JPH05163838A - Fiber reinforced resin member fixture for it made of metal, and their fixing method - Google Patents

Abstract

PURPOSE:To couple a fixture and an FRP member using a simple means easily, strongly, and at a low cost. CONSTITUTION:A fiber reinforced resin member 1 is formed in a single piece molding in the form that the middle part has a rectangular section and the ends overhang to the left and right to embody a wedge form, wherein the reinforcing fibers are oriented in the longitudinal direction, while a fixture 2 of metal is provided which is equipped with an opening in the form of wedge corresponding to the end shape of the resin member 1. The two are fitted together, and a buffer layer 3 is provided between the metal fixture and the wedge-form part of the end of resin member in the fixation part. Fitting together the resin member 1 and the metal fixture 2 is followed by fixation of the resin member 1 for loading a pressing force from behind the wedge form part of the resin member 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber reinforced resin member for use in a large structure such as a building structure, a metal fixing tool therefor, and a fixing method thereof.

[0002]

2. Description of the Related Art A fiber-reinforced resin composite material has a high specific strength and a high specific rigidity by using a light weight fiber having high strength and high elastic modulus typified by carbon fiber as a reinforcing fiber. Applications have been tried in various fields.
As an application field, in the United States where the technology of composite materials field has advanced, it is mainly applied to the aviation and space fields, and in Japan, it is mainly applied to the sports and leisure fields such as tennis rackets, fishing rods and bicycle frames. However, application to general industrial fields such as rolls for rewinding machines and propeller shafts for automobiles is gradually being tried. Carbon fiber reinforced plastic (CFR
The fiber-reinforced resin composite material (FRP) represented by P) is currently used in a portion having a relatively low load-bearing ratio, but by utilizing its strength and elastic modulus, it is used in the field of application of the present invention. The application to a primary structural member such as a strength member of a large structure is also being actively studied. At that time, the method of joining the fiber-reinforced resin composite material and the metal fixing tool for joining different kinds of materials is a technical key.

A fiber reinforced resin member having a rectangular cross section (hereinafter referred to as F
The fixing method between the FRP member and the metal fixing portion is an adhesive bonding type fixing in which an adhesive material is filled between the FRP member and the metal fixing portion and the fixing is performed, and the FRP member is pierced and bolted. There is known a mechanical joint for fixing to a metal fixing portion by the above method.

In the above-mentioned prior art, in the case of the former fixing only by the adhesive force, the binding force per unit length of the fixing portion is weak, so that the length of the fixing portion becomes extremely long and the reliability is low. Further, in the latter case of mechanical joining with bolts or the like, since the FRP member is perforated, the reinforcing fibers in the FRP member are cut and the strength of the base material is reduced. Further, the fact that the surface pressure strength of the FRP member is remarkably low with respect to metal has also been a factor that causes the strength of the fixing part to be reduced (reference: FRP (Reinforced Plastic) Design Handbook, Masuji Uemura, edited by (Company). Published by Reinforced Plastics Association, 1979).

[0005]

SUMMARY OF THE INVENTION The present invention provides a fixing method and a fixing tool for a fiber reinforced resin member, which can easily and strongly bond the fixing tool and the FRP member by a simple means. The purpose is.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a fiber-reinforced resin in which a middle portion has a rectangular cross-sectional shape and end portions project in both left and right directions, and reinforcing fibers are oriented in the longitudinal direction and integrally molded. Member and a metal fixing tool having a wedge-shaped opening corresponding to the end shape of the fiber reinforced resin member are prepared, both are fitted together, and the wedge shape of the end portion of the fiber reinforced resin member at the fixing portion is prepared. A method for fixing a fiber reinforced resin member, characterized in that a buffer layer is provided between the shaped portion and the metal fixing tool. Furthermore, it is also a fixing method in which a pressing force is applied from behind the wedge-shaped portion of the fiber reinforced resin member after fitting the fiber reinforced resin member and the metal fixing tool. The present invention also includes the above-described metal fixing device and the integrally molded fiber reinforced resin member.

In the fixing method and fixing tool for the fiber reinforced resin member (FRP member) of the present invention, as shown in FIG. 1 and FIG. 2 which is a sectional view taken along line AA of FIG. A member 1 having an intermediate portion having a tapered outer surface that fits the wedge-shaped opening is fitted into a fixing tool 2 provided with an opening corresponding to the wedge-shaped opening that expands toward the end, A buffer layer 3 for relieving stress concentration is provided between the FRP member 1 and the fixing tool, and the fiber reinforced resin member is fixed to the fixing tool 2 by pressure bonding the FRP member 1 and the fixing tool. After the FRP member 1 is loaded into the fixing tool 2, the member pressing fitting 4 is fixed to the fixing tool 2 with a bottle or the like to prevent the FRP member 1 from coming off the fixing tool 2. Further, after the wedge-shaped end of the FRP member 1 and the fixing tool 2 are fitted together, a pressing plate 5 made of metal or the like is applied to the bottom of the wedge-shaped portion, and a screw 6 is applied from the rear thereof. When pressed with, for example, the FRP member 1 can be fixed, the mounting and the like can be facilitated, and even if a compressive force acts through the FRP member 1, the compressive force can be transmitted without deforming the fixing portion. The method of applying a pressing force from the rear of the FRP member is not limited to the above-mentioned screw, but adopts a simple type in which a spring or the like is pressed into the gap formed behind the opening of the metal fixing unit and the FRP member to constantly press it. You may.

The FRP member uses continuous fibers as reinforcing fibers,
It is produced by adopting a method in which the taper portion and the parallel portion are reinforced by continuous fibers in the longitudinal direction by orienting in one direction and integrally molding. That is, as shown in FIG. 3 and FIG. 4 when viewed from the B direction in FIG. 3, the reinforcing fibers are spread in a broom shape in the thickness direction in the taper portion of the FRP member. FIG. 3 shows an FRP member having a rectangular cross-sectional shape and having a wedge-shaped end portion used in an embodiment of the present invention. The end portion has a wedge-shaped shape protruding to the left and right sides of the end portion. Is made. Considering that a sufficient fixing force can be obtained as the taper angle of the wedge at the end and the stress concentration is kept low,
3 to 10 ° is suitable. It is more preferably 4 to 8 °.

The reason why the parallel portion of the FRP member has a rectangular sectional shape is that the second moment of area can be freely changed in the case of a constant sectional area by changing the plate thickness, and the buckling load of the member can be changed. This makes it easier to design.

The fixing device 2 has a form shown in FIG. 6 which is a sectional view taken along the line CC of FIG. 5 and FIG. 5, and is not deformed by the force of expanding to the outside due to the wedge effect of the FRP member 1. The structure will have enough rigidity. As the material used for the metal fixing tool, general carbon steel for machine structure is used, but when high design load is required, it is necessary to use steel material with higher tensile strength. It is not particularly limited.

For example, when the metal fixing device is built in the main structure as it is, a wedge-shaped opening is provided only on one end and the other end is fixed to the main structure using a bolt or a pin. When joining FRP members together,
It can also be used by providing wedge-shaped openings at both ends of the metal fixing device.

The reinforcing fibers used in the FRP member of the present invention include glass fibers having high tensile strength, carbon fibers,
Aramid fiber or the like is used. The matrix resin is a thermosetting resin such as polyester resin, epoxy resin,
Nylon or the like is used as the thermoplastic resin.

As a material for forming the buffer layer, a surface frictional force which is lower in hardness than the FRP member and the metal fixing tool in order to relieve stress concentration and which can surely transmit the shearing force to the metal fixing tool. A material having the same is used, and an adhesive such as an epoxy resin or a sheet such as Teflon is used as a material satisfying the requirements.

[0014]

The buffer layer 3 includes the FRP member 1 having a wedge-shaped end in the fixing body 2 having a hole corresponding to a wedge-shaped opening.
It is charged together with it, and the wedge action causes FR with a metal fixing tool.
Hold the P member. Thereby, the tensile force can be transmitted through the FRP member. Further, by applying a pressing force from the rear of the FRP member to press the FRP member against the fixing tool, the compressive force can be transmitted via the FRP member. Furthermore, when one fixing portion is constructed, the construction is easy without being affected by the construction state of the other fixing portion.

[0015]

[Example] Plate thickness 4 mm, plate width 13 mm, parallel part length 350 m
A carbon fiber reinforced resin member having m, a taper angle of 5 ° and a taper length of 100 mm was prepared. This carbon fiber reinforced member has a fiber volume content of about 60% and a carbon fiber lengthwise ratio of about 8%.
0%, the ratio of fibers perpendicular to the longitudinal direction was 10%, and the ratio was ± 45 ° with respect to the longitudinal direction of 10%. As the metallic fixing tool, a fixing tool made of carbon steel (S45C) provided with a wedge-shaped opening corresponding to the end shape of the carbon fiber resin reinforced member was used. A nylon epoxy resin adhesive was used for the buffer layer. When fitting the FRP member to the fixing tool, 80% of the taper portion of the FRP member is fitted to the taper portion of the fixing tool, and the boundary portion between the taper portion and the parallel portion of the FRP member where stress concentration easily occurs is the fixing tool. The FRP member was fixed so that it was on the outside (Fig. 1). When the tensile load is applied with a universal testing machine in the state shown in Fig. 1 in which the FRP member is fitted to the fixing tool, a load of up to 60 kN can be applied, and the parallel portion of the carbon fiber reinforced resin member is broken. Considering the area, it bears a stress of 1200 MPa as a carbon fiber reinforced resin member, which corresponds to the tensile strength peculiar to the material of which the member is made. Power was obtained. In addition, when a compressive force was applied with a universal testing machine in the state of Fig. 1, it was F at a compressive load of 4 kN.
The RP member elastically buckled, and the compression force was satisfactorily transmitted at the fixing portion.

[0016]

According to the present invention, the wedge is formed by a simple operation of fitting the wedge-shaped FRP member into the metal fixing device having the wedge-shaped opening through the cushioning material. By using the wedge action of the mold-shaped end, the metal fixing device and F
The RP member can be pressed firmly. Also, FR
By constantly pressing the P member from the rear against the metal fixing device, not only the tensile force but also the compression force can be sufficiently transmitted. Furthermore, since the structure is simple, it is possible to manufacture a fixing tool of a fiber reinforced resin member at low cost,
It is possible to easily and quickly fix the fiber-reinforced resin member.

The wedge-shaped tapered portion at the end of the FRP member is
By molding using fibers that are continuous from the parallel portion in the longitudinal direction, it is possible to avoid a decrease in strength due to the peeling of the tab, which is conceivable in the case of a member obtained by manufacturing the tapered portion by bonding the flat plate and the tab, and High strength can be imparted also to the contact portion with the fixing tool, which is likely to be broken due to stress concentration of the contact pressure.

By providing the buffer layer, the contact between the FRP member and the metal fixing device is completed, the tensile force is transmitted from the FRP member to the metal fixing device as a uniform surface pressure, and the contact that occurs in the FRP member occurs. The pressure can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a fixing tool of a fiber-reinforced resin member fixed according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a side view of the fiber reinforced resin member of the present invention.

FIG. 4 is a view seen from the direction B in FIG.

FIG. 5 is a side view of the metal fixing tool of the present invention.

6 is a cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

 1 Fiber Reinforced Resin Member 2 Metal Fixing Tool 3 Cushioning Body 4 Member Holding Metal Fitting 5 Member Holding Plate 6 Member Holding Screw

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Kenji Kubomura 1618 Ida, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Nippon Steel Corporation Advanced Technology Research Laboratories

Claims (4)

[Claims] 1. A fiber-reinforced resin member having a wedge-shaped end portion protruding in both left and right directions, and a middle portion having a rectangular cross-sectional shape, in which reinforcing fibers are oriented in the longitudinal direction and integrally molded. 2. A metal comprising a wedge-shaped opening corresponding to a fiber-reinforced resin member having a wedge-shaped end portion protruding in both left and right directions and an intermediate portion having a rectangular cross-sectional shape. Fixing tool. 3. A wedge type in which an intermediate portion is composed of a fiber reinforced resin member having a rectangular cross section and a metal fixing tool that receives a tensile load together with the fiber reinforced resin member, and an end portion of the fiber reinforced resin member is projected in both left and right directions. And forming a wedge-shaped opening corresponding to the end formation of the fiber reinforced resin member in the fixing tool, and fitting both of them together, and the wedge-shaped member at the end of the fiber reinforced resin member at the fixing portion. A method for fixing a fiber-reinforced resin member, comprising providing a buffer layer between the metal fixing device and the metal fixing device. 4. The pressing force is applied from the rear of the wedge-shaped portion of the fiber-reinforced resin member after fitting the wedge-shaped end portion of the fiber-reinforced resin member and the metal fixing tool. The method for fixing a fiber-reinforced resin member according to item 3.