Приветствую Вас Guest
|The category section|
|The entrance to the site|
Last Added Files
Материалов за текущий период нет.
Total online: 1
|Home » Articles » Civil|
Composites in aircraft construction - there are problems.
The anxiety associated with the new composite materials used in modern aircraft construction.
It should be noted that the manufacturers of commercial aircraft using composite materials in some parts of the aircraft for several decades. And since 2011 began to build large aircraft, almost entirely using composite materials. At the beginning of the Boeing 787, and later Airbus A350. Some observers expressed concern about the fact that this technology is poorly understood, and may conceal madapollam associated with increasing use of composite materials in commercial categories of aircraft. Readiness for this transition. European and American aviation authorities (FAA and EASA) take measures to address security-related problems associated with the use of composite structures and signed the Protocol in October 2011 to Express their concerns.
Here is the dynamics of the use of composites in aviation for years
Composite materials in the nodes of aircraft used for decades. Until the mid 80-ies manufacturers use composite materials in the category of secondary structures (for example, the stroke of the wings and tail surfaces). In 1988 introduced the Airbus A320, the first aircraft produced telecompetition tail, and in 1995, Boeing introduced the Boeing 777, the tail of which is also manufactured in composite performance.
Composite materials used in commercial aircraft is usually made by combining layers of carbon or glass fibers with epoxy resin.
In recent years, manufacturers have increased the use of composites in the fuselage and wings because these materials are usually lighter and more resistant to corrosion than metal traditionally used in aircraft.
Boeing 787 is the first airliner in which composite materials are about 50 percent by weight (without engine). He holds 210-290 passengers when the flight distance from 13000 km up to 16,000 km,depending on the modification.
Soon came the Airbus A350, the composite material having approximately the same proportion as its competitor Boeing. The A350 family has an incredible range of up to 16000 km, if passazhiroemkosti from 250 to 550 people.
Who is responsible for the safe use of composite structure
Responsible for the safety of the aircraft or its parts made of composite materials, distributed between three parties:
The bodies of airworthiness (for example: ABC in the United States, EASA in Europe) are responsible for the development of certification standards and certifying that the aircraft manufacturers and suppliers meet these standards. They also conduct periodic inspections of production facilities for monitoring compliance and control aircraft repair base, to ensure proper maintenance and procedures flight preparation.
madeprostitutes responsible for strict adherence to these rules create a safe aircraft. They also develop programs aircraft maintenance and repair instructions and provide the requested technical assistance on the spot.
Technical services is responsible for the operation of the aircraft according to the flight rules specifications of the authority and the initiator of the approved manuals. This includes proper maintenance if necessary. The crew is also involved in the continuing airworthiness of the fleet. Tracked history of exploitation and reporting appropriate repair and incidents to the competent authorities and manufacturers.
Security issues with composite structures
In connection with the use of a large proportion of the composite structure of the aircraft there were some fears. These problems arose mainly from the state of the science underlying the increased use of composite materials in civil aircraft and the lack of experience of such technologies. Although the GAO (Government Accountability Office) has not made any recommendations, he found four problems related to security:
The first problem is limited information on the behavior of composite airframe structures. This concern requires a response , as the structure of composite airframe behave if the damage is and how they age. These concerns are partly due to the limited experience of the use of composite materials in airframe design of commercial boards and, therefore, very little information is available information about the behavior of these materials, in contrast to the behavior of the metal.
GAO also found problems related to the detection of damage in composite materials and associated with the unique properties of composite materials. "The impact damage of composite structures is unique because they can be visible or may be barely noticeable, which causes problems with detection by aircraft damage and makes the repair more difficult than metal structures". "Repair is also a problem in part because the integral of such repairs are more susceptible to human error than the repair of metal parts.". Experience has shown that repair of the aircraft can be tightened for a few days , while just a few hours it will take to composity repair. This can be a serious drawback for airlines, both financially and in provoking the human factor.
In addition there are restrictions standardization of composite materials and methods of repair, compared to the repair of metal components. This is partly due to their own business practices of airlines and relative immaturity" use of composite materials in aircraft structure. "A technician can easily confuse the materials or processes, which can lead to "unqualified repair," declares GAO. It can also have negative economic consequences for airlines and units of service for repair facility, you may have to have a larger supply of repair materials and parts. Additionally, composite materials, as a rule, should be kept at a certain temperature, and the materials have a limited shelf life.
The organization also identified problems associated with the level of training and awareness of personnel to repair and processing of composites. "The technicians and engineers who worked with metal for decades, usually unfamiliar with composite materials for use in aircraft relatively recently, and unique characteristics, which will cause technical problems."- also fixes GAO.
Composite technology is not a revolution in aviation, and has already been used in the past for some parts of the aircraft. However, starting in 2011, to build a large commercial aircraft mainly in the composite began to attract commercial structures, and it creates a lot of security problems in the aviation industry, mainly due to the lack of experience with such work, and because of the huge differences between the metal tested for safety and nadezhnosti and composite materials.
Commercial aviation grew in history thanks to the consistent jump into the unknown, not the studied area. But each jump has brought many questions and concerns, although we eventually we strive for progress,using new technology and pay greatention to security. Unfortunately, many accidents and disasters is the price we pay for progress .
The creation of a large aircraft aircraft mainly from composite materials and is another jump, which will be the future of aviation. Near the time the aircraft more efficient and environmentally friendly in the mass production of world-class. But today, the accident aircraft due to the use of composite materials is not an option, and you should not force the issue because of the stiff competition aircraft corporations
|Views: 1212 | ||
|Total Comments: 0|