JPH0899381A - Impact-resistant structural material - Google Patents

Abstract

PURPOSE: To realize an impact-resistant structural material reduced in wt., having large residual strength after an impact and having effect on a low mass high speed impact. CONSTITUTION: A impact-resistant structural material is formed by superposing a two-dimensional laminated type reinforcing composite material 8 and a three- dimensional reinforcing composite material 9 one upon another. Since the two-dimensional laminated reinforcing fiber composite material 8 generating ply separation against the impact from the outside absorbs the greater part of impact energy and the three-dimensional reinforcing composite material 9 absorbs the residual impact energy and holds residual strength, the impact-resistant structural material having impact energy absorbing force and high residual strength after an impact, excellent in the resistance against a low mass high speed impact and reduced in wt. is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact resistant structural material applied to aircraft, space equipment, and various transportation equipment.

[0002]

2. Description of the Related Art Among conventional impact resistant structural materials, a so-called sturdy structural material having a margin capable of sufficiently receiving an impact that may be applied, and absorbing impact energy by intentionally deforming the member. There are two types of so-called crushable structural materials.

The former forms a sturdy structure represented by a railway bollard, but since the impact energy can be converted only into the motion of the molecules constituting the structural material, the volume and weight of the structural material itself inevitably increase. .

The latter is a structural material often seen in automobiles in recent years. Since the impact energy can be converted into the deformation energy of members, the volume and weight are smaller than those of the former, but they are completely usable after the impact is applied. Will not happen.

Aircraft and space equipment have to take the latter form due to their weight restrictions, but they are severely restricted in terms of shape and function in addition to weight. There is. Also, it has a small mass / volume like bullets and cosmic dust, but is less effective against impacts applied at high speed.

As a countermeasure against this, as shown in FIG. 4 (a), two kinds of metal materials 01 and 02 are stacked, and FIG. 4 (b).
As shown in Fig. 1, an impact resistant structural material has been proposed in which a metal material and a two-dimensional laminated reinforced fiber composite material are stacked and the characteristics of the material itself and the structure of the structural material are taken into consideration. Not all points have been resolved.

[0007]

As described above, the conventional impact resistant structural material is a so-called sturdy structural material having a sufficient margin for receiving an impact that may be applied, and the member is intentionally deformed. By doing so, it can be roughly classified into two types, so-called crushable structural materials that absorb impact energy.

However, the former has a very large weight and volume, the latter has a small residual strength after impact, and the mass such as bullets and cosmic dust has a small mass, so that it is not effective for impact applied at high speed.

Structural materials for aircraft and space equipment are extremely required to have a small weight and a high residual strength after impact, and therefore these two structural materials cannot be used. In addition, depending on the application, it is necessary to receive the impact of low mass and high speed, but this could not be satisfied.

The present invention is intended to solve the above problems, has a small weight, has a large residual strength after an impact, and is effective even for an impact with a low mass and a high speed. The present invention intends to provide an impact resistant structural material applicable to.

[0011]

The impact resistant structural material of the present invention is characterized by being formed of a two-dimensional laminated reinforced fiber composite material and a three-dimensional reinforced fiber composite material laminated on the composite material. There is.

[0012]

In the above, the two-dimensional laminated reinforced fiber composite material can absorb large impact energy by causing delamination between layers due to impact. However, since delamination occurs over a wide range, the residual strength after impact is small.

On the other hand, the three-dimensional reinforced fiber composite material does not cause delamination because it is reinforced with fibers also in the interlaminar direction, and therefore the three-dimensional reinforced fiber composite material 8 is absorbed more than the two-dimensional laminated reinforced fiber composite material 8. The impact energy that can be generated is small, but the residual area after impact is large because the damaged area is small.

In the impact resistant structural material of the present invention, this 2
When two kinds of composite materials are piled up, the two-dimensional laminated reinforced fiber composite material absorbs most of the impact energy, and then the three-dimensional reinforced fiber composite material absorbs the impact energy. Absorb. Therefore, high residual strength is maintained even after impact.

In addition to absorbing energy, the two-dimensional laminated reinforced fiber composite material also has a function of blunting the tip shape of the colliding object to prevent penetration, so that it can be applied to low-mass high-speed impacting objects such as bullets and cosmic dust. It also works effectively. Furthermore,
Since it is formed of only the composite material, the weight can be significantly reduced as compared with the case where the conventional metal material is used.

Therefore, in the present invention, an impact resistant structural material having impact energy absorption capacity and high residual strength after impact, excellent resistance to low mass high speed impact, and low weight is realized.

[0017]

FIG. 1 shows an impact resistant structural material according to an embodiment of the present invention.
Will be described. The structural material of this embodiment shown in FIG.
The two-dimensional laminated reinforced fiber composite material 8 shown in (b) and FIG.
The three-dimensional reinforcing fiber composite material 9 shown in (c) is shown in FIG.
As shown in FIG. 5, they are formed by being laminated and adhered.

Here, the two-dimensional laminated reinforced fiber composite material 8
Has a high strength in each of the two-dimensional directions, so that it is orthogonally anisotropic (0 ° / 90 °) or pseudo-isotropic (0 ° / 90 °).
It is preferable that the reinforcing fibers 7 are oriented in the same manner (° / ± 45 °) (the ratio is the same in the multilayer). The three-dimensional reinforced fiber composite material 9 is
Since the strength in each of the three-dimensional directions is high,
(A) or a woven structure material of orthogonal triaxial type 5-axis woven fabric shown in FIG. 2 (b) (the reinforcing fiber 7 orientation ratio is the same in multiple directions) is preferable.

In addition to the woven structure described above, the three-dimensional reinforcing fiber composite material 9 is also effective in stitching weave in which the two-dimensional laminated reinforcing fiber composite material 8 is sewn in the interlayer direction, interlock weave and the like. It is preferable that the reinforcing fiber 7 is made of aramid fiber having high toughness, and the resin is made of epoxy resin or polyester resin having high toughness and compatible with the reinforcing fiber 7.

However, the constitution and material of the reinforcing fiber 7 shown here are examples considered to be the best in the present situation, and even if another reinforcing fiber 7 having a different constitution and material is used, the structure and material shown in FIG.
As long as it is a structural material in which the two-dimensional laminated reinforced fiber composite material 8 and the three-dimensional reinforced fiber composite material 9 shown in (3) are combined, it is possible to have high-performance impact resistance as compared with conventional structural materials.

The thickness ratio between the two-dimensional laminated reinforced fiber composite material 8 and the three-dimensional reinforced fiber composite material 9 is determined according to the design requirements for the amount of impact energy absorbed and the residual strength after impact. .

Next, the operation of the structural material according to this embodiment will be described below. Two-dimensional laminated reinforced fiber composite material 8
Can absorb large impact energy by causing delamination in which layers are separated from each other by impact. However, since delamination occurs over a wide range, the residual strength after impact is small.

On the other hand, the three-dimensional reinforced fiber composite material 9
Is reinforced with fibers also in the interlaminar direction in the two-dimensional laminated reinforced fiber composite material 8, so delamination does not occur, and therefore, it can be absorbed as compared with the two-dimensional laminated reinforced fiber composite material 8. Although the impact energy is small, the residual area after impact is large because the damage area is small.

In the case of the impact resistant structural material of this embodiment, the impact energy from the outside is first absorbed by the two-dimensional laminated reinforced fiber composite material 8 to a large extent. Next, the three-dimensional reinforcing fiber composite material 9 absorbs the impact energy that cannot be absorbed by the two-dimensional laminated reinforcing fiber composite material 8,
Maintains high residual strength after impact. Therefore, the residual strength is high.

Further, the two-dimensional laminated reinforced fiber composite material 8 not only absorbs impact energy but also has a function of blunting the tip shape of the colliding object to prevent penetration, so that it has a low mass such as bullets and cosmic dust. It also works effectively on high-speed impact objects. Further, since the composite material is used, the weight can be significantly reduced as compared with the conventional metal material.

Therefore, in the present embodiment, it has an impact energy absorption capacity, a high residual strength after impact, an excellent resistance to a low mass and high speed impact, and a low weight, which is an unprecedented high performance resistance. We were able to realize an impact structure material.

Next, first, second and third application examples to which the structural material according to this embodiment is applied will be described below with reference to FIG. A first application example shown in FIG. 3A is a case where the first application example is applied as an outer plate structural material of an aircraft.

The outer skin structural material of an aircraft is frequently subjected to various impacts. For example, fighter planes are expected to receive bullets, and civilian planes may suffer bird strikes. Also,
The bottom skin 1 of the aircraft is designed to have a structure capable of withstanding a large impact assuming a fuselage landing.

Since the outer skin of an aircraft also plays a role as a strength member, even if it can absorb a shock, if the residual strength after the shock is small, it will seriously hinder the subsequent flight and even cause a crash. It is also expected. The structural material of the present embodiment is very effective as a structural material that requires such impact resistance, and is also lightweight and has excellent residual strength after impact.

Although slightly different from the outer plate, the structural material of this embodiment is also effective for the engine cover. This is because the engine cover has the role of preventing the fan blades from being damaged by the engine sucking in foreign matter and the like, and prevents the fragments from sticking to the wings or fuselage of the aircraft, and requires strength.

The second application example shown in FIG. 3B is applied to the space dust protection wall 2 of the space station.
In the universe, the remains of rockets and satellites launched in the past are floating at high speed.

In the future, when the manned space station 4 is launched, the protective wall 2 against such suspended matter (space dust 3) is required. Most of the cosmic dust 3 has a mass of 1 to 2 g, but their speed is very high at several tens Km / sec. In addition, launching a heavy and sturdy space dust protection wall 2 for use in space is not a good cost measure.

Furthermore, since it is expected that the collision of the cosmic dust 3 will occur not only once but continuously, the residual strength after impact is also required. Therefore, the structural material of this embodiment is used as such a protective wall for cosmic dust. When applied to 2, the protective wall 2 can be given very effective characteristics.

A third application example shown in FIG. 3C is a bulletproof shield 5.
When applied to. As the bulletproof shield 5 used in the police and the riot police, a structure having a combination of a two-dimensional laminated reinforced fiber composite material and a metal plate can be seen in the past, but if the structural material of this embodiment is applied, By using all-composite materials, weight reduction and high elasticity can be realized.

[0035]

In the impact resistant structural material of the present invention, since the two-dimensional laminated reinforced fiber composite material and the three-dimensional reinforced fiber composite material are laminated and formed, it is possible to prevent inter-layer impact against external impact. The two-dimensional laminated reinforced fiber composite material that causes peeling absorbs most of the impact energy, and the three-dimensional reinforced fiber composite material that absorbs the remaining impact energy retains the residual strength. It has high residual strength, excellent resistance to low-mass high-speed impact, and low impact weight structural material.

[Brief description of drawings]

FIG. 1 is an explanatory view of an impact resistant structural material according to an embodiment of the present invention, (a) is a side view, (b) is an explanatory view of a two-dimensional laminated reinforced fiber composite material forming the structural material, ( c) is an explanatory view of a three-dimensional reinforcing fiber composite material forming a structural material.

2A and 2B are explanatory views of a three-dimensional reinforced fiber composite material according to the above-mentioned embodiment, and FIG. 2A is an explanatory diagram in the case of an orthogonal triaxial weave and FIG.

FIG. 3 is an explanatory diagram of an application example of the structural material according to the above-mentioned embodiment, (a) is a first application example, (b) is a second application example, and (c).
FIG. 13 is an explanatory diagram of a third application example.

FIG. 4 is an explanatory view of a conventional structural material.

[Explanation of symbols]

 7 Reinforcing fiber 8 Two-dimensional laminated reinforcing fiber composite material 9 Three-dimensional reinforcing fiber composite material

Claims (1)

[Claims] 1. An impact resistant structural material, which is formed of a two-dimensional laminated reinforced fiber composite material and a three-dimensional reinforced fiber composite material laminated on the composite material.