JPS6027879B2 - Reinforcement method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for reinforcing a material to be reinforced with a reinforcing beam made of fiber-reinforced synthetic resin. It's about how to do it.

Beams with a sun-shaped cross section are widely used in structural materials and other applications.

For example, steel beams called H-beams are used as building structural materials and are extremely common. The present inventors aimed at reducing the weight of transportation equipment such as automobiles, etc.
We have been investigating various ways to replace conventional steel equipment with lightweight materials such as synthetic resin. Researching the application of fiber-reinforced synthetic resin, which has particularly high strength as a synthetic resin, and examining various ways to use fiber-reinforced synthetic resin equipment in fields where conventional Japanese-shaped steel was used or in new fields where it can be applied. did. Fiber-reinforced thermosetting resins such as glass fiber-reinforced unsaturated polyester resins are commonly used as fiber-reinforced synthetic resins. beams are also known.

For example, a desired molded article can be obtained by impregnating a glass fiber roving with an unsaturated polyester resin and curing the resin while drawing the resin through a die having a diagonal cross section. When we investigated the use of a beam made of fiber-reinforced synthetic resin with a day-shaped cross section in which these reinforcing fibers were arranged in the length direction to reinforce the reinforced material, we found that this beam was different from the conventional H-shaped steel beam. It was noticed that the mechanical behavior of the One of the reasons is the directionality of mechanical strength,
That is, the tensile strength in the direction in which the reinforcing fibers are arranged is high, but the tensile strength in the direction perpendicular to this is low. Second
The third reason is that it has low rigidity and is easily deformed, and the third reason is that it has low hardness. These are the original properties of fiber-reinforced synthetic resins. These properties lead to various disadvantages when using this beam as a reinforcement. FIG. 1 is a front view and a side view showing a state in which a flat plate 1 such as an iron plate is reinforced with a reinforcing beam 2 made of fiber-reinforced synthetic resin by a conventional method.

The reinforcing beam 2 has two flanges 3, 4 and one web 5.
and a flat plate 1 which is the reinforced material on the upper surface of the flange 3.
is located. The reinforcing beam 2 is connected to a flat plate at both ends to prevent deformation when stress is applied to the flat plate, for example in the direction of the arrow. However, in this conventional method, the reinforcing beam 2 made of fiber-reinforced synthetic resin is easily deformed, for example, as shown by the dotted line in FIGS. 2A, B, and C, the cross sections of which are schematically shown. The reinforcing beam 2 has a high tensile strength in the longitudinal direction, but a low tensile strength in a direction perpendicular to the longitudinal direction, so there is a high possibility that cracks will occur in the web part in A, and in the flange parts in B and C in the longitudinal direction. Therefore, the inventor of the present invention conducted various research studies to solve this problem, and found that, contrary to conventional wisdom, a solution could be achieved by attaching the ends of the two flanges of the cross-sectional sun-shaped beam to the reinforced material. I got it.

Conventionally, when using beams with a circular cross section, the outer surface of one flange was always brought into contact with the material to be reinforced, and the web portion was oriented in a direction parallel to the compressive or tensile stress. For example, the part that supports stress, as seen in the rails of railroad tracks, is the web part. If this is made of fiber-reinforced synthetic resin, the cross-section of the reinforcing beam 2 is as shown in Figure 3.
By laying it on its side and supporting the tips of the two flanges against the reinforced material 1, its strength is improved compared to the conventional method.
However, with this method, if the tips of the two flanges are deformed in the opening or closing direction, cracks tend to occur in the length direction at the joint between the flange and the web, so this method alone is not effective enough. I can't. Therefore, as shown in FIG. 4A, we considered a method in which the web portions were placed at the tips of the two flanges, and the cross section was U-shaped so that the web portions supported the material to be reinforced. However, in this method, the deformation of the reinforced material directly causes deformation of the web part, and as schematically shown in Figure 4B, the deformation of the web part causes cracks in the length direction of the web part, as shown by the dotted line. There is a risk that this will occur. In particular, both ends of the web part that are connected to the flange part are likely to buckle due to their low hardness, and therefore, the reinforcing material contacts the web part and stress is easily applied to the web part, making it easy for the web part to break. . Therefore, the inventor of the present invention investigated the position of the web part and solved all the problems by locating the web part on the side of the reinforced material from the midpoint of the flange in the height direction and not at the tip of the flange. I looked at the scales and took them out. The reinforcing beam according to the present invention has a structure as shown in the perspective view of FIG. The reinforcing beams 9 are unevenly distributed on the sides. FIG. 5 is a sectional view thereof, in which a reinforcing beam 9 is attached to the lower part of the reinforced material 10. FIG. 7 is a side view of the reinforcing beam 9, in which both ends of the reinforcing beam 9 are loosened by the joining odors 11 and 12 against the reinforced material. That is, the method of the present invention provides reinforcement made of fiber-reinforced synthetic resin, which has a cross-sectional shape consisting of two flanges and one web connecting them, and in which reinforcing fibers are arranged in the longitudinal direction of the reinforcing beam. In a method of reinforcing a reinforced material with a beam, the tips of the two flanges of the reinforcing beam are located on the side of the reinforcing material, and the web in the reinforcing beam is located at the midpoint of the height of the two flanges. This is a method of reinforcing a material to be reinforced using fiber-reinforced synthetic resin reinforcing beams, which is characterized in that the fiber-reinforced synthetic resin reinforcing beams are unevenly distributed on the side of the material to be reinforced and are not present at the tip of the web portion. The reinforced material reinforced with the reinforcing beam shown in FIG. 7 is a relatively thin iron plate.

This iron plate is used for the hood, trunk cover, door, etc. of a car, for example, and the top side in FIG. 7 is the front side. A reinforcing beam is provided on the back side, and both ends of the beam are attached to the reinforced material. When stress is applied to the steel plate from the outside, this stress becomes tensile stress in the length direction of the reinforcing beam and is applied to the reinforcing beam. This tensile stress is mainly applied to the two flanges, and a portion of it also becomes the tensile stress of the web portion. The reinforcing beam made of fiber-reinforced synthetic resin has reinforcing fibers arranged in the longitudinal direction, so it is particularly strong against tensile stress in this direction and can absorb stress from the outside. Since the web part is not in contact with the reinforced material,
Due to the deformation of the reinforced material, bending stress in the direction perpendicular to the reinforcing fibers is not applied to the web.

Moreover, even if stress is applied to the tips of the two flanges in the direction of opening or closing, the distance between the web attachment portion and the tip of the flange is short, so the stress applied to the web attachment portion is small. The position of the web is shown schematically in Figure 8, where the height of the flange is a, the length of the web is b, and the length from the tip of the flange to the web part on the side that comes into contact with the reinforced material is C. , there is a need for the relationship a>C>〇,
Preferably, a≧C≧a, and it is particularly appropriate that C=a.

Further, the relationship between a and b is not particularly limited, but it is preferable that pine>b>kyoa, especially 1. The string ZbZa is suitable. As a specific reinforcing beam, a reinforcing beam made of glass fiber-reinforced unsaturated polyester resin (glass fiber content: 6% by weight) having a cross section as shown in FIG. 6 with glass fiber rovings arranged in the length direction is mentioned. .

This cross section is shown in Figure 8 where a = 3.2 skin, b = 4.5
The skin, c=0.7 skin, the thickness of the flange is 0.5 skin, and the length of the web portion is 0.4. On the other hand, for comparison, using the same material, c=]. An H-shaped beam having the same attachment method as the reinforcing beam of the present invention described above was manufactured except that the reinforcing beam was 6-shaped. Both were subjected to a bending test with a concentrated load at the center on a free support stand with a fulcrum distance of 75 skin, with the load direction changed, and the amount of work (k9.k) from the load to the shading drawing to the shading 10 skin was measured. The results are shown in the table below. However, the load direction m is a load applied in the opposite direction to the load direction 1, and c=3.2
-0.7=2.5. The reinforcing beams are made of fiber-reinforced synthetic fibers. The reinforcing fiber is glass fiber,
Carbon fibers, composite fibers, other inorganic fibers, high tensile strength synthetic fibers, synthetic fibers, cellulose fibers, and other organic fibers can be used. Glass fibers are particularly preferred, and fibers in rovings, roving cloths, cloths, mats, chopped strands, and other forms can be used alone or in combination. The fibers arranged in the longitudinal direction may of course be arranged only in that direction, or may include fibers arranged in directions other than the longitudinal direction. As the longitudinal fibers, not only rovings continuous in the longitudinal direction, but also chopped strands arranged in the longitudinal direction can be used. Most preferably, reinforcing fibers include longitudinally arranged rovings, either alone or in combination with rovings and mats, cloths, or other forms of fibers. Suitable synthetic resins include unsaturated polyester resins, vinylester resins, epoxy resins, and other thermosetting resins. Thermoplastic resins can be used in some cases, but it is not as easy to arrange the fibers in the longitudinal direction as with thermoplastic resins. Other known materials are used to form the reinforcing beam. The most common molding method is pultrusion, but other methods include press molding, hand lay-up,
It can also be molded by other molding methods. The material to be reinforced in the present invention is generally a metal plate such as an iron plate, but it can be applied to various materials such as a synthetic resin plate, a slate plate, and a wooden plate.

In addition, the shape can be applied not only to flat plates but also to plate-shaped bodies formed into various shapes such as automobile parts. The reinforcing beams are usually attached to the back side of these plate-like bodies with both ends fixed. In this case, not only one reinforcing beam but also two or more reinforcing beams can be used in combination, and these beams may or may not be parallel to each other. The reinforcing beam reinforces the plate-shaped body against stress applied to the plate-shaped body, for example, external force at the time of collision or contact in the case of automobile parts, and prevents the plate-shaped body from being deformed or destroyed. Moreover, since it is lighter than conventional reinforcing beams, it is suitable for the purpose of reducing the weight of automobiles.

[Brief explanation of the drawing]

FIG. 1 is a front view and a side view showing a conventional reinforcing method, and FIGS. 2 A, B, and C are schematic diagrams showing deformation of a reinforcing beam caused by this conventional reinforcing method. Figures 3 and 4A and 4B show a still insufficiently reinforced beam showing one step in its improvement. FIG. 5 is a perspective view of the reinforcing beam of the present invention, FIGS. 6 and 7 are cross-sectional views and side views of the reinforced material reinforced with the reinforcing beam of the present invention, and FIG. 8 is a perspective view of the reinforcing beam of the present invention. It is a Hayashiki diagram of a cross section. 6,7
...Flange, 8...Wave, 9...Reinforcement beam, 10
...Reinforced material. Tanomadara ticket 2 figure hair 3 figure hair 4 figure hairzuzutsumuzu neighbor hair 7 figure hair 8 figure

Claims (1)

[Claims] 1. A reinforcing beam made of fiber-reinforced synthetic resin, which has an H-shaped cross section and consists of two flanges and one web connecting them, and in which reinforcing fibers are arranged in the longitudinal direction of the reinforcing beam. In the method of reinforcing a material to be reinforced by A method for reinforcing a material to be reinforced using a fiber-reinforced synthetic resin reinforcing beam, which is characterized in that the reinforcing beam is unevenly distributed on the side of the material to be reinforced rather than the point and is not present at the tip of the flange. 2. The reinforcing method according to claim 1, wherein the fiber-reinforced synthetic resin is a glass fiber-reinforced thermosetting resin. 3
The reinforcing method according to claim 1, wherein 3/8a≦c≦1/8a, where a is the height of the flange, and c is the distance between the tip of the flange on the side of the material to be reinforced and the web. 4. The reinforcing method according to claim 1, wherein the material to be reinforced is a plate-shaped member.