Design method of freeze-thaw sensitive composite material for 3D printing

Abstract

The invention provides a design method of a freeze-thaw sensitive composite material for 3D printing. The design method comprises the following steps: S1, selecting a matrix material with differentiated heat conductivity coefficient, thermal expansion coefficient and specific heat capacity; s2, doping microcapsule phase change materials with different phase change temperatures and latent heat values into the matrix material; s3, reinforced fibers are selectively added, and the cementation effect between the base materials is changed; s4, 3D printing process parameters are determined, wherein the 3D printing process parameters comprise the layer thickness, the filling density and the temperature; s5, permutation and combination are performed according to different base materials, microcapsule phase change materials and reinforced fibers and proportions thereof, corresponding freeze-thaw sensitive composite materials are manufactured through 3D printing with different process parameters, corresponding physical and mechanical property tests are performed, a freeze-thaw sensitive-process-performance database is established according to physical and mechanical property test results, and the freeze-thaw sensitive composite material is obtained. And obtaining a mapping relationship among different parameters for subsequent further material development.

Description

Technical Field

[0001] The present invention relates to the field of geotechnical engineering technology, and in particular to a design method for freeze-thaw sensitive composite materials for 3D printing. Background Art

[0002] The number of infrastructure construction projects in my country's high-altitude cold regions is increasing, and projects often face the complex environment of frozen-thaw rock and soil. Under the action of freeze-thaw cycles, the mechanical properties of rock and soil often change significantly, manifested as decreased strength, increased permeability and other problems. These changes directly affect the stability of rock and soil and the safety of engineering structures. Therefore, in-depth research on the behavior of rock and soil in high-altitude cold regions under different environmental conditions is of great significance for engineering construction, especially to provide guarantees for key infrastructure construction projects in high-altitude cold regions.

[0003] Traditional testing methods include in-situ testing and indoor testing, but in-situ testing is often time-consuming and laborious, and sampling for indoor testing also faces many difficulties, making it impossible to achieve repeatability of test results. For this reason, using 3D printing technology to make similar substitutes to simulate rock and soil in high-cold areas for indoor testing has become an effective alternative. However, existing conventional 3D printing technology and its materials have not yet been able to fully reproduce the complex mechanical properties of rock and soil, and it is even more difficult to accurately reflect the impact of freeze-thaw cycles on its performance.

[0004] Therefore, the technical problem that needs to be solved urgently is how to solve the limitations of current materials and technologies, and to simulate the thermal response of real rock and soil by designing a freeze-thaw sensitive composite material for 3D printing, so as to achieve more accurate simulation and performance testing of rock and soil under the influence of freeze-thaw cycles. Summary of the invention

[0005] The present invention is made to solve the above-mentioned problems, and aims to provide a design method of freeze-thaw sensitive composite materials for 3D printing.

[0006] The present invention provides a design method for freeze-thaw sensitive composite materials for 3D printing, which has the following characteristics and specifically includes the following steps: S1, selecting a matrix material with differentiated thermal conductivity, thermal expansion coefficient, and specific heat capacity to simulate the particle skeleton of rock and soil, match the thermal response under different freeze-thaw cycle stages, and increase the basic controllability of freeze-thaw response. The thermal conductivity is used to control the heat transfer during the freeze-thaw process. The difference in thermal expansion coefficient induces controllable microcracks to simulate frost heave stress. The difference in specific heat capacity regulates the absorption of phase change energy, thereby achieving dynamic matching of different freeze-thaw cycle stages and enhancing the response accuracy of the material to temperature field changes; S2, adding microcapsule phase change materials with different phase change temperatures and latent heat values ​​into the matrix material, and forming a thermal response field with different spatial gradient distributions through the interface thermal resistance regulation of the microcapsule wall material to further simulate the water ice phase change process; S3, selectively adding reinforcing fibers to change the bonding effect between the matrix materials, which is used to regulate the strength and freeze-thaw durability of the freeze-thaw sensitive composite material, match the response of the physical and mechanical properties of the material to freeze-thaw, and the reinforcing fibers are used to optimize the bonding of the matrix material. The bridging effect can inhibit the expansion of freeze-thaw cracks, realize the coordinated control of strength and freeze-thaw durability, and match the progressive mechanical attenuation law of materials in freeze-thaw cycles; S4, determine the 3D printing process parameters, which include layer thickness, filling density, and temperature. By adjusting the layer thickness and filling density, an artificial pore network is constructed. By adjusting the temperature, different phase change temperatures and thermal parameters are matched. By systematically studying the relationship between printing process parameters and material properties, the parameter combination can be further optimized, the printing efficiency, material properties and cost are balanced, and the requirements of specific applications are ultimately met; S5, according to different matrix materials, microcapsule phase change materials and reinforcing fibers and their proportions, they are arranged and combined, and corresponding freeze-thaw sensitive composite materials are produced through 3D printing with different process parameters, and corresponding physical and mechanical properties tests are carried out. The physical and mechanical properties tests include uniaxial compressive strength, permeability coefficient, and freeze-thaw durability tests. According to the results of physical and mechanical properties tests, a freeze-thaw sensitivity-process-performance database is established to obtain the mapping relationship between different parameters for subsequent further material development.

[0007] In the design method of freeze-thaw sensitive composite materials for 3D printing provided by the present invention, the following characteristics may also be provided: wherein the matrix material has certain strength and processability, and has differentiated thermal conductivity, thermal expansion coefficient, specific heat capacity, and can form an effective composite material with other components, and the matrix material includes polylactic acid, photocurable resin and silicate gelling material.

[0008] In the design method of freeze-thaw sensitive composite materials for 3D printing provided by the present invention, it can also have the following characteristics: wherein, the steps of simulating the water-ice phase change process are specifically as follows: through the precise regulation of the core material phase change temperature and the latent heat value, the latent heat release and absorption process of the water-ice phase change is simulated in stages, and at the same time, the directional design of the frost heave stress concentration zone is realized through the spatial gradient distribution, the core material phase change temperature is -15°C~5°C, and the latent heat value is 80~220 kJ / kg.

[0009] In the design method of the freeze-thaw sensitive composite material for 3D printing provided by the present invention, it can also have the following characteristics: wherein, the microcapsule phase change material is used to absorb and release heat, thereby regulating the temperature change of the material, imitating the thermodynamic behavior in the freeze-thaw process, including the water ice phase change process, and the microcapsule phase change material includes: encapsulated paraffin, anhydrous sodium sulfate, and the content of the microcapsule phase change material in the freeze-thaw sensitive composite material is 5~15wt% by mass.

[0010] In the design method of the freeze-thaw sensitive composite material for 3D printing provided by the present invention, it can also have the following characteristics: wherein, the reinforcing fiber is used to regulate the strength and freeze-thaw durability of the matrix material and change the physical and mechanical properties of the material, and the reinforcing fiber includes: sisal fiber, glass fiber, polyester fiber, the length of the reinforcing fiber is 0.5~2cm, and the content of the reinforcing fiber in the freeze-thaw sensitive composite material is 0.5~5wt% by mass.

[0011] In the design method of the freeze-thaw sensitive composite material for 3D printing provided by the present invention, it can also have the following characteristics: among the 3D printing process parameters, the printing layer thickness is 0.05~0.2mm, the filling density is 50~100%, the filling method is honeycomb filling or grid filling, and the printing temperature is dynamically adjusted according to the phase change temperature of the matrix material and the microcapsule phase change material.

[0012] In the design method of freeze-thaw sensitive composite materials for 3D printing provided by the present invention, it can also have the following characteristics: wherein, the physical and mechanical properties test in step S5 includes: unconfined compressive strength test to obtain uniaxial compressive strength; permeability test to obtain permeability coefficient; freeze-thaw cycle test to obtain freeze-thaw durability, and the physical and mechanical properties test is carried out according to the "Standard for Geotechnical Test Methods", GB / T50123-2019 and "Physical and Mechanical Properties Test of Artificial Frozen Soil", MT / T593.

[0013] Functions and Effects of the Invention According to the design method of the freeze-thaw sensitive composite material for 3D printing involved in the present invention, the present invention has the following beneficial effects: 1) The present invention can achieve accurate simulation of real rock and soil bodies (such as moraine, clay, etc.), especially their strength changes and permeability changes during freeze-thaw cycles, by regulating the combination of matrix materials, microcapsule phase change materials and reinforcing fibers, and changing corresponding printing process parameters.

[0014] 2) The present invention can meet the characteristic requirements of different rock and soil bodies through the combination of different materials and flexible adjustment of 3D printing process parameters, providing a customized solution for research.

[0015] 3) The present invention uses freeze-thaw sensitive composite materials for 3D printing to conduct indoor freeze-thaw cycle related tests simulating real rock and soil bodies, which can effectively reduce the demand for on-site testing and the complexity of indoor testing, and provide higher repeatability and controllability for the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Flow chart of freeze-thaw sensitive composite material selection in an embodiment of the present invention.

[0017] Figure 2 It is a schematic diagram of the design and test of freeze-thaw sensitive composite materials in an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0019] It should be noted that the structures, proportions, sizes, etc. drawn in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0020] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the following embodiments and accompanying drawings specifically illustrate the design method of the freeze-thaw sensitive composite material for 3D printing of the present invention.

[0021] S1. Select matrix materials with differentiated thermal conductivity, thermal expansion coefficient, and specific heat capacity to simulate the particle skeleton of rock and soil, match the thermal response at different freeze-thaw cycle stages, and increase the basic controllability of freeze-thaw response.

[0022] The thermal conductivity controls the heat transfer during the freezing and thawing process, the difference in thermal expansion coefficients induces controllable microcracks to simulate frost heave stress, and the difference in specific heat capacity regulates the absorption of phase change energy, thereby achieving dynamic matching of different freeze-thaw cycle stages and enhancing the material's response accuracy to changes in temperature field.

[0023] The matrix material has certain strength and processability, and has differentiated thermal conductivity, thermal expansion coefficient, specific heat capacity, and can form an effective composite material with other components. The matrix material includes polylactic acid, photocurable resin and silicate gelling material.

[0024] Polylactic acid, or PLA, is an environmentally friendly material commonly used in 3D printing, with good biodegradability, low printing temperature and excellent surface quality. Due to its low melting point and good layer adhesion, PLA is suitable for rapid prototyping, but its tensile strength and heat resistance are relatively weak, making it unsuitable for use in high load or high temperature environments.

[0025] Photocurable resins are widely used in 3D printing for the manufacture of high-precision and complex models. They can print objects with smooth surfaces and rich details. At the same time, a variety of resin types can be selected to meet different physical property requirements. However, they are expensive, fragile, easy to break or crack, and are not suitable for parts that withstand impact or bending.

[0026] Silicate cementitious materials are widely used in the fields of construction and civil engineering. They have good printability and plasticity, and have high durability and compressive strength.

[0027] S2. Adding microcapsule phase change materials with different phase change temperatures and latent heat values ​​into the matrix material, the microcapsule phase change materials include: encapsulated paraffin wax and anhydrous sodium sulfate. The content of the microcapsule phase change materials in the freeze-thaw sensitive composite material is 5-15wt% by mass.

[0028] Microcapsule phase change materials are used to absorb and release heat, thereby regulating the temperature changes of the material and simulating the thermodynamic behavior during freezing and thawing, including the water-ice phase change process. By regulating the interfacial thermal resistance of the microcapsule wall material, a thermal response field with different spatial gradient distributions is formed to further simulate the water-ice phase change process.

[0029] The specific steps for simulating the water-ice phase change process are as follows: through the precise control of the core material phase change temperature and latent heat value, the latent heat release and absorption process of the water-ice phase change is simulated in stages, and the directional design of the frost heave stress concentration zone is achieved through spatial gradient distribution. Among them, the core material phase change temperature is -15℃~5℃, and the latent heat value is 80~220 kJ / kg.

[0030] S3. Selectively add reinforcing fibers to regulate the strength and freeze-thaw durability of freeze-thaw sensitive composite materials.

[0031] The reinforcing fibers include sisal fibers, glass fibers, and polyester fibers. The length of the reinforcing fibers is 0.5 to 2 cm. Calculated by mass, the content of the reinforcing fibers in the freeze-thaw sensitive composite material is 0.5 to 5 wt %.

[0032] Reinforcing fibers can change the bonding and stress transfer path between matrix materials, change the physical and mechanical properties of materials, inhibit the expansion of freeze-thaw cracks through the bridging effect, achieve coordinated control of strength and freeze-thaw durability, and match the progressive mechanical attenuation law of materials in freeze-thaw cycles.

[0033] S4. Determine the 3D printing process parameters. During the 3D printing process, the 3D printing process parameters including layer thickness, filling density, temperature, etc. have an important influence on the structure and performance of the material.

[0034] By adjusting the layer thickness and filling density, an artificial pore network is constructed. The printing layer thickness is 0.05~0.2mm, the filling density is 50~100%, and the filling method is honeycomb filling or grid filling. The layer thickness determines the printing accuracy and surface quality. Thinner layer thickness can improve accuracy but increase printing time. Filling density directly affects strength and material consumption. High density can enhance strength but increase cost. Temperature control affects material fluidity and adhesion. Too high or too low temperature will cause quality problems. By adjusting the temperature, different phase change temperatures and thermal parameters are matched. The printing temperature is dynamically adjusted according to the phase change temperature of the matrix material and the microcapsule phase change material.

[0035] By systematically studying the relationship between printing process parameters and material properties, we can further optimize parameter combinations, balance printing efficiency, material properties and costs, and ensure that the requirements of specific applications are ultimately met.

[0036] S5. Arrange and combine different matrix materials, microcapsule phase change materials and reinforcing fibers and their proportions, and produce corresponding freeze-thaw sensitive composite materials through 3D printing with different process parameters. Perform corresponding physical and mechanical property tests, including uniaxial compressive strength, permeability and freeze-thaw durability tests. Establish a freeze-thaw sensitivity-process-performance database based on the test results of physical and mechanical properties, and obtain the mapping relationship between different parameters for further material development.

[0037] Table 1 Test plan

[0038] As shown in Table 1, a freeze-thaw sensitivity-process-performance test scheme is established based on a combination of parameters. Specifically, the design test can be performed as in Examples 1-3, which can provide data support for the subsequent use of intelligent methods to produce an alternative model of a rock mass with target properties.

[0039] Example 1 Figure 1 Flow chart of freeze-thaw sensitive composite material selection in an embodiment of the present invention.

[0040] like Figure 1 As shown, the design method of the freeze-thaw sensitive composite material for 3D printing in this embodiment is as follows: S1. Select polylactic acid, i.e. PLA, as the base material for printing.

[0041] S2. Select encapsulated paraffin as the microcapsule phase change material.

[0042] S3, sisal fiber was selected as the reinforcing fiber.

[0043] S4. Determine the 3D printing process parameters, the layer thickness is 0.05 mm, the filling density is 50%, and the filling method is honeycomb filling.

[0044] S5. Based on PLA, encapsulated paraffin and sisal fiber, corresponding freeze-thaw sensitive composite materials are made, and corresponding physical and mechanical properties tests are carried out. The physical and mechanical properties tests include uniaxial compressive strength, permeability coefficient, freeze-thaw durability, and a freeze-thaw sensitivity-process-performance database is established based on the test results for further material development.

[0045] PLA, encapsulating paraffin wax and sisal fibers were mixed to obtain a freeze-thaw sensitive composite material for 3D printing.

[0046] The matrix material should have certain strength and processability, and be able to form an effective composite material with other components. PLA, as a matrix material, is an environmentally friendly material commonly used in 3D printing, with good biodegradability, low printing temperature and excellent surface quality. Due to its low melting point and good layer adhesion, PLA is suitable for rapid prototyping, but its tensile strength and heat resistance are relatively weak, and it is not suitable for use in high load or high temperature environments.

[0047] In order to further simulate the phase change effect of the original rock mass during the freezing and thawing process, microcapsule phase change material is introduced as part of the material for simulation. The encapsulated paraffin in this embodiment is one of the microcapsule phase change materials. Microcapsule phase change materials can absorb and release heat, thereby regulating the temperature change of the material and simulating the thermodynamic behavior during the freezing and thawing process.

[0048] In order to regulate the strength, durability, etc. of the matrix material, reinforcing fibers are added. The sisal fiber in this embodiment is one of the reinforcing fibers, which improves the mechanical properties of the material, especially the compressive strength and tensile strength. These fibers help to enhance the structural stability and freeze-thaw durability of the composite material.

[0049] In the 3D printing of the freeze-thaw sensitive composite material for 3D printing in this embodiment, the printing parameters are as follows: The layer thickness is 0.05mm, the filling density is 50%, and the filling method is honeycomb filling.

[0050] During the 3D printing process, printing parameters such as layer thickness, filling density, and temperature have an important impact on the structure and performance of the material. Layer thickness determines the printing accuracy and surface quality. Thinner layer thickness can improve accuracy but increase printing time; filling density directly affects strength and material consumption. High density can enhance strength but increase cost; temperature control affects material fluidity and adhesion. Too high or too low temperature will cause quality problems. By systematically studying the relationship between printing process parameters and material properties, it is possible to further optimize parameter combinations, balance printing efficiency, material performance, and cost, and ensure that the requirements of specific applications are ultimately met.

[0051] Figure 2 It is a schematic diagram of the design and test of freeze-thaw sensitive composite materials in an embodiment of the present invention.

[0052] like Figure 2 As shown, the freeze-thaw sensitive composite material for 3D printing in this embodiment is tested for physical and mechanical properties, including compressive strength, tensile strength, permeability coefficient, and freeze-thaw cycle durability, etc., to establish a freeze-thaw sensitivity-process-performance database to provide data support for the subsequent use of intelligent methods to make alternative models of rock and soil with target properties. According to the "Standards for Geotechnical Test Methods" and "Physical and Mechanical Properties Tests of Artificial Frozen Soil", uniaxial compression tests, triaxial tests, permeability tests, and freeze-thaw cycle tests are carried out.

[0053] Example 2 like Figure 1 As shown, the design method of the freeze-thaw sensitive composite material for 3D printing in this embodiment is as follows: S1. Select a photocurable resin as the base material for printing.

[0054] S2. Select encapsulated paraffin as the microcapsule phase change material.

[0055] S3, glass fiber is selected as the reinforcing fiber.

[0056] S4. Determine the 3D printing process parameters, the layer thickness is 0.1 mm, the filling density is 100%, and the filling method is grid filling.

[0057] S5. Based on photocurable resin, encapsulation paraffin and glass fiber, corresponding freeze-thaw sensitive composite materials are made, and corresponding physical and mechanical properties tests are carried out. The physical and mechanical properties tests include uniaxial compressive strength, permeability coefficient, freeze-thaw durability, and a freeze-thaw sensitivity-process-performance database is established based on the test results for further material development.

[0058] The photocurable resin, encapsulating paraffin wax and glass fiber are mixed to obtain a freeze-thaw sensitive composite material for 3D printing.

[0059] Photocurable resins are widely used in 3D printing for the manufacture of high-precision and complex models. They can print objects with smooth surfaces and rich details. At the same time, a variety of resin types can be selected to meet different physical property requirements. However, they are expensive, fragile, easy to break or crack, and are not suitable for parts that withstand impact or bending.

[0060] In the 3D printing of the freeze-thaw sensitive composite material for 3D printing in this embodiment, the printing parameters are as follows: The layer thickness is 0.1 mm, the filling density is 100%, and the filling method is grid filling.

[0061] like Figure 2 As shown, the freeze-thaw sensitive composite material for 3D printing in this embodiment is tested for physical and mechanical properties, including compressive strength, tensile strength, permeability coefficient, and freeze-thaw cycle durability, etc., to establish a freeze-thaw sensitivity-process-performance database, and provide data support for the subsequent use of intelligent methods to make alternative models of rock and soil bodies with target properties. According to the "Standard for Geotechnical Test Methods" (GB / T50123-2019) and "Test for Physical and Mechanical Properties of Artificial Frozen Soil" (MT / T593), uniaxial compression tests, triaxial tests, permeability tests, and freeze-thaw cycle tests are carried out, wherein the uniaxial compression test is used to obtain the uniaxial compressive strength; the permeability test is carried out to obtain the permeability coefficient; and the freeze-thaw cycle test is carried out to obtain the freeze-thaw durability.

[0062] Example 3 like Figure 1 As shown, the design method of the freeze-thaw sensitive composite material for 3D printing in this embodiment is as follows: S1. Select silicate gelling material as the base material for printing.

[0063] S2. Select anhydrous sodium sulfate as the microcapsule phase change material.

[0064] S3, polyester fiber is selected as the reinforcing fiber.

[0065] S4. Determine the 3D printing process parameters, the layer thickness is 0.2 mm, the filling density is 50%, and the filling method is honeycomb filling.

[0066] S5. Based on silicate cementitious materials, anhydrous sodium sulfate and polyester fibers, corresponding freeze-thaw sensitive composite materials are manufactured and corresponding physical and mechanical properties tests are carried out. The physical and mechanical properties tests include uniaxial compressive strength, permeability coefficient and freeze-thaw durability. According to the test results, a freeze-thaw sensitivity-process-performance database is established for further material development.

[0067] Silicate gelling material, anhydrous sodium sulfate and polyester fiber are mixed to obtain a freeze-thaw sensitive composite material for 3D printing.

[0068] Silicate cementitious materials are widely used in the fields of construction and civil engineering. They have good printability and plasticity, and have high durability and compressive strength.

[0069] In the 3D printing of the freeze-thaw sensitive composite material for 3D printing in this embodiment, the printing parameters are as follows: The layer thickness is 0.2 mm, the filling density is 50%, and the filling method is honeycomb filling.

[0070] like Figure 2 As shown, the freeze-thaw sensitive composite material for 3D printing in this embodiment is tested for physical and mechanical properties, including compressive strength, tensile strength, permeability coefficient, and freeze-thaw cycle durability, etc., to establish a freeze-thaw sensitivity-process-performance database to provide data support for the subsequent use of intelligent methods to make alternative models of rock and soil with target properties. According to the "Standards for Geotechnical Test Methods" and "Physical and Mechanical Properties Tests of Artificial Frozen Soil", uniaxial compression tests, triaxial tests, permeability tests, and freeze-thaw cycle tests are carried out.

[0071] Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for designing freeze-thaw sensitive composite materials for 3D printing, characterized in that: The specific steps include: S1. Select a matrix material with differentiated thermal conductivity, thermal expansion coefficient, and specific heat capacity to simulate the particle skeleton of rock and soil, match the thermal response at different freeze-thaw cycle stages, and increase the basic controllability of freeze-thaw response. The thermal conductivity is used to control the heat transfer during the freeze-thaw process. The difference in thermal expansion coefficient induces controllable microcracks to simulate frost heave stress. The difference in specific heat capacity regulates the absorption of phase change energy, thereby achieving dynamic matching of different freeze-thaw cycle stages and enhancing the response accuracy of the material to temperature field changes. S2. Adding microcapsule phase change materials with different phase change temperatures and latent heat values ​​into the matrix material, and regulating the interface thermal resistance of the microcapsule wall material to form a thermal response field with different spatial gradient distributions, further simulating the water ice phase change process; S3, selectively adding reinforcing fibers to change the bonding effect between the matrix materials, so as to adjust the strength and freeze-thaw durability of the freeze-thaw sensitive composite material, and match the response of the physical and mechanical properties of the material to freeze-thaw. The reinforcing fibers are used to optimize the bonding effect and stress transfer path of the matrix material, inhibit the expansion of freeze-thaw cracks through the bridging effect, achieve coordinated control of strength and freeze-thaw durability, and match the progressive mechanical attenuation law of the material in the freeze-thaw cycle; S4. Determine 3D printing process parameters, wherein the 3D printing process parameters include layer thickness, filling density, and temperature. By adjusting the layer thickness and filling density, an artificial pore network is constructed. By adjusting the temperature, different phase change temperatures and thermal parameters are matched. By systematically studying the relationship between printing process parameters and material properties, the parameter combination can be further optimized, the printing efficiency, material properties, and cost can be balanced, and the requirements of specific applications can be ultimately met. S5. Arrange and combine the matrix material, the microcapsule phase change material and the reinforcing fiber and their proportions, produce corresponding freeze-thaw sensitive composite materials through 3D printing with different process parameters, and conduct corresponding physical and mechanical property tests, wherein the physical and mechanical property tests include uniaxial compressive strength, permeability coefficient and freeze-thaw durability tests. According to the physical and mechanical property test results, a freeze-thaw sensitivity-process-performance database is established to obtain the mapping relationship between different parameters for further material development.

2. The method for designing a freeze-thaw sensitive composite material for 3D printing according to claim 1, characterized in that: in, The matrix material includes polylactic acid, light-curable resin and silicate gelling material.

3. The method for designing a freeze-thaw sensitive composite material for 3D printing according to claim 1, characterized in that: in, The steps of simulating the water ice phase change process are as follows: adjusting the phase change temperature of the microcapsule core material to -15°C~5°C and the latent heat value distribution to 80~220 kJ / kg, and combining the spatial arrangement of the microcapsules to achieve simulation.

4. The method for designing a freeze-thaw sensitive composite material for 3D printing according to claim 1, characterized in that: in, The microcapsule phase change material comprises: encapsulated paraffin and anhydrous sodium sulfate. The content of the microcapsule phase change material in the freeze-thaw sensitive composite material is 5-15wt% by mass.

5. The method for designing a freeze-thaw sensitive composite material for 3D printing according to claim 1, characterized in that: in, The reinforcing fibers include sisal fibers, glass fibers, and polyester fibers. The length of the reinforcing fibers is 0.5 to 2 cm. The content of the reinforcing fibers in the freeze-thaw sensitive composite material is 0.5 to 5 wt % by mass.

6. The method for designing a freeze-thaw sensitive composite material for 3D printing according to claim 1, characterized in that: in, Among the 3D printing process parameters, the printing layer thickness is 0.05-0.2 mm, the filling density is 50-100%, the filling method is honeycomb filling or grid filling, and the printing temperature is dynamically adjusted according to the phase change temperature of the matrix material and the microcapsule phase change material.

7. The method for designing a freeze-thaw sensitive composite material for 3D printing according to claim 1, Features: Among them, the physical and mechanical properties test in step S5 includes: unconfined compressive strength test to obtain uniaxial compressive strength; permeability test to obtain permeability coefficient; freeze-thaw cycle test to obtain freeze-thaw durability, and the physical and mechanical properties test is carried out according to the "Standard for Geotechnical Test Methods", GB / T50123-2019 and "Physical and Mechanical Properties Test of Artificial Frozen Soil", MT / T593.

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