Engineering application of fracture mechanics to aircraft structure damage tolerance estimation

The corrosion, corrosion fatigue and fracture failure process of aircraft structure is directly concerned with combined effect of many factors, such as load, material characteristics, corrosive environment and so on. The process is very complicated, and there is typical randomness. Based on probabilistic fracture mechanics, with consideration of the limitation of the conventional probabilistic approaches for prediction of corrosion fatigue life of aircraft structure at present, and a new reliability approach under loading spectrum was proposed, in which corrosion damage and fatigue crack damage was united as a same damage parameter. Short crack and long crack growth behavior was separately discussed, and influence of short crack aspect ratio on structure life was discussed. The Advanced First-Order Reliability Method, Importance Sampling Method and iteratively advanced Second-Order Reliability Method were used to compute the fracture failure probability. The results show that the model is feasible. By sensitivity analysis of random parameter, the important parameter was obtained, which helped to monitor the structure fatigue life.

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Damage tolerance based design optimisation of a fuel flow vent hole in an aircraft structure

Structural and Multidisciplinary Optimization ◽

10.1007/s00158-008-0278-8 ◽

2008 ◽

Vol 38 (3) ◽

pp. 245-265 ◽

Cited By ~ 9

Author(s):

R. Das ◽

R. Jones

Keyword(s):

Damage Tolerance ◽

Aircraft Structure ◽

Design Optimisation ◽

Fuel Flow

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Experimental Study of a Certain Type of Aircraft Structure Repair Adhesive

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.633-634.387 ◽

2014 ◽

Vol 633-634 ◽

pp. 387-390

Author(s):

Yang Huang ◽

Ling Tian

Keyword(s):

Epoxy Resin ◽

Curing Temperature ◽

Basic Material ◽

Curing Time ◽

Tensile Shear ◽

Aircraft Structure ◽

Loading Test ◽

Structure Damage ◽

Epoxy Resin Adhesive ◽

Modified Epoxy

Based on a certain type of aircraft structure repair adhesive was studied, the curing temperature of aircraft structure repair commonly used adhesive process of high, long curing time, curing thermal stress problem, with epoxy resin as basic material, by adding elastic toughening Ding Jin g rubber, curing agent and silane coupling agent modification on Toughening of epoxy resin. The mechanical properties of adhesive were analyzed through the cyclic loading test and tensile shear test, and the best ratio of modified epoxy resin adhesive. The adhesive prepared at 80 °C for 90 min after curing shear strength can reach 35MPa, which can meet the aircraft structure damage daily emergency repair requirements.

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Corrosion Monitoring of Aircraft Based on the Corrosion Prognostic Health Management (CPHM) System

Journal of Konbin ◽

10.2478/jok-2020-0082 ◽

2020 ◽

Vol 50 (4) ◽

pp. 205-216

Author(s):

Patryk Ciężak ◽

Adam Rdzanek

Keyword(s):

Damage Tolerance ◽

Health Management ◽

Actual State ◽

Corrosion Monitoring ◽

Field Site ◽

Aircraft Structure ◽

Corrosion Detection ◽

Preliminary Results ◽

Forecasting Methods ◽

Prognostic Health Management

AbstractThe article presents methods to monitor the actual state of aircraft’s airframe, in particular, the onset of corrosion. The greatest emphasis is put on the “Corrosion Prognostic Health Management” CPHM system. Authors discuss corrosion detection using NDT methods as well as the possibilities of forecasting methods for estimating the onset of corrosion basing on the data gathered by means corrosion sensors. Based on the results of the previous research and analyses, authors focus on monitoring the internal microclimate and the factors causing corrosion in the aspect of damage tolerance operation of the aircraft. The results of the preliminary studies giving credibility to the concepts of predicting corrosion onset in the aircraft structure are presented. Preliminary results of tests carried out in supervised flights are also presented. The final part of the article presents the concept of modernizing the corrosion field site in order to use it in hermetic and non-hermetic tests of aircraft spaces.

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Investigation on Damage Tolerance of Thick Laminate Composite Structure

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.665.149 ◽

2015 ◽

Vol 665 ◽

pp. 149-152

Author(s):

Hyun Bum Park

Keyword(s):

Standardized Test ◽

Damage Tolerance ◽

Impact Damage ◽

Specimen Thickness ◽

Aircraft Structure ◽

Functional Capability ◽

Damage Level ◽

Typical Specimen ◽

Standard Design ◽

Laminate Composite Structure

This study is to investigate the compressive strength of the carbon/epoxy thick laminate after damage. Through damage tolerance of thick laminate is not standardized test because specimens exceed typical specimen thickness described in the ASTM standard, design allowable of thick laminate shall be determined by the experiment to address design criteria of the structure and incorporate functional capability with damage level. In this study, it is performed the research on damage tolerance of thick laminate adopting aircraft structure. The damage tolerance of thick laminates such as no damage and impact damage is evaluated under compression loading.

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