Stress-adjustable composite material plate and preparation method thereof

Abstract

The present application discloses a stress-adjustable composite material plate and its preparation method, comprising: an ECC plate layer; a sandwich panel laid on the back of the ECC plate layer, the CFRP plate layers of the sandwich panel being bonded to opposite sides of the Fe-SMA plate layer of the sandwich panel, a reinforcement section being provided in the middle of the Fe-SMA plate layer, an anchoring section being provided at opposite ends of the Fe-SMA plate layer, a heat-activated section being formed between the reinforcement section and the anchoring section, the CFRP plate layer comprising a reinforcement plate section bonded to the reinforcement section and an anchoring plate section bonded to the anchoring section, the anchoring plate section being fixedly mounted on the back side by anchoring pieces; and a fire-resistant insulation layer being provided between the heat-activated section and the back side. The present invention solves the problem that, for composite materials combining Fe-SMA and ECC, during the process of heating and activating Fe-SMA, the mechanical properties of ECC may be reduced due to its sensitivity to high temperatures, thereby affecting the overall performance of the composite material.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, and in particular to a stress-adjustable composite material plate and a preparation method thereof. Background Art

[0002] Fe-SMA (iron-based shape memory alloy) has been widely used in civil engineering structural reinforcement in recent years due to its unique shape memory effect and excellent mechanical properties. This shape memory effect enables Fe-SMA to return to its preset shape after heating to a certain temperature, introducing prestress in the process, significantly improving the load-bearing capacity and durability of the reinforced structure. After being activated by heating, Fe-SMA retains its preset shape upon cooling to room temperature and maintains prestress under external loads. This characteristic makes Fe-SMA excellent for long-term reinforcement. For example, Soroushian et al. successfully applied Fe-SMA sheets to control the propagation of shear cracks in a bridge repair project in Michigan. By securing the Fe-SMA sheets with anchor bolts and combining them with heat activation, the Fe-SMA effectively introduced prestress, significantly extending the service life of the bridge. This reinforcement effect is not only stable in the short term but also durable over the long term, making it particularly suitable for infrastructure such as bridges and tunnels subject to dynamic loads.

[0003] Compared with traditional materials, Fe-SMA materials can be activated and restore their preset shape at a specific temperature, which brings flexibility to structural reinforcement. By locally heating the Fe-SMA material, prestress can be introduced at specific locations, thereby achieving local reinforcement of the structure and optimizing the overall performance. In addition, the high-temperature stability and fatigue resistance of Fe-SMA materials give it obvious advantages in engineering structures that require long-term load-bearing and fatigue resistance. The research of Wu et al. shows that Fe-SMA plate layers exhibit excellent fatigue life in steel structure reinforcement, and can still maintain prestress under long-term loads, effectively improving the durability of the structure.

[0004] Fe-SMA materials exhibit a unique shape memory effect in civil engineering structural reinforcement, enabling the introduction of prestress through heating activation, significantly enhancing the structure's load-bearing capacity and durability. Their temperature responsiveness and high-temperature stability make them excellent under dynamic load conditions, making them particularly suitable for strengthening infrastructure such as bridges and tunnels that require long-term stability. However, when used in combination with other materials such as ECC, the heating activation process of Fe-SMA may affect the bonding interface, which requires further design optimization to address.

[0005] ECC (engineered cementitious composite) is a high-performance cement-based material known for its excellent crack resistance and ductility. ECC significantly improves the tensile strength and toughness of the material by introducing a small amount of chopped fibers (such as PVA fibers) into the cement matrix, making it widely used in the reinforcement and repair of civil engineering structures. The outstanding feature of ECC material is that it can form multiple microcracks when bearing loads, rather than a small number of large cracks like traditional concrete. This multi-crack behavior effectively limits the width of the cracks and significantly improves the ductility and crack resistance of the material. Kang Liping's research shows that the combination of ECC and FRP for strengthening reinforced concrete beams not only improves the bearing capacity of the beams, but also effectively controls the development of cracks and extends the service life of the structure. This feature enables ECC to provide better crack protection and reduce the risk of crack expansion in structures subjected to repeated loads or seismic effects.

[0006] The high ductility of ECC allows it to maintain excellent integrity under extreme loads, avoiding the brittle failure of traditional concrete upon damage. Furthermore, ECC exhibits a certain degree of self-healing ability, repairing microcracks under appropriate conditions and thereby restoring some of its mechanical properties. This self-healing property is particularly important during long-term use, helping to slow the degradation of material properties. Yang Shan's research has shown that while ECC exhibits some degradation in mechanical properties at high temperatures, its self-healing ability at room temperature helps restore its crack resistance and strength to a certain extent. ECC not only exhibits excellent crack resistance and ductility, but also can be formulated to suit specific engineering requirements, adapting to varying environmental conditions and functional needs. For example, ECC can optimize its tensile strength, flexural properties, and durability by adjusting the fiber type and ratio, making it suitable for a variety of applications, including bridges, tunnels, and buildings in seismic zones. Kang Liping's research has shown that composite structures formed by combining ECC with FRP rebar exhibit excellent load-bearing capacity and crack resistance under high-temperature conditions. This combination holds great promise for applications in seismic performance and high-temperature environments.

[0007] Although Fe-SMA and ECC each exhibit significant advantages in structural reinforcement and repair, their combination in practical applications presents technical challenges. Fe-SMA can induce stress concentration at the interface during heating and activation, particularly when combined with ECC. Due to ECC's sensitivity to high temperatures, this can lead to a decrease in its mechanical properties, thus affecting the overall performance of the composite material. The core issue addressed by this invention is how to protect the ECC material during Fe-SMA heating and activation, reduce the adverse effects of heat conduction on ECC performance, and simultaneously ensure the bond strength and long-term stability between the two. Summary of the Invention

[0008] In order to overcome the defects of the existing technology, a stress-adjustable composite material plate and a preparation method thereof are provided to solve the problem that during the heating activation process of the Fe-SMA composite material, the mechanical properties of the ECC may decrease due to the sensitivity of ECC to high temperature, thereby affecting the overall performance of the composite material.

[0009] To achieve the above object, a stress-adjustable composite material plate is provided, comprising:

[0010] An ECC board layer, wherein the ECC board layer has a front surface and a back surface;

[0011] a sandwich panel laid on the back side of the ECC plate layer, the sandwich panel comprising a CFRP plate layer and an Fe-SMA plate layer, the CFRP plate layers being bonded to opposite sides of the Fe-SMA plate layer, a reinforcement section being provided in the middle of the Fe-SMA plate layer, and anchoring sections being provided at opposite ends of the Fe-SMA plate layer, a heat-activated section being formed between the reinforcement section and the anchoring section, the CFRP plate layer comprising a reinforcement plate section bonded to the reinforcement section and an anchoring plate section bonded to the anchoring section, the anchoring plate section being fixedly mounted to the back side via anchoring pieces;

[0012] A fire-resistant insulation layer is provided between the heating activation section and the back surface.

[0013] Furthermore, the sandwich panel is arranged in the middle of the back side.

[0014] Furthermore, the anchoring section and the anchoring plate section are respectively provided with through-holes, and the anchoring piece is passed through the through-holes of the anchoring section and the anchoring plate section and anchored to the ECC board layer.

[0015] Furthermore, there are multiple perforations, and the multiple perforations are arranged in a matrix.

[0016] Furthermore, the CFRP plate layer is bonded to the Fe-SMA plate layer by an adhesive.

[0017] Furthermore, the fire-resistant isolation layer is bonded to the back surface by a high-temperature fire-resistant adhesive.

[0018] Furthermore, the fire-resistant isolation layer is a ceramic fiber cloth layer, a high-temperature silica gel layer, or a graphite sheet layer.

[0019] The present invention provides a method for preparing a stress-adjustable composite material plate, comprising the following steps:

[0020] Lay fire-resistant insulation layers at opposite ends of the ECC slab;

[0021] Bonding CFRP sheets to opposite sides of the Fe-SMA sheet to form a sandwich panel, such that the reinforcement section of the CFRP sheet is bonded to the reinforcement section of the Fe-SMA sheet, and the anchoring section of the CFRP sheet is bonded to the anchoring section of the Fe-SMA sheet;

[0022] Laying the sandwich panel on the back side of the ECC board layer so that the fire-resistant insulation layer is interposed between the heat-activated section and the back side;

[0023] The heating activation section of the Fe-SMA plate layer is subjected to scanning heating so that the heating activation section of the Fe-SMA plate layer is uniformly activated.

[0024] Furthermore, the heating temperature of the heating activation section is 200°C.

[0025] The beneficial effects of the present invention lie in that the stress-adjustable composite material sheet of the present invention, by introducing a thermal insulation layer or FRP material between the Fe-SMA and the ECC and employing a combination of bonding and mechanical anchoring, ensures that the composite material maintains excellent mechanical properties and long-term durability even in high-temperature environments. The stress-adjustable composite material sheet of the present invention not only fully utilizes the shape memory effect of the Fe-SMA to achieve internal stress regulation, but also protects the ECC material in high-temperature environments, improving the service life and safety of the overall structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0027] Figure 1 Schematic diagram of the structure of a stress-adjustable composite material plate according to an embodiment of the present invention.

[0028] Figure 2 This is a front view of a stress-adjustable composite material plate according to an embodiment of the present invention.

[0029] Figure 3 This is a side view of a stress-adjustable composite material plate according to an embodiment of the present invention.

[0030] Figure 4 This is a schematic diagram of the decomposed structure of the stress-adjustable composite material plate according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the invention are shown in the accompanying drawings.

[0032] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0033] Reference Figures 1 to 4 As shown, the present invention provides a stress-adjustable composite material plate, comprising: an ECC plate layer 1, a sandwich panel 2 and a fire-resistant isolation layer 3.

[0034] In this embodiment, the ECC board layer 1 is rectangular and has a front surface and a back surface.

[0035] The sandwich panel 2 is laid on the back side of the ECC board layer 1. As a preferred embodiment, the sandwich panel 2 is arranged in the middle of the back side.

[0036] Specifically, the sandwich panel 2 includes a CFRP plate layer and a Fe-SMA plate layer 21 .

[0037] CFRP sheet layers are bonded to opposite sides of the Fe-SMA sheet layer 21 .

[0038] A reinforcement section is provided in the middle of the Fe-SMA plate layer 21. Anchor sections are provided at opposite ends of the Fe-SMA plate layer 21. A heat activation section a is formed between the reinforcement section and the anchor section.

[0039] The CFRP sheet layer includes a reinforcement plate segment 221 and an anchoring plate segment 222. The reinforcement plate segment 221 is bonded to the reinforcement section. The anchoring plate segment 222 is bonded to the anchoring section. The anchoring plate segment 222 is fixed to the back surface via anchors 23.

[0040] As a preferred embodiment, the anchoring section of the Fe-SMA plate layer 21 and the CFRP plate layer anchoring plate section 222 are respectively provided with through-holes. Anchor bolts are passed through the through-holes of the anchoring section and the anchoring plate section 222. The anchor bolts are anchored to the ECC plate layer 1.

[0041] In this embodiment, see Figure 4 As shown, anchor bolts are embedded at each end of the ECC slab 1. There are multiple anchor bolts, arranged in a matrix. Correspondingly, there are multiple perforations in the anchoring section of the Fe-SMA slab 21 and the anchoring section of the CFRP slab 222. These perforations are arranged in a matrix.

[0042] As a preferred embodiment, the CFRP plate layer is bonded to the Fe-SMA plate layer 21 by an adhesive 24 .

[0043] In the present invention, the connection between the ECC sheet and the CFRP and Fe-SMA sheets primarily relies on a high-strength adhesive. Various adhesive types can be used, such as modified epoxy resins and polyurethane adhesives. Adhesives offer different advantages in different environments, such as higher shear resistance or better chemical resistance.

[0044] In addition to adhesives, mechanical connections can be used to connect ECC sheets to CFRP and Fe-SMA sheets, such as snaps, screws, or specialized connectors. These methods can reduce or eliminate the need for adhesives, especially in environments with large temperature fluctuations. Mechanical connections can effectively avoid stress concentration caused by differences in thermal expansion coefficients.

[0045] In this embodiment, the stress-adjustable composite material plate of the present invention uses a combination of CFRP, Fe-SMA and ECC.

[0046] In some embodiments, the stress-adjustable composite sheet of the present invention may utilize other high-performance fiber materials (e.g., glass fiber, basalt fiber, etc.) to replace the CFRP sheet layer, or shape memory alloys (e.g., NiTi shape memory alloy) to replace the Fe-SMA sheet layer. These materials may offer better cost-performance or specific environmental tolerance in specific application scenarios.

[0047] In addition to using adhesives, the interlayer bonding of CFRP sheets, Fe-SMA sheets and ECC sheets can also be enhanced through surface physical treatment (such as sandblasting and chemical etching) to enhance the interface bonding strength, or by using nano-reinforced materials to form a stronger bonding force at the interface to reduce the risk of interface failure.

[0048] The fire-resistant insulation layer 3 is interposed between the heat-activated section a of the Fe-SMA board layer 21 and the back surface of the ECC board layer 1 .

[0049] In this embodiment, the fire-resistant insulation layer 3 is bonded to the back surface by a high-temperature fire-resistant adhesive.

[0050] Specifically, the fire-resistant isolation layer 3 is a ceramic fiber cloth layer, a high-temperature silica gel layer, or a graphite sheet layer.

[0051] In this embodiment, ceramic fiber cloth is used as the fire-resistant insulation layer, which has high temperature resistance and heat insulation effect.

[0052] In some embodiments, the fire-resistant insulation layer is a high-performance thermal insulation coating, such as a high-temperature resistant polyimide coating, which can be directly coated on the surface of the Fe-SMA board layer and the ECC board layer, simplifying the construction of the thermal insulation layer and reducing the impact on the overall thickness of the structure.

[0053] The stress-adjustable composite material sheet of the present invention incorporates a thermal insulation layer or FRP material between the Fe-SMA and ECC, and employs a combination of bonding and mechanical anchoring to ensure the composite material maintains excellent mechanical properties and long-term durability even in high-temperature environments. The stress-adjustable composite material sheet of the present invention not only fully utilizes the shape memory effect of the Fe-SMA to achieve internal stress regulation, but also protects the ECC material in high-temperature environments, improving the service life and safety of the overall structure.

[0054] The present invention provides a method for preparing a stress-adjustable composite material plate, comprising the following steps:

[0055] S1. Lay fire-resistant insulation layers 3 at opposite ends of the ECC board layer 1.

[0056] In this embodiment, the preparation of the ECC board layer includes the following steps:

[0057] S11. Raw material preparation: Use high-performance cement, fine aggregate, PVA fiber and appropriate amount of admixtures (such as water reducer, expansion agent, etc.) to prepare the materials for the ECC board layer.

[0058] S12. Mix ratio design: According to the design requirements, mix the materials in proportion and stir them evenly through mechanical stirring to ensure the uniformity of the materials and good workability.

[0059] S13, Forming and Curing: Pour the mixed ECC board material into the mold and vibrate it to form the ECC board. Then, carry out appropriate curing to ensure that the strength and ductility of the ECC board meet the design requirements.

[0060] The pretreatment of the ECC board surface includes the following steps:

[0061] S14. Sandblasting and polishing: The surfaces of the ECC and CFRP panels are sandblasted and polished to enhance the surface roughness and improve the adhesion of the adhesive.

[0062] S15. Cleaning: Use a detergent to clean the treated surface to remove residual dust and oil, and ensure that the surface is clean for good adhesion of the adhesive.

[0063] Pasting of refractory cloth for refractory isolation layer:

[0064] Ceramic fiber cloth is applied beneath the pre-set heating activation zone of the Fe-SMA slab to reduce the impact of high temperatures on the ECC slab's performance. The refractory insulation layer should be flat and cover the heated area, secured with a high-temperature refractory adhesive to prevent displacement during heating.

[0065] S2. CFRP plate layers are bonded to opposite sides of the Fe-SMA plate layer 21 to form a sandwich panel 2, so that the reinforcing plate section 221 of the CFRP plate layer is bonded to the reinforcing section of the Fe-SMA plate layer 21, and the anchoring plate section 222 of the CFRP plate layer is bonded to the anchoring section of the Fe-SMA plate layer 21.

[0066] In this embodiment, the combined installation of the Fe-SMA plate layer and the CFRP plate layer includes the following steps:

[0067] S21, between the bottom ECC plate layer and the bottom CFRP plate layer:

[0068] Apply a high-strength adhesive evenly to the surface of the pre-treated ECC sheet. Place the perforated CFRP sheet (base layer) on top of the adhesive-coated ECC sheet, ensuring a tight fit. The holes in the CFRP sheet should be aligned with the intended locations to facilitate subsequent bolting.

[0069] S22, between Fe-SMA plate layer and CFRP plate layer:

[0070] Lay the Fe-SMA sheet on the bottom CFRP sheet. The Fe-SMA sheet should be placed flat on the CFRP sheet, and both ends of the Fe-SMA sheet should be within the designed heating activation area. After laying the Fe-SMA sheet, apply a layer of high-strength adhesive evenly on it.

[0071] S23, between the top CFRP layer and the bottom CFRP layer:

[0072] Before installing the top CFRP sheet, the adhesive should be evenly applied to the area of ​​the bottom CFRP sheet not covered by the Fe-SMA sheet to ensure that the upper and lower CFRP sheets have good bonding properties over the entire contact surface.

[0073] S24. Placement of the top CFRP plate layer:

[0074] The second CFRP sheet (top layer) is placed over the adhesive-coated Fe-SMA sheet and the bottom CFRP sheet. The holes in the top CFRP sheet should align with those in the bottom sheet, ensuring a complete "sandwich" structure and excellent bond strength and structural integrity for the entire assembly.

[0075] S25, anchor bolt fixation:

[0076] Anchor bolts are used through pre-reserved holes to secure the upper and lower CFRP and Fe-SMA sheets together. Moderate tightening force is required to ensure structural integrity and even force distribution. The adhesive not only enhances the bond strength at the interface but also provides additional shear resistance, ensuring the long-term stability of the overall structure.

[0077] The connection between the S26 and CFRP panels' central reinforcement sections, the Fe-SMA panels, and the bottom ECC panels is entirely bonded with a high-strength adhesive, eliminating the need for bolt anchoring. This design ensures a tight bond between the panels, avoiding stress concentration associated with mechanical connections. It also improves structural uniformity and bond strength, thereby enhancing the overall performance and long-term stability of the composite panels.

[0078] S3. Lay the sandwich panel 2 on the back of the ECC board layer 1 so that the fire-resistant insulation layer 3 is placed between the heating activation section a and the back.

[0079] The whole composite panel is cured under appropriate environmental conditions to ensure that the adhesive and bolt connection parts reach the designed strength.

[0080] S4. Scanningly heating the heating activation section a of the Fe-SMA plate layer 21 so that the heating activation section a of the Fe-SMA plate layer 21 is uniformly activated.

[0081] The heating temperature of the heating activation section a is 200°C.

[0082] In this embodiment, a thermal spray gun is used for heat activation.

[0083] Specifically, a thermal spray gun is used to perform scanning heating on the Fe-SMA sheet, with the temperature controlled at around 200°C. An infrared thermometer monitors the temperature in real time to ensure uniform heating across the heated area while preventing the binder's glass transition temperature (Tg) from exceeding the required temperature. To protect the ECC sheet, a refractory cloth is applied beneath the Fe-SMA sheet and secured with a high-temperature refractory adhesive to prevent high temperatures from affecting the ECC material's performance. This allows the Fe-SMA sheet to be uniformly prestressed, improving the overall performance and durability of the composite sheet.

[0084] In some embodiments, heating activation is performed using an electric heating plate, induction heater, or high-frequency heating device. These devices can provide more uniform and precise heating, particularly when precise temperature control is required to avoid negative effects on the adhesive and surrounding materials.

[0085] S5. Quality inspection and performance evaluation.

[0086] S51. Inspection process: Conduct quality inspection on the completed composite material panels, including interface bonding strength, prestress level, high temperature resistance and overall structural performance.

[0087] S52. Performance evaluation: Based on the test results, evaluate whether the composite material sheet meets the design requirements and make adjustments or rework if necessary.

[0088] The stress-adjustable composite material sheet of the present invention uses a sandwich layer formed by Fe-SMA sheets and CFRP sheets, which is then combined with ECC sheets to form a multilayer sandwich structure. This design achieves efficient structural reinforcement through the clamping of the upper and lower CFRP sheets, the active stress regulation of the Fe-SMA sheets, and the high ductility and crack resistance of ECC. The multilayer sandwich structure of the present invention not only improves overall stiffness and strength, but also optimizes stress distribution, avoiding failure modes such as delamination and crack propagation that may occur with single-layer reinforcement.

[0089] The stress-adjustable composite material sheet of this invention utilizes a thermal spray gun to precisely scan and heat the Fe-SMA sheet, coupled with real-time monitoring using an infrared thermometer. This ensures uniform activation of the Fe-SMA sheet while preventing the negative effects of excessive temperatures on the binder and ECC material. This sophisticated temperature control technology ensures that prestressing can be achieved in the Fe-SMA sheet without affecting the properties of other materials, safeguarding the overall performance of the composite sheet.

[0090] The stress-adjustable composite material sheet of this invention utilizes a high-strength adhesive to bond the intermediate CFRP layer, the Fe-SMA layer, and the underlying ECC layer, eliminating the need for bolt anchoring. This technology effectively reduces stress concentration caused by mechanical connections, ensures a tight bond between the sheet layers, and improves interfacial bonding strength, thereby enhancing the overall stability and durability of the composite structure.

[0091] The stress-adjustable composite material panel of the present invention incorporates a fire-resistant insulation layer, such as ceramic fiber cloth, between the Fe-SMA and ECC layers to effectively isolate the ECC material from the high temperatures associated with activation. This fire-resistant insulation layer protects the ECC material from degradation due to high temperatures, ensuring the long-term reliability and stability of the composite panel in high-temperature environments.

[0092] The stress-adjustable composite material sheet of the present invention improves the fatigue resistance of the composite sheet by optimizing the material bonding interface and using a high-strength adhesive combined with mechanical fixation. This multi-layer bonding method not only enhances the overall strength of the structure, but also significantly improves the fatigue life, enabling it to maintain long-term stability under complex dynamic load conditions.

[0093] The stress-adjustable composite material sheet of this invention achieves active stress regulation through the heat activation function of the Fe-SMA layer, introducing prestress into the structure and enhancing its crack and fatigue resistance. This active stress regulation technology enables the composite sheet to automatically adjust its stress distribution in response to dynamic loads, significantly improving the structure's adaptability and service life.

[0094] The stress-adjustable composite material sheet of the present invention utilizes a high-strength adhesive to bond the individual sheet layers together, creating a compact, stable multilayer sandwich structure. The use of the adhesive avoids stress concentrations that can occur with bolt anchoring, while significantly enhancing the bond strength at the interface. By optimizing the interface, the present invention effectively addresses the issues of thermal expansion differences and unstable bonding between different materials, ensuring the durability of the overall structure.

[0095] During the heat activation process, the stress-adjustable composite material sheet of this invention incorporates a fire-resistant insulation layer between the Fe-SMA and ECC layers, effectively reducing the effects of high temperatures on the ECC and protecting its mechanical properties from the negative effects of high-temperature activation. This thermal insulation ensures the stability of the composite sheet under high-temperature conditions, broadening its application in harsh environments.

[0096] The stress-adjustable composite material sheet of the present invention can be prestressed simply by heating and activating it, eliminating the need for large-scale tensioning equipment and complex construction steps. This simplified construction method not only reduces equipment and labor costs, but also improves construction efficiency and is applicable to various engineering environments.

[0097] The stress-adjustable composite sheet of this invention leverages the high strength of CFRP, the active stress regulation of Fe-SMA, and the high ductility of ECC through a rational multi-layered material combination. This composite design provides the sheet with excellent bending, shear, crack, and fatigue resistance, leveraging the complementary strengths of the different materials and maximizing the reinforcement effect.

[0098] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention herein is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the inventive concept. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features having similar functions disclosed in this application.

Claims

1. A stress-adjustable composite material plate, characterized in that: include: An ECC board layer, wherein the ECC board layer has a front surface and a back surface; a sandwich panel laid on the back side of the ECC plate layer, the sandwich panel comprising a CFRP plate layer and an Fe-SMA plate layer, the CFRP plate layers being bonded to opposite sides of the Fe-SMA plate layer, a reinforcement section being provided in the middle of the Fe-SMA plate layer, and anchoring sections being provided at opposite ends of the Fe-SMA plate layer, a heat-activated section being formed between the reinforcement section and the anchoring section, the CFRP plate layer comprising a reinforcement plate section bonded to the reinforcement section and an anchoring plate section bonded to the anchoring section, the anchoring plate section being fixedly mounted to the back side via anchoring pieces; A fire-resistant insulation layer is provided between the heating activation section and the back surface.

2. The stress-adjustable composite material plate according to claim 1, characterized in that: The sandwich panel is arranged in the middle of the back surface.

3. The stress-adjustable composite material plate according to claim 2, characterized in that: The anchoring section and the anchoring plate section are respectively provided with through holes, and the anchoring piece is passed through the through holes of the anchoring section and the anchoring plate section and anchored to the ECC plate layer.

4. The stress-adjustable composite material plate according to claim 3, characterized in that: There are multiple through-holes, and the multiple through-holes are arranged in a matrix.

5. The stress-adjustable composite material plate according to claim 1, characterized in that: The CFRP plate layer is bonded to the Fe-SMA plate layer by an adhesive.

6. The stress-adjustable composite material plate according to claim 1, characterized in that: The fire-resistant insulation layer is bonded to the back surface by a high-temperature fire-resistant adhesive.

7. The stress-adjustable composite material plate according to claim 6, characterized in that: The fire-resistant isolation layer is a ceramic fiber cloth layer, a high-temperature silica gel layer, or a graphite sheet layer.

8. A method for preparing a stress-adjustable composite material plate according to any one of claims 1 to 7, characterized in that: The following steps are involved: Lay fire-resistant insulation layers at opposite ends of the ECC slab; Bonding CFRP sheets to opposite sides of the Fe-SMA sheet to form a sandwich panel, such that the reinforcement section of the CFRP sheet is bonded to the reinforcement section of the Fe-SMA sheet, and the anchoring section of the CFRP sheet is bonded to the anchoring section of the Fe-SMA sheet; Laying the sandwich panel on the back side of the ECC board layer so that the fire-resistant insulation layer is interposed between the heat-activated section and the back side; The heating activation section of the Fe-SMA plate layer is subjected to scanning heating so that the heating activation section of the Fe-SMA plate layer is uniformly activated.

9. The preparation method according to claim 8, characterized in that The heating temperature of the heating activation zone is 200°C.

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