CZ29817U1 - Material for absorption of explosion energy - Google Patents

Description

Technical field

The technical solution relates to a material intended to be used as a very lightweight core of sandwich walls for absorbing the effect of a shock wave in an explosion.

BACKGROUND OF THE INVENTION

At present, the cores of explosion-proof constructions are made mainly of materials based on metal honeycombs and polymers and metallic foams, or even a combination thereof. If weight is not emphasized and the final design of the structure permits, sand or coarse aggregates are preferably used.

The most commonly used materials for lightweight construction are metal honeycombs. In a panel according to US 4198454 intended to protect objects from light bullets, explosion and heat, the honeycomb plate forms a single layer to compensate for the effects of the explosion.

U.S. Pat. No. 4,352,484 describes a device for vehicles for absorbing energy on impact. It consists of several layers having a hexagonal honeycomb structure filled with polyurethane foam. Metal honeycombs and foams are a good variant in terms of effects, but their use in non-planar structures is limited.

The explosion-proof modular panel of US 7980165 has a core consisting of particles of material, such as pumice lumps, which are converted into dust by the explosion. The energy required to atomise the material is taken from the energy of the explosion, thereby dampening its effects.

EP 2721365 discloses an explosion reduction system intended for the underbody of military vehicles. The core of the protective structure is rigid, closed-cell polyurethane foam. This material is sprayed onto the underside of the vehicle at the selected thickness and covered with a protective sheet. The disadvantage of this material is flammability, which is a limiting factor for use in safety structures.

Utility model CZ 28659 describes an explosion absorption material consisting of an expanded inorganic aggregate bonded with an organic resin. This composite fills well in any space and is non-flammable, but for some applications its weight may be too high (bulk density is between 350 and 650 kg / m ³ ).

The term 'microspheres' generally refers to both inorganic and organic formations in the form of bubbles with a diameter of less than 0.5 mm. They are created by heating and expansion of small drops of the starting material - glass, plastic, or they are obtained by separation from power fly ash. Microspheres are widely used in a variety of industries, especially in the construction industry as fillers for lightweight building components. Their ability to withstand shock pressure waves has not yet been tested.

The object of the invention is to propose a composite which, while maintaining the advantages of the expanded inorganic aggregate solution, absorbs the pressure wave energy better and is characterized by a low bulk density (up to 200 kg / m &^lt; ³ & gt ^; ).

The essence of the technical solution

The object of the present invention is to solve the explosion energy absorption material, which consists of a composite of 20-40 wt. % microspheres up to 0.2 mm in diameter and 60-80 wt. polymeric binder.

Suitable microspheres may be based on glass, optionally a non-flammable polymer; the polymeric binder is a polyurethane, epoxy or polyester resin.

In a preferred composition, the composite composition comprises 35 to 40 wt. % microspheres with a diameter of 0.1 mm and 55 to 60 wt. binders.

-1 CZ 29817 Ul

Examples of technical solutions

Example 1

A blend was prepared to make a light explosion energy absorption composite of the following composition (sample labeled SK-LG60). The sample thus prepared has a density of 165 kg / m @ ³ .

Component % In wt. Glass microspheres 40.0 Polyurethane resin 60.0

The mixture was formed into 500 x 500 x 100 mm plates. These plates were subsequently used as the core of a sandwich construction with sheet metal walls on both sides of the core. During the explosion tests, the relative deformation of the metal sheet of the side of the explosion was observed. The lower the value of relative deformation, the higher the absorption capacity of the material.

Sample Relative deformation [%] SK-LG60 0.150 Reference Sample - Commercial Absorption Foam 0.239

Relative deformation means the ratio of the measured value of the sheet elongation by its dynamic deflection to the original sheet size. Thus, a higher deformation value means a higher dynamic displacement and the associated lower damping ability of the absorbent material.

Example 2

A blend was prepared to make a light composite for absorbing the energy of an explosion of the following composition (sample labeled FP-LG15). The sample thus prepared has a bulk density of 145 kg / m @ ³ .

Component % In wt. Polymeric microspheres 30.0 Polyurethane resin 70.0

The mixture was formed into 500 x 500 x 100 mm plates. These plates were subsequently used as the core of a sandwich construction with sheet metal walls on both sides of the core. During the explosion tests, the relative deformation of the side of the averted explosion was monitored. The lower the relative deformation is, the higher the absorbency of the material.

Sample Relative deformation (%) FP-LG70 0.139 Reference Sample - Commercial Absorption Foam 0.239

The material was tested in a sandwich panel having the following composition: 4 mm steel sheet, 100 mm absorbent material, 4 mm steel sheet. Testing was carried out by placing the specimen in a test bench, supporting it around the perimeter, and firing an equivalent of 100 g of TNT at a distance of 18 mm from the face of the sandwich. The resulting pressure wave is very fast, acting on the sample in milliseconds.

The core had the form of a plate in the construction under test. The composite core can be used in combination with other materials, eg sandwich with concrete, steel, laminate, etc. The material in the fresh state can also fill various gaps, for example cavities in vehicle chassis, or spaces in safety waste bins and other elements with protective functions.

Claims (5)

Explosion energy absorption material, characterized in that it consists of a composite composed of 20 to 40 wt. Microspheres up to 0 grain size 2 mm and 60 to 80 wt. polymeric binder. Material according to claim 1, characterized in that the microspheres consist of expanded glass. Material according to claim 1, characterized in that the microspheres consist of an expanded non-flammable polymer. Material according to any one of claims 1 to 3, characterized in that the polymeric binder is a polyurethane, polyester or epoxy resin. Material according to one of Claims 1 to 4, characterized in that it consists of 35 to 40 wt. % microspheres with a diameter of 0.1 mm and 55 to 60 wt. binders.