Composite slab-type draw piece and shear resistance calculation method

Abstract

The present application relates to the field of building, specifically to a composite panel-type tie member and a shear performance calculation method; comprising a steel core layer and outer cover layers located on both sides of the steel core layer to clamp and position the steel core layer; the outer cover layers are made of GFRP material, and the sizes of the two outer cover layers correspond; the size of the steel core layer is smaller than that of the outer cover layer, and the steel core layer and the outer cover layer have an equal proportion corresponding relationship; after the centers of the steel core layer and the outer cover layer are aligned, the gap area between the edges of the outer cover layers and the edges of the steel core layer is filled with bonding material. The tie member has high shear strength and stiffness, and effectively reduces the influence of wallboard thermal bridge effect.

Description

Technical Field

[0001] This invention relates to the field of construction, specifically to a composite plate tie member and a method for calculating its shear resistance. Background Technology

[0002] Precast concrete sandwich insulated wall panels, as a new type of precast reinforced concrete wall panel integrating load-bearing and thermal insulation, place the insulation layer between inner and outer reinforced concrete leaf panels. They feature high fire resistance, excellent safety, and superior durability, achieving a lifespan equal to the structure itself, and are widely used in precast assembled buildings. The inner and outer leaf panels are connected as a whole by tie rods to form a complete structural insulation system. Initially, concrete blocks and steel trusses were often used as tie rods. While these tie rods are inexpensive and easy to use, the high thermal conductivity of steel and concrete leads to significant thermal bridging effects in the resulting wall panels, making it difficult to meet high standards of energy conservation and environmental protection. Furthermore, steel is prone to corrosion during use, which can reduce the safety of the wall panels.

[0003] To avoid thermal bridging, some existing tie rods are made of fiber-reinforced resin composites, which have the advantage of low thermal conductivity. However, while reducing thermal bridging in wall panels, they cannot guarantee effective shear force transfer. Therefore, how to build a new tie rod system that effectively reduces the impact of thermal bridging in wall panels while ensuring high shear strength and stiffness has become an urgent technical problem to be solved. Summary of the Invention

[0004] To avoid and overcome the technical problems existing in the prior art, this invention provides a composite plate tie member and a method for calculating its shear performance. The tie member of this invention possesses high shear strength and stiffness while effectively reducing the impact of thermal bridging in wall panels.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A composite plate-type tie member includes a steel core layer and outer cladding layers located on both sides of the steel core layer to clamp and position the steel core layer; the outer cladding layers are made of GFRP material, and the two outer cladding layers correspond in size; the size of the steel core layer is smaller than the size of the outer cladding layers, and the steel core layer and the outer cladding layers are proportionally corresponding; after the centroids of the steel core layer and the outer cladding layers are aligned, the gap area between the edge of the outer cladding layer and the edge of the steel core layer is filled with adhesive material.

[0006] As a further embodiment of the present invention: the adhesive material is a resin layer, and the two outer covering layers cover the steel core layer and fill it with resin layer to form a tie. A limiting sleeve corresponding to the size of the tie member is fitted on the outside of the tie member. The limiting sleeve has an integrally formed limiting collar with an outward flange structure. The limiting collar is perpendicular to the anchoring insertion direction of the tie member.

[0007] As a further embodiment of the present invention: the tie member is fixed as an insert into the injection mold, and ABS plastic is injected into the injection mold to wrap the corresponding area of ​​the tie member, forming a limiting sleeve that is integrally connected with the tie member.

[0008] As a further embodiment of the present invention: along the anchoring insertion direction of the tie member, dovetail grooves are symmetrically provided on both sides of each anchoring end of the steel core layer and the outer cladding layer.

[0009] As a further aspect of the present invention: the depth of the dovetail groove is d 1,3 mm≤ d 1 ≤ 8 mm; the angle of the dovetail groove 5 is θ 60°≤ θ ≤ 85°.

[0010] As a further aspect of the present invention: the thickness of the steel core layer is... t 1, width is w 1, length is l 1,2 mm≤ t 1 ≤ 4 mm, 26 mm ≤ w 1 ≤76 mm, 96 mm≤ l 1 ≤146 mm; The thickness of the outer cover is t 2, width is w 2, length is l 2,1 mm≤ t 2 ≤ 4 mm, 30 mm ≤ w 2 ≤ 80 mm, 100 mm ≤ l 2 ≤150 mm; The distance between the edge of the steel core layer and the edge of the outer cladding layer is d 2,2 mm≤ d 2 ≤5 mm; The anchorage depth of the tie member is d 3, 25 mm≤ d 3 ≤50 mm.

[0011] As a further embodiment of the present invention: the raw material of the outer coating is obtained from the recycled material after the decommissioning of the wind turbine blade; after the wind turbine blade is disassembled, the blade main beam is obtained, the composite material surface layer of the blade main beam is peeled off to obtain a glass fiber reinforced resin composite material laminate, and the glass fiber reinforced resin composite material laminate is peeled off layer by layer to obtain a glass fiber reinforced resin composite material.

[0012] A method for calculating the shear resistance of a composite plate tie member is proposed, wherein the area between the two anchoring ends of the tie member is defined as the shear resistance segment; the shear resistance of the tie member is determined based on the geometric dimensions and material properties of the steel core layer and the outer cladding layer, as well as the length of the shear resistance segment, and the shear resistance includes shear strength and shear stiffness.

[0013] As a further aspect of the present invention: the shear strength of the tie member is P u : ; in, t 1 represents the thickness of the steel core layer; w 1 represents the width of the steel core layer; l s This refers to the shear strength section length of the steel core layer; A s This refers to the cross-sectional area of ​​the shear section of the steel core layer; f ts The tensile strength of the steel core layer; t 2 represents the thickness of the outer coating; w 2 represents the width of the outer covering layer; l f The shear strength of the outer cladding layer; f tf The tensile strength of the outer cladding layer; A f This represents the cross-sectional area of ​​the shear section of the outer cladding.

[0014] As a further aspect of the present invention: the shear stiffness of the tie member is k : ; t 1 represents the thickness of the steel core layer; w 1 represents the width of the steel core layer; l s This refers to the shear strength section length of the steel core layer; E s The elastic modulus of the steel core layer; A s This refers to the cross-sectional area of ​​the shear section of the steel core layer; t 2 represents the thickness of the outer coating; w 2 represents the width of the outer covering layer; l f The shear strength of the outer cladding layer; A f This refers to the cross-sectional area of ​​the shear section of the outer cladding layer; E f This represents the elastic modulus of the outer coating.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention uses a steel core layer to provide core tensile and shear stiffness, combined with a GFRP outer cladding layer to isolate external corrosive media. The tie-fitting components have high shear strength and stiffness as a whole, while effectively reducing the impact of the steel core on the thermal bridging effect of the prefabricated sandwich insulated wall panels. Its application in prefabricated sandwich insulated wall panels can achieve a high degree of integration.

[0016] 2. This invention ensures that the steel core layer and the outer cladding layer can deform together under stress by aligning their centroids before resin filling, thus avoiding eccentric stress or interlayer slippage. This allows the composite structure section to fully utilize the advantages of each material under bending and shear conditions.

[0017] 3. The limiting sleeve and limiting collar of this invention form an integrated design, which can ensure the verticality and embedment depth of the tie member in the concrete formwork, prevent displacement during pouring and vibration, and improve construction quality; the dovetail groove design of the anchoring end of the tie member can significantly improve the pull-out resistance after bonding with the concrete; the selection of the thickness, width, length and gap size of the steel core layer and the outer covering layer can cover different application scenarios, and the use of GFRP profiles from retired wind turbine blades as the material to wrap the steel core enables the recycling and reuse of retired wind turbine blades.

[0018] 4. This invention provides theoretical calculation formulas for the shear strength and shear stiffness of the improved composite plate tie members, which can accurately evaluate their mechanical properties and facilitate engineering design and safety verification. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention.

[0020] Figure 2 This is a schematic diagram showing the state after the outer cladding layer and the steel core layer are stacked in this invention.

[0021] Figure 3 This is an exploded view of the present invention.

[0022] Figure 4 This is a schematic diagram of the finite element model used in the direct shear test of this invention.

[0023] Figure 5 This is a strain contour map of the steel core layer during the experiment of this invention.

[0024] Figure 6 This is a strain cloud diagram of the outer coating layer during the experiment of this invention.

[0025] Figure 7 This is a schematic diagram comparing the calculated shear bearing capacity with the numerical analysis results of the present invention.

[0026] Figure 8 This is a schematic diagram comparing the calculated shear stiffness value and the numerical analysis result of the present invention.

[0027] In the diagram: 1. Outer cladding layer; 2. Steel core layer; 3. Resin layer; 4. Limiting sleeve; 41. Limiting collar; 5. Dovetail groove. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0029] Please see Figures 1 to 8 In this embodiment of the invention, a composite plate-type tie member and a method for calculating its shear resistance include a steel core layer 2 and outer cladding layers 1 located on both sides of the steel core layer 2, clamping and positioning the steel core layer 2. The outer cladding layers 1 are made of GFRP material, i.e., glass fiber reinforced resin composite material, and the dimensions of the two sets of outer cladding layers 1 are completely corresponding. The planar dimensions of the steel core layer 2 are smaller than the planar dimensions of the outer cladding layers 1, and the steel core layer 2 and the outer cladding layers 1 are proportionally related.

[0030] After the steel core layer 2 and the outer cladding layer 1 are aligned and clamped in place, an adhesive material is filled into the annular gap area between the edge of the outer cladding layer 1 and the edge of the steel core layer 2. The adhesive material is preferably a resin material. After the resin solidifies, a resin layer 3 is formed, and the edge of the resin layer 3 is flush with the edge of the outer cladding layer 1.

[0031] When manufacturing the steel core layer 2, the steel plate is cut to a thickness of [missing information]. t 1, width is w 1, length is l 1,2 mm≤ t 1 ≤ 4 mm, 26 mm ≤ w 1 ≤76 mm, 96 mm≤ l 1 ≤146 mm.

[0032] The raw material for outer layer 1 is a glass fiber reinforced resin composite board obtained after dismantling the main beam of a decommissioned wind turbine blade. Its manufacturing process is as follows: The retired wind turbine blades are disassembled, yielding the blade main beam and shear web. When disassembling the blade main beam using composite materials, the surface layer of the composite material is peeled off to obtain a glass fiber reinforced resin composite laminate. This laminate is then peeled layer by layer to obtain the glass fiber reinforced resin composite material, which is then cut and processed to form the corresponding outer cladding layer 1. When disassembling the shear web using composite materials, since the shear web is an externally bonded GFRP profile with a thickness of 1 mm to 2 mm, multiple layers of material can be bonded together to achieve the desired thickness.

[0033] After cutting, the thickness of the outer layer 1 is t 2, width is w 2, length is l 2,1 mm≤ t 2 ≤ 4 mm, 30 mm ≤ w 2≤80 mm, 100 mm≤ l 2 ≤150 mm.

[0034] After the outer cladding layer 1 and the steel core layer 2 are centroidally aligned, the distance between the edge of the steel core layer 2 and the edge of the outer cladding layer 1 is [missing information]. d 2,2mm≤ d 2 ≤ 5 mm. After filling and solidifying the resin within this gap, the limiting sleeve 4 is further manufactured.

[0035] A limiting sleeve 4 is fitted onto the outside of the tie member, with one end integrally forming a limiting collar 41 with an outwardly flanged structure. The plane of the limiting collar 41 is perpendicular to the anchoring insertion direction of the tie member. The limiting sleeve 4 is used to position the tie member in the concrete formwork. It abuts against the concrete blade through the limiting collar 41 to determine the anchoring depth of the tie member. The anchoring depth of the tie member is... d 3, 25 mm≤ d 3 ≤50 mm.

[0036] During the fabrication of the tie-up component, the cured tie-up component is fixed as an insert into the injection mold. ABS plastic is injected into the injection mold, and the molten plastic encapsulates the shear-resistant section of the tie-up component. After cooling, a limiting sleeve 4 is integrally connected to the tie-up component. The thickness of the limiting sleeve 4 is... d 4,1 mm≤ d 4 ≤3 mm. The length of the limiting sleeve 4 is l3. The two ends of the tie member located outside the limiting sleeve 4 are inserted into the corresponding concrete blade as anchoring sections. The length of the section where the limiting sleeve 4 is located corresponds to the thickness of the insulation board.

[0037] To improve the anchorage between the tie member and the concrete, dovetail grooves 5 are symmetrically formed on both sides of each anchorage end of the steel core layer 2 and the outer cladding layer 1 along the anchorage insertion direction of the tie member. The depth of the dovetail grooves 5 is... d 1,3 mm≤ d 1 ≤ 8 mm; the angle of the dovetail groove 5 is θ 60°≤ θ ≤ 85°. This structure allows the concrete to interlock within the dovetail groove 5 when the tie member is under tension, thereby improving the pull-out bearing capacity.

[0038] The area between the two anchoring ends of the tie member is defined as the shear-resistant segment. The shear performance of the tie member is determined based on the geometry and material properties of the steel core layer 2 and the outer cladding layer 1, as well as the length of the shear-resistant segment. The shear performance includes shear strength and shear stiffness.

[0039] The shear strength of the tie member is P u : ; in, t 1 represents the thickness of the steel core layer 2; w 1 represents the width of the steel core layer 2; l s This refers to the shear section length of the steel core layer 2; ; A s Let be the cross-sectional area of ​​the shear section of the steel core layer 2; ; f ts The tensile strength of the steel core layer 2; t 2 represents the thickness of the outer coating layer 1; w 2 represents the width of the outer covering layer 1; l f The shear section length of the outer cladding layer 1; f tf The tensile strength of the outer cladding layer 1; A f is the shear cross-sectional area of ​​the outer cladding layer 1.

[0040] The shear stiffness of the tie member is k : ; t 1 represents the thickness of the steel core layer 2; w1 represents the width of the steel core layer 2; l s This refers to the shear section length of the steel core layer 2; E s The elastic modulus of the steel core layer 2; A s Let be the cross-sectional area of ​​the shear section of the steel core layer 2; t 2 represents the thickness of the outer coating layer 1; w 2 represents the width of the outer covering layer 1; l f The shear section length of the outer cladding layer 1; ; A f This represents the shear cross-sectional area of ​​the outer cladding layer 1; ; E f is the elastic modulus of the outer cladding layer 1.

[0041] like Figure 4 As shown, a numerical model for the direct shear test of the tie member in this application was established using the nonlinear finite element software ABAQUS. An eight-node solid element (C3D8R) was used to simulate the concrete and tie member. The concrete blade length was 300 mm, width was 300 mm, and thickness was 50 mm. The influence of the insulation board on the shear performance of the tie member was not considered in the model and was therefore not included. Considering that the anchorage depth, dovetail groove depth, and angle of the tie member only affect the anchorage performance between the tie member and the concrete, and assuming no anchorage failure occurs between the tie member and the concrete, they do not affect its shear strength and stiffness. Therefore, in all numerical models, the anchorage depth of the tie member was set to 30 mm, the dovetail groove depth to 5 mm, and the dovetail groove angle to 75.96°. The concrete strength was set to C60, the tensile strength of GFRP was set to 330 MPa, and the elastic modulus was set to 18.6 GPa. The tensile strength of the steel core layer 2 was set to 540 MPa, and the elastic modulus was set to 200 GPa.

[0042] The experiment analyzed 36 working conditions. The main parameters studied included the thickness of the outer cladding layer 1 (1 mm, 2 mm, 3 mm), the thickness of the steel core layer 2 (2 mm, 3 mm), the width of the tie member (30 mm, 45 mm, 60 mm), and the shear length of the tie member (50 mm, 80 mm). The shear length of the tie member is equivalent to the thickness of the insulation board. The data obtained from the numerical model are shown in Table 1 below.

[0043] Table 1

[0044] in, P test The shear bearing capacity obtained from the model analysis; k test This represents the shear stiffness force obtained from the model analysis. (Based on Table 1 above...) Figure 7 as well as Figure 8 The numerical analysis results show that this application can predict the shear bearing capacity and shear stiffness of the tie members relatively well.

[0045] Combination Figure 5 as well as Figure 6 As shown in the cloud diagram, the final failure mode of the tie member is the fracture of the outer GFRP cladding material, at which point the inner steel core is still in the yielding stage. The maximum strain of the outer GFRP cladding is significantly higher than that of the steel core, indicating that the outer cladding can absorb the damage generated during the service stage of the tie member, effectively constraining the inner steel core to participate in shear resistance, while the steel core can fully utilize its metallic ductility, avoiding the brittle failure mode common in pure composite material connectors.

[0046] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0047] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

Claims

1. A composite plate-type tie member, characterized in that, It includes a steel core layer (2) and an outer cover layer (1) located on both sides of the steel core layer (2) to clamp and position the steel core layer (2); the outer cover layer (1) is made of GFRP material, and the two outer cover layers (1) correspond in size; the size of the steel core layer (2) is smaller than the size of the outer cover layer (1), and the steel core layer (2) and the outer cover layer (1) are proportionally corresponding; after the centroids of the steel core layer (2) and the outer cover layer (1) are aligned, the gap area between the edge of the outer cover layer (1) and the edge of the steel core layer (2) is filled with adhesive material.

2. The composite plate tie member according to claim 1, characterized in that, The adhesive material is a resin layer (3), and the two outer layers (1) cover the steel core layer (2) and fill the resin layer (3) to form a tie. A limiting sleeve (4) corresponding to the size of the tie member is fitted on the outside of the tie member. A limiting collar (41) with an outward flange structure is integrally formed on the limiting sleeve (4). The limiting collar (41) is perpendicular to the anchoring insertion direction of the tie member.

3. A composite plate tie member according to claim 2, characterized in that, The tie member is fixed to the injection mold as an insert, and ABS plastic is injected into the injection mold to wrap the corresponding area of ​​the tie member, forming a limiting sleeve (4) that is integrally connected with the tie member.

4. The composite plate tie member according to claim 1, characterized in that, Along the anchoring insertion direction of the tie member, dovetail grooves (5) are symmetrically provided on both sides of each anchoring end of the steel core layer (2) and the outer covering layer (1).

5. A composite plate tie member according to claim 4, characterized in that, The depth of the dovetail groove (5) is d 1, 3mm≤ d 1 ≤ 8 mm; the angle of the dovetail groove (5) is θ 60°≤ θ ≤ 85°.

6. A composite plate tie member according to any one of claims 1 to 5, characterized in that, The thickness of the steel core layer (2) is t 1, width is w 1, length is l 1,2 mm≤ t 1 ≤ 4 mm, 26 mm ≤ w 1 ≤76 mm, 96 mm≤ l 1 ≤146 mm; The thickness of the outer cladding layer (1) is t 2, width is w 2, length is l 2,1 mm≤ t 2 ≤ 4 mm, 30 mm ≤ w 2 ≤ 80 mm, 100 mm ≤ l 2 ≤150 mm; The distance between the edge of the steel core layer (2) and the edge of the outer cladding layer (1) is d 2,2 mm≤ d 2 ≤5 mm; The anchorage depth of the tie member is d 3, 25 mm≤ d 3 ≤50 mm.

7. A composite plate tie member according to any one of claims 1 to 5, characterized in that, The raw material of the outer layer (1) is obtained from the material recycling after the decommissioned wind turbine blades are dismantled; after the wind turbine blades are dismantled, the blade main beam is obtained, the composite material surface layer of the blade main beam is peeled off to obtain a glass fiber reinforced resin composite material laminate, and the glass fiber reinforced resin composite material laminate is peeled off layer by layer to obtain a glass fiber reinforced resin composite material.

8. A method for calculating the shear resistance of a composite plate tie member according to any one of claims 1 to 5, characterized in that, The area between the two anchoring ends of the tie member is the shear resistance section; the shear resistance of the tie member is determined based on the geometric dimensions, material properties and shear resistance section length of the steel core layer (2) and the outer cladding layer (1), and the shear resistance performance includes shear strength and shear stiffness.

9. The method for calculating the shear resistance of a composite plate tie member according to claim 8, characterized in that, The shear strength of the tie member is P u : ； in, t 1 represents the thickness of the steel core layer (2); w 1 represents the width of the steel core layer (2); l s The shear section length of the steel core layer (2); A s The shear section cross-sectional area of ​​the steel core layer (2); f ts The tensile strength of the steel core layer (2); t 2 represents the thickness of the outer cladding layer (1); w 2 represents the width of the outer covering layer (1); l f The shear section length of the outer cladding layer (1); f tf The tensile strength of the outer cladding layer (1); A f is the shear cross-sectional area of ​​the outer cladding layer (1).

10. The method for calculating the shear resistance of a composite plate tie member according to claim 8, characterized in that, The shear stiffness of the tie member is k : ； t 1 represents the thickness of the steel core layer (2); w 1 represents the width of the steel core layer (2); l s The shear section length of the steel core layer (2); E s The elastic modulus of the steel core layer (2); A s The shear section cross-sectional area of ​​the steel core layer (2); t 2 represents the thickness of the outer cladding layer (1); w 2 represents the width of the outer covering layer (1); l f The shear section length of the outer cladding layer (1); A f The shear cross-sectional area of ​​the outer cladding layer (1); E f is the elastic modulus of the outer cladding layer (1).

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