A bamboo-wood connecting structure and a connecting method

Abstract

The application discloses a bamboo-wood connecting structure, which comprises a plate member, a connecting shaft and an elastic layer for connecting two groups of bamboo-wood members; the connecting structure has the functions of shearing plate connection and pin shaft connection, has high bearing capacity, good ductility, good durability and good fire resistance; for two bamboo-wood members which need to be connected together, the connecting shaft penetrates the bamboo-wood members and the plate member, and plays a role in transmitting load; the load is transmitted from the connecting shaft to the bamboo-wood members through the plate member with the elastic layer; even if the elastic layer is degraded, the external load can still be transmitted to the bamboo-wood members through the connecting shaft and the plate member, that is, the function of pin shaft connection is played, so that the reliability of the structure is ensured. The application further discloses a bamboo-wood connecting method; the surface energy of the rubber layer is increased through sulfuric acid etching oxidation, so that the bonding strength of the rubber layer and the adhesive can meet the requirements; compared with developing a new type of adhesive, the method is obviously more applicable.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of bamboo-wood structure, in particular to a bamboo-wood connecting structure and a connecting method. BACKGROUND

[0002] The connecting nodes of modern bamboo-wood structure are all metal connecting pieces, mainly including pin shaft type connections and other type connections, the pin shaft type connections are for example: nail connection, pin connection and bolt connection, the other type connections are for example: toothed plate connection, shear plate connection, embedded steel bar connection, etc. The bearing capacity of pin shaft type connection is relatively low, but its ductility performance is better, so the pin shaft type connection is widely used, among which, the steel panel bolt connection is more commonly used for the beauty and applicability of bamboo-wood structure.

[0003] The existing problems of bamboo-wood connecting structure are: 1. In the steel panel bolt connection of bamboo-wood structure, the steel plate and bolt are all buried in the bamboo-wood component, due to the influence of moisture content and other factors (the sugar content of bamboo is relatively high, easy to mold and insect), the steel connecting piece is easy to corrode, and its fire resistance is poor, which affects the durability and safety of bamboo-wood structure; 2. Although the bearing capacity of shear plate connection of bamboo-wood structure is relatively high, its ductility is poor, and the steel shear plate also has the defects of easy corrosion and poor fire resistance; 3. Although the steel plate in the steel clamp plate bolt connection of bamboo-wood structure is relatively easy to maintain, it is more easy to corrode for long-term exposure to air, and affects the beauty of bamboo-wood structure.

[0004] In summary, there is an urgent need for a bamboo-wood connecting structure and a connecting method to solve the problems of poor fire resistance, poor durability, low bearing capacity or poor ductility in the prior art. SUMMARY

[0005] The present application aims to provide a bamboo-wood connecting structure and a connecting method to solve the problems of poor fire resistance, poor durability, low bearing capacity or poor ductility in the prior art, and the specific technical solutions are as follows:

[0006] A bamboo-wood connecting structure, the connecting structure comprises a plate piece for connecting two adjacent groups of bamboo-wood components, a connecting shaft and an elastic layer; one side surface of the elastic layer is connected to the two groups of bamboo-wood components; one side surface of the plate piece is connected to the other side surface of the elastic layer; the plate piece, the elastic layer and the bamboo-wood components are all provided with a preformed hole corresponding thereto; the connecting shaft is arranged through the preformed holes of the plate piece, the elastic layer and the bamboo-wood components.

[0007] Preferably, the diameter of the preformed hole on the bamboo-wood component is D1; the diameter of the preformed hole on the plate piece is D2; D1>D2.

[0008] Preferably, the connecting shaft is cylindrical, the outer diameter of the connecting shaft is D3; D2 is greater than D3 0.8mm-2mm; D1 is greater than D3 8mm-12mm.

[0009] Preferably, a plurality of groups of prefabricated holes are arranged on the plate, the elastic layer and the bamboo-wood component in a one-to-one correspondence.

[0010] Preferably, the bamboo-wood connecting structure comprises two groups of plates and two groups of elastic layers, and the two groups of plates are arranged on the outer side of the bamboo-wood component through the elastic layers, or the bamboo-wood connecting structure comprises one group of plates and two groups of elastic layers, and the two sides of the group of plates are arranged on the bamboo-wood component through the two groups of elastic layers.

[0011] Preferably, the Shore hardness of the elastic layer is 50-70 degrees, and the thickness of the elastic layer is 0.8-2.5 mm.

[0012] Preferably, the connection between the plate and the elastic layer and the connection between the elastic layer and the bamboo-wood component are both adhesive.

[0013] Preferably, the material of the plate and the connecting shaft is glass fiber reinforced plastic, and the material of the elastic layer is rubber.

[0014] A bamboo-wood connecting method using the bamboo-wood connecting structure comprises the following steps.

[0015] Step S1: According to the specification of the connecting shaft, prefabricated holes are drilled on the plate, the elastic layer and the bamboo-wood component.

[0016] Step S2: Under the premise of ensuring that the prefabricated holes of the plate, the elastic layer and the bamboo-wood component are aligned, the one side of the elastic layer and the plate surface are bonded together through an adhesive, and the other side of the elastic layer is bonded to the two groups of bamboo-wood components that need to be connected.

[0017] Step S3: The connecting shaft is inserted into the prefabricated holes of the plate, the elastic layer and the bamboo-wood component, and the connection is completed.

[0018] Preferably, between step S1 and step S2, the surface of the plate and the elastic layer is subjected to a modification treatment, which is as follows.

[0019] The plate is subjected to a modification treatment: the plate is placed in the mouth of a plasma spray gun for surface modification.

[0020] The surface of the elastic layer is subjected to a modification treatment:

[0021] First step: polish the surface of the elastic layer and clean the elastic layer;

[0022] Second step: immerse the elastic layer in 95%-98% concentrated sulfuric acid for 30 seconds to etch the surface of the elastic layer.

[0023] Third step: clean the elastic layer and dry it.

[0024] The technical scheme of the present application has the following beneficial effects:

[0025] (1) The bamboo-wood connecting structure of the present application comprises a plate member for connecting two adjacent groups of bamboo-wood members, a connecting shaft and an elastic layer; the connecting structure has the functions of both plate shearing connection and pin shaft connection, has high bearing capacity, good ductility, good durability and good fire resistance; for two bamboo-wood members that need to be connected together, the connecting shaft penetrates the bamboo-wood members and the plate member, and plays a role in transmitting load; the load is transmitted from the connecting shaft to the bamboo-wood members through the plate member with the elastic layer; even if the elastic layer degrades in a fire, the external load can still be transmitted to the bamboo-wood members through the connecting shaft and the plate member, i.e., the pin shaft connection, to ensure the reliability of the structure.

[0026] (2) In the present application, D1>D2 is set to fully play the role of the elastic layer, so that the external load is transmitted to the plate member through the connecting shaft, and then to the connecting surface (i.e., the bonding surface) between the bamboo-wood member and the elastic layer.

[0027] (3) In the present application, a plurality of preformed holes are correspondingly matched with a plurality of connecting shafts to ensure the reliability of the structure.

[0028] (4) In the present application, the plate member and the connecting shaft are both made of glass fiber reinforced plastic (GFRP), so that the structure has stronger durability and fire resistance; the elastic layer is a rubber layer, so that the functions of both plate shearing connection and pin shaft connection are concentrated together, and the ductility of the structure is increased.

[0029] (5) In the present application, two plate members are arranged on the outer side of the bamboo-wood member through the elastic layer, so that the structure is stable because two plate members and the elastic layer participate in force bearing.

[0030] (6) The failure mode of ordinary plate shearing connection is brittle failure, and the failure mode of ordinary pin shaft connection is ductile failure, but the bearing capacity of ordinary pin shaft connection is relatively low, and more importantly, the metal connecting member in ordinary plate shearing connection and pin shaft connection is prone to corrosion and has poor fire resistance; the present application concentrates the functions of both plate shearing connection and pin shaft connection together, greatly improves the durability and fire resistance, and the failure mode is ductile failure; specifically, the metal connecting member is replaced with GFRP material which has stronger durability and fire resistance; secondly, the elastic layer (i.e., the rubber layer) is added to concentrate the functions of both plate shearing connection and pin shaft connection together, and to increase the ductility of the structure.

[0031] (7) In the connecting method of the present application, the surface energy of the rubber layer (i.e., the elastic layer) is increased by sulfuric acid etching oxidation, so that the bonding strength of the rubber layer and the adhesive can meet the requirements; compared with developing a new type of adhesive, the method of the present application is obviously more applicable, and is also more applicable to the present scheme.

[0032] In addition to the objects, features and advantages described above, the present application has other objects, features and advantages. These and other objects, features and advantages of the present application will become apparent with reference to the drawings, in which: BRIEF DESCRIPTION OF DRAWINGS

[0033] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an implementation of the application and, together with the description, serve to explain the application without limiting it.

[0034] In the drawings:

[0035] Figure 1a Figure 1b is the first schematic diagram of the embedded connection structure in this embodiment; wherein: Figure 1a represents the side view angle, Figure 1b represents the front view angle;

[0036] Figure 2 is the second schematic diagram of the embedded connection structure in this embodiment, Figure 2 the arrow direction in indicates the texture direction of the bamboo-wood member;

[0037] Figure 3 is the first schematic diagram of the external clamping connection structure in this embodiment; wherein: (a) represents the side view angle, (b) represents the front view angle;

[0038] Figure 4 is the second schematic diagram of the external clamping connection structure in this embodiment, Figure 4 the arrow direction in indicates the texture direction of the bamboo-wood member;

[0039] Figure 5 is the schematic diagram of the lap joint test piece in the first experiment in this embodiment; wherein, GLT represents the glued wood member; Rubber represents the elastic layer (i.e. rubber layer); Adhesive represents the adhesive; SBR represents the styrene-butadiene rubber; PUR represents the two-component polyurethane; the stress direction of the glued wood is the grain direction;

[0040] Figure 6 is the schematic diagram of the steel-clip-plate-nail connection in the prior art in the second experiment in this embodiment; wherein: (a) represents the side view angle, (b) represents the front view angle;

[0041] Figure 7 is the external clamping connection structure (illustrating the first external clamping structure form in this embodiment) in the second experiment in this embodiment; wherein: (a) represents the side view angle, (b) represents the front view angle;

[0042] Figure 8 ​is the embedded connection structure in the second experiment of the embodiment (illustrates the first embedded structure form in the embodiment); wherein: (a) represents a side view angle, (b) represents a front view angle;

[0043] Figure 9 is the structural schematic diagram of the test piece in the fifth experiment of the embodiment; wherein: (a) represents a side view angle, (b) represents a front view angle;

[0044] Wherein, 1, the plate; 2, the connecting shaft; 3, the elastic layer; 4, the bamboo and wood component; 4.a, the wood column; 4.b, the wood beam; 4.1, the embedded groove; 5, the steel plate; 6, the steel nail;

[0045] Figure 6 to Figure 8 In the figure, P represents the test comparison area (i.e. the dashed line frame shown);

[0046] Figure 5 to Figure 9 In the figure, F represents the load direction. DETAILED DESCRIPTION

[0047] The embodiments of the application are described in detail below in combination with the drawings, but the application can be implemented in various different ways limited and covered by the claims.

[0048] Embodiment:

[0049] A bamboo and wood connecting structure, the connecting structure comprises a plate 1 for connecting two adjacent groups of bamboo and wood components 4, a connecting shaft 2 and an elastic layer 3;

[0050] In the connecting structure of the embodiment, the shapes of the plate 1 and the elastic layer 3 are both square plate shapes, and preferably the length-width specifications of the plate 1 and the elastic layer 3 are the same; the connecting shaft 2 is cylindrical, wherein the materials of the plate 1 and the connecting shaft 2 are both glass fiber reinforced plastic materials (i.e. GFRP materials), and the elastic layer 3 adopts a rubber material (preferably pure styrene-butadiene rubber). Figure 1a 、 Figure 1b 、 Figure 3 and Figure 6 to Figure 9 In the figure, (a) represents a side view angle, (b) represents a front view angle.

[0051] The bamboo and wood connecting structure of the embodiment mainly has the following application forms, i.e. embedded and externally clamped:

[0052] Embedded: as shown in Figure 1a 、 Figure 1b and Figure 2 , specifically: the embedded connecting structure comprises a group of plates 1, two groups of elastic layers 3 and multiple groups of connecting shafts 2;

[0053] The connecting regions of the two groups of bamboo-wood components 4 to be connected are each provided with a corresponding embedded groove 4.1; the plate 1 and the elastic layer 3 are arranged in the two embedded grooves 4.1, and one side surface of the plate 1 is connected (bonded) with one side surface of one group of elastic layers 3, and the other side surface of the elastic layer 3 is connected (bonded) with the inner wall of the embedded groove 4.1. Similarly, the other side surface of the plate 1 is also connected (bonded) with the inner wall of the embedded groove 4.1 through the elastic layer 3; wherein the plate 1, the two groups of elastic layers 3 and the bamboo-wood components 4 are each provided with a corresponding preformed hole, and the connecting shaft 2 is arranged through the preformed holes of the plate 1, the two groups of elastic layers 3 and the bamboo-wood components 4 to play a role in transmitting load;

[0054] wherein, Figure 1a 、 Figure 1b The first embedded structure form is shown, that is, at this time the two groups of bamboo-wood components 4 are on the same straight line;

[0055] Figure 2 The second embedded structure form is shown, Figure 2 In the figure, the arrow direction represents the grain direction of the bamboo-wood component (that is, the bamboo-wood component includes a wood column and a wood beam), Figure 2 The wood column 4.a in the figure bears the load in the grain direction, and the wood beam 4.b bears the load in the cross grain direction.

[0056] The outer clamping type is shown in Figure 3 and Figure 4 Specifically, the outer clamping type connection structure includes two groups of plates 1, two groups of elastic layers 3 and multiple groups of connecting shafts 2; the plate 1 and the elastic layer 3 are arranged one by one in correspondence; the two groups of plates 1 are respectively located on the outer sides (opposite outer sides) of the bamboo-wood components 4, and one side surface of the plate 1 close to the bamboo-wood component 4 is connected (bonded) with one side surface of one group of elastic layers 3, and the other side surface of the elastic layer 3 is connected (bonded) with the outer side surface of the bamboo-wood component 4, that is, the two groups of plates are arranged on the outer side surfaces of the bamboo-wood components 4 through the two groups of elastic layers, wherein the two groups of plates 1, the two groups of elastic layers 3 and the bamboo-wood components 4 are each provided with a corresponding preformed hole, and the connecting shaft 2 is arranged through the preformed holes of the two groups of plates 1, the two groups of elastic layers 3 and the bamboo-wood components 4 to play a role in transmitting load;

[0057] wherein, Figure 3 The first outer clamping structure form is shown, that is, the two groups of plates 1 are bonded on the outer side surfaces of the two groups of bamboo-wood components 4 through the elastic layers 3, and the connecting shaft 2 penetrates the entire structure;

[0058] Figure 4 The second outer clamping structure form is shown, Figure 4 In the figure, the arrow direction represents the grain direction of the bamboo-wood component, Figure 4 The wood column 4.a in the figure bears the load in the grain direction, and the wood beam 4.b bears the load in the cross grain direction.

[0059] In the aforementioned embedded and external clamping structures, the number of connecting shafts 2 corresponds one-to-one with the pre-made holes on the plate 1. The connecting shafts 2, plate 1, elastic layer 3, and bamboo and wood components 4 are all independent components. They are assembled to form a complete connection node. Furthermore, the size of plate 1, the diameter of connecting shaft 2, and the thickness of elastic layer 3 can be adjusted. In this embodiment, in the external clamping connection structure, the thickness of plate 1 is between 3 and 8 mm, and in the embedded connection structure, the thickness of plate 1 is between 8 and 12 mm.

[0060] In the field of bamboo and wood structures, the slippage and deformation of the connection nodes cannot be too large. In the connection structure of this embodiment, the stiffness of the elastic layer 3 (rubber layer) depends on its hardness and thickness. The hardness of the elastic layer 3 is generally taken as Shore hardness 50 to 70 degrees (60 degrees in this embodiment), and the thickness of the elastic layer 3 is in the range of 0.8mm to 2.5mm, and 1.0 to 1.2mm in this embodiment. The stiffness of the elastic layer 3 has little effect on the load-bearing capacity of the node. Under normal circumstances, the connection structure of this embodiment plays a role similar to a shear plate connection. However, when the relative slippage of the node exceeds 5mm, both the shear plate connection function and the pin-type connection function of the connection structure of this embodiment will be activated, which will further increase its load-bearing capacity.

[0061] The connection structure in this embodiment can be used as a shear plate connection or as a pin-type connection. The connection structure in this embodiment includes an elastic layer 3 (i.e., a rubber layer). The elastic layer 3 has low stiffness and a high critical fracture energy release rate (wherein, the high critical fracture energy release rate is defined as the energy required for crack propagation per unit area as the crack propagation resistance rate G). C When the energy release rate G reaches G C At this point, the crack loses its stability and begins to propagate; the critical fracture energy release rate is expressed as the work done during material fracture divided by the area at fracture, i.e. The critical fracture energy release rate of bamboo and wood is generally around 300 J / m. 2 -500J / m 2 Within this range, the maximum generally will not exceed 1500 J / m 2 The critical fracture energy release rate of rubber is generally around 1.0*10. 7 J / m 2 In this embodiment, the elastic layer 3 overcomes the problems of poor ductility in shear plate connections and low load-bearing capacity in pin-type connections, while also leveraging the advantages of strong corrosion resistance and strong fire resistance of fiberglass material.

[0062] The preferred connection structure in this embodiment is as follows:

[0063] In this embodiment, the connecting shaft 2 of the connecting structure is provided in multiple sets, and the specific number is selected according to the number of pre-made holes on the plate 1.

[0064] The diameter of the preformed hole (a round hole) on the bamboo-wood component 4 is D1; the diameter of the preformed hole (a round hole) on the plate 1 is D2; D1>D2, and the outer diameter of the connecting shaft 2 (a cylinder) is D3, and the specific size relationship is: D2 is greater than D30.8mm-2mm; D1 is greater than D38mm-12mm.

[0065] The principle of the connecting structure of the embodiment is as follows (the following principle takes the embedded structure as an example): for two bamboo-wood components 4 that need to be connected together, the connecting shaft 2 penetrates the plate 1, the elastic layer 3 and the bamboo-wood component 4, and plays a role in transmitting loads, and the plate 1 bonded inside the bamboo-wood component 4 (i.e. in the embedded groove) transmits the load from the connecting shaft 2 to the bamboo-wood component 4.

[0066] In the embedded connecting structure, in order to fully play the role of the elastic layer 3, the connecting shaft 2 cannot be in direct contact with the bamboo-wood component 4, but the diameter of the preformed hole of the bamboo-wood component 4 should be greater than the diameter of the preformed hole of the plate 1 (i.e. D1>D2), so that the external load can be transmitted to the plate 1 through the connecting shaft 2, and then to the bonding surface of the bamboo-wood component 4 and the elastic layer 3, wherein when the embedded connecting structure is subjected to a fire, even if the elastic layer 3 degrades, the external load can still be transmitted to the bamboo-wood component 4 through the connecting shaft 2 and the plate 1, i.e. to play the role of a pin shaft type connection.

[0067] The embodiment also discloses a bamboo-wood connecting method using the bamboo-wood connecting structure, which comprises steps S1 to S3, and the specific steps are as follows:

[0068] Step S1: according to the diameter specification of the connecting shaft 2, preformed holes are drilled on the plate 1, the elastic layer 3 and the bamboo-wood component 4, and the specific steps are as follows:

[0069] Step S1.1: according to the diameter size of the connecting shaft 2, preformed holes are drilled on the plate 1 and the elastic layer 3;

[0070] Step S1.2: preformed holes are drilled on the bamboo-wood component 4, and the preformed holes on the bamboo-wood component 4 need to be coaxial with the preformed holes on the plate 1 and the elastic layer 3 (so that the connecting shaft 2 can pass through the preformed holes of each component in the subsequent process), and the diameter of the preformed hole on the bamboo-wood component 4 is greater than the outer diameter of the connecting shaft 2 (i.e. D1>D3), and the value is 8mm-12mm (for example, 10mm);

[0071] Preferably, the center distance of the preformed hole on the bamboo-wood component 4 is equal to 4 times the diameter of the preformed hole (i.e. equal to 4 times D1), and the distance from the center of the preformed hole to the edge of the bamboo-wood component 4 is greater than 7 times the diameter of the preformed hole (i.e. greater than 7 times D1).

[0072] Preferably, before step S2, the surface of the plate 1 and the elastic layer 3 is modified, specifically:

[0073] The surface of the plate 1 is modified by placing it in a plasma spray gun (wide jet type atmospheric low temperature plasma treatment machine) with a distance of 15 mm between the spray gun and the surface of the plate 1, and a spray gun speed of 100 mm / s;

[0074] The surface of the elastic layer 3 (rubber layer) is etched, including the following first to third steps:

[0075] First step: lightly polish the surface of the elastic layer 3 with 100 mesh sandpaper to remove impurities, then wash the rubber surface with water, and then wash it again with alcohol;

[0076] Second step: immerse the elastic layer 3 in 95% to 98% (preferably 95% in this embodiment) concentrated sulfuric acid for 30 seconds to etch the surface of the elastic layer 3;

[0077] Third step: rinse the etched elastic layer with water for 15-30 minutes, then dry and air dry.

[0078] The mechanism of sulfuric acid etching is as follows: concentrated sulfuric acid is a strong oxidizing acid that can open the carbon-carbon bonds on the surface of the elastic layer 3 (styrene-butadiene rubber), oxidize the carbon atoms to hydroxyl, carbonyl, carboxyl, etc., and convert the chemically inert surface of the styrene-butadiene rubber to a polar surface, thereby increasing its surface free energy and improving its surface adhesion. The contact angle of the styrene-butadiene rubber surface with water before treatment is generally 80-100 degrees, and after 20 minutes of concentrated sulfuric acid treatment, the contact angle is reduced to less than 30 degrees. The main reasons are as follows: first, the benzene ring in the styrene-butadiene rubber is easily sulfonated, then a sulfonic acid group is generated, increasing the polarity of the styrene-butadiene rubber surface; second, sulfuric acid has a cyclization effect, making the styrene-butadiene rubber have a cyclic hydrocarbon structure on the surface, which helps to improve the adhesion of the rubber; at the same time, oxidation will form fine cracks on the surface of the styrene-butadiene rubber, which is more conducive to the mechanical connection of the styrene-butadiene rubber and the adhesive.

[0079] Step S2: under the premise of ensuring the coaxial alignment of the plate 1, the elastic layer 3 and the preformed holes of the bamboo-wood components 4, the one side surface of the elastic layer 3 is bonded to the plate surface of the plate 1 by adhesive, and the other side surface of the elastic layer 3 is bonded to the two groups of bamboo-wood components 4 that need to be connected, specifically as follows:

[0080] Step S2.1: clean the surface near the preformed hole of the bamboo-wood component 4 with alcohol, and apply a hydroxymethyl resorcinol (HMR) coupling agent (HMR coupling agent formula: sodium hydroxide 2.44%, distilled water 90.43%, formaldehyde solution 3.79%, crystalline resorcinol 3.34%) and let it stand for 24 hours, with a coating amount of 200 g / m 2 ;

[0081] Step S2.2: clean the surface of the elastic layer 3 with water and alcohol, and adhere the plate surface of the plate member 1 to the oxidized elastic layer 3 through epoxy resin glue;

[0082] Step S2.3: according to the operation requirements of the adhesive, apply the adhesive to the surface near the preformed hole of the bamboo-wood member 4, and adhere the elastic layer 3 after the plate member 1 to the bamboo-wood member 4, and pre-tighten through bolts at the preformed hole to further ensure the adhesion effect; after adhesion, remove the excess adhesive.

[0083] Step S3: after adhesion, remove the bolts, and insert the coaxial connecting shafts 2 into the preformed holes of the plate member 1, the elastic layer 3, and the bamboo-wood member 4 one by one, and complete the connection.

[0084] The following contents need to be explained in this embodiment:

[0085] I. The rigidity of the plate member 1 (GFRP material, i.e. glass steel plate) is relatively low, which has a certain influence on the overall rigidity of the connecting structure for bearing pressure load, in this embodiment, the plate member 1 and the bamboo-wood member 4 are bonded together through the elastic layer 3 to improve the rigidity;

[0086] II. Generally, the bonding strength of the elastic layer 3 and the adhesive is difficult to meet the requirements, because the surface energy of many types of rubber is low, in order to obtain higher bonding strength, the strain energy of the adhesive must be lower, however, this is almost impossible, compared to developing a new type of adhesive, a more practical way is selected in this embodiment, i.e. increasing the surface energy of the rubber layer through sulfuric acid etching oxidation.

[0087] In addition, the following experiments (including Experiment One to Experiment Five) prove the feasibility of the connecting structure in this embodiment and the technical effects obtained, as follows:

[0088] Experiment One (elastic layer 3 long lap joint test):

[0089] The comparison of the traditional adhesive long lap joint and the elastic layer 3 long lap joint involved in this embodiment is shown in Table 1, and the structures of the test pieces used for comparison are as follows Figure 5GLT represents the glued wood member, Rubber represents the elastic layer 3 (i.e. rubber layer), and Adhesive represents the adhesive; the height of the glued wood member is 225 mm, the widths of the middle glued wood member and the side glued wood member are 280 mm and 230 mm respectively, the lap length is between 200-700 mm, the elastic layer 3 is styrene butadiene rubber (after oxidation etching treatment), denoted as SBR, and the adhesive is two-component polyurethane, denoted as PUR; the thickness of the SBR is 3.5 mm, the hardness is Shore A60, the tensile strength is 21.6 MPa, and the elongation is 644%; according to literature data, the shear strength of the adhesive is about 1000 MPa, and the comparison results are shown in Table 1:

[0090] Table 1 Comparison results

[0091] Test type Lap length / mm Number of tests Carrying capacity / kN Shear strength / MPa Wooden element relative slip / mm SBR 200 3 445 4.95 2.58 SBR 400 3 870 4.8 5.12 SBR 700 3 1473 4.68 7.86 PUR 200 3 400 4.45 0.09 PUR 400 3 760 4.2 0.16 PUR 700 3 1290 4.1 0.39

[0092] As can be seen from Table 1, compared with the traditional adhesive directly bonding two groups of bamboo-wood members 4, the elastic layer 3 of the embodiment improves the bearing capacity of the lap joint, and the ductility performance is significantly improved, and the elastic layer 3 ensures the uniformity of the shear stress borne by the bamboo-wood members 4.

[0093] Experiment two (glass steel plate 1 glued wood lap joint test):

[0094] The comparison results of the glass steel plate (i.e. the plate 1 in the embodiment) glued wood lap joint test are shown in Table 2, and the structures of the test pieces used for comparison are shown in Figure 6 to Figure 8 ; Figure 6 The steel plate clamp nail connection in the prior art is shown in Figure 6 , in which the steel plate is denoted as 5, and the steel nail is denoted as 6; Figure 7 The outer clamping type connection structure (the first outer clamping type structure form) in the embodiment is shown in Figure 8 The embedded type connection structure (the first embedded type structure form) in the embodiment is shown in

[0095] Figure 6 The thicknesses of the steel plate 5 in Figure 7 and Figure 8 are both 10 mm, the lap length is 160 mm, the elastic layer 3 is styrene butadiene rubber (after oxidation etching treatment), the adhesive is two-component polyurethane, the thickness of the elastic layer 3 is 1.0 mm, the hardness is Shore A60, the tensile strength is 21.6 MPa, and the elongation is 644%; according to literature data, the shear strength of the adhesive (two-component polyurethane) is about 1000 MPa;

[0096] Table 2 Comparison results

[0097]

[0098] From Table 2, compared with the existing steel plate nail connection, the connecting structure involved in the embodiment not only improves the bearing capacity of the lap joint, but also basically does not reduce the ductility.

[0099] Experiment three (connection shaft 2 test of glass steel material) :

[0100] Taking 12mm and 16mm connection shaft 2 (glass steel material) as the object, three-point bending test is adopted to test the bending moment of connection shaft 2 with span as the variable; the test results are shown in Table 3, and the bending yield strength of 5.6 grade bolts made of Q235 steel is 70.1kN·mm (diameter is 12mm, span is 138mm), 166.2kN·mm (diameter is 16mm, span is 184mm) respectively;

[0101] Table 3 connection shaft bending test results

[0102] Diameter / mm Number Span / mm Carrying capacity / kN Maximum moment / (kN mm) 12 3 300 1.54 116 12 3 150 2.82 106 12 3 100 4.43 111 12 3 50 6.33 79.1 12 3 25 9.5 59.4 12 3 12.5 22.04 58.9 16 3 400 2.59 259 16 3 200 5.06 253 16 3 100 8.43 211 16 3 50 11.8 142 16 3 25 26.5 159

[0103] From Table 3, by comparing the bending strength of connection shaft 2 (glass steel material) and steel material, it is feasible to use glass steel material connection shaft 2 to replace steel material.

[0104] Experiment four (glass steel material plate 1 test) :

[0105] The pin groove bearing strength test results of the plate 1 of the embodiment are shown in Table 4, wherein the pin groove bearing strength is equal to the maximum bearing capacity divided by the plate thickness and the pin bolt diameter, the test piece size is 8mm*100mm*100mm, the pin groove diameter is 13mm, the pin bolt diameter is 12mm, and the pin groove bearing strength design value of Q235 steel material is 320MPa;

[0106] Table 4 pin groove bearing strength test results of plate

[0107] Test type Number of tests Carrying capacity / kN Pin and slot bearing strength / MPa Parallel fabric direction 6 35.4 285 Perpendicular fabric direction 6 29.6 138

[0108] From Table 4, by comparing the pin groove bearing strength of the two materials (i.e. glass steel material plate in parallel fabric direction and steel plate), it is also feasible to replace the steel plate with the glass steel material plate 1.

[0109] Experiment five (glass steel material plate 1-glass steel material connection shaft 2 connection, i.e. pin shaft connection test) :

[0110] In the embedded connection structure of the embodiment, the test results of the connection between the plate 1 and the connection shaft 2 are shown in Table 5, wherein the plate thickness of the plate 1 is 8mm, the diameter d of the connection shaft 2 is 12mm and 16mm, and t is the distance from the surface of the plate 1 to the side of the bamboo wood member 4; the structure of the test piece is as shown in Figure 9 ;

[0111] Table 5 Test results of embedded plate-connection shaft connection of the present embodiment

[0112] d / mm t / mm Number of tests Yield carrying capacity / kN Ultimate carrying capacity / kN European yield mode class 12 21 5 6.1 6.9 I s ]] 12 46 5 6.4 9.7 I s ]] 12 66 5 6.4 10.6 III s ]] 16 26 5 10.7 12.1 I s ]] 16 56 5 10.6 15.8 I s ]] 16 90 5 11.4 18.3 III s ]]

[0113] As shown in Table 5, with the increase of the thickness of the glued wood member, the yield load of the test piece is basically unchanged, the ultimate load gradually increases, and the failure mode of the test piece is the European yield mode. Since the toughness of the connection shaft 2 (glass steel material) is slightly worse than that of steel, the European yield mode IV does not occur in the test piece, and the pin slot pressure yield does not occur in the plate 1 (glass steel material). Therefore, it is feasible to replace the steel plate and pin bolt with the plate 1 (glass steel material) and the connection shaft 2 (glass steel material), but the ductility is slightly lower.

[0114] The preferred embodiments of the present application have been described above by way of example only, not for the purpose of limiting the present application, and various changes and modifications can be made by those skilled in the art based on the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A bamboo-wood connecting method, characterized in that, a bamboo-wood connecting structure is provided, the connecting structure comprising a plate (1) for connecting two groups of bamboo-wood members (4), a connecting shaft (2), and an elastic layer (3); one side of the elastic layer (3) is connected to the two groups of bamboo-wood members (4); one side of the plate (1) is connected to the other side of the elastic layer (3); the plate (1), the elastic layer (3), and the bamboo-wood members (4) are all provided with preformed holes corresponding to each other; the connecting shaft (2) is arranged through the preformed holes of the plate (1), the elastic layer (3), and the bamboo-wood members (4); the connection between the plate (1) and the elastic layer (3) and the connection between the elastic layer (3) and the bamboo-wood members (4) are both adhesive bonding; the plate (1) and the connecting shaft (2) are both made of glass fiber reinforced plastic; and the elastic layer (3) is made of rubber. The bamboo-wood connecting method comprises the following steps: Step S1: drilling preformed holes on the plate (1), the elastic layer (3), and the bamboo-wood members (4) according to the specifications of the connecting shaft (2); the surfaces of the plate (1) and the elastic layer (3) are subjected to modification treatment, which is as follows: modification treatment of the plate (1): placing the plate (1) at the mouth of a plasma spray gun for surface modification; modification treatment of the surface of the elastic layer (3): first step: polishing the surface of the elastic layer (3) and then cleaning the elastic layer (3); second step: immersing the elastic layer (3) in 95%-98% concentrated sulfuric acid for 30 seconds to etch the surface of the elastic layer (3); third step: cleaning the elastic layer (3) and then air-drying it; Step S2: under the premise that the preformed holes of the plate (1), the elastic layer (3), and the bamboo-wood members (4) are aligned, the one side of the elastic layer (3) is bonded to the surface of the plate (1) by an adhesive, and then the other side of the elastic layer (3) is bonded to the two groups of bamboo-wood members (4) that need to be connected; Step S3: inserting the connecting shaft (2) into the preformed holes of the plate (1), the elastic layer (3), and the bamboo-wood members (4) to complete the connection.

2. The bamboo-wood connecting method according to claim 1, characterized in that, The diameter of the preformed hole on the bamboo-wood member (4) is ; and the diameter of the preformed hole on the plate member (1) is ; .

3. The bamboo-wood connecting method according to claim 2, characterized in that, The connecting shaft (2) is cylindrical, and the outer diameter of the connecting shaft (2) is... ; Greater than 0.8mm-2mm; Greater than 8mm-12mm.

4. The bamboo-wood connecting method according to any one of claims 1-3, characterized in that, The plate (1), the elastic layer (3), and the bamboo-wood members (4) are all provided with multiple groups of preformed holes, and the preformed holes of the plate (1), the elastic layer (3), and the bamboo-wood members (4) are arranged one-to-one.

5. The bamboo-wood connecting method according to claim 4, wherein Two groups of plates (1) and two groups of elastic layers (3) are included; the two groups of plates (1) are arranged on the outer surfaces of the bamboo-wood members (4) through the elastic layers (3), or one group of plate (1) and two groups of elastic layers (3) are included; the two sides of the one group of plate (1) are arranged on the bamboo-wood members (4) through the two groups of elastic layers (3).

6. The bamboo-wood connecting method according to claim 1, wherein The Shore hardness of the elastic layer (3) is 50-70 degrees, and the thickness of the elastic layer (3) is 0.8-2.5 mm.

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