Stress-adjustable composite material plate and preparation method thereof

Abstract

The invention discloses a stress-adjustable composite material plate and a preparation method thereof. The stress-adjustable composite material plate comprises an ECC plate layer, the ECC plate layer is laid on the back face of the base plate, the sandwich plate is laid on the back face of the ECC plate layer, CFRP plate layers of the sandwich plate are bonded to the two opposite sides of an Fe-SMA plate layer of the sandwich plate respectively, a reinforcing section is arranged in the middle of the Fe-SMA plate layer, anchoring sections are arranged at the two opposite ends of the Fe-SMA plate layer, and heating activation sections are formed between the reinforcing section and the anchoring sections. The CFRP plate layer comprises a reinforcing plate section bonded to the reinforcing section and an anchoring plate section bonded to the anchoring section, and the anchoring plate section is fixedly installed on the back face through an anchoring part. And the fire-resistant isolation layer is arranged between the heating activation section and the back surface. The problems that in the process of heating and activating the Fe-SMA by the Fe-SMA and ECC combined composite material, due to the sensitivity of ECC to high temperature, the mechanical property of the composite material is possibly reduced, and the overall performance of the composite material is influenced are solved.

Description

Technical Field

[0001] The 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 structure reinforcement in recent years due to its unique shape memory effect and excellent mechanical properties. The shape memory effect of Fe-SMA enables it to return to a preset shape after heating to a certain temperature, and introduces prestress in the process, thereby significantly improving the bearing capacity and durability of the reinforced structure. After the Fe-SMA material is activated by heating, it can maintain the preset shape during the cooling process to room temperature, and can still maintain prestress under the action of external loads. This feature makes Fe-SMA perform well in long-term reinforcement. For example, Soroushian et al. successfully applied Fe-SMA slabs to control the expansion of shear cracks in a bridge repair project in Michigan. By fixing the Fe-SMA slabs with anchor bolts and combining heating activation, Fe-SMA effectively introduces prestress, significantly extending the service life of the bridge. This reinforcement effect is not only stable in the short term, but also has long-term durability, which is particularly suitable for infrastructure such as bridges and tunnels that are 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 plates show 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 have a unique shape memory effect in civil engineering structural reinforcement, and can introduce prestress through heating activation, thereby greatly improving the bearing capacity and durability of the structure. Its temperature responsiveness and high temperature stability make it perform well under dynamic load conditions, and it is especially suitable for infrastructure reinforcement 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 have an impact on its bonding interface, which requires further design optimization to solve.

[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 subjected to 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 the reinforcement of 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 materials enables them to maintain good integrity under extreme load conditions, avoiding the brittle failure of traditional concrete when destroyed. In addition, ECC materials also have a certain self-healing ability, which can repair their own microcracks under appropriate conditions, thereby restoring some mechanical properties. This self-healing property is particularly important in long-term use and helps to delay the degradation of material properties. Yang Shan's research shows that although ECC materials show a certain decline in mechanical properties at high temperatures, their self-healing ability at room temperature helps to restore their crack resistance and strength to a certain extent. ECC not only has excellent crack resistance and ductility, but also can be adjusted according to specific engineering needs to adapt to different environmental conditions and functional requirements. For example, ECC materials can optimize their tensile strength, bending resistance and durability by adjusting the fiber type and proportion, making them suitable for a variety of scenarios such as bridges, tunnels, and buildings in earthquake zones. In Kang Liping's research, the composite structure formed by combining ECC with FRP bars showed good bearing capacity and crack resistance in high temperature environments. This combination has broad application prospects in seismic performance and high temperature environments.

[0007] Although Fe-SMA and ECC each show significant advantages in structural reinforcement and repair, there are technical challenges in combining the two in practical applications. Fe-SMA may cause stress concentration at the interface during the heating activation process, especially when combined with ECC. Due to the sensitivity of ECC to high temperatures, its mechanical properties may decrease, thereby affecting the overall performance of the composite material. How to protect the ECC material during the heating activation of Fe-SMA, reduce the adverse effects of heat conduction on the performance of ECC, and ensure the bonding strength and long-term stability between the two are the core issues to be solved by the present invention. Summary of the invention

[0008] In order to overcome the defects of the prior art, a stress-adjustable composite material plate and a preparation method thereof are provided to solve the problem that during the heating and activation 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] In order 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 side and a back side;

[0011] A sandwich panel laid on the back of the ECC board layer, the sandwich panel includes a CFRP board layer and a Fe-SMA board layer, the CFRP board layers are bonded to opposite sides of the Fe-SMA board layer respectively, a reinforcement section is provided in the middle of the Fe-SMA board layer, and anchoring sections are provided at opposite ends of the Fe-SMA board layer, a heating activation section is formed between the reinforcement section and the anchoring section, the CFRP board layer includes a reinforcement board section bonded to the reinforcement section and an anchoring board section bonded to the anchoring section, and the anchoring board section is fixedly installed on the back side by an anchoring piece;

[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 insulation 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 reinforcing sheet section of the CFRP sheet is bonded to the reinforcing section of the Fe-SMA sheet, and the anchoring sheet 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 placed 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 zone is 200°C.

[0025] The beneficial effect of the present invention is that the stress-adjustable composite material plate of the present invention introduces a heat insulation layer or FRP material between Fe-SMA and ECC, and adopts a combination of bonding and mechanical anchoring to ensure that the composite material still has excellent mechanical properties and long-term durability in a high-temperature environment. The stress-adjustable composite material plate of the present invention can not only give full play to the shape memory effect of Fe-SMA and realize stress adjustment inside the structure, but also protect the ECC material in a high-temperature environment, thereby 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 by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0027] Figure 1 It is a schematic structural diagram of a stress-adjustable composite material plate according to an embodiment of the present invention.

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

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

[0030] Figure 4 It 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 in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant inventions, rather than to limit the inventions. It should also be noted that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0032] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present 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 side and a back side.

[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 plate layers are bonded to opposite sides of the Fe-SMA plate 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 heating activation section a is formed between the reinforcement section and the anchor section.

[0039] The CFRP plate layer includes a reinforcing plate segment 221 and an anchoring plate segment 222. The reinforcing plate segment 221 is bonded to the reinforcing section. The anchoring plate segment 222 is bonded to the anchoring section. The anchoring plate segment 222 is fixedly mounted on the back side by an anchoring piece 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 respectively embedded at both ends of the ECC plate layer 1. The number of anchor bolts is multiple. The multiple anchor bolts are arranged in a matrix. Correspondingly, the number of perforations on the anchoring section of the Fe-SMA plate layer 21 and the anchoring plate section 222 of the CFRP plate layer is multiple. The multiple perforations are arranged in a matrix.

[0042] As a preferred implementation mode, 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 plate layer and the CFRP plate layer and the Fe-SMA plate layer mainly relies on a high-strength adhesive. The adhesive can be of different types, such as modified epoxy resin, polyurethane adhesive, etc. The adhesive has different advantages in different environments, such as higher shear resistance or better chemical resistance.

[0044] In addition to adhesives, the connection between ECC plates and CFRP plates and Fe-SMA plates can also be replaced by mechanical connection methods, such as using clips, screws or special connectors. These methods can reduce or avoid the use of adhesives, especially when the ambient temperature changes greatly. Mechanical connection can effectively avoid stress concentration problems caused by different 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 material sheet of the present invention uses other high-performance fiber materials (such as glass fiber, basalt fiber, etc.) to replace the CFRP plate layer or memory alloys (such as NiTi shape memory alloy) to replace the Fe-SMA plate layer. These materials may provide better cost-effectiveness or special 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, chemical etching) to enhance the interface bonding strength, or use 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 arranged 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 plate of the present invention introduces a heat-insulating layer or FRP material between Fe-SMA and ECC, and adopts a combination of bonding and mechanical anchoring to ensure that the composite material still has excellent mechanical properties and long-term durability in a high-temperature environment. The stress-adjustable composite material plate of the present invention can not only give full play to the shape memory effect of Fe-SMA and achieve stress adjustment inside the structure, but also protect the ECC material in a high-temperature environment, thereby 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 isolation 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 reducing agent, expansion agent, etc.) to prepare the materials for the ECC board layer.

[0058] S12. Mix ratio design: According to the design requirements, the materials are mixed in proportion and evenly stirred by 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, vibrate and compact it to form the ECC board. Then carry out proper 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 grinding: The surface of the ECC plate layer and the CFRP plate layer is sandblasted and polished to enhance the surface roughness and improve the adhesion effect of the adhesive.

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

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

[0064] Ceramic fiber cloth is pasted under the preset heating activation section of the Fe-SMA board to reduce the impact of high temperature on the performance of the ECC board. The refractory insulation layer should cover the heating area flatly and be fixed with a high-temperature refractory adhesive to ensure that it does not shift during the heating process.

[0065] S2. CFRP plate layers are respectively bonded to the 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 board layer and the bottom CFRP board layer:

[0068] Apply high-strength adhesive evenly on the surface of the pre-treated ECC sheet, and then place the perforated CFRP sheet (bottom layer) on the ECC sheet coated with adhesive to ensure that it fits tightly with the ECC sheet. The holes of the CFRP sheet should be aligned with the predetermined position for subsequent bolt fixing.

[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 located within the designed heating activation area. After laying the Fe-SMA sheet, evenly apply a layer of high-strength adhesive on it.

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

[0072] Before installing the top CFRP sheet, the adhesive should be evenly applied to the area of ​​the bottom CFRP sheet that is not covered with 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 layer:

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

[0075] S25, anchor bolt fixing:

[0076] The upper and lower CFRP sheets and Fe-SMA sheets are fixed together with anchor bolts through the reserved holes. The tightening force of the anchor bolts should be moderate to ensure the overall firmness and uniform force distribution of the structure. The adhesive not only enhances the bonding strength of the interface, but also provides additional shear resistance to ensure the long-term stability of the overall structure.

[0077] S26, the connection between the middle reinforcement plate section of the CFRP plate layer and the Fe-SMA plate layer and the bottom ECC plate layer is completely bonded by high-strength adhesive, without bolt anchoring. This design ensures the close connection between the plates, avoids the stress concentration problem caused by mechanical connection, and improves the uniformity and bonding strength of the structure, thereby enhancing the overall performance and long-term stability of the composite plate.

[0078] S3. Lay the sandwich panel 2 on the back side 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 side.

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

[0080] S4. Scanningly heat the heating activation section a of the Fe-SMA plate layer 21 to make the heating activation section a of the Fe-SMA plate layer 21 uniformly activated.

[0081] The heating temperature of the heating activation zone 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 plate layer, and the temperature is controlled at about 200°C. The temperature is monitored in real time by an infrared thermometer to ensure that the heating area is heated evenly while avoiding exceeding the glass transition temperature (Tg) of the binder. In order to protect the ECC plate layer, a refractory cloth is pasted under the Fe-SMA plate layer and fixed with a high-temperature refractory adhesive to prevent high temperature from affecting the performance of the ECC material. In this way, the Fe-SMA plate layer can evenly introduce prestress, improving the overall performance and durability of the composite material plate.

[0084] In some embodiments, an electric heating plate, an induction heater, or a high frequency heating device is used for heating activation. The heating device can provide a more uniform and precise heating effect, especially suitable for scenarios that require precise temperature control 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 plate of the present invention uses a Fe-SMA plate layer and a CFRP plate layer to form a sandwich layer, and then combines the sandwich layer with the ECC plate layer to form a multilayer sandwich structure. This design achieves efficient reinforcement of the structure through the clamping of the upper and lower CFRP plate layers, the active stress adjustment of the Fe-SMA plate layer, and the high ductility and crack resistance of the ECC. The multilayer sandwich structure of the present invention not only improves the overall stiffness and strength, but also optimizes the stress distribution, avoiding the failure modes that may occur in single-layer material reinforcement, such as peeling and crack expansion.

[0089] The stress-adjustable composite material sheet of the present invention uses a heat spray gun to perform precise scanning heating on the Fe-SMA sheet layer, and cooperates with an infrared thermometer for real-time monitoring, thereby ensuring uniform activation of the Fe-SMA sheet layer and avoiding the negative impact of excessive temperature on the binder and ECC material. This sophisticated temperature control technology ensures that the Fe-SMA sheet layer can achieve prestressing without affecting the performance of other materials, thereby ensuring the overall performance of the composite sheet.

[0090] The stress-adjustable composite material plate of the present invention uses a high-strength adhesive to bond the middle CFRP plate layer, the Fe-SMA plate layer and the bottom ECC plate layer, eliminating the reliance on bolt anchoring. This technology effectively reduces the stress concentration problem caused by mechanical connection, ensures the close bonding between the layers of the plate, improves the interface bonding strength, and thus enhances the overall stability and durability of the composite structure.

[0091] The stress-adjustable composite material plate of the present invention introduces a fire-resistant insulation layer, such as ceramic fiber cloth, between the Fe-SMA plate layer and the ECC plate layer to effectively isolate the influence of high temperature on the ECC material during heating activation. The fire-resistant insulation layer of the present invention protects the mechanical properties of the ECC material from the influence of high temperature degradation, ensuring the long-term reliability of the composite material plate and the stability in a high temperature environment.

[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 and mechanical fixation bonding method. This multi-layer bonding method not only enhances the overall strength of the structure, but also significantly improves the fatigue resistance life, allowing it to maintain stability for a long time under complex dynamic load conditions.

[0093] The stress-adjustable composite material sheet of the present invention realizes active stress adjustment through the heating activation function of the Fe-SMA sheet layer, and can introduce prestress into the structure, thereby enhancing the crack resistance and fatigue resistance. This active stress adjustment technology enables the composite sheet to automatically adjust the stress distribution when responding to dynamic loads, significantly improving the adaptability and service life of the structure.

[0094] The stress-adjustable composite material sheet of the present invention uses a high-strength adhesive to combine the layers of the sheet to form a compact and stable multi-layer sandwich structure. The use of the adhesive avoids stress concentration that may be caused by bolt anchoring, and greatly enhances the bonding strength of the interface. By optimizing the interface treatment, the present invention effectively solves the problems of thermal expansion differences and unstable bonding between different materials, and ensures the durability of the overall structure.

[0095] During the heating activation process, the stress-adjustable composite material plate of the present invention effectively reduces the influence of high temperature on ECC by introducing a fire-resistant isolation layer between the Fe-SMA plate layer and the ECC plate layer, and protects its mechanical properties from the negative influence of high temperature activation. This thermal insulation protection measure ensures the stability of the composite plate under high temperature conditions and broadens its application range in harsh environments.

[0096] The stress-adjustable composite material plate of the present invention can realize prestress introduction by heating activation, without the need for large-scale tensioning equipment and complicated construction steps. This simplified construction method not only reduces equipment and labor costs, but also improves construction efficiency and is suitable for various engineering environments.

[0097] The stress-adjustable composite material sheet of the present invention makes full use of the high strength of CFRP, the active stress adjustment of Fe-SMA and the high ductility of ECC through a reasonable combination of multi-layer materials. Such a composite design enables the sheet to have excellent bending, shear, crack and fatigue resistance, realizes the complementary advantages of different materials, and maximizes the reinforcement effect.

[0098] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present 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 side and a back side; A sandwich panel laid on the back of the ECC board layer, the sandwich panel includes a CFRP board layer and a Fe-SMA board layer, the CFRP board layers are bonded to opposite sides of the Fe-SMA board layer respectively, a reinforcement section is provided in the middle of the Fe-SMA board layer, and anchoring sections are provided at opposite ends of the Fe-SMA board layer, a heating activation section is formed between the reinforcement section and the anchoring section, the CFRP board layer includes a reinforcement board section bonded to the reinforcement section and an anchoring board section bonded to the anchoring section, and the anchoring board section is fixedly installed on the back side by an anchoring piece; A fire-resistant insulation layer is provided between the heating activation section and the back surface.

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

3. The stress-adjustable composite material sheet 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 board layer.

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

5. The stress-adjustable composite material sheet 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 sheet 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 sheet 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 sheet 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 reinforcing sheet section of the CFRP sheet is bonded to the reinforcing section of the Fe-SMA sheet, and the anchoring sheet 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 placed 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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