JPS5915804B2 - Optimal structure manufacturing method using fiber-reinforced materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing optimal structures using fiber reinforced materials.

The optimal design method for structures that minimizes the weight or material cost of the structure or maximizes its rigidity or strength under conditions where the shape of the structure and the external forces and displacements that act on it are regulated is based on theory. However, there is currently no manufacturing method that can achieve this, and only a few fiber-reinforced composite materials are insufficiently ``optimized.''

Moreover, even when using fiber-reinforced composite materials, the fiber content Vf and fiber orientation θ correspond to the stress state in the structure.
can be determined theoretically at each point of the structure, they (Vf
, θ) in a three-dimensional manner on a structure or object is extremely difficult. Therefore, it has been considered to divide the structure into a plurality of elements using a numerical analysis method such as the finite element method, and approximately realize the theoretical (Vf, θ) in each element. For example, the fibers are oriented in one direction within each element so that the strength of the cantilever beam 1 that receives the load o and the weight W as shown in Fig. 1 is equal in each element, and the fiber content is also varied. The solution to the weight-equal-strength beam design problem is the first
As shown in the figure (Oda: Proceedings of the Japan Society of Mechanical Engineers, Volume 810-
2 (1981), 5 p. 42). In FIG. 1, the direction of the line indicates the direction of reinforcing fibers within each triangular element, and the length of the line segment indicates the content. However, in this case, it is quite difficult to make the distribution of the reinforcing fibers uniform and to keep the direction of the reinforcing fibers correct and constant. )0 This invention was made in view of the above circumstances, and
The object of the present invention is to provide a method for easily manufacturing an optimal structure using fiber-reinforced materials. Corresponding to this purpose, the method for manufacturing an optimal structure using the fiber-reinforced material of the present invention is to uniformly mix the material to be the matrix of the fiber-reinforced material with reinforcing fibers in a molten state in a zero-gravity environment. to form a mixture of the material and the reinforcing fibers, and applying a magnetic field to the mixture to orient the reinforcing fibers, and then cooling and solidifying the mixture,
Next, the solidified mixture is processed to produce structural elements, and the thus obtained elements are fixed to adjacent elements by pressure welding under a minute load in a vacuum environment to produce the structure. There are 35 people.

Hereinafter, the details of this invention will be explained with reference to one embodiment.

In the method of manufacturing an optimal structure using a fiber-reinforced material according to the present invention, first, a matrix material, which is a matrix of a fiber-reinforced material such as aluminum or other metal, or plastic, is brought into a molten state.

For this purpose, for example, a melting device 11 as shown in FIG. 2 is used. The melting device 11 includes a furnace vessel 12.
A heater 13 is disposed around 2. An electromagnet 14 is disposed near the periphery of the furnace vessel 12, and this electromagnet 14 can apply a magnetic field to the material within the furnace vessel 12. These devices and equipment are housed in a chamber 15 and maintained in a zero gravity environment. A fiber material 17 for fiber reinforcement is mixed into the matrix material 16 which has become molten in the furnace vessel 12.

The fiber material is preferably short fibers or whiskers of a magnetic material such as iron, nickel, or tungsten.If the fiber material is a non-magnetic material such as various ceramic whiskers, carbon, or glass fiber, these non-magnetic fibers may be used. Coating iron or other magnetic material on the surface. Furnace vessel 1
The molten matrix material 16 and the fiber material 17 in 2 are mixed so as to have a uniform distribution.

Since this mixing is performed under a zero gravity condition, even if there is a difference in specific gravity between the matrix material 16 and the fiber material 17, it is possible to uniformly mix them without being affected by the difference in specific gravity. When a magnetic field is applied by the electromagnet 14 to the mixture of matrix material and fiber material thus formed, the fiber materials 17 in the mixture are arranged in the direction of the magnetic field. Just before the fibers begin to move along the magnetic field lines, the magnetic field is turned off and the mixture is cooled and solidified to form a fiber-reinforced material (F.R.M. or F.R.P.
．． ) is produced. The above-mentioned weightless state can be easily obtained, for example, by using a so-called space laboratory in a recently developed artificial satellite.

Next, the fiber-reinforced material obtained as described above is cut into a predetermined shape and size in consideration of the shape of the structure, etc., to obtain a structural element of the structure.

In this way, as shown in FIG. 3, various structural elements having different shapes, sizes, fiber contents, or fiber directions are prepared. The elements having the fiber content and orientation determined by the design are arranged in a zero gravity state as shown in FIG. 4, and the whole is uniformly heated in a vacuum.

Because this heating is performed in a vacuum, the interfaces of the materials are highly clean, and the interfaces of each element are welded with a small amount of heat and load.
No discontinuous surfaces occur and a structure that meets design specifications is obtained. Further, even if the matrix is melted, the arrangement of the fibers is maintained because it is in a weightless state.

[Brief explanation of the drawing]

Figure 1 shows the solution to the minimum weight equal strength beam design problem, Figure 2
The figure is a configuration explanatory diagram showing an apparatus used for carrying out this invention.
FIG. 3 is an explanatory diagram illustrating various elements of the structure, and FIG. 4 is an explanatory diagram illustrating an example of the structure. 1... Cantilever beam, 11... Melting device,
12...Furnace vessel, 14...Electromagnet, 1
5... Chamber, 16... Matrix material, 1
7...Fiber material.

Claims (1)

[Claims] 1 A material to be a matrix of the fiber-reinforced material is uniformly mixed with reinforcing fibers in a molten state in a zero-gravity environment to form a mixture of the material and the reinforcing fibers, and a magnetic field is applied to the mixture to strengthen the reinforcing material. After orienting the fibers, the mixture is cooled and solidified, the solidified mixture is then processed to produce structural elements, and the elements thus obtained are combined with adjacent elements in a vacuum environment. An optimal method for manufacturing structures using fiber-reinforced materials, which is characterized by manufacturing a structure by bonding by pressure welding under a minute load.