High-compressive-strength bicontinuous curved surface structure cement-based piezoelectric composite material and design method thereof

Abstract

The invention provides a high-compressive-strength bicontinuous curved surface structure cement-based piezoelectric composite material and a design method thereof, and relates to the technical field of composite materials. According to the piezoelectric ceramic material of the bicontinuous curved surface shell Schwarz P structure, the Schwarz P structure has unique advantages compared with other structures, the mechanical stability is higher, and the manufacturing feasibility is more prominent. According to the cement-based piezoelectric composite material system with the Schwarz P bicontinuous curved surface as the core, the problems of insufficient compressive strength and uneven stress distribution of the material are solved.

Description

Technical Field

[0001] This invention relates to the technical field of composite materials, and more particularly to a high compressive strength double continuous curved surface structure cement-based piezoelectric composite material and its design method. Background Technology

[0002] Cement-based piezoelectric composites, as a novel intelligent material integrating structural load-bearing and functional sensing properties, have demonstrated unique application value in the field of civil engineering. By combining piezoelectric ceramics with a cement matrix, they can utilize the piezoelectric effect to achieve functions such as structural vibration monitoring and energy harvesting, while also relying on the cement matrix to meet load-bearing requirements. This gives them irreplaceable advantages in scenarios such as bridge health monitoring and building structure vibration control. However, the current engineering applications of this type of material are limited by mechanical performance bottlenecks, especially insufficient compressive strength and uneven stress distribution, which have become key technical obstacles restricting its large-scale promotion.

[0003] Traditional cement-based piezoelectric composites are typically prepared by using particle filling or simple geometric embedding to disperse piezoelectric ceramics within a cement matrix. This conventional structural design has significant drawbacks: Firstly, the difference in elastic modulus between the piezoelectric ceramics and the cement matrix (the elastic modulus of piezoelectric ceramics is typically 60-80 GPa, while that of the cement matrix is ​​approximately 20-30 GPa) leads to significant stress concentration at the interface. When the material is subjected to compressive loads, stress rapidly accumulates at the edges and corners of the piezoelectric ceramic particles, triggering the initiation and propagation of local microcracks, ultimately causing premature material failure. Secondly, the simple geometric shapes of the piezoelectric ceramics cannot form an effective stress transfer network, making it difficult to fully utilize the overall mechanical properties of the material. The compressive strength of traditional granular composites is generally below 19 MPa, severely impacting the material's durability and reliability.

[0004] In existing technologies, some studies have attempted to improve mechanical properties by optimizing the volume fraction of piezoelectric ceramics, but the effects have been limited. When the volume fraction is below 10%, the reinforcing effect of piezoelectric ceramics on the matrix is ​​not significant; when it exceeds 15%, the internal porosity of the material increases, leading to a decrease in strength. Furthermore, while fiber reinforcement or surface modification can improve interfacial bonding to some extent, they cannot solve the inherent defects in stress distribution caused by the geometric structure. In terms of structural design, traditional composite materials often adopt regular geometric configurations (such as cubes and spheres), which are prone to stress concentration points under pressure. Theoretical analysis shows that the stress concentration factor of regular geometric bodies can reach 1.8-2.3, while the stress concentration factor of bicontinuous surface structures can be reduced to below 1.2. However, existing technologies have not yet introduced bicontinuous surface structures into the design of cement-based piezoelectric composite materials, lacking in-depth research on the correlation mechanism between the material's microstructure and macroscopic mechanical properties, thus failing to fundamentally solve the problems of stress concentration and insufficient strength. Summary of the Invention

[0005] Based on the aforementioned technical problems of insufficient mechanical properties, uneven stress distribution, and limited durability of traditional piezoelectric composite materials, this invention provides a solution for improving the performance of cement-based composite materials based on Schwarz P double-continuous surface piezoelectric ceramics. This invention proposes a piezoelectric ceramic material with a double-continuous surface shell Schwarz P structure. The Schwarz P structure has unique advantages compared to other structures, including higher mechanical stability and significantly improved manufacturing feasibility. A cement-based piezoelectric composite material system with the Schwarz P double-continuous surface as its core addresses the problems of insufficient compressive strength and uneven stress distribution in traditional piezoelectric composite materials.

[0006] The technical means employed in this invention are as follows: A piezoelectrically reinforced cement-based composite material based on Schwarz P double continuous surface, comprising a double continuous interpenetrating three-dimensional network structure formed by a cement matrix and a piezoelectric ceramic phase.

[0007] Furthermore, the three-dimensional network structure is constructed through the following steps: A parametric modeling method was used to construct a three-dimensional topological structure of the Schwarz P double continuous surface, and its periodic symmetry characteristics were used to optimize the spatial mesh distribution and reduce the number of sharp corners and grooves. The cement matrix is ​​characterized using a concrete damage plasticity model, and the material parameters are defined as follows: viscosity parameter 0.005~1×10⁻⁶. -4 The stress ratio is 0.667~1.16, and the expansion angle is 30°~35°; the piezoelectric ceramic phase is PZT-5H, adopting a linear elastic constitutive relationship, and the interface between the two phase materials is set with bonded contact, i.e., Tie constraint; the volume fraction of the piezoelectric ceramic phase is 10%~15%. The three-dimensional network structure generates a periodic unit cell structure through the implicit function equation of the Schwarz P surface, and the array is expanded into a cubic specimen. The bottom of the specimen is subject to a fixed constraint of full degrees of freedom, i.e., UX=UY=UZ=0, and the top is loaded using a displacement control mode with a loading rate of 0.01mm / s~0.1mm / s. Activate the compressive damage evolution parameters of the CDP model, define the correlation curve between the compressive damage variable DAMAGEC and the plastic strain, and initiate damage evolution when the stress reaches 70% of the peak strength. By adjusting the radius of curvature of the Schwarz P bicontinuous surface using a topology optimization algorithm, the peak height of the surface is reduced by 15%, resulting in a gradient distribution of stress along the thickness direction. A force-electric coupling module is introduced to apply a short-circuit boundary condition, i.e., potential V=0, to the piezoelectric ceramic phase; The piezoelectric ceramic phase is arranged along the principal stress direction of the Schwarz P double continuous surface, and a 0.2 mm thick carbon fiber mesh is embedded in the edge region of the specimen to form a composite reinforcement structure with the Schwarz P double continuous surface; The stiffness reduction rate SDEG is defined as the evaluation index. When SDEG exceeds 0.5, a support rib with a thickness of 0.5 mm is added to the Schwarz P double continuous surface. When the tensile damage DAMAGET exceeds 0.6, the tensile stress is borne by the carbon fiber mesh.

[0008] Furthermore, a 0.1mm transition radius is provided at the sharp corners of the piezoelectric ceramic phase.

[0009] Furthermore, the compression damage evolution parameters of the CDP model are correlated with plastic strain and energy dissipation threshold Gc=50N / m.

[0010] Furthermore, the interfaces between the carbon fiber mesh and the cement matrix and the piezoelectric ceramic phase are all bonded, i.e., tied, forming an integrated stress system.

[0011] Furthermore, the period length of the Schwarz P double continuous surface three-dimensional topology is 50~100μm. After the resin template is prepared by photopolymerization 3D printing technology, it is formed by sintering and grouting processes.

[0012] Furthermore, the elastic modulus of the cement matrix is ​​25 GPa and the Poisson's ratio is 0.2, and the elastic modulus of the piezoelectric ceramic phase is 65 GPa and the Poisson's ratio is 0.3.

[0013] Furthermore, the compressive strength Equivalent plastic strain The maximum value of tensile damage DAMAGET is ≤0.74, the maximum value of compressive damage DAMAGET is ≤0.5099, and the stiffness reduction rate SDEG is ≤0.51.

[0014] Furthermore, the support ribs are evenly distributed along the trough region of the Schwarz P double continuous surface, and the spacing between adjacent support ribs is 1 / 3 of the period length of the surface.

[0015] This invention also includes a design method for piezoelectrically reinforced cementitious composite materials based on Schwarz P double continuous surfaces, comprising the following steps: Step a: Based on the implicit function equation of the Schwarz P surface, a periodic unit cell structure is generated through parametric modeling, and the array is expanded into a 200mm cube specimen model; Step b: Schwarz P double continuous surface resin template is prepared using photopolymerization 3D printing technology, PZT-5H piezoelectric ceramic slurry is injected into the template, and sintering is carried out at 1350℃ to form a continuous ceramic network skeleton. Step c: Inject high-strength cement grout with a water-cement ratio of 0.3 into the voids of the ceramic network skeleton, and compact it by ultrasonic vibration to eliminate interfacial air bubbles; Step d: Before the cement paste initially sets, embed a 0.2 mm thick carbon fiber mesh into the edge area of ​​the specimen, and obtain the finished product after 28 days of standard curing. Step e: Conduct a uniaxial compression test on the finished product to verify whether the compressive strength, damage evolution, and stiffness stability indicators meet the design requirements.

[0016] Compared with the prior art, the present invention has the following advantages: This invention constructs a three-dimensional topological structure of a Schwarz P double continuous surface and optimizes the volume fraction of piezoelectric ceramics to 10%~30%. Utilizing its periodic symmetry, it reduces stress concentration, resulting in a 1.45% increase in compressive strength and a 12%~18% increase in peak load capacity compared to traditional cement-based material models. Through parametric modeling, it reduces the surface peak height by 15%, sets interface transition fillets and binding contacts, and combines this with a CDP model to accurately simulate the damage evolution process, improving stress distribution uniformity by 20% and reducing the top stress concentration factor from 1.82 to 1.35. By employing displacement-controlled loading and full-degree-of-freedom fixed constraints to eliminate force-electric coupling interference, it establishes a multi-parameter evaluation system including SDEG and DAMAGET, embeds carbon fiber mesh to suppress damage propagation, and uses DIC technology to iteratively calibrate simulation parameters, improving the consistency between simulation and experimental data to 92%. This comprehensively solves the problems of insufficient compressive strength, uneven stress distribution, and low simulation accuracy in existing technologies. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating the overall design and analysis method of the present invention.

[0019] Figure 2 This is a structural diagram of the piezoelectric ceramic of the present invention.

[0020] Figure 3 Schwarz structural force-displacement curves.

[0021] Figure 4 Schwarz structural stress-strain curves.

[0022] Figure 5 Compressive damage contour map of Schwarz P bicontinuous structure. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0024] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0025] like Figure 1-5As shown, this invention provides a piezoelectrically reinforced cement-based composite material based on a Schwarz P double-continuous surface, comprising a double-continuous interpenetrating three-dimensional network structure formed by a cement matrix and a piezoelectric ceramic phase. In this application, the three-dimensional network structure is constructed through the following steps: A parametric modeling method was used to construct a three-dimensional topological structure of the Schwarz P double continuous surface, and its periodic symmetry characteristics were used to optimize the spatial mesh distribution and reduce the number of sharp corners and grooves. The cement matrix is ​​characterized using a concrete damage plasticity model, and the material parameters are defined as follows: viscosity parameter 0.005~1×10⁻⁶. -4 The stress ratio is 0.667~1.16, and the expansion angle is 30°~35°; the piezoelectric ceramic phase is PZT-5H, adopting a linear elastic constitutive relationship, and the interface between the two phase materials is set with bonded contact, i.e., Tie constraint; the volume fraction of the piezoelectric ceramic phase is 10%~15%. The three-dimensional network structure generates a periodic unit cell structure through the implicit function equation of the Schwarz P surface, and the array is expanded into a cubic specimen. The bottom of the specimen is subject to a fixed constraint of full degrees of freedom, i.e., UX=UY=UZ=0, and the top is loaded using a displacement control mode with a loading rate of 0.01mm / s~0.1mm / s. Activate the compressive damage evolution parameters of the CDP model, define the correlation curve between the compressive damage variable DAMAGEC and the plastic strain, and initiate damage evolution when the stress reaches 70% of the peak strength. By adjusting the radius of curvature of the Schwarz P bicontinuous surface using a topology optimization algorithm, the peak height of the surface is reduced by 15%, resulting in a gradient distribution of stress along the thickness direction. A force-electric coupling module is introduced to apply a short-circuit boundary condition, i.e., potential V=0, to the piezoelectric ceramic phase; The piezoelectric ceramic phase is arranged along the principal stress direction of the Schwarz P double continuous surface, and a 0.2 mm thick carbon fiber mesh is embedded in the edge region of the specimen to form a composite reinforcement structure with the Schwarz P double continuous surface; The stiffness reduction rate SDEG is defined as the evaluation index. When SDEG exceeds 0.5, a support rib with a thickness of 0.5 mm is added to the Schwarz P double continuous surface. When the tensile damage DAMAGET exceeds 0.6, the tensile stress is borne by the carbon fiber mesh.

[0026] Preferably, the sharp corners of the piezoelectric ceramic phase are provided with a 0.1mm transition fillet.

[0027] In this application, preferably, the compressive damage evolution parameter of the CDP model is correlated with plastic strain and energy dissipation threshold Gc=50N / m.

[0028] In a preferred embodiment of this application, the interfaces between the carbon fiber mesh and the cement matrix and the piezoelectric ceramic phase are all bonded, i.e., tied, to form an integrated stress system.

[0029] Preferably, the period length of the Schwarz P double continuous surface three-dimensional topology is 50~100μm. After the resin template is prepared by photopolymerization 3D printing technology, it is formed by sintering and grouting processes.

[0030] Preferably, the elastic modulus of the cement matrix is ​​25 GPa and the Poisson's ratio is 0.2, and the elastic modulus of the piezoelectric ceramic phase is 65 GPa and the Poisson's ratio is 0.3.

[0031] Preferably, the compressive strength Equivalent plastic strain The maximum value of tensile damage DAMAGET is ≤0.74, the maximum value of compressive damage DAMAGET is ≤0.5099, and the stiffness reduction rate SDEG is ≤0.51.

[0032] Preferably, the support ribs are evenly distributed along the trough region of the Schwarz P double continuous surface, and the spacing between adjacent support ribs is 1 / 3 of the period length of the surface.

[0033] This application also includes a design method for piezoelectrically reinforced cementitious composite materials based on Schwarz P double continuous surfaces, comprising the following steps: Step a: Based on the implicit function equation of the Schwarz P surface, a periodic unit cell structure is generated through parametric modeling, and the array is expanded into a 200mm cube specimen model; Step b: Schwarz P double continuous surface resin template is prepared using photopolymerization 3D printing technology, PZT-5H piezoelectric ceramic slurry is injected into the template, and sintering is carried out at 1350℃ to form a continuous ceramic network skeleton. Step c: Inject high-strength cement grout with a water-cement ratio of 0.3 into the voids of the ceramic network skeleton, and compact it by ultrasonic vibration to eliminate interfacial air bubbles; Step d: Before the cement paste initially sets, embed a 0.2 mm thick carbon fiber mesh into the edge area of ​​the specimen, and obtain the finished product after 28 days of standard curing. Step e: Conduct a uniaxial compression test on the finished product to verify whether the compressive strength, damage evolution, and stiffness stability indicators meet the design requirements.

[0034] Example: As one embodiment of this application, a three-dimensional network structure of bicontinuous interpenetrating cement matrix and piezoelectric ceramic phase is constructed based on the Schwarz bicontinuous surface topology. This structure generates periodic minimum surfaces through rigorous mathematical surface equations, ensuring that the two phases are uniformly distributed and intertwined in space, forming a composite material system integrating mechanics and function. The volume fraction of the piezoelectric ceramic is precisely controlled within the range of 10%-15%, a parameter determined through Abaqus finite element multi-condition optimization, simultaneously maximizing compressive strength (above 22.36 MPa) and minimizing damage accumulation. The matrix material is a cement-based material characterized by the concrete damage plasticity (CDP) model, with its expansion angle set to [value missing]. The stress ratio (fb0 / fc0) is taken as 1.16, and the viscosity coefficient is set to... The parameters were calibrated by uniaxial compression tests to ensure that the model accurately reflects the nonlinear hardening, softening behavior and damage evolution of the material.

[0035] First, a finite element model of a double-continuous interpenetrating structure was constructed based on the Schwarz minimal surface topology, and the entire simulation process was implemented using Abaqus software. Periodic unit cell structures were generated according to the implicit function equations of the Schwarz P-surface, and the array was expanded into 200mm cube specimens. The piezoelectric ceramic network strictly adhered to the surface geometric boundaries to ensure three-dimensional continuity. The cement matrix was modeled using the concrete damage plasticity (CDP) model (elastic modulus 25 GPa, Poisson's ratio 0.2, expansion angle...). The stress ratio is 1.16, and the piezoelectric ceramic phase is simplified as a linear elastic material (elastic modulus 65 GPa, Poisson's ratio 0.3). A "Tie" constraint is applied at the two-phase interface to simulate ideal bonding. A full-degree-of-freedom fixed constraint is applied at the bottom. Simulates rigid support, with displacement control mode at the top. Apply axial compressive load at a certain rate to avoid numerical instability caused by force control. Set the viscosity coefficient to... Compression damage evolution is related to plastic strain and energy dissipation threshold. This ensures that the simulation error rate of the nonlinear response is less than 5%. This modeling mechanism lays the technical foundation for subsequent strength optimization and damage analysis.

[0036] Subsequently, numerical simulations were used to reveal the compressive mechanical behavior of the Schwarz structure and determine the optimal strength parameters. Load-displacement curves ( Figure 2 It exhibits typical three-stage characteristics—the initial linear elastic stage (displacement 0-0.4mm, stiffness...). The compressive strength reaches 22.36 MPa (load capacity) during the plastic transition stage (displacement 0.4-0.8 mm, microcrack propagation) and the peak stage (displacement 0.8-1.0 mm), when the piezoelectric ceramic volume fraction is 10%. At 15%, it is 21.72 MPa. All were significantly higher than the concrete reference value of 20.1 MPa; the strength showed a gradual decreasing trend with increasing volume fraction. : The decline Combined with damage cloud map analysis, it was confirmed that 10%-15% is the optimal range for the synergistic effect of compressive strength and damage inhibition, providing a quantitative basis for material design.

[0037] Furthermore, damage evolution patterns were revealed and suppression strategies were formulated based on compressive damage (DAMAGEC), tensile damage (DAMAGET), and stiffness reduction rate (SDEG). Schwarz structures in... At the piezoelectric ceramic volume fraction, compressive damage is concentrated in the edge region of the specimen (maximum DAMAGEC). Tensile damage is distributed in a controllable "X" shape in the center of the cement matrix (maximum DAMAGET). ), damage value is higher High volume fraction operating conditions reduce Meanwhile, stiffness degradation is significantly limited (SDEG maximum value). Stress concentration at the edges and ceramic-cement interface is dispersed through surface topology optimization, achieving the dual goals of "local load-bearing strengthening + overall damage suppression", providing theoretical support for high durability design.

[0038] During the design process, deformation behavior is precisely quantified and control strategies are formulated using logarithmic strain components (LE) and equivalent plastic strain (PEEQ). At the optimal volume fraction ( Under these conditions, the maximum logarithmic strain component of the Schwarz structure is as low as... (V=10%) and (V=15%), the cloud map shows that the area >85% is blue. This confirms that elastic deformation dominates the overall response; the equivalent plastic strain limit is only... (V=10%) and (V=15%), which is an order of magnitude lower than the above 20% condition, and the strain distribution is highly uniform (with slight concentration in the edge area). The strain characteristics indicate that: (1) the Schwarz surface topology effectively disperses stress and avoids local failure; (2) the accumulation of plastic deformation in the material is significantly suppressed (PEEQ reduction). This provides deformation resistance protection for high-precision piezoelectric devices.

[0039] Finally, the manufacturing process and performance verification are implemented through the following closed-loop process: First, high-precision photopolymerization 3D printing technology is used to prepare Schwarz minimal curved surface resin templates (cycle length 50-100). PZT-5H piezoelectric ceramic slurry was injected into a template and sintered at 1350℃ to form a continuous ceramic network skeleton. Subsequently, high-strength cement slurry with a water-cement ratio of 0.3 was poured into the skeleton voids, and ultrasonic vibration was used to compact and eliminate interfacial air bubbles. After standard curing for 28 days, a double-continuous composite material specimen was obtained. Performance verification showed: (1) Strength matching: The measured compressive strength of the specimen with 10% piezoelectric ceramic volume fraction reached (Simulated value 22.36 MPa), error <3%, 15% volume fraction specimen is (Simulated value 21.72 MPa); Comprehensive analysis shows that this invention achieves a breakthrough improvement in the mechanical properties of materials through the synergistic effect of three technologies: Schwarz double-continuous surface double-continuous topology design, precise control of the piezoelectric ceramic volume fraction (10%-15%), and CDP model parameter optimization. The load is efficiently transferred along the surface normal (the piezoelectric ceramic network bears >60% of the compressive stress), achieving a compressive strength of 22.36 MPa at a 10% volume fraction, an improvement of 11.2% compared to the concrete benchmark, and reducing interfacial stress concentration by 40% compared to traditional composite materials. Stiffness degradation is deeply suppressed to SDEG≤0.51 (approaching a lossless state), tensile damage exhibits a controllable "X"-shaped distribution (DAMAGET≤0.74), and localization of edge compression damage delays overall failure displacement by >0.2 mm. In terms of deformation control, elastic strain dominates >85% (logarithmic strain). The cumulative magnitude of plastic deformation has significantly decreased. (Equivalent plastic strain PEEQ≤) This ensures the stability of the piezoelectric function; the finite element model calibrated with a damage energy threshold of Gc=50N / m forms a closed-loop verification with experiments, and the measured strength... With an error of less than 3% between MPa and the simulated value of 22.36MPa, it provides a long-life solution for demanding engineering scenarios such as nuclear power plant sensor bases (pressure requirements >20MPa) and bridge monitoring nodes (SDEG annual growth rate <0.1).

[0040] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. In the above embodiments of the present invention, the descriptions of each embodiment have their own emphasis; parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments. It should be understood that the disclosed technical content in the several embodiments provided in this application can be implemented in other ways.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A piezoelectrically reinforced cement-based composite material based on a Schwarz P double continuous surface, characterized in that, This includes a bicontinuous interpenetrating three-dimensional network structure formed by a cement matrix and a piezoelectric ceramic phase.

2. The piezoelectrically reinforced cement-based composite material based on the Schwarz P double continuous surface according to claim 1, characterized in that, The three-dimensional network structure is constructed through the following steps: A parametric modeling method was used to construct a three-dimensional topological structure of the Schwarz P double continuous surface, and its periodic symmetry characteristics were used to optimize the spatial mesh distribution and reduce the number of sharp corners and grooves. The cement matrix is ​​characterized using a concrete damage plasticity model, and the material parameters are defined as follows: viscosity parameter 0.005~1×10⁻⁶. -4 The stress ratio is 0.667~1.16, and the expansion angle is 30°~35°; the piezoelectric ceramic phase is PZT-5H, adopting a linear elastic constitutive relationship, and the interface between the two phase materials is set with bonded contact, i.e., Tie constraint; the volume fraction of the piezoelectric ceramic phase is 10%~15%. The three-dimensional network structure generates a periodic unit cell structure through the implicit function equation of the Schwarz P surface, and the array is expanded into a cubic specimen. The bottom of the specimen is subject to a fixed constraint of full degrees of freedom, i.e., UX=UY=UZ=0, and the top is loaded using a displacement control mode with a loading rate of 0.01mm / s~0.1mm / s. Activate the compressive damage evolution parameters of the CDP model, define the correlation curve between the compressive damage variable DAMAGEC and the plastic strain, and initiate damage evolution when the stress reaches 70% of the peak strength. By adjusting the radius of curvature of the Schwarz P bicontinuous surface using a topology optimization algorithm, the peak height of the surface is reduced by 15%, resulting in a gradient distribution of stress along the thickness direction. A force-electric coupling module is introduced to apply a short-circuit boundary condition, i.e., potential V=0, to the piezoelectric ceramic phase; The piezoelectric ceramic phase is arranged along the principal stress direction of the Schwarz P double continuous surface, and a 0.2 mm thick carbon fiber mesh is embedded in the edge region of the specimen to form a composite reinforcement structure with the Schwarz P double continuous surface; The stiffness reduction rate SDEG is defined as the evaluation index. When SDEG exceeds 0.5, a support rib with a thickness of 0.5 mm is added to the Schwarz P double continuous surface. When the tensile damage DAMAGET exceeds 0.6, the tensile stress is borne by the carbon fiber mesh.

3. The piezoelectrically reinforced cement-based composite material based on the Schwarz P double continuous surface according to claim 1, characterized in that, The sharp corners of the piezoelectric ceramic phase are provided with a 0.1mm transition fillet.

4. The piezoelectrically reinforced cement-based composite material based on the Schwarz P double continuous surface according to claim 1, characterized in that, The compression damage evolution parameters of the CDP model are correlated with plastic strain and energy dissipation threshold Gc=50N / m.

5. The piezoelectrically reinforced cement-based composite material based on the Schwarz P double continuous surface according to claim 1, characterized in that, The interfaces between the carbon fiber mesh and the cement matrix and the piezoelectric ceramic phase are all bonded, i.e., tied, forming an integrated stress system.

6. The piezoelectrically reinforced cement-based composite material based on the Schwarz P double continuous surface according to claim 1, characterized in that, The period length of the Schwarz P double continuous surface three-dimensional topology is 50~100μm. After the resin template is prepared by photopolymerization 3D printing technology, it is formed by sintering and grouting processes.

7. The piezoelectrically reinforced cement-based composite material based on the Schwarz P double continuous surface according to claim 1, characterized in that, The elastic modulus of the cement matrix is ​​25 GPa and the Poisson's ratio is 0.2, while the elastic modulus of the piezoelectric ceramic phase is 65 GPa and the Poisson's ratio is 0.

3.

8. The piezoelectrically reinforced cement-based composite material based on the Schwarz P double continuous surface according to claim 1, characterized in that, The compressive strength Equivalent plastic strain The maximum value of tensile damage DAMAGET is ≤0.74, the maximum value of compressive damage DAMAGET is ≤0.5099, and the stiffness reduction rate SDEG is ≤0.

51.

9. The piezoelectrically reinforced cement-based composite material based on the Schwarz P double continuous surface according to claim 1, characterized in that, The support ribs are evenly distributed along the trough region of the Schwarz P double continuous surface, and the spacing between adjacent support ribs is 1 / 3 of the period length of the surface.

10. A design method for piezoelectrically reinforced cement-based composite materials based on Schwarz P double continuous surfaces, using the composite material described in any one of claims 1-9, characterized in that, Includes the following steps: Step a: Based on the implicit function equation of the Schwarz P surface, a periodic unit cell structure is generated through parametric modeling, and the array is expanded into a 200mm cube specimen model; Step b: Schwarz P double continuous curved surface resin template is prepared using photopolymerization 3D printing technology, PZT-5H piezoelectric ceramic slurry is injected into the template, and sintering is carried out at 1350℃ to form a continuous ceramic network skeleton. Step c: Inject high-strength cement grout with a water-cement ratio of 0.3 into the voids of the ceramic network skeleton, and compact it by ultrasonic vibration to eliminate interfacial air bubbles; Step d: Before the cement paste initially sets, embed a 0.2 mm thick carbon fiber mesh into the edge area of ​​the specimen, and obtain the finished product after 28 days of standard curing. Step e: Conduct a uniaxial compression test on the finished product to verify whether the compressive strength, damage evolution, and stiffness stability indicators meet the design requirements.

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