A kind of cargo deck lower part endergonic structure unit for fitting pendant property for improving aircraftTechnical field
The invention belongs to aircraft composite fuselage construction design fields, and in particular to one kind is for improving aircraftThe cargo deck lower part endergonic structure unit of suitable pendant property.
Background technique
The primary requirement of civil aircraft operation is safety.Since the 1990s, although civilian carrierAccident rate gradually decreasing, but because service time and number of occupants are quickly incremented by, aviation accident sum and be rated for calamityThe accident number of difficulty consequence does not substantially reduce.70% or more civil aircraft accident occurs at flying height lowerFly, landing phases, belongs to the scope for the accident that can survive.In order to improve the occupant's survival rate hit in accident in the pendant that can survive, flyingSuitable pendant property must be taken into consideration in machine structured design process, to fully absorb the kinetic energy generated during pendant is hit, and guarantee that pendant hits processThe shock loading that middle occupant bears is within Human Tolerance limit range.Therefore in recent years, the suitable pendant Journal of Sex Research of aircaft configuration is more nextAttention more by each aviation big country.
Improving the suitable pendant property of aircaft configuration is to solve pendant to hit the main path for leading to occupant's injures and deaths, and cargo deck substructureIt is one of the key position of the suitable pendant property design of aircaft configuration.One basic principle of the suitable pendant property design of aircaft configuration is exactly can be sacrificialThe insignificant structure of domestic animal fuselage, so that it destroys (conquassation) to exchange the existence of occupant for.Under normal conditions, this target is to pass through controlFloor level and fuselage lower abdomen structure processed is plastically deformed to realize.Strictly speaking, various energy dissipation measures should collectIn be arranged in fuselage keel bar frame, so that the METHOD FOR LARGE DEFORMATION ELASTOPLASTIC of airframe structure is limited in floor level lower area, fromAnd meet occupant to the maximum extent can living space requirement.Under certain specific operating conditions (such as landing in an emergency), existing structureIt is difficult to absorb all pendants and hits energy, therefore just needs to design special power-absorbing as energy dissipation unit in ventral structure.Good energy absorption device is designed, the suitable pendant of aircraft can be improved.
Research is expanded to endergonic structure/energy absorption device in the world, American-European aeronautical chart is carried out in terms of endergonic structureExtensive work.German Aerospace Center DLR proposes a kind of floor lower part endergonic structure being made of plastic hinge and endergonic structure partConcept.For helicopter floor substructure, Holland country spacelab NLR is designed and has been manufactured one kind based on corrugated platingWant the floor lower part endergonic structure of power-absorbing.The U.S. research center NASA Langley and FAA are to composite material frame sectionsSuitable pendant property has carried out more in-depth study, proposes 4 kinds of different floor lower part endergonic structure forms: member structure, sandwichHardened structure, foam interstitital texture and tubular structure.For composite material airplane in transportation category, to propose composite material thin for BoeingThe cargo deck substructure of wall c-type column.
In the existing case unit design in China, mainly the endergonic structures such as metal thin-wall are placed under aircraft cargo bay floorImpact energy is hit to absorb pendant using the plastic deformation of metal during body pendant is hit in portion.Metal endergonic structure not only energyThe proportion of goods damageds are not high, and need to pay biggish weight cost.
Therefore, it is necessary to design and develop it is a kind of it is novel, energy absorbing efficiency is high, the goods for the suitable pendant property that can improve aircaft configurationCabin floor lower part endergonic structure unit.
Summary of the invention
To solve the above-mentioned problems, the purpose of the present invention is to provide a kind of for improving the cargo deck of the suitable pendant property of aircraftLower part endergonic structure unit.
In order to achieve the above object, the cargo deck lower part endergonic structure of pendant property is fitted provided by the present invention for improving aircraftUnit includes top panel, lower panel, multiple composite material thin wall square tubes and sponge layer；The upper surface of described plate and lower panel positionIn upper and lower two sides, wherein the bottom surface of top panel is equidistantly equipped with multiple upper boss；The surface of lower panel is equidistantly equipped with multipleLower boss, and the position of multiple upper boss is corresponding with the position of multiple lower boss respectively；Multiple composite materials are thinWall square tube is set in qually spaced between top panel and lower panel and central axis is in top panel and lower panel, and each compoundA upper boss and a lower boss are inserted into inside the upper and lower port of material thin wall square tube respectively；Sponge layer setting existsThe outside surrounding of composite material thin wall square tube.
The multilayer carbon fiber or glass layer that the composite material thin wall square tube is laid with by 0 °, ± 45 ° and 90 ° directionIt closes, lower port has 45 ° of inner chamfers, and upper port is without chamfering.
The outer end edges of the upper boss have arc angling without chamfering, the outer end edges of lower boss.
The upper surface of described plate and lower panel are made of high-strength aluminum alloy material or by carbon fiber/epoxy resin composite woodsThe bed of material closes.
The position between upper boss on the upper surface of described plate is formed with top panel lightening hole；Lower part on lower panel is convexPosition between platform is formed with lower panel lightening hole, and top panel lightening hole and lower panel lightening hole are rectangular, round or ellipse.
Cargo deck lower part endergonic structure unit provided by the present invention for improving the suitable pendant property of aircraft has following beneficialEffect:
1, upper and lower panel use high-strength aluminum alloy or carbon fiber/epoxy resin composite material, be placed in upper and lower panel itBetween composite material thin wall square tube use carbon fiber or glass fiber compound material, therefore the gold of endergonic structure unit and same volumeBelong to endergonic structure unit to compare, the weight cost paid is relatively small, can reduce airplane load, improves economic performance.
2, during pendant is hit, composite material thin wall square tube generates cracking phenomena along four apex angles, and layer beam bendsWith the failure such as layering, most of energy finally is absorbed in the form of layer beam bending failure mode (open mode) conquassation.
3,45 ° of inner chamfers of the chamfering of the lower boss on lower panel and composite material thin wall square tube lower port can be protectedCard composite material thin wall square tube is first destroyed 45 ° of inner chamfer sides, and composite material thin wall square tube can be designed to be moreIt is long, there can be longer stable crush stroke, and be unlikely to that composite material thin wall square tube is made to generate buckling.
4, the boss on top panel and lower panel has certain altitude, is inserted in the both ends of composite material thin wall square tubePortion is in close contact with inner wall, can be further improved its ability for resisting transversely deforming, to improve energy-absorbing energy.
5, the shape of panel, the position of boss and arrangement, composite material can be changed according to airframe structure design featureThe parameters such as the quantity of thin-walled square tube and the cross-sectional length of composite material thin wall square tube and height, to be suitable for different types.
Detailed description of the invention
Fig. 1 is the cargo deck lower part endergonic structure cellular construction signal provided by the present invention for improving the suitable pendant property of aircraftFigure.
Fig. 2 is provided by the present invention for improving top panel in the cargo deck lower part endergonic structure unit of the suitable pendant property of aircraftBottom surface upward when structural schematic diagram.
Fig. 3 is the upper boss structural side view on top panel.
Fig. 4 is provided by the present invention for improving lower panel in the cargo deck lower part endergonic structure unit of the suitable pendant property of aircraftStructural schematic diagram.
Fig. 5 is the lower boss structural side view on lower panel.
Fig. 6 is provided by the present invention for improving composite wood in the cargo deck lower part endergonic structure unit of the suitable pendant property of aircraftExpect structural schematic diagram when thin-walled square tube is inverted.
Fig. 7 is provided by the present invention for improving composite wood in the cargo deck lower part endergonic structure unit of the suitable pendant property of aircraftExpect the failure mode schematic diagram after thin-walled square tube is axially crushed.
Specific embodiment
Below by the drawings and specific embodiments under the cargo deck provided by the present invention for improving the suitable pendant property of aircraftPortion's endergonic structure unit is described further.
As shown in Fig. 1-Fig. 6, provided by the present invention for improving the cargo deck lower part endergonic structure list of the suitable pendant property of aircraftMember 1 includes top panel 2, lower panel 3, multiple composite material thin wall square tubes 4 and sponge layer 5；The upper surface of described plate 2 and followingPlate 3 is located at upper and lower two sides, and wherein the bottom surface of top panel 2 is equidistantly equipped with multiple upper boss 6；The surface of lower panel 3 is equidistantEquipped with multiple lower boss 8, and the position of multiple upper boss 6 is corresponding with the position of multiple lower boss 8 respectively；It is multipleComposite material thin wall square tube 4 is set in qually spaced between top panel 2 and lower panel 3 and central axis is in top panel 2 and followingPlate 3, and a upper boss 6 is inserted into inside the upper and lower port of each composite material thin wall square tube 4 respectively and a lower part is convexPlatform 8；The outside surrounding of composite material thin wall square tube 4 is arranged in sponge layer 5.
The multilayer carbon fiber or glass fibre that the composite material thin wall square tube 4 is laid with by 0 °, ± 45 ° and 90 ° directionLaminated to form, lower port has 45 ° of inner chamfers, and upper port is without chamfering.
The outer end edges of the upper boss 6 have arc angling without chamfering, the outer end edges of lower boss 8.
The upper surface of described plate 2 and lower panel 3 are made or compound by carbon fiber/epoxy resin of high-strength aluminum alloy materialMaterial is laminated to be formed.
The position between upper boss 6 on the upper surface of described plate 2 is formed with top panel lightening hole 7；Under on lower panel 3Position between portion's boss 8 is formed with lower panel lightening hole 9.Top panel lightening hole 7 and lower panel lightening hole 9 are rectangular, roundOr ellipse
It is now former provided by the present invention for improving the work of the cargo deck lower part endergonic structure unit of the suitable pendant property of aircraftReason is described below:
This cargo deck lower part endergonic structure unit can be used as load carrying unit, multiple cargo deck lower part endergonic structure listsMember, which is planar stitched together, constitutes fuselage cargo deck substructure, or as the special energy-absorbing knot for improving suitable pendant propertyStructure unit uses.The structure type is light-weight, and structure is simple, good integrity, and S. E. A. is high.
During pendant is hit, as shown in fig. 7, composite material thin wall square tube 2 will generate cracking phenomena, layer along four apex anglesBeam such as bends and is layered at the failure, finally absorbs most of energy in the form of layer beam bending failure mode (opening mode) conquassationAmount.