
The second polygonal shape is any one of the quadrangular shape, the hexagonal shape, and the octagonal shape, and
In the case of the quadrangular shape, the interior angle of any one of the two vertices is formed to be a dominant angle and the interior angles of the remaining three vertices are formed to be minor angles,
In the case of the hexagonal shape, the interior angles of the two vertices are formed to be dominant angles, and the interior angles of the remaining four vertices are minor angles,
In the case of the octagonal shape, the interior angles of every other four vertices including both vertices are dominant angles, and the interior angles of the remaining four vertices are minor angles.
Structure. 3. The structure of claim 2, wherein
The first surface portion includes a first row unit in which a plurality of the S-shaped first unit units are connected in the first direction with the vertical direction of the S-shaped unit as the first direction, and the inverted S-shaped unit. and second row units in which a plurality of the first unit units are connected in the first direction with the up-down direction of the inverted S shape as the first direction, and are arranged alternately in the second direction. formed in the shape of
The second surface portion includes a third row unit in which a plurality of the S-shaped second unit units are connected in the first direction with the left-right direction of the S-shaped unit as the first direction, and the inverted S-shaped unit. A fourth row unit in which a plurality of the second unit units are connected in the first direction with the left-right direction of the inverted S-shape as the first direction are arranged alternately in the second direction. formed in the shape of
Structure. The structure of claim 1, wherein
The first surface portion is formed in a honeycomb structure as a whole,
The second surface portion is formed in a reentrant honeycomb structure as a whole,
Structure. The structure of claim 1, wherein
A first through hole whose diameter gradually increases from the first surface portion to the second surface portion, and a second through hole whose diameter increases in a cross shape from the second surface portion to the first surface portion,
Structure. The structure of claim 1, wherein
Further comprising a covering portion covering at least one of the first and second surface portions,
Structure. The structure of claim 1, wherein
The structure is an integrally molded product,
Structure.

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