SELECTION AND OPTIMIZATION OF FUSELAGE COMPONENTS FOR MODERN AIRPLANES

摘要

Nowadays the level of development of airplane materials shows the tendency of usage of advanced composite structures. However, these materials have plenty of advantages and disadvantages, the most crucial is the ability to absorb water from the environment and because of this layers of composite structures disbonded and consequently became useless. This issue demonstrates the limitation of usage of advanced composite structures. Despite this fact application of conventional materials (such as Aluminum or Titanium alloys) are limited by the weight of structure and manufacturability. In given article question of optimization for choosing of the airplane, the material is considered. The necessity to maintain equilibrium between minimal weight and appropriate strength pushes designers to develop new advanced materials, mechanical properties of which satisfy strict criteria of strength, despite lightweight of the material.  The goal of this research elaborating work is to estimate the necessity of usage of advanced composite structures vs well known conventional materials.  It was researched sizing and optimization of choosing of structural materials for the primary structure. On top of this, properties and peculiarities of conventional materials (such as Aluminum and Titanium alloys) and advanced composite structure. It was demonstrated that the usage of conventional materials for primary structure has a significant advantage in comparison with advanced composite structures. Additionally, manufacturability and maintainability of materials were discussed in the given article. As a result, the application of conventional materials for primary airplane structure is the most suitable way for the design of modern airplanes. Today, the structural designer no longer chooses a material solely based on its strength qualities, but on its proven ability to withstand minor damage in service without endangering the safety of the aircraft. The residual strength after damage, described as the toughness, is now uppermost in the engineer’s mind when he chooses alloys for airframes. Damage caused by fatigue is the main factor because it is difficult to detect and can disastrously weaken the strength of critical components. So whereas about a decade ago aluminum alloys looked as if they had reached a technical plateau, engineers have now been able to clarify their needs as a result of the work done on fracture mechanics, and metallurgists have changed their composition and treatment techniques to meet the new toughness requirements. The best option to consider the usage of both advanced composite structure (for secondary structures) and conventional material (for primary structures).