SU689080A1 - Method of manufacturing structural elements from oriented fibrous composition materials - Google Patents

Description

three types of composite material: fiberglass plastic grades AG-4C, carbon fiber grades KMU-1 and boroplastic grades KMB-1 as follows: pre-impregnated bonding fiber filler (fiberglass, carbon fiber tow or fiber) is wound on a drum cut along the drum generator, complete the package; of four layers with the same direction of the fibers and cure it in the mold with the appropriate pressing modes. A semifinished 10x200 size is cut out from the obtained blank and subjected to stretching with a force of up to 85% of the carrying capacity of the lining of the corresponding material.

Thickness of the monolayer of linings, technological mode of curing (temperature, pressure and holding), tensile strength, forces and stresses of preliminary stretching, as well as calculated data on the damping ability of products made using the prototype method, and products according to the proposed method for three types of composite material compiled

in tabl, 1.

Table

Continuation of the table. And

74 120 50

502 488 510 42, 5

63,102

2.3 1.0

0.85

Monolayer thickness, mm 0.3 0.2 Cure temperature, € 155 200 Specific Pressure, kgf / cm 350 15 Curing time, min. 3.3 240

Characteristic

Prototype method Strength at stretching, kgf / mm 50 Compressive strength limit, kgf / mm20 Flexural strength, kgf / mm 25 Flexural modulus, kgf / mm 3900 16 000 18 90

Proposed method Determined with an amplitude load of cyclic stretching equal to 25% of the maximum load. From Table 1, it can be seen that the damping capacity of the material Hg: masonry1 increases by 30% compared with the prototype method. At the same time, the physicomechanical properties of the Materials manufactured according to the proposed method, as compared with the materials produced according to the prototype method, remain unchanged, as can be seen from Table 2. Table 2 900 16 000 18 900

By using the proposed method of manufacturing structural elements made of oriented fibrous composite materials, the following advantages are provided as compared with the existing manufacturing method:

- an increase in the damping capacity of the structural elements, which makes it possible to reduce the amplitudes of their forced vibrations; This is of particular importance in resonant regions, where the phenomenon of energy dissipation ensures the limitation of the amplitudes of the oscillations;

- obtaining various damping abilities of structural elements, which makes it possible to design the damping properties of products according to the conditions of operation.

An increase in the damping capacity of the structural element in the above example reduces by 30% the amplitudes of the forced oscillations and, accordingly, the level of the maximum effective voltages in it in the most dangerous resonant regions also by 30%. Analysis of the known experimental fatigue strength curves, including for composite materials, shows that a decrease in the level of acting stresses on the base elements of structures by only 5–10% on the basis of up to 10 cycles increases their durability by a factor of 1.5–2. An increase in the resource will allow to obtain the corresponding

profits from the use of the product, depending on its class, and, consequently, to increase the efficiency of using modern oriented fibrous composite materials in these products.

Claims (2)

1. Abibov A.L. and others. The use of engineering plastics in the manufacture of aircraft. M., Mechanical Engineering, 1971, p. 137. 2. Abibov A.L. and others. The use of engineering plastics in the manufacture of aircraft, I., Mechanical Engineering, 1971, p. 138 (prototype).