CN219138154U - Fiber-reinforced composite tendon combined extrusion anchorage - Google Patents

Abstract

A combined extrusion anchor for fiber reinforced composite material ribs relates to an extrusion anchor, which comprises a plurality of extrusion sleeves which are anchored on a single fiber reinforced composite material rib in series, wherein the extrusion sleeves are closely attached together. The diameter of the inner hole of the extrusion sleeve is 0-2 mm larger than that of the fiber reinforced composite material rib, and the inner hole of the extrusion sleeve is provided with internal threads or coated with silicon carbide and adhesive; the outer diameter of the extrusion sleeve before extrusion is b; among the plurality of extrusion sleeves connected in series on the single fiber reinforced composite material rib, the extrusion sleeve extrusion front outer diameter b which is closer to the free end is larger, the extrusion sleeve extrusion front outer diameter b which is closer to the loading end is smaller, the extrusion sleeve extrusion front outer diameter of the free end is 1.0-1.5 times of the extrusion sleeve extrusion front outer diameter of the loading end, and the value range of b is 1.6-5 times of the fiber reinforced composite material rib diameter. The utility model can reduce bending deformation of the extrusion sleeve after extrusion, reduce damage of the fiber material, realize longer extrusion anchoring section, and ensure reliable anchoring, and can meet the anchoring and use requirements of the fiber material rib.

Description

Fiber-reinforced composite tendon combined extrusion anchorage

technical field

The utility model relates to an extruded anchor, in particular to an extruded anchor with fiber-reinforced composite tendon combination.

Background technique

Fiber reinforced composites (FRP) such as carbon fiber and glass fiber have the advantages of high axial tensile strength, light weight, corrosion resistance and fatigue resistance, and have extremely high engineering application value. However, the transverse shear strength of FRP material is low, and the traditional anchoring structure is difficult to anchor it. The development of a practical and reliable anchoring structure is the key to the application of FRP material in engineering practice. FRP tendon anchorage structures can usually be divided into bonding type, clamping type, extruded type and composite type. Among them, there are many researches and applications on bonding type, clamping type and composite anchoring structure. There are relatively few studies on anchorage structures.

The extruded anchorage structure is small in size, easy to construct, and has extremely high economic value. It is suitable for combining with other forms of anchorage to form a composite anchorage. However, traditional extrusion anchors have problems such as unstable anchoring systems and easy breakage of fiber materials. In order to achieve reliable anchoring, the structural dimensions of the anchorage are larger and much longer than those of steel wires and steel bars with the same force value, and the extrusion anchorage needs to pass through the extrusion die, and produce plastic deformation after radial compression, so as to hold and wrap Compress the reinforcement; due to the inevitable size and installation errors, if the length of the extrusion anchor is too long, it will be easily bent and deformed during the extrusion process, resulting in damage to the reinforcement and poor anchoring effect.

Contents of the invention

The technical problem to be solved by the utility model is: to provide a fiber-reinforced composite material tendon combined extrusion anchorage that can reduce the damage of the tendon and anchor reliably, so as to meet the anchoring and use requirements of the fiber material tendon.

The technical solution to solve the above technical problems is: a fiber-reinforced composite bar combined extrusion anchorage, including a plurality of extruded sleeves anchored in series on a single fiber-reinforced composite bar, and each extruded sleeve is tightly attached to the Together.

A further technical solution of the present invention is: the diameter of the inner hole of the extrusion sleeve is a, and the diameter of a is 0-2 mm larger than the diameter of the fiber-reinforced composite material rib, and the inner hole of the extrusion sleeve is provided with an internal thread or coated with emery, adhesive.

The further technical solution of the utility model is: the two ends of the extrusion sleeve are provided with a lead angle, and the value θ thereof is 1-30°.

The further technical scheme of the utility model is: the outer diameter of the extrusion sleeve before extrusion is b; in the plurality of extrusion sleeves anchored in series on a single fiber-reinforced composite material tendon, the extrusion sleeve closer to the free end The larger the outer diameter b of the sleeve before extrusion, the smaller the outer diameter b of the extrusion sleeve near the loaded end is, and the outer diameter of the extruded sleeve at the free end is equal to the outer diameter of the extruded sleeve at the loaded end. 1.0 to 1.5 times, and the value range of b is 1.6 to 5 times the diameter of the fiber reinforced composite material.

Due to the adoption of the above structure, compared with the prior art, the fiber-reinforced composite tendon combined extrusion anchorage of the utility model has the following beneficial effects:

1. It can reduce the bending deformation of the extrusion sleeve after extrusion

The fiber-reinforced composite tendon combined extrusion anchor of the utility model includes a plurality of extruded sleeves anchored in series on a single fiber-reinforced composite tendon, and each extruded sleeve is tightly bonded together. The utility model divides the conventional extruded anchorage extruded sleeve into several extruded sleeves along the length direction, so that the length of each extruded sleeve can be effectively shortened, and the bending deformation after being extruded is greatly reduced.

2. It can avoid the individual bearing of each extrusion sleeve

In the extrusion process of the utility model, a plurality of extrusion sleeves are extruded in series, and there is a certain force value between each extrusion sleeve to ensure that they are closely fitted together, and each extrusion sleeve is prevented from being individually loaded; it can reduce the number of ribs Damage, and can achieve a very long extrusion anchorage section.

3. It can not only reduce the damage of the reinforcement, but also realize a very long extrusion anchorage section

The utility model divides the extrusion sleeve of the conventional extrusion anchor into several extrusion sleeves along the length direction. Compared with the single extrusion anchor with the same total length, it is not easy to bend, and it not only has little damage to the reinforcement, but also can realize a very long extrusion. Anchor segment. Moreover, the tapping thread of the inner hole of the extrusion sleeve is more centered, reducing the extrusion deviation, avoiding the shear damage of the fiber material, and further reducing the damage to the reinforcement.

4. Reliable anchoring

Each extrusion sleeve of the utility model shares a part of the anchoring force of the fiber reinforcement, and according to the equal strength theory deduced from the Tsai-Wu failure criterion and the stress state requirements of the reinforcement, the outer diameter of each extrusion sleeve connected in series is adjusted, The outer diameter of the extrusion sleeve closer to the free end is larger before extrusion, and the outer diameter of the extrusion sleeve closer to the loaded end is smaller before extrusion; thereby adjusting the extrusion allowance so that the extrusion stress of each extrusion sleeve on the reinforcement conforms to The distribution state of the better anchoring effect achieves the purpose of reliably anchoring the fiber-reinforced composite tendons.

Further, the utility model screwed the inner hole of the extrusion sleeve, applied adhesive, applied micro-expansion cement, or attached emery and other media that can increase the anchoring effect. After the extrusion anchor was squeezed, the emery, emery, Adhesive or micro-expansion cement is tightly pressed against the reinforcement, which produces higher friction or bonding force on the reinforcement, and better grip and anchoring effect.

5. Simple structure and convenient construction

The extruded anchor of the utility model includes a plurality of extruded sleeves anchored in series on a single fiber-reinforced composite tendon, and has a relatively simple structure. Moreover, when extruding, a plurality of extruding sleeves connected in series are sequentially pushed into the extruding die through a jack and a pressing head, and the construction is relatively convenient.

6. It can meet the anchoring and use requirements of fiber material reinforcement

The utility model can not only reduce the damage of the tendons, but also realize a very long extrusion anchoring section, and the anchoring is relatively reliable, which can completely meet the anchoring and use requirements of the fiber material tendons.

Below, the technical features of the fiber-reinforced composite tendon combined extrusion anchor of the present invention will be further described in conjunction with the accompanying drawings and examples.

Description of drawings

Figure 1: Schematic diagram of the structure of the fiber-reinforced composite bar combined extrusion anchor of the present invention described in Embodiment 1,

Figure 2: Schematic diagram of the structure of the single extrusion sleeve described in Embodiment 1,

Fig. 3: Schematic diagram of the structure of the extrusion device described in Embodiment 1,

Fig. 4: the structural representation of extrusion die described in embodiment one;

In the above-mentioned accompanying drawings, each reference numeral is explained as follows:

1- Fibre-reinforced composite tendons,

2- Squeeze sleeve,

3- extrusion device,

301-extrusion die backing plate, 302-top pressure head, 303-connecting cylinder, 304-top pressure backing plate,

305-jack, 306-fixed backing plate, 307-tie rod, 308-nut, 309-extrusion die,

Z-free end, S-loaded end.

Detailed ways

Embodiment one:

A fiber-reinforced composite tendon combined extrusion anchorage, comprising a plurality (three in this embodiment) of extruded sleeves 2 anchored in series on a single fiber-reinforced composite tendon 1, each extruded sleeve is extruded When pressing, there is a certain force value, so that the extrusion sleeves fit together tightly, so as to ensure that the extrusion sleeves are cooperating to bear the force.

The diameter of the inner hole of the extrusion sleeve 2 is a, which is 0-2mm larger than the diameter of the fiber-reinforced composite rib. In order to enhance the anchoring effect of the extrusion sleeve, the inner hole of the extrusion sleeve 2 is provided with internal threads or painted Carborundum, adhesive.

In order to make the fiber-reinforced composite tendon bear a reasonable force in the anchorage end, the two ends of the single extruded sleeve 2 are provided with a lead angle, and its value θ is 1-30°. By changing the size of the lead angle θ, the radial stress of the extrusion sleeve on the reinforcement at the loaded end or the free end is adjusted to reduce the stress peak value there.

The outer diameter of the extrusion sleeve 2 before extrusion is b; the outer diameter b is designed according to the equal strength theory derived from the Tsai-Wu failure criterion and the force characteristics of the fiber reinforced composite tendons. Among the multiple extruded sleeves 2 anchored in series on a single fiber-reinforced composite tendon, the closer to the free end of the extruded sleeve, the larger the outer diameter b before extrusion, and the closer to the loaded end, the extruded extruded outer diameter b The smaller the outer diameter b, the outer diameter of the extrusion sleeve at the free end before extrusion is 1.0 to 1.5 times the outer diameter of the extrusion sleeve at the loaded end, and the value range of b is 1.6 to 5 times the diameter of the fiber reinforced composite material. times.

The process of designing the outer diameter b according to the equal-strength theory derived from the Tsai-Wu failure criterion and the stress characteristics of the fiber-reinforced composite bars is as follows:

The Tsai-Wu failure criterion is suitable for orthotropic fiber reinforced composite bars, and the general formula of the criterion equation is written as:

F _i σ _i +F _ij σ _i σ _j ...＝1(i,j＝1,2,...,6) (1)

When the fiber-reinforced composite material is in a linear elastic state, the left side of formula (1) should be less than or equal to 1. For an orthotropic single-layer material under plane stress, formula (1) can be transformed into:

F ₁₁ σ ₁ ² +F ₂₂ σ ₂ ² +F ₆₆ σ ₆ ² +F ₁ σ ₁ +F ₂ σ ₂ +F ₆ σ ₆ +2F ₁₂ σ ₁ σ ₂ +2F ₁₆ σ ₁ σ ₆ +2F ₂₆ σ ₂ σ ₆ ≤ 1 (2)

In formulas (1) and (2), σ ₁ is the longitudinal (axial) stress along the fiber direction, σ ₂ is the transverse (radial) stress perpendicular to the fiber direction, and σ ₆ is the shear stress;

In formulas (1) and (2), F _i and F _ij are the strength tensors of the material, describing the principal stress interaction of i and j, which can be obtained through experiments and calculated according to the following formula:

In formula (3), X _t and X _c are longitudinal tensile and compressive strengths; Y _t and Y _c are transverse tensile and compressive strengths; S is shear strength. Since the vertical and horizontal direction of the fiber reinforced composite tendon is basically the same as the principal stress direction in the anchorage, then σ ₆ =0, after simplifying the expression (2), the expression (4) is obtained:

F ₁ σ ₁ +F ₂ σ ₂ +F ₁₁ σ ₁ ² +F ₂₂ σ ₂ ² +2F ₁₂ σ ₁ σ ₂ ≤1 (4)

The curve is a quadratic elliptic curve, and according to the properties of the elliptic curve, its necessary condition is formula (5):

时，可获得理论与实际值符合较好的结果，对于高强纤维增强复合材料筋，其通过拉挤工艺成型，纤维丝沿纵向平行均匀排布，因此X_t由纤维丝强度确定；纤维增强复合材料筋其余方向的抗压、抗拉强度由基体材料强度确定，其各向同性，有X_c＝Y_t＝Y_c，则F₂＝0。When to take

When , a good agreement between theory and actual value can be obtained. For high-strength fiber-reinforced composite bars, which are formed by pultrusion process, the fiber filaments are evenly arranged in parallel in the longitudinal direction, so X _t is determined by the fiber filament strength; fiber-reinforced composite The compressive and tensile strengths of the other directions of the ribs are determined by the strength of the matrix material, which is isotropic, X _c =Y _t =Y _c , then F ₂ =0.

Simplify expression (4) and get formula (6):

F ₁ σ ₁ +F ₁₁ σ ₁ ² +F ₂₂ σ ₂ ² +2F ₁₂ σ ₁ σ ₂ ≤1 (6)

定义压应力集中系数/>

得：Put (3) into formula (6), let

Define compressive stress concentration factor />

have to:

This curve is a convex function on |σ ₂ |∈[0,X _c ], and is basically a straight line, so it is partial to perform linear fitting based on |σ ₂ |=0 and |σ ₂ |=X _c If it is safe, the relationship between the longitudinal (axial) stress and the transverse (radial) stress of the fiber reinforced composite reinforcement in the anchorage area in the safe state is:

The slope k of formula (10) is:

Due to the existence of frictional resistance, the longitudinal (axial) stress σ ₁ on the reinforcement gradually decreases from the loaded end to the free end. Therefore, according to formula (11) in an ideal state, the anchorage to the fiber reinforced composite tendon The absolute value of the transverse (radial) stress _σ2 should gradually increase from the loaded end to the free end. The larger the outer diameter of the extrusion sleeve, the greater the radial stress on the reinforcement after extrusion. According to the equal-strength theory deduced above, the closer the extruded sleeve of the combined extrusion anchorage to the free end is, the larger the extruded outer diameter b should be, and the closer to the loaded end the extruded outer diameter b of the extruded sleeve should be The smaller the value is, the more reasonable the extrusion stress distribution of fiber reinforced composite bars can be adjusted. The outer diameter of the extrusion sleeve at the free end before extrusion is 1.0 to 1.5 times the outer diameter of the extrusion sleeve at the loaded end before extrusion.

The fiber-reinforced composite tendon combined extrusion anchorage of the utility model uses an extruding device 3 to extrude the fiber-reinforced composite tendon 1 and the extrusion sleeve 2 .

Described extruding device 3 comprises extrusion die backing plate 301, push head 302, connecting cylinder 303, top pressure backing plate 304, jack 305, fixed backing plate 306, pull rod 307, nut 308, extrusion die 309; Wherein :

The four corners of the extrusion die backing plate 301 are respectively provided with threaded holes for being connected with the pull rods 307, and the four corners of the pressing backing plate 304 and the fixed backing plate 306 are respectively provided with pull rod passages for passing the pull rods 307. Holes; the pull rods 307 respectively pass through the four corners of the extrusion die backing plate 301, the pressing backing plate 304, and the fixed backing plate 306, and the extrusion die backing plate 301, the pressing backing plate 304 are passed through the nut 308 1. The fixed backing plate 306 is connected as a whole; one end of the fixed backing plate 306 is provided with a cylinder positioning groove II, one end of the pressing backing plate 304 is provided with a connecting cylinder positioning groove, and the other end of the pressing backing plate 304 There is an oil cylinder positioning groove I; the jack 305 is installed between the top pressure backing plate 304 and the fixed backing plate 306, and the two ends of the oil cylinder of the jack 305 are respectively matched with the oil cylinder positioning groove II and the oil cylinder positioning groove I Connection; the end of the piston rod of the jack 305 passes through the pressing backing plate 304 and is fixedly connected with the pressing head 302; In the barrel positioning groove, and the connecting barrel 303 is sleeved on the outside of the piston rod of the pressing head 302 and the jack 305. The extrusion die 309 is installed in the extrusion die backing plate 301 relative to the top pressure head 302. The center hole of the extrusion die 309 is a tapered hole, and the value range of the diameter d of the small end of the center hole is fiber-reinforced. 1.2 to 4 times the diameter of the composite rib.

The extrusion method of the fiber-reinforced composite tendon combined extrusion anchorage described in the first embodiment is to first install the extruding device 3, and then pass the single fiber-reinforced composite tendon 1 through the center hole of the extrusion die 309, and insert A plurality of extrusion sleeves 2 are connected in series to the end of the fiber-reinforced composite material ribs that have passed through the central hole of the extrusion die after being coated with lubricant, and finally the fiber-reinforced composite material ribs are inserted into the top pressure head 302, and the operation jack 305 is used for multiple The squeeze sleeves 2 connected in series implement squeeze anchoring.

The content of the installation extrusion device includes passing the tie rods 307 through the fixed backing plate 306 respectively, fixing the tie rods 307 with the pre-twist nut 308, placing one end of the jack 305 in the oil cylinder positioning groove of the fixing backing plate 306, and passing the tie rods 307 through Press the backing plate 304, insert the connecting cylinder 303 into the end of the piston rod of the jack 305, place the pressing head 302 in the connecting cylinder 303 and be fixedly connected with the end of the piston rod of the jack 305; place the connecting cylinder 303 on the top pressure In the positioning groove of the connecting cylinder at one end of the backing plate 304, the other end of the oil cylinder of the jack 305 is placed in the positioning groove of the oil cylinder at the other end of the pressing backing plate 304, and finally the pull rod 307 is screwed into the extrusion die backing plate 301, and the nut is tightened 308, the jack 305 is fixed, and the installation is completed.

Claims (1)

1. The utility model provides a fibre reinforced composite muscle combination formula extrusion ground tackle which characterized in that: comprises a plurality of extrusion sleeves (2) which are anchored on a single fiber reinforced composite material rib (1) in series, wherein each extrusion sleeve (2) is tightly attached together; the diameter of the inner hole of the extrusion sleeve (2) is a, the a is 0-2 mm larger than the diameter of the fiber reinforced composite material rib (1), and an inner thread or a coated diamond or a coated adhesive is arranged in the inner hole of the extrusion sleeve (2); both ends of the extrusion sleeve (2) are provided with guide angles, and the value theta of the guide angles is 1-30 degrees; the outer diameter of the extrusion sleeve (2) before extrusion is b; in the extrusion sleeves (2) which are anchored on a single fiber reinforced composite material rib (1) in series, the larger the extrusion outer diameter b of the extrusion sleeve which is closer to the free end is, the smaller the extrusion outer diameter b of the extrusion sleeve which is closer to the loaded end is, the larger the extrusion outer diameter of the extrusion sleeve which is closer to the free end is 1.0-1.5 times of the extrusion outer diameter of the extrusion sleeve which is closer to the loaded end, and the value range of b is 1.6-5 times of the diameter of the fiber reinforced composite material rib.

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