scholarly journals Structural repair on a composite aircraft fuselage damaged by fire.

2021 ◽  
Author(s):  
Christopher D. Cosentino
Keyword(s):  
Composite Materials ◽  
Great Increase ◽  
Advanced Materials ◽  
Fire Damage ◽  
Structural Components ◽  
Large Section ◽  
Structural Repair ◽  
Aircraft Fuselage ◽  
Repair Patch ◽  
Extent Of Damage

Composite materials have been used on aircraft for decades with tremendous benefits. Through the use of these advanced materials we have seen a great increase in the aircraft’s efficiency, while improving the strength of the aircraft. Unfortunately due to the complexity of this material, it has not been used in large structural components such as the fuselage until very recently. Because of this, there are still some unknown aspects of implementing this material which have not yet been researched. One example that demonstrates this is a large section of an aircraft’s composite fuselage structure which has sustained fire damage. The main difficulties here are the unknown extent of damage caused by the fire, the unproven repair methods, and the durability of the repair patch itself. This report outlines some of these challenges as well as offers two different repair methods that are then analyzed using CATIAs FEA suite.

scholarly journals Structural repair on a composite aircraft fuselage damaged by fire.

2021 ◽  
Author(s):  
Christopher D. Cosentino
Keyword(s):  
Composite Materials ◽  
Great Increase ◽  
Advanced Materials ◽  
Fire Damage ◽  
Structural Components ◽  
Large Section ◽  
Structural Repair ◽  
Aircraft Fuselage ◽  
Repair Patch ◽  
Extent Of Damage

Composite materials have been used on aircraft for decades with tremendous benefits. Through the use of these advanced materials we have seen a great increase in the aircraft’s efficiency, while improving the strength of the aircraft. Unfortunately due to the complexity of this material, it has not been used in large structural components such as the fuselage until very recently. Because of this, there are still some unknown aspects of implementing this material which have not yet been researched. One example that demonstrates this is a large section of an aircraft’s composite fuselage structure which has sustained fire damage. The main difficulties here are the unknown extent of damage caused by the fire, the unproven repair methods, and the durability of the repair patch itself. This report outlines some of these challenges as well as offers two different repair methods that are then analyzed using CATIAs FEA suite.

Robot Controlled Rotary Peen Forming by Laser-Assisted Distance Control

2015 ◽  
Vol 651-653 ◽  
pp. 1084-1089 ◽  
Author(s):  
Markus Gottschalk ◽  
Markus Bambach ◽  
Gerhard Hirt
Keyword(s):  
Machine Design ◽  
Shear Stresses ◽  
Structural Components ◽  
Principal Stresses ◽  
Aircraft Fuselage ◽  
Innovative Process ◽  
Distance Control ◽  
Peen Forming ◽  
Set Up ◽  
Intrusion Depth

Surface curvature radii required for aircraft fuselage as well as structural components can be produced by peen forming processes. The innovative process idea of Rotary Peen Forming is a modification of the well-known Shot Peen Forming. Here, the impactors are flexibly connected to a rotating hub and thus moving on circular trajectories. As a consequence, there is no need to pressurize and recirculate the shots, as it is essential in Shot Peen Forming. Using a six axes robot, the rotating hub can be guided flexibly. The resulting machine design is more compact compared to traditional Shot Peen Forming.However, in Rotary Peen Forming not only principal stresses but also shear stresses are caused in the deformation zone which has a fundamental influence on the curvature. In order to generate defined curvatures on the workpiece, the capability to precisely adjust the intrusion depth of the impactors is essential.In this paper, a laser-assisted distance control for the Robot Controlled Rotary Peen Forming is introduced. By means of a point laser, the set-up allows for a distance control to adjust and keep a determined intrusion depth. This way, the machine design provides a mechanism to readjust the intrusion depth of the impactors while the desired curvature is formed during the process by the introduced plastic strains at the specimen’s surface. Using the distance control, the resulting curvature is two to four times bigger compared to experiments without a readjustment of the intrusion depth.

Advanced materials for structural components of Indian sodium-cooled fast reactors

2016 ◽  
Vol 139-140 ◽  
pp. 123-136 ◽  
Author(s):  
A.K. Bhaduri ◽  
K. Laha ◽  
V. Ganesan ◽  
T. Sakthivel ◽  
M. Nandagopal ◽  
...  
Keyword(s):  
Advanced Materials ◽  
Structural Components ◽  
Fast Reactors

Study of Environmental Corrosion Behavior and Mechanism of the Carbon/Epoxy Composite

2007 ◽  
Vol 539-543 ◽  
pp. 913-918
Author(s):  
Xiao Fei Li ◽  
Qi Zhang ◽  
Jun Hua Xu
Keyword(s):  
Surface Layer ◽  
Composite Materials ◽  
Environmental Factors ◽  
Absorption Rate ◽  
Epoxy Composite ◽  
Advanced Technology ◽  
Advanced Materials ◽  
Effect Of Temperature ◽  
Corrosion Failure ◽  
Test Parameters

Polymer composite materials, as advanced materials have been widely used worldwide, especially in the advanced technology field, due to their outstanding properties. Nowadays, a growing attention has been paid to the environmental corrosion failure of composites. Since it is environment related corrosion, the test parameters selected were temperature, humidity and ultraviolet. Among all the environmental factors, the temperature, especially acts with humidity, is the most affective factor. In order to get detailed information, the weight gains of the samples tested were measured regularly during the test. By the comparison, it can be seen that the water absorption rate had been affected remarkably due to the salt existence or the temperature change. The observation of the sample microstructure showed that there were many holes on the surface, indicating that the surface of the samples was destroyed by the test, and that there were some interactions between the surface layer and the absorbed component. It is that only the effect of temperature and humidity was discussed in this paper, the effect of the rest environmental factors will be discussed in following paper.

scholarly journals Numerical method for the prediction of bending properties of glass-epoxy composites

2007 ◽  
pp. 85-95
Author(s):  
Marina Stamenovic ◽  
Slavisa Putic ◽  
Branislav Bajceta ◽  
Dragana Vitkovic
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Numerical Model ◽  
Outer Layer ◽  
Mechanical Test ◽  
Epoxy Composites ◽  
Future Research ◽  
Structural Components ◽  
Bending Properties ◽  
The Relationship

Mechanical properties of composite materials are conditioned by their structure and depend on the characteristics of structural components. In this paper is presented a numerical model by which the bending properties can be predicted on the basis of known mechanical properties of tension and pressure. Determining the relationship between these properties is justified having in mind the mechanics of fracture during bending, where the fracture takes place on the outer layer which is subjected to bending while the break ends on the layer subjected to pressure. The paper gives the values of tension, pressure and bending properties obtained by the corresponding mechanical test. A comparison of the numerical results of bending properties obtained on the basis of the model with the experimental ones, shows their satisfactory agreement. Therefore, this model can be used for some future research to predict bending properties without experiments.

Design Development of Unitized Titanium Structure

2001 ◽  
Author(s):  
Daniel Groneck ◽  
Dave Harmon
Keyword(s):  
Rapid Prototyping ◽  
Primary Structure ◽  
Structural Components ◽  
Design Development ◽  
Aircraft Fuselage ◽  
Web Stiffeners ◽  
Titanium Structure ◽  
Metal Tooling ◽  
Product Forms

Traditional airframe primary structure is fabricated from wrought product forms that are transformed by machining, forming, and joining into structural components. These individual parts are assembled together by fasteners to create the structure. Under the program reported herein, and in conjunction with a casting vendor, prototype titanium (Ti-6Al-4V) cast airframe components were designed and fabricated. The typical overall dimensions of each casting are 50 inches × 40 inches × 30 inches (127 cm × 102 cm × 76 cm), and weigh approximately 190 pounds (86 kg) per casting. The castings were modeled on generic aircraft fuselage structure that incorporated smooth inner moldline surface and integral webs and keels, capped by a T-element, web stiffeners, access holes, and other detail features. Multiple castings are joined to create the airframe structure. A rapid prototyping method was utilized to create the pattern, which eliminated the requirement for expensive metal tooling. The prototype castings successfully demonstrated the producibility of this generic airframe structure.

Model of fatigue damage in strain-rate-sensitive composite materials

2003 ◽  
Vol 18 (1) ◽  
pp. 77-80 ◽  
Author(s):  
Sanboh Lee ◽  
Tinh Nguyen ◽  
Tze-jer Chuang
Keyword(s):  
Composite Materials ◽  
Strain Rate ◽  
Fatigue Damage ◽  
Damage Accumulation ◽  
Maximum Stress ◽  
Paris Law ◽  
Damage Rate ◽  
Fatigue Damage Accumulation ◽  
Damage Accumulation Model ◽  
Extent Of Damage

A fatigue damage accumulation model based on the Paris law is proposed for strain-rate-sensitive polymer composite materials. A pre-exponent factor c2/f and strain-rate-sensitive exponent n are introduced. Numerical analysis of the model was performed using experimental data obtained in the literature. Both factors were found to enhance fatigue damage accumulation. The analysis also revealed that the extent of damage increases with decreasing frequency and that the damage rate is more sensitive to the applied maximum stress than to the stiffness of the material.

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