RU2756744C1 - Method for repairing long-dimensional damages of large-sized structures from composite materials - Google Patents

Abstract

FIELD: damage repairing.

SUBSTANCE: invention relates to a method for lengthy damage repairing. The effect is achieved by the method for repairing long-length damages on leaking large-sized structures made of polymer composite materials using devices that provide excess pressure in the repair zone. At the same time, in the repair zone, a continuous series of compensating patches is formed, laid sequentially with an overlap according to a pattern typical for the location of fish scales. Wherein each subsequent patch is installed after gluing the previous patch and machining the damage to install the next patch, including grinding out a part of the conical groove on the edge of the previous patch for laying out the layers of the next patch.

EFFECT: improving the efficiency of repairs and restoring the operational qualities of products.

1 cl, 3 dwg

Description

The invention relates to a technology for repairing predominantly large-sized structures made of polymer composite materials with lengthy damage, the leakage of which does not allow the use of a vacuum bag for gluing patches that compensate for the loss of strength, for example, panels of aircraft and ships.

There is a known adhesive method for repairing damage to aggregates made of polymer materials using vacuum pressure, which is indicated, as the only possible one, in aircraft repair manuals of all leading aircraft developers, including BOEING and AIRBUS, which consists in the fact that on the repaired surface of the unit, in addition to the technological a bag containing layers of adhesive prepreg that form a patch, technological films, fabrics and a heater, a fragment of a polymer film is attached using a sealing strand - a vacuum bag shell, from under which air is removed through a fitting installed in the film using a vacuum pump, and a technological the pressure is carried out due to the difference between the atmospheric pressure outside the film and the vacuum created under the film.

In case of leakage of a large-sized structure being repaired, especially if the leakage cannot be eliminated, this repair method loses its meaning due to the impossibility of providing a vacuum process pressure.

For the repair of these design options, equipment can be used to provide excess pressure in the repair zone (RF patent 1630210 A1 class B66F 3/35, RF patent 1462914 A1 class F16B 47/00). However, the size of the repair area and, accordingly, the compensating patch in this case is limited by the size of the air bag, which makes it impossible to repair long damage.

The technical result of the present invention lies in the fact that the possibility of repairing long-length damages on leaking large-sized structures made of polymer composite materials can be provided by molding, using devices that provide excessive pressure in the repair zone, a continuous series of compensating patches laid in series with an overlap according to a pattern characteristic of the location fish scales, and each subsequent patch is installed after gluing the previous patch and machining the damage to install a subsequent patch, including grinding out a conical depression on the edge of the previous patch for laying out the layers of the subsequent patch, and the dimensions of each of the number of patches to be installed depend on the size of the air bag, which is the working body of the specified options of equipment.

The technical result is achieved due to the fact that in the method of repairing large-sized structures made of polymer composite materials, the leakage of which does not allow the use of a vacuum bag for installing compensating patches during the repair of lengthy damages, a tooling is used that has an air bag with compressed air placed in a metal box, providing overpressure in the repair area and fixed on the unit being repaired using clamps or vacuum suction cups, while a number of overlapping compensating patches is formed in the damaged area, similar to the pattern typical for fish scales.

In more detail, the proposed repair technology is shown in the drawings, where:

in fig. 1 shows the layout (assembly) of a continuous row of compensating patches, laid according to the "fish scales" scheme;

in fig. 2 shows a diagram of the use of overpressure using an air bag, a metal box and clamps when repairing small-width units;

in fig. 3 shows a diagram of the use of overpressure using a device with vacuum suction cups when repairing units with significant dimensions.

The method is as follows.

On the structure 1 to be repaired, the location of the damage 2 is determined, at one end of which, taking into account the size of the air bag, the contour of the zone 3 is determined for installing the first patch, in which the corresponding machining of a part of the damaged area 4 is performed, after which the first patch is glued (molded), and then the processing area is determined for installing the second patch 5, taking into account the overlap, avoiding the presence of untreated areas of damage, in accordance with the accepted layout of the fish scale type, then, after installing the second patch, the entire complex of preparatory work is repeated for installing the third patch 6, etc. .d .; when repairing through damage, a separating film 7 with a technological gasket 8 (Fig. 1) can be laid on the lower side of the repair zone; the assembly of the layers of the patch and the technological package in all cases is carried out according to a single scheme 9, on units with a limited width, an air bag 10 in a metal box 11 is used to ensure excess pressure, fixed with clamps 12 (Fig. 2), on large units an air bag in a metal box fixed by means of a device 13 equipped with vacuum suction cups 14 (Fig. 3).

The magnitude of the excess pressure in the described loading scheme is limited by the inadmissibility of deformation (punching) of the surface of the unit being repaired or, when using device 13 (Fig. 3), by the ratio of the sizes of the air bag and vacuum suction cups, determined by the relationship:

0.7 * n _p * S _vac > P _g * S _vm ,

where 0.7 is a coefficient that takes into account the real amount of vacuum in the suction cup;

n _p is the number of suction cups, pcs;

S _vac - area of the sucker, cm ² ;

R _h - excess pressure in the air bag, kgf / cm ² ;

S _вм - area of the air bag, cm ² .

The implementation of the claimed repair method makes it possible to provide the possibility of effective adhesive repair of large, complex and critical units of aircraft and ships made of polymer composite materials.

The proposed method for the repair of large-sized units of aircraft and sea vessels, allows you to restore their performance using available methods and tools.

Claims (1)

A method of repairing long-length damages on leaking large-sized structures made of polymer composite materials using devices that provide excessive pressure in the repair zone, characterized in that a continuous row of compensating patches is formed in the repair zone, stacked sequentially with an overlap according to a pattern typical for the location of fish scales, and each subsequent patch is installed after pasting the previous patch and machining the damage to install the next patch, including grinding out a part of the tapered recess on the edge of the previous patch to lay out the layers of the subsequent patch.

Images