阅读说明：本技术 一种无支撑3d打印三维负泊松比结构的方法 (Method for 3D printing of three-dimensional negative Poisson ratio structure without support ) 是由 黄进 甘霖 夏涛 胡欢 黄奕 黄海涛 于 2020-12-30 设计创作，主要内容包括：本发明属于3D打印技术领域,涉及一种无支撑3D打印三维负泊松比结构的方法,根据无支撑3D打印的条件和算法,对三维负泊松比结构特定设计；通过标准CAD软件建立符合要求的三维负泊松比结构模型,通过在打印软件中调控打印工艺,并且清除全部添加支撑材料的选项,再上传至3D打印机层层无支撑构建模型；本发明所述的无支撑3D打印技术在制造负泊松比材料时不需添加任何支撑材料,从而适用于各类打印材料制造,解除使用常规3D打印技术制造负泊松比材料时对打印原材料的苛刻要求。(The invention belongs to the technical field of 3D printing, and relates to a method for 3D printing of a three-dimensional negative Poisson ratio structure without support, which is specially designed for the three-dimensional negative Poisson ratio structure according to the condition and algorithm of 3D printing without support; establishing a three-dimensional negative Poisson ratio structural model meeting the requirements through standard CAD software, regulating and controlling a printing process in printing software, removing all options of adding supporting materials, and uploading to a 3D printer to construct a model layer by layer without support; the unsupported 3D printing technology does not need to add any supporting material when manufacturing the negative Poisson ratio material, thereby being suitable for manufacturing various printing materials and relieving the rigorous requirement on printing raw materials when manufacturing the negative Poisson ratio material by using the conventional 3D printing technology.)

1. A method for unsupported 3D printing of three-dimensional negative Poisson's ratio structures is characterized by comprising the following steps:

A. the three-dimensional negative Poisson ratio structure model is designed by using standard CAD software, the whole three-dimensional negative Poisson ratio structure is constructed by repeated sixteen-surface-body units with thickness, wherein each sixteen-surface-body unit is composed of six surface crease lines and eight outer boundary lines, and the plane parameters of each sixteen-surface-body unit are as follows: a (0, a, -b); b (B, a, 0); c (b, 0, -b); d (b, -a, 0); e (0, -a, -b); f (-b, -a, 0); g (-b, 0, -b); h (-b, a, 0); o (0, 0, 0); wherein the value range of the value a is 80-90, and the value bThe value range is 45-55; the thickness of the hexadecahedron unit is defined in the z-axis direction, and the z-coordinate value is obtained by increasing or decreasing the coordinate of each corresponding point by 20-60 so as to form a hexadecahedron unit entity with different thicknesses; the built sixteen-face body unit entities are respectively arranged in the space in the x and y directions to form a plane plate structure with thickness, and the quantity of the sixteen-face body units is as follows: x direction N_xN in the y direction of not less than 2_yNot less than 1; two adjacent planar sheet structures are assembled at a dihedral angle theta to form a regular tetrahedral frame, 30 DEG < theta < 40 DEG, the dihedral angle theta being defined as:

B. selecting different 3D printing raw materials;

C. inputting a proper file format and importing the file format into printing software, setting a printing process according to the viscous flow characteristics of different printing raw materials, and adding no supporting material in the printing process;

D. slicing the model, forming a printing path, establishing the model, and uploading the model to a 3D printer;

E. and (4) carrying out integral forming by unsupported 3D printing to obtain a negative Poisson ratio structure printing finished product.

2. The method for unsupported 3D printing of a three-dimensional negative poisson's ratio structure according to claim 1, wherein the three-dimensional positive tetrahedral frame negative poisson's ratio structure in step a has no absolute overhang features to meet the condition that no supporting material is added by the 3D printing process.

3. The method for unsupported 3D printing of a three-dimensional negative poisson's ratio structure of claim 2, wherein in step a, the value of a is 86.603 and the value of b is 50.

4. The method for unsupported 3D printing of three-dimensional negative Poisson's ratio structure according to claim 3, wherein N in step A_xIs 7, N_yIs 3, theta is 35.264 degrees.

5. The method for unsupported 3D printing of a three-dimensional negative Poisson's ratio structure according to claim 4, wherein the 3D printing raw material in step B is one of thermoplastic polyurethane elastomer rubber (TPU), polylactic acid (PLA), Polycaprolactone (PCL), acrylonitrile-butadiene-styrene copolymer (ABS).

6. The method for unsupported 3D printing of a three-dimensional negative poisson's ratio structure of claim 5, wherein in step C the three-dimensional negative poisson's ratio structure is manufactured by 3D printing techniques, eliminating all support option settings, and maintaining good print quality during stacking of layers.

Technical Field

The invention belongs to the technical field of 3D printing, and relates to a method for unsupported 3D printing of a three-dimensional negative Poisson's ratio structure.

Background

Compared with the traditional positive poisson ratio material, the negative poisson ratio material has unique advantages in many performances such as shearing resistance, fracture resistance, energy absorption and the like. The properties of the negative poisson's ratio material are usually obtained by special structural design, namely, the negative poisson's ratio material is composed of periodically arranged negative poisson's ratio units, such as a chiral structure, a reentrant structure and the like. In recent years, rapid development of manufacturing techniques, such as 3D printing techniques, have enabled the manufacture of arbitrarily complex structures ranging from microscopic to macroscopic, making structure and function integrated manufacturing possible. 3D printing is a manufacturing technology for creating a complex three-dimensional object by a controllable structure predefined layer by layer through computer aided design, and overcomes the long-term obstacle that the traditional manufacturing technology cannot realize complex design by utilizing a highly ordered structure in a three-dimensional space.

However, most three-dimensional negative poisson's ratio structures are mainly constructed based on concave polyhedrons, and when the structures are manufactured by the conventional 3D printing technology, extra supporting materials are required to be added to downward concave point parts to ensure the integral molding of the structures. While materials requiring development of adaptations are manufactured by specific 3D printing principles that do not require the addition of support, such as digital light processing printing techniques. Therefore, the material selection of the negative poisson ratio material for different application scenes is greatly limited in the manufacturing process of the poisson ratio material.

In view of the above problem, a method for unsupported 3D printing of a negative poisson's ratio structure needs to be designed, which stably supports the use of multiple types of raw materials for unsupported 3D printing and relieves the harsh requirements of the raw materials for manufacturing negative poisson's ratio materials by using the conventional 3D printing technology.

Disclosure of Invention

In view of this, the invention provides a method for unsupported 3D printing of a three-dimensional negative poisson ratio structure, in order to solve the problems that the conventional 3D printing and manufacturing of negative poisson ratio materials have great raw material selection limitation and influence the negative poisson ratio materials to different application scenes.

In order to achieve the purpose, the invention provides the following technical scheme: a method of unsupported 3D printing of three-dimensional negative Poisson's ratio structures, comprising the steps of:

A. the three-dimensional negative Poisson ratio structure model is designed by using standard CAD software, the whole three-dimensional negative Poisson ratio structure is constructed by repeated sixteen-surface-body units with thickness, wherein each sixteen-surface-body unit is composed of six surface crease lines and eight outer boundary lines, and the plane parameters of each sixteen-surface-body unit are as follows: a (0, a, -b); b (B, a, 0); c (b, 0, -b); d (b, -a, 0); e (0, -a, -b); f (-b, -a, 0); g (-b, 0, -b); h (-b, a, 0); o (0, 0, 0); wherein the value range of the value a is 80-90, and the value range of the value b is 45-55; the thickness of the hexadecahedron unit is defined in the z-axis direction, and the z-coordinate value is obtained by increasing or decreasing the coordinate of each corresponding point by 20-60 so as to form a hexadecahedron unit entity with different thicknesses; the built sixteen-face body unit entities are respectively arranged in the space in the x and y directions to form a plane plate structure with thickness, and the quantity of the sixteen-face body units is as follows: x direction N_xN in the y direction of not less than 2_yNot less than 1; two adjacent planar sheet structures are assembled at a dihedral angle theta to form a regular tetrahedral frame, 30 DEG < theta < 40 DEG, the dihedral angle theta being defined as:

B. selecting different 3D printing raw materials;

C. inputting a proper file format and importing the file format into printing software, setting a printing process according to the viscous flow characteristics of different printing raw materials, and adding no supporting material in the printing process;

D. slicing the model, forming a printing path, establishing the model, and uploading the model to a 3D printer;

E. and (4) carrying out integral forming by unsupported 3D printing to obtain a negative Poisson ratio structure printing finished product.

Further, the three-dimensional negative poisson's ratio structure in step a has no absolute overhang feature to satisfy the condition that no support material is added by the 3D printing process.

Further, in step A, the value of a is 86.603 and the value of b is 50.

Further, N in step A_xIs 7, N_yIs 3, theta is 35.264 degrees.

Further, in the step B, the 3D printing raw material is one of thermoplastic polyurethane elastomer rubber (TPU), polylactic acid (PLA), Polycaprolactone (PCL), acrylonitrile-butadiene-styrene copolymer (ABS).

Further, in the step C, the three-dimensional negative poisson's ratio structure is manufactured by the 3D printing technology, all support option settings are removed, and a good printing form is maintained in the process of stacking one layer on another.

The invention has the beneficial effects that:

1. the method for printing the three-dimensional negative Poisson ratio structure in the unsupported 3D mode disclosed by the invention is used for reasonably designing the three-dimensional negative Poisson ratio structure according to the unsupported 3D printing condition and algorithm. A three-dimensional negative Poisson ratio structure meeting the requirements is designed through standard CAD software, a printing process is regulated and controlled in printing software, all options of adding supporting materials are eliminated, and then the three-dimensional negative Poisson ratio structure is uploaded to a 3D printer to build a model layer by layer without support. The unsupported 3D printing technology does not need to add any supporting material when manufacturing the negative Poisson ratio material, thereby being suitable for manufacturing various printing materials and relieving the rigorous requirement on printing raw materials when manufacturing the negative Poisson ratio material by using the conventional 3D printing technology.

2. The method for printing the three-dimensional negative Poisson ratio structure in the unsupported 3D mode, disclosed by the invention, has the advantages that the conditions and the algorithm for printing in the unsupported 3D mode are clear, and the structure is reasonably designed, so that the part needing to be extended out in the stacking process of each layer forms a larger outline than the previous layer. The printing method is constructed layer by layer on the basis of the negative Poisson ratio structure, and the unsupported 3D printing of the whole negative Poisson ratio structure is realized. The negative Poisson ratio structure is integrally constructed by repeated tetrahedral frames, and the single body is a sixteen-surface-body structural unit and is configured with different thickness parameters. And (3) constructing a stable three-dimensional negative Poisson's ratio structure by arranging, assembling, stacking and other processes of the sixteen-sided structure units with the thickness characteristics. The three-dimensional negative poisson's ratio structure manufactured by the unsupported 3D printing also presents a good printing form.

3. The method for manufacturing the three-dimensional negative Poisson ratio structure through the unsupported 3D printing technology adopts the conventional 3D printing technology and uses different raw materials to manufacture the three-dimensional negative Poisson ratio structure, the printing process is stable, no additional supporting material is added, the printed finished product is good in shape, the material selection range is wide, and the material utilization rate is improved. The method relieves the rigorous raw material requirements of manufacturing the main negative Poisson ratio structure constructed based on the concave polyhedron through conventional 3D printing.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.

Drawings

For the purposes of promoting a better understanding of the objects, aspects and advantages of the invention, reference will now be made to the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a process flow diagram of a method of the present invention for unsupported 3D printing of three-dimensional negative Poisson's ratio structures;

FIG. 2 is a three-dimensional negative Poisson ratio structure diagram in the method for 3D printing a three-dimensional negative Poisson ratio structure without support according to the present invention;

FIG. 3 is a three-dimensional negative Poisson ratio hexadecahedron unit parameter definition diagram in the method for unsupported 3D printing of a three-dimensional negative Poisson ratio structure according to the invention;

FIG. 4 is a frame diagram of a regular tetrahedron in the method for unsupported 3D printing of a three-dimensional negative Poisson's ratio structure according to the invention;

FIG. 5 is a flow chart of the construction of a three-dimensional negative Poisson's ratio structure in the method for unsupported 3D printing of a three-dimensional negative Poisson's ratio structure according to the present invention;

FIG. 6 is a diagram of a finished product of a three-dimensional negative Poisson ratio structure unsupported 3D printed TPU material in example 1 of the invention;

fig. 7 is a finished product diagram of a three-dimensional negative poisson's ratio structure unsupported 3D printed ABS material in embodiment 2 of the present invention.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention in a schematic way, and the features in the following embodiments and examples may be combined with each other without conflict.

Wherein the showings are for the purpose of illustrating the invention only and not for the purpose of limiting the same, and in which there is shown by way of illustration only and not in the drawings in which there is no intention to limit the invention thereto; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", etc., based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of description, but it is not an indication or suggestion that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes, and are not to be construed as limiting the present invention, and the specific meaning of the terms may be understood by those skilled in the art according to specific situations.

Conventional 3D printing has a certain width of material deposited on one layer, and the printed layer can be larger than the previous layer in contour by means of staggered bonding, thereby creating the condition of unsupported 3D printing. And reasonably designing a negative Poisson ratio structure according to the condition and algorithm of the unsupported 3D printing. The negative poisson's ratio structure must ensure that there are no absolute overhang features to meet the condition that the printing process does not add any supporting material. The three-dimensional negative poisson's ratio structure according with the structural characteristics can keep a good printing form in the process of stacking one layer by one layer after all supporting option settings are eliminated when the three-dimensional negative poisson's ratio structure is manufactured by a conventional 3D printing technology. The support-free 3D printing technology is suitable for support-free 3D printing and manufacturing of negative Poisson ratio structures by various materials (such as TPU, PLA, PCL and the like).

As shown in fig. 1, the method for unsupported 3D printing of a three-dimensional negative poisson's ratio structure maintains the same functions and other printing characteristics as those of the conventional 3D printing technology on the premise of removing the limitation of the conventional 3D printing raw materials, and comprises the following steps:

A. the three-dimensional negative Poisson ratio structure model is designed by using standard CAD software, the whole three-dimensional negative Poisson ratio structure is constructed by repeated sixteen-surface-body units with thickness, wherein each sixteen-surface-body unit is composed of six surface crease lines and eight outer boundary lines, and the plane parameters of each sixteen-surface-body unit are as follows: a (0, a, -b); b (B, a, 0); c (b, 0, -b); d (b, -a, 0); e (0, -a, -b); f (-b, -a, 0); g (-b, 0, -b); h (-b, a, 0); o (0, 0, 0); wherein the value range of the value a is 80-90, and the value range of the value b is 45-55; the thickness of the hexadecahedron unit is defined in the z-axis direction, and the z-coordinate value is obtained by increasing or decreasing the coordinate of each corresponding point by 20-60 so as to form a hexadecahedron unit entity with different thicknesses; the built sixteen-face body unit entities are respectively arranged in the space in the x and y directions to form a plane plate structure with thickness, and the quantity of the sixteen-face body units is as follows: x direction N_xN in the y direction of not less than 2_yNot less than 1; two adjacent planar sheet structures are assembled at a dihedral angle θ to form a regular tetrahedral frame, the dihedral angle θ being defined as:

B. selecting different 3D printing raw materials;

C. inputting a proper file format and importing the file format into printing software, setting a printing process according to the viscous flow characteristics of different printing raw materials, and adding no supporting material in the printing process;

D. slicing the model, forming a printing path, establishing the model, and uploading the model to a 3D printer;

E. and (4) carrying out integral forming by unsupported 3D printing to obtain a negative Poisson ratio structure printing finished product.

Example 1

Example 1 Process for unsupported 3D printing of TPU three-dimensional negative Poisson's ratio material

As shown in FIGS. 1-5, a three-dimensional negative Poisson ratio structural model conforming to structural features is designed in standard CAD software according to the conditions and algorithms of unsupported 3D printing.

Each sixteen-surface body unit consists of six surface crease lines and eight outer boundary lines, and the plane parameters of each sixteen-surface body unit are as follows: a (0, 86.603, -50); b (50, 86.603, 0); c (50, 0, -50); d (50, -86.603, 0); e (0, -86.603, -50); f (-50, -86.603, 0); g (-50, 0, -50); h (-50, 86.603, 0); o (0, 0, 0); a' (0, 86.603, -70); b' (50, 86.603, -20); c' (50, 0, -70); d' (50, -86.603, -20); e' (0, -86.603, -70); f' (-50, -86.603, -20); g' (-50, 0, -70); h' (-50, 86.603, -20); o' (0, 0, -20); obtaining a hexadecahedron unit entity with the thickness of 0.2;

the constructed 7 x 3 arrays of the decahedron units form a planar plate structure, two planar plates are combined pairwise at a dihedral angle of 35.264 degrees, one planar plate combination is horizontally rotated by 90 degrees and then vertically rotated by 180 degrees to be assembled with the other planar plate to construct a three-dimensional regular tetrahedron structure precursor, and the three-dimensional regular tetrahedron structure precursors with the same geometric structures are stacked in a mirror image mode to complete the design of the three-dimensional negative Poisson's ratio structure. And outputting the STL file, importing the STL file into printing software matched with the 3D printer, setting parameters in the software and processing the model. And removing all support material adding options, slicing the model to form a printing preview, and checking whether the unsupported 3D printing process is smoothly carried out or not through the preview. Uploading to a 3D printer, and then printing a layer of unsupported construction model.

And carrying out unsupported 3D printing by using TPU consumables, wherein the printing process is set according to the viscous flow characteristics of the materials. The printing process of the TPU printing consumables is set as follows:

the obtained printing finished product of the three-dimensional negative Poisson ratio structure model is shown in FIG. 6, the model presents a good printing form, and the detail processing meets the printing requirement.

Example 2

Embodiment 2 is a process for unsupported 3D printing of ABS three-dimensional negative Poisson's ratio material

And designing a three-dimensional negative Poisson's ratio structural model according to the structural characteristics in standard CAD software according to the conditions and algorithms of the unsupported 3D printing as shown in FIGS. 1-5.

Each sixteen-surface body unit consists of six surface crease lines and eight outer boundary lines, and the plane parameters of each sixteen-surface body unit are as follows: a (0, 86.603, -50); b (50, 86.603, 0); c (50, 0, -50); d (50, -86.603, 0); e (0, -86.603, -50); f (-50, -86.603, 0); g (-50, 0, -50); h (-50, 86.603, 0); o (0, 0, 0); a' (0, 86.603, -70); b' (50, 86.603, -20); c' (50, 0, -70); d' (50, -86.603, -20); e' (0, -86.603, -70); f' (-50, -86.603, -20); g' (-50, 0, -70); h' (-50, 86.603, -20); o' (0, 0, -20); obtaining a hexadecahedron unit entity with the thickness of 0.2;

the constructed 7 x 3 arrays of the decahedron units form a planar plate structure, two planar plates are combined pairwise at a dihedral angle of 35.264 degrees, one planar plate combination is horizontally rotated by 90 degrees and then vertically rotated by 180 degrees to be assembled with the other planar plate to construct a three-dimensional regular tetrahedron structure precursor, and the three-dimensional regular tetrahedron structure precursors with the same geometric structures are stacked in a mirror image mode to complete the design of the three-dimensional negative Poisson's ratio structure. And outputting the STL file, importing the STL file into printing software matched with the 3D printer, setting parameters in the software and processing the model.

And processing by printing software and uploading to a 3D printer, removing all support adding options, and constructing layer by layer without support.

The printing process of the ABS printing supplies is set as follows:

the obtained printing finished product of the three-dimensional negative Poisson ratio structure model is shown in FIG. 7, the model presents a good printing form, and the detail processing meets the printing requirement.

In addition, the printing consumables can adopt a wider variety of printing materials (such as PLA, PCL and the like), and all the printing materials stably support the method for manufacturing the three-dimensional negative Poisson's ratio structure through the unsupported 3D printing. Different materials are endowed with negative Poisson ratio properties through the unsupported 3D printing technology, and the mechanical property enhancement of various materials is realized.

Finally, the above embodiments are only intended to illustrate the technical solutions of the present invention and not to limit the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all of them should be covered by the claims of the present invention.