The Fuselage of a passenger plane connects the wings, tail and in some cases the chassis. It is intended to accommodate equipment, crew, cargo. Aircraft without a fuselage is referred to as a flying wing. In his oelstrom compartment is all that is in the case of conventional apparatus. Next, let's consider in detail what the fuselage of the aircraft. The photo of this component will be also presented in the article.
Explaining in two words, what is the fuselage of the aircraft, we can say that the body of the device. To this component of the aircraft has a number of requirements:
Geometry of the aircraft fuselage represented by an axisymmetric body with a smooth tapering at the tail and nose parts. In this form, there is a minimum surface area with given dimensions. Accordingly, the reduced weight of the plating, the resistance decreases. Light weight gives you certain advantages under the influence of excess pressure in a pressurized cabin. However, for a number of reasons, this ideal form is not respected. The smoothness of the contours of the violated, in particular, such elements of the aircraft fuselage as the cabin lights, radar antennas. This, in turn, leads to increased resistance and weight gain. The same effect occurs when there is a deviation from the smooth forms in the caudal compartments. In this case, provided the increase in the angle of capsizing or the shortening of the ramp and the cargo hatch.
In terms of what the aircraft fuselage (photo provided in the article illustrates its features), you have to say about the influences that he experiences. When landing and in flight on this component are:
All of these loads are fully balanced. Considering what the aircraft fuselage in the framework of structural mechanics, it is possible to present it in the form of box beams. In any section it is affected by horizontal and vertical force, a torque. In sealed compartments they added to excessive internal pressure.
The Most optimal is the scheme the aircraft fuselage in which he can perceive all of the above loads at a sufficiently low own weight. Thin-walled shell in this case is fixed on the power frame. Rationality is ensured by the wide use of skin. In the place where the fuselage of the plane, there are local aerodynamic forces, internal pressure, General power work. Thin-walled sheath through the inside of the frame, in the respect of ease of layout, provides technological simplicity, performance. Such structure of the fuselage of the plane is called the beam. Previously used truss modules. They are losing much of the beam by their mass. What is the fuselage truss type? Plating in this case is completely excluded from the work force. She sees only the local aerodynamic loads. If we talk about what the fuselage of the aircraft in this case, it can be defined as an add-on module increases the overall weight of the apparatus. Spatial farm complicates the layout of the cargo. The disadvantages of this module has led to the fact that in modern aircraft they are not used. They're useful only on slow light devices small aircraft.
There are three types of aircraft fuselages:
The Last two differ from each other in shape and square in cross section. Trailing set in the place where the fuselage of the plane,consists of stringers and spars. Sheathing the module in cross-section includes the frames. They ensure the preservation of a given shape in the deformation of the shell and transfer concentrated and distributed loads. In the place where the plane fuselage, present the areas where there can be a huge concentration of forces. To prevent deformation in these cases, install reinforced frames. In the beams of the modules the impact of any direction is perceived completely covering. It occurs tangential flow efforts. Their distribution depends on the direction of the external impact and the cross-sectional shape of the module. The lining is also fully perceive torque. In this case, shear flow is evenly distributed around the perimeter. The shell in this case, as a rule, has odesabrody contour in cross section. In areas where there are cutouts in the shell, set the power trim. They provide in these areas the transfer of all effort.
Longitudinal fuselage of the aircraft are usually throughout its length. Along with covering they take the normal efforts of the bend. Production of simple stringers and spars is usually from bent or extruded sections with different cross-section. The longitudinal elements have a greater stiffness. At high loads, in some cases, can be installed composite spars. They include several sections connected with each other. Edged cutouts large size used beams - longitudinal box-section elements. They are manufactured from extruded profiles that are linked with paneling and walls.
They can be reinforced or normal. Provides for the safety of the cross-sectional shape of the module. Reinforced frames are used in areas of accumulation of large loads on the body. They are the nodes stikoudi units, fixing cargo, large equipment, engines, and so the Gain also set on the boundaries of large openings in the Cabinet. Conventional frames are usually frame construction. They are made of sheet or flexible sheet. Reinforced elements are performed in the form of a closed frame or channel beam cross section. The tangential flow acts as a reference reaction. The external frame distributes impact around the perimeter. She herself acts on the bending. It determines its section. The design of this frame monolithic or team. In the areas of installation of partitions reinforced frame sewn wall completely. It is supported by horizontal and vertical profiles. The trim frame may also be a spherical shell. Supporting elements are located radially.
It is made of metal sheets. Formed on the profile surface of the housing and fix. The joints of the leaves have transverse and longitudinal parts of the module. For sheathing frames are used monolithic rib panel. Lately quite common is the use of composite materials.
The Covering can be attached to the frames or stringers, or both, and those to others. The first option is used in the cladding modules. When attaching only to the stringers used riveted longitudinal seams. The cross coupling is absent in this case. This improves the aerodynamic properties of the module. But in this case with lower capacity sheathing loses its stability. This leads to increased structural weight. To prevent this, the shell is often associated with the compensator for frame - extra overlay.
At the beam-spar scheme of the fuselage they are made using nodes, which are located exclusively on the longitudinal parts. These joints are called point. Contour of the connection used in girder-stringer fuselage. The joints are fitted around the perimeter of the frame with the binding reinforced binding skin and stringers. Connection near the fuselage, usually carried out by means of flanges. Such a junction provides a power connection with the parts in contact along the contour.
The connection Nodes mounted on reinforced frames. They perform the function of the hard drive. Due to them is the distribution of the concentrated longitudinal loads. Units butt should make contact with the power rails. To reduce the weight of the whole structure of the fuselage it is advisable to reduce the amount of reinforced frames. On each such element can be placed several of the attachment units.
As the specific features of these parts standstrim bending moments in the joint of the wing panels. Rational will be considered as balancing the right and left elements on the wing passing through the fuselage. For longerenong type of module it is enough to pass the longitudinal elements to be trim bend. To connect the monoblock and the wing box through the housing must pass all power panel. If for some reason the elements pass through the fuselage cannot be carried out, the bending moments at the right and left should focus on the power frames. This solution, however, can be used for longerone wings, because the amount of detail in them is small. One-piece and caisson components will require a greater number of strengthened frames. It is quite difficult to carry on the design. In such cases it is advisable to use a spar scheme.
The device require transmission of the bending moment on the fuselage. To do this, each longitudinal element of the keel combined with a reinforced frame. Possible to use a mast type bookmarks of the spar at two points. They are placed along the height of the frame. Sagittate longitudinal element has a kink at the site of crossing with him. This requires the installation of additional gain. It can be waived in the case if the bulkhead is placed obliquely relative to the axis of the fuselage below the plane was a continuation of the wall of the spar. But the implementation of this option will be accompanied by certain difficulties.
The Central part of the fuselage of the aircraft includes openings for Windows, doors, hatches, lights, landing gear. All these cuts violate the closed contour of the hull. Accordingly, the substantially reduced resistance and strength of the frame. To compensate for losses along the contours of the holes miss the frame rigid piping. At small sizes of the cutouts it is a monolithic structure. It operates from the sheet produced by stamping or otherwise. Large holes and fringes on the ends of the reinforced frames. In the longitudinal direction set the beams. However, they do not end within the neckline, and beyond reinforced frames. So by hard tab longitudinal parts. Landing gear are fixed on reinforced frames and longerons in the bottom of the hull.
When flying at high altitude they supported excessive pressure. To ensure the minimum mass of the sealed cabs they are made in the shape of a sphere or cylinder with spherical bottoms. This requires strengthening of the frame, located at the junction of the segments. This is because it takes quite a large compressive load. In pressurized cabins sheathing under load excessive pressure does not experience bending deformations. She works only in tension. In some cases, from the forms they have to retreat. This, in turn, leads to an increase in the weight of the whole structure. To ensure the necessary bending stiffness used flat panel. While under the influence of excess pressure, they are reinforced by transverse and longitudinal beams (ribs). To increase stiffness of the panel details are in the form of sandwich structures. The cabins should be provided with reliable sealing all the bolt and rivet the seams. For this purpose a special tape. They are impregnated with sealant, coat the non-drying mastic, covered with a special composition with subsequent drying. At the junction of shell plates used multi-row riveted joints in small increments. Very carefully treated with a sealant doors, Windows, lights, doors. Sealing is ensured by the use of special sealing means. It may be rubber tubing, strip, inflatable rubber tubes, strip.
To enforce the requirements that apply to the fuselage, needs to be performed certain actions. These include:
For the crew and passengers must be creatednecessary conditions and a proper level of comfort during flight at high altitudes. A mandatory requirement is the provision of acoustic and thermal insulation cabin, the possibility safe and quick emergency exit from the cabin. Crew also need to be created comfortable conditions. In particular, pilots should be provided with a good overview, ease of flight and control of aircraft.
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