Additive manufacturing method for tough structures based on multiple printing parameter combinations of a single material and its applications

Abstract

The present invention provides a method for additive manufacturing of a tough structure based on a combination of multiple printing parameters of a single material and its application, belonging to the technical field of additive manufacturing. The present invention optimizes the strength and toughness properties by means of alternating deposition of a single material and a combination of two printing parameters, constructs an experimental matrix using key printing parameters, establishes a quantitative relationship between the parameters and key mechanical properties in combination with a response surface model, and obtains two different combinations of printing parameters through a multi-objective optimization method. One set of parameter combinations can achieve stronger mechanical properties, while the other provides weaker interlayer and inter-filament mechanical properties. By alternately using these two parameter combinations, an alternating structure of strong and weak phases in the additive manufactured part is realized. The manufacturing method of the present invention can optimize the mechanical properties of the bionic layered structure obtained by additive manufacturing, avoid the problem of multi-material compatibility, simplify the manufacturing process, reduce costs, improve manufacturing efficiency, improve energy absorption capacity and impact strength, and can adapt to complex structure designs.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing, and relates to the process of additive manufacturing, and to data acquisition / data processing for controlling or regulating an additive manufacturing process. Specifically, the present invention relates to a method for additive manufacturing of a tough structure based on a combination of multiple printing parameters of a single material and its application. Background Art

[0002] Additive Manufacturing (AM) technology, especially 3D printing technology, has developed rapidly in recent years and has been widely used in many fields such as aerospace, automotive, medical, and construction. Due to its unique forming method, it can directly manufacture parts with complex shapes according to a digital model and can reduce waste during design. Therefore, additive manufacturing has become one of the core technologies in many industries. However, existing additive manufacturing technologies still face many challenges, especially in optimizing the mechanical properties of printing materials. Common additive manufacturing technologies usually use a single material and a single printing parameter. Although this method can achieve the manufacture of structures, it often cannot meet the requirements of complex application scenarios with high strength and toughness at the same time.

[0003] To solve this problem, researchers have tried to optimize the mechanical properties of materials by adjusting printing parameters. Different printing parameters, such as printing temperature, printing speed, layer height, and build plate temperature, directly affect the mechanical properties of the printed material, including strength, toughness, impact resistance, etc. However, existing technologies mainly focus on using a single combination of printing parameters to optimize the performance of a single material. For example, based on the adjustment of parameters such as printing temperature, layer height, and printing speed, existing research has tried to improve the tensile strength, compressive strength, and impact resistance of materials. However, the limitation of these methods is that they cannot take into account different mechanical properties of materials, resulting in the inability to achieve a balance between high strength and high toughness in some engineering applications, and the comprehensive mechanical properties of additive manufacturing parts are limited.

[0004] Therefore, some research has begun to explore multi-material additive manufacturing methods, aiming to achieve performance regulation in different regions by combining different materials. For example, by alternately using different materials or material combinations during printing, researchers hope to achieve structural diversity and performance optimization. However, the technology of using multi-material printing still faces many challenges, such as poor compatibility between materials, poor interlayer bonding, and mismatched thermal expansion coefficients. Therefore, existing multi-material additive manufacturing technologies are difficult to be widely applied in the actual manufacture of structures requiring high strength and toughness.

[0005] In summary, the following problems exist in additive manufacturing under the existing technology:

[0006] (1) Mechanical properties balance problem: Existing technologies usually rely on a combination of a single material and a single printing parameter to optimize the mechanical properties of the material. However, this method can often only optimize one aspect of the material's performance (such as strength or toughness), but it is difficult to take both strength and toughness into account at the same time, resulting in insufficient mechanical properties of additively manufactured parts in actual applications, and unable to meet the structural requirements of high strength and high toughness.

[0007] (2) Compatibility issues of multi-material additive manufacturing: Although multi-material additive manufacturing can adjust the performance of different regions by combining different materials, multi-material printing technology still faces many challenges, such as poor compatibility between materials, poor interlayer bonding, mismatched thermal expansion coefficients, etc. These problems not only affect the overall performance of additively manufactured parts, but also increase manufacturing costs, limiting their widespread application.

[0008] (3) Complex manufacturing process and high cost: Existing multi-material additive manufacturing methods usually require the use of multiple materials and complex printing processes, which not only increases the difficulty of manufacturing, but also increases production costs. In addition, material selection and adjustment of printing parameters are too dependent on experimental experience and lack a systematic optimization method, resulting in limited effect in the application of high-strength and toughness structures.

[0009] Therefore, how to regulate the mechanical properties of different areas through a reasonable combination of printing parameters, and then synergistically optimize the strength and toughness of additively manufactured parts, is a technical problem that needs to be solved urgently. Summary of the invention

[0010] The present invention is made to solve the above-mentioned problems, and aims to provide a method for additive manufacturing of a strong and tough structure based on a combination of multiple printing parameters of a single material and its application.

[0011] The present invention provides a method for additive manufacturing of a strong and tough structure based on a combination of multiple printing parameters of a single material, which has the following characteristics and includes the following steps: S10, selecting a single material suitable for additive manufacturing, the single material having adjustable brittle and plastic properties; S20, selecting mechanical properties for modeling in the single material; S30, selecting printing parameters to be optimized in the additive process; S40, after designing an experimental matrix for the single material, establishing a mathematical model between the mechanical properties and printing parameters of the single material by means of a response surface method; S50, according to the mathematical model, determining two groups of printing parameter combinations that produce the strongest comprehensive mechanical properties and the weakest comprehensive mechanical properties respectively by means of a multi-objective optimization method; S60, performing additive manufacturing by alternatingly using a combination of printing parameters with the strongest comprehensive mechanical properties and a combination of printing parameters with the weakest comprehensive mechanical properties, thereby achieving alternating deposition of strong phases and weak phases in the same additive manufacturing sample, and constructing a bionic layered structure of alternating strong / weak phases with soft / hard filament and interlayer interface properties.

[0012] In the method for additive manufacturing of a tough structure based on a single material with multiple combinations of printing parameters provided by the present invention, it may further have the following characteristics: Among them, in step S10, the single material includes Onyx.

[0013] In the method for additive manufacturing of a tough structure based on a single material with multiple combinations of printing parameters provided by the present invention, it may further have the following characteristics: Among them, in step S20, the mechanical properties include tensile strength TS, tensile modulus TM, inter-filament bond strength IF-TS, inter-filament bond modulus IF-TM, and inter-layer shear strength ILSS. In step S30, the printing parameters include printing temperature T n , printing speed S p , printing layer height LT and extrusion multiple EM .

[0014] In the method for additive manufacturing of a tough structure based on a single material with multiple combinations of printing parameters provided by the present invention, it may further have the following characteristics: Among them, in step S40, the test matrix includes: performing a 0° tensile test on the single material in the X direction to test the tensile modulus TM and tensile strength TS; performing a 90° tensile test on the single material in the Y direction to test the inter-filament bond strength IF-TS and inter-filament bond modulus IF-TM; performing a short beam shear test on the single material in the Z direction to test the inter-layer shear strength ILSS.

[0015] In the method for additive manufacturing of a tough structure based on a single material with multiple combinations of printing parameters provided by the present invention, it may further have the following characteristics: Among them, in step S50, the combination of the printing parameters for the weakest comprehensive mechanical property is:

[0016] ,

[0017] The combination of the printing parameters for the strongest comprehensive mechanical property is:

[0018] ,

[0019] and 260 °C ≤ T n ≤ 290 °C, 0.1 mm ≤ LT ≤ 0.2 mm, 20 mm / s ≤ S p ≤ 60 mm / s, 95 % ≤ EM ≤ 105 %, where x represents different combinations of printing parameters, f 1 ( x ) is the 0° tensile property in the X direction used to represent the tensile modulus TM and tensile strength TS of the single material, f2 ( x ) is the comprehensive property representing the inter-filament properties and inter-layer properties of IF-TS, IF-TM, and ILSS for a single material.

[0020] In the method for additive manufacturing of a tough and strong structure based on a combination of multiple printing parameters for a single material provided by the present invention, it may further have the following characteristics: Among them, the combination of printing parameters with the strongest comprehensive mechanical properties is used to optimize the TS, TM, IF-TS, IF-TM, and ILSS of a single material, so as to adapt to structures requiring high-strength performance. The combination of printing parameters with the weakest comprehensive mechanical properties is used to optimize the plasticity and toughness of the strong phase, so that the single material has better energy absorption capacity and impact strength.

[0021] In the method for additive manufacturing of a tough and strong structure based on a combination of multiple printing parameters for a single material provided by the present invention, it may further have the following characteristics, and further includes the following steps: S70, measuring the energy absorption value of the bionic layered structure through a Charpy impact test, measuring the strain distribution and energy absorption behavior of the bionic layered structure during the bending process through a three-point bending test combined with DIC technology, and analyzing the internal microstructure damage through SEM images of the bionic layered structure in the Charpy impact test and the change of the strain field through DIC images to obtain its crack propagation mechanism and energy absorption path; S80, combining the test results in step S70 to verify the strength and energy absorption characteristics of the bionic layered structure.

[0022] The present invention also provides an application of a method for additive manufacturing of a tough and strong structure based on a combination of multiple printing parameters for a single material as described in any one of the foregoing in aerospace, automotive industry, protective equipment, and sports equipment.

[0023] According to a method for additive manufacturing of a tough and strong structure based on a combination of multiple printing parameters for a single material and its application involved in the present invention, because the alternate deposition printing using a single material and a combination of two printing parameters is used to optimize the strong and tough properties, by selecting several printing parameters (such as printing temperature, printing speed, layer height, extrusion multiple, etc.) most relevant to the mechanical properties of the additive manufacturing part (including strength, toughness, inter-filament and inter-layer bonding properties, etc.), after designing the test matrix of a single material, a mathematical model between the mechanical properties of a single material and the printing parameters is established through the response surface method, and two different combinations of printing parameters are obtained through the multi-objective optimization (MOO) method. One set of parameter combinations can achieve stronger mechanical properties, and the other set provides weaker inter-layer and inter-filament mechanical properties. By alternately using these two parameter combinations, an alternate structure of strong and weak phases in the additive manufacturing part is realized.

[0024] Therefore, the method for additive manufacturing of a tough and strong structure based on a combination of multiple printing parameters for a single material and its application of the present invention have the following beneficial effects:

[0025] (1) Optimize mechanical properties: By alternately using two different combinations of printing parameters during the additive manufacturing process (i.e., the printing parameter combinations that respectively achieve the strongest and weakest comprehensive mechanical properties), the adjustment of mechanical properties is realized on a single material. By alternately depositing to form a strong-weak phase alternating structure, the additive manufactured part can simultaneously possess excellent strength and toughness in the same component, meeting the requirements of complex application scenarios with high strength and high toughness.

[0026] (2) Avoid multi-material compatibility problems: Different from multi-material additive manufacturing methods, the present invention only uses a single material and adjusts the mechanical properties of different regions by optimizing the combination of printing parameters. This not only avoids problems such as poor compatibility, poor interlayer bonding, and mismatched thermal expansion coefficients that may occur between multi-materials, but also greatly reduces the material cost and manufacturing complexity.

[0027] (3) Simplify the manufacturing process, reduce costs, and improve manufacturing efficiency: Compared with the existing multi-material additive manufacturing technologies, the present invention only needs to optimize two combinations of printing parameters, simplifies the manufacturing process, reduces material switching and printing pause time, thereby improving manufacturing efficiency. And by the way of alternate deposition, the complexity in material selection and switching is reduced, material waste is reduced, and production costs are lowered. At the same time, the optimized combination of printing parameters provides a more systematic solution, reduces the blindness in experiments, and improves the stability of the process.

[0028] (4) Improve energy absorption capacity and impact strength: By the method of the present invention, the manufactured additive parts not only have high bending strength and stiffness in mechanical properties, but also have strong toughness, can effectively improve the energy absorption capacity and impact strength, and are suitable for high-demand engineering applications such as aerospace and automotive fields.

[0029] (5) Adapt to complex structure design: The design method provided by the present invention can realize the manufacturing of complex bionic hierarchical structures. By precisely controlling the printing parameters of each layer, a structure with soft / hard interfaces and alternating strong and tough properties is manufactured, which is suitable for high-performance requirement fields such as aerospace and automotive, and expands the application scope of 3D printing technology.

[0030] (6) The present invention provides a brand-new idea for the application of additive manufacturing technology in high-strength and high-toughness structures. It can manufacture structural parts with excellent strength and toughness on the basis of a single material by adjusting and alternately using two combinations of printing parameters, significantly improving the energy absorption capacity and impact strength of the material, solving the technical problems of traditional multi-material additive manufacturing, and having broad application prospects. Brief Description of the Drawings

[0031] Figure 1It is a flowchart of the method for additive manufacturing of a tough structure based on a combination of multiple printing parameters of a single material in an embodiment of the present invention.

[0032] Figure 2 It is a technical roadmap of the method for additive manufacturing of a tough structure based on a combination of multiple printing parameters of a single material in an embodiment of the present invention.

[0033] Figure 3 It is a comparison of the Charpy impact test (pendulum impact) results in step S71 in an embodiment of the present invention, where S is a pure strong phase, W is a pure weak phase, and S-W is an alternating strong and weak phase.

[0034] Figure 4 It is a comparison of the static three-point bending stiffness, strength, and energy absorption results in step S72 in an embodiment of the present invention, where S is a pure strong phase, W is a pure weak phase, and S-W is an alternating strong and weak phase.

[0035] Figure 5 It is an analysis of the strong / tough mechanism of the bionic hierarchical structure of the method for additive manufacturing of a tough structure based on a combination of multiple printing parameters of a single material in an embodiment of the present invention. Detailed implementation manners

[0036] In order to make the technical means, creative features, achieved purposes, and effects of the present invention easy to understand, the following embodiments will specifically describe a method for additive manufacturing of a tough structure based on a combination of multiple printing parameters of a single material and its application in conjunction with the accompanying drawings.

[0037] <Embodiment>

[0038] Figure 1 It is a flowchart of the method for additive manufacturing of a tough structure based on a combination of multiple printing parameters of a single material in an embodiment of the present invention; Figure 2 It is a technical roadmap of the method for additive manufacturing of a tough structure based on a combination of multiple printing parameters of a single material in an embodiment of the present invention.

[0039] As Figure 1 and Figure 2 shown, this embodiment provides a method for additive manufacturing of a tough structure based on a combination of multiple printing parameters of a single material, including the following steps:

[0040] S10, select a single material suitable for additive manufacturing.

[0041] Specifically, in this embodiment, a single material Onyx (with adjustable brittle and plastic properties) suitable for additive manufacturing is selected as the printing material.

[0042] Onyx can exhibit different mechanical properties under different printing parameters, showing both brittleness and plasticity.

[0043] S20. Select the mechanical properties for modeling in a single material: tensile strength TS, tensile modulus TM, inter-filament bond strength IF-TS, inter-filament bond modulus IF-TM, and interlaminar shear strength ILSS.

[0044] S30. Select the printing parameters to be optimized during the additive process.

[0045] The combination of printing parameters has an important impact on the final mechanical properties of a single material (Onyx). Specifically, in this embodiment, the printing parameters selected for optimization are:

[0046] Printing temperature T n (°C), printing speed S p (mm / s), printing layer height LT (mm), and extrusion multiple EM (%).

[0047] S40. Establish a mathematical model between the mechanical properties and the printing parameters, including the following sub-steps S41 - S42:

[0048] S41. Design the test matrix for a single material: (1) Tensile test of the single material in the X direction at 0° to measure the tensile modulus TM and tensile strength TS; (2) Tensile test of the single material in the Y direction at 90° to measure the inter-filament bond strength IF-TS and inter-filament bond modulus IF-TM; (3) Short beam shear test of the single material in the Z direction to measure the interlaminar shear strength ILSS.

[0049] S42. Establish a mathematical model between the mechanical properties (TS, TM, IF-TS, IF-TM, ILSS) of the single material and the printing parameters ( T n , S p , LT , EM ) through the Response Surface Methodology (RSM).

[0050] S50. According to the mathematical model established in step S42, determine the combinations of printing parameters that produce the strongest comprehensive mechanical properties and the weakest comprehensive mechanical properties respectively through the Multi-Objective Optimization (MOO) method.

[0051] (1) Combinations of printing parameters for the strongest comprehensive mechanical properties:

[0052]

[0053] The combinations of printing parameters for the strongest comprehensive mechanical properties are used to optimize the TS, TM, IF-TS, IF-TM, and ILSS of the single material, so as to adapt to structures that require high strength performance.

[0054] (2) Combinations of printing parameters with the weakest comprehensive mechanical properties:

[0055]

[0056] Combinations of printing parameters with the weakest comprehensive mechanical properties are used to optimize the plasticity and toughness of the strong phase, so that a single material has better energy absorption capacity and impact strength.

[0057] Wherein, x represents different combinations of printing parameters ( T n , S p , LT , EM ), f 1 ([[]] x ) is the tensile property in the X-direction at 0° for representing the tensile modulus TM and tensile strength TS of a single material, f 2 ([[]] x ) is the comprehensive property representing the inter-filament and inter-layer properties of IF-TS, IF-TM and ILSS of a single material.

[0058] 260 °C ≤ T n ≤ 290 °C, 0.1 mm ≤ LT ≤ 0.2 mm, 20 mm / s ≤ S p ≤ 60 mm / s, 95 % ≤ EM ≤ 105 %.

[0059] S60, constructing a bionic hierarchical structure, including the following sub-steps:

[0060] S61, strong phase deposition: printing with a combination of printing parameters with the strongest comprehensive mechanical properties to ensure that this part has high strength and stiffness when stressed.

[0061] Specifically, the printing thickness in this step is 0.4 mm.

[0062] S62, weak phase deposition: printing with a combination of printing parameters with the weakest comprehensive mechanical properties to ensure that this part has good plasticity and toughness and can effectively absorb impact energy.

[0063] Specifically, the printing thickness in this step is 0.4 mm.

[0064] S63. By adjusting the combination of printing parameters between different phases and repeating steps S61 - S62, alternately deposit strong and weak phases in the same additive manufacturing sample, enabling effective deformation of a single material under stress, avoiding premature structural rupture, enhancing energy absorption capacity, and ultimately constructing a bionic hierarchical structure with alternating strong / weak phases having soft / hard inter - filament and inter - layer interface properties.

[0065] S70. Performance evaluation, including the following sub - steps S71 - S73:

[0066] S71. Determine the impact strength value of the bionic hierarchical structure through Charpy impact tests, which represents the energy absorbed by the sample when subjected to impact loads. The test results are as Figure 3 shown: S is the sample prepared with the single comprehensive strongest mechanical property printing parameter combination; W is the sample prepared with the single comprehensive weakest mechanical property printing parameter combination; S - W is the method of this embodiment, that is, the sample prepared by alternately depositing two printing parameter combinations, where 0 and 90 represent different printing directions as pure 0° printing and pure 90° printing. From the comparison of the test results, it can be seen that the impact strengths of S - W with two different printing directions are higher than those of the S and W samples in the corresponding printing directions. This indicates the high energy absorption capacity, that is, high toughness, of the samples prepared in this embodiment.

[0067] S72. Determine the strain distribution and energy absorption behavior during bending of the bionic hierarchical structure through a three - point bending test combined with digital image correlation (DIC) technology. The results are as Figure 4 shown: Figure 4 From the force - displacement curve in (a), it can be seen that the initial slope and peak force of the S - 0 specimen are the largest, followed by the S - W - 0 specimen, and the W - 0 specimen is the smallest. In Figure 4 (b), it can be seen that when the force value decays to 15% of the peak level, the S - W - 0 specimen absorbs the highest energy, followed by the W - 0 specimen, and the S - 0 specimen is the lowest. This shows that the S - W - 0 sample maintains a comparable level of bending modulus and bending strength to the S - 0 sample, and its energy absorption capacity has been greatly improved.

[0068] S73. Analyze the internal micro - structural damage through SEM images of the bionic hierarchical structure after Charpy impact tests, observe micro - failure modes (such as matrix failure, inter - filament and inter - layer interface debonding, etc.), and confirm the causal relationship between macroscopic crack initiation and micro - defects; accurately locate the crack initiation position from the analysis of the strain field change in the DIC images in the three - point bending test, combine with the corresponding load moment of the load - displacement curve, synchronously capture the mechanical state at the moment of crack initiation and during crack propagation, and track the crack propagation path. Combine the above characterization techniques to obtain its crack propagation mechanism and energy absorption path.

[0069] S80, Performance Verification: Obtain and comparatively analyze the strength and absolute energy absorption values of the specimens of the three printing strategies from the standardized tests in step S70. Combine the microscopic failure characterization of the SEM images after the Charpy impact test and the analysis of the strain field distribution and the force-displacement curve from the DIC images during the three-point bending test to capture the mechanical state at the moment of crack initiation and during crack propagation, and trace the crack propagation path, so as to verify the strength and energy absorption characteristics of the bionic hierarchical structure.

[0070] Analysis of the strength / toughness mechanism of the bionic hierarchical structure is as Figure 5 shown. The S specimens prepared from the combination of process parameters with the strongest comprehensive mechanical properties have good inter-filament and inter-layer bonding properties and a low porosity, enabling stress to be evenly transmitted between the filaments, while strain is concentrated at the notch tip, causing the crack to rapidly propagate and form a brittle fracture mode; the W specimens prepared from the combination of process parameters with the weakest comprehensive mechanical properties have poor inter-filament and inter-layer bonding properties and a high porosity, resulting in the stress on the fiber bundles being difficult to transmit, and the strain being dispersed, causing debonding at the inter-filament and inter-layer interfaces to form a serrated failure morphology, which is a ductile damage mode; the S-W specimens prepared by alternately depositing the combinations of the two process parameters with the strongest and weakest comprehensive mechanical properties alternately have the inter-filament and inter-layer bonding properties of the S and W specimens. The strong phase is more likely to transmit stress to the weak phase while maintaining the load-bearing capacity, improving the toughness of the strong phase and increasing the inter-layer shear stress of the weak phase, resulting in debonding at the soft interface, crack deflection to reduce stress concentration, delaying the fracture process, and enhancing the overall strength and toughness.

[0071] This embodiment also provides an application of an additive manufacturing method for a strong and tough structure based on multiple printing parameter combinations of a single material:

[0072] The bionic hierarchical structure prepared by the additive manufacturing method for a strong and tough structure based on multiple printing parameter combinations of a single material in this embodiment and verified through performance evaluation greatly improves the energy absorption capacity and impact strength of the additive manufacturing specimens, and is applicable to aerospace, automotive industry, protective equipment, and sports equipment.

[0073] (1) Aerospace: Provide additive manufacturing components with excellent strength and toughness for aerospace structural parts.

[0074] (2) Automotive industry: Manufacture high-energy absorption structural parts to improve the collision safety performance of vehicles.

[0075] (3) Protective equipment: Used to fabricate protective equipment and materials with high impact performance.

[0076] (4) Sports equipment: Provide high-strength and tough, impact-resistant sports equipment components.

[0077] Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for additive manufacturing of a strong and tough structure based on a combination of multiple printing parameters of a single material, characterized in that: The following steps are involved: S10, selecting a single material Onyx suitable for additive manufacturing, wherein the single material has adjustable brittle and plastic properties; S20, selecting mechanical properties for modeling in the single material, the mechanical properties comprising tensile strength TS, tensile modulus TM, inter-filament bonding strength IF-TS, inter-filament bonding modulus IF-TM, and interlaminar shear strength ILSS; S30, selecting printing parameters to be optimized in the additive process, wherein the printing parameters include the printing temperature T n , Printing speed S p , printing layer height LT and extrusion multiple EM; S40, after designing the test matrix of the single material, a mathematical model between the mechanical properties of the single material and the printing parameters is established by response surface methodology, wherein the test matrix includes stretching the single material in the X direction at 0° to test the tensile modulus TM and the tensile strength TS, stretching the single material in the Y direction at 90° to test the inter-filament bonding strength IF-TS and the inter-filament bonding modulus IF-TM, and a short beam shear test in the Z direction to test the interlaminar shear strength ILSS; S50, according to the mathematical model, respectively determine the combination of the two printing parameters that produce the strongest comprehensive mechanical properties and the weakest comprehensive mechanical properties through a multi-objective optimization method, and the combination of the printing parameters that produces the weakest comprehensive mechanical properties is: The combination of printing parameters with the strongest comprehensive mechanical properties is: And 260℃≤T n ≤290℃,0.1mm≤LT≤0.2mm,20mm / s≤S p ≤60mm / s, 95%≤EM≤105%, wherein x represents different combinations of the printing parameters, f1(x) is used to represent the X-axis 0° tensile properties of the tensile modulus TM and tensile strength TS of the single material, and f2(x) is used to represent the comprehensive properties of the inter-filament properties and inter-layer properties of IF-TS, IF-TM and ILSS of the single material; S60, additive manufacturing is performed by alternating between a combination of printing parameters with the strongest comprehensive mechanical properties and a combination of printing parameters with the weakest comprehensive mechanical properties, thereby achieving alternating deposition of strong and weak phases in the same additively manufactured sample, and constructing a bionic layered structure with alternating strong / weak phases having soft / hard inter-filament and inter-layer interface properties.

2. The method for manufacturing a strong and tough structure based on a single material and a combination of multiple printing parameters according to claim 1, characterized in that: in, The combination of printing parameters with the strongest mechanical properties is used to optimize the TS, TM, IF-TS, IF-TM and ILSS of the single material to adapt to the structure requiring high strength performance. The combination of printing parameters that integrate the weakest mechanical properties is used to optimize the plasticity and toughness of the strong phase, so that the single material has better energy absorption capacity and impact strength.

3. The method for manufacturing a strong and tough structure based on a combination of multiple printing parameters of a single material according to claim 1 or 2, characterized in that: The following steps are also included: S70, determining the energy absorption value of the bionic layered structure by a Charpy impact test, The strain distribution and energy absorption behavior of the bionic layered structure during bending were determined by a three-point bending test combined with DIC technology. The crack propagation mechanism and energy absorption path of the bionic layered structure are obtained by analyzing the internal microstructure damage through SEM images and the change of strain field through DIC images in Charpy impact test and three-point bending test; S80, combining the test results in step S70 to verify the strength and energy absorption characteristics of the bionic layered structure.

4. An application of the method for additive manufacturing of a strong and tough structure based on a single material and a combination of multiple printing parameters as described in any one of claims 1 to 3 in aerospace, automotive industry, protective equipment and sports equipment.

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