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Article
Publication date: 2 February 2015

Martin Kadlec, Robin Hron and Timo Grieser

T-sections of carbon fibre-reinforced composites are prone to delamination because they lack reinforcement through their thicknesses. The purpose of this paper is to…

Abstract

Purpose

T-sections of carbon fibre-reinforced composites are prone to delamination because they lack reinforcement through their thicknesses. The purpose of this paper is to present the structural response of cost-effective laminated T-sections when subjected to various types of loads and impacts.

Design/methodology/approach

The core of the automated manufactured beams is analysed. Pull-off, flange tension, and flange bending were tested for specimens extracted from an I-beam. The failure processes for all of the specimens were investigated in detail, leading to the statistical evaluation of the failure modes.

Findings

A correlation is apparent between the impact damage energy and certain fracture patterns. These results can be used to assess damage tolerance when designing stiffeners, beams, and various complex structures. The increase in strength by 25 per cent was measured for the advanced stitching located in the web section for the flange tension test.

Originality/value

The resistance displayed by the T-sections toward impact damage was studied experimentally, as the literature describing this topic is limited. The prevalence of one fracture mode for higher impact energies shows a possible advantage of the cost-effective preforms for the damage tolerant philosophy.

Details

International Journal of Structural Integrity, vol. 6 no. 1
Type: Research Article
ISSN: 1757-9864

Keywords

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Article
Publication date: 1 December 2005

H. Eduardo Salamanca and L. Luis Quiroz

To present a method of interaction between flight loads that is applied to a probabilistic damage tolerance analysis in an acrobatic aircraft.

Abstract

Purpose

To present a method of interaction between flight loads that is applied to a probabilistic damage tolerance analysis in an acrobatic aircraft.

Design/methodology/approach

The uncertainties concerning material strength, initial crack size and loads in the aircraft are considered. We place special emphasis on stress distribution, using superposition criteria that distinguish between gust, maneuver and ground‐air‐ground loads. Gust load is generated form its power spectral density and modified using service load data (exceedance curves). Crack initiation time and propagation time are considered in calculating the service time.

Findings

A new and realistic method of interaction between loads during acrobatic flight is proposed. This method was compared with other methods in an example. The effects of the interaction criteria are related to the influence between loads (stress levels and frequency).

Originality/value

In commercial aircraft, maneuver loads have a lower influence than gust loads, and the mission concept is the correct approach. Training aircraft have the opposite king of behavior and the proposed superposition method is shown to be better approach. This method would have more pronounced effects in aircraft types with behaviors between commercial and training (for example, amphibious aircraft).

Details

Aircraft Engineering and Aerospace Technology, vol. 77 no. 6
Type: Research Article
ISSN: 0002-2667

Keywords

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Article
Publication date: 1 September 1993

Terry Ford

THE ATR consortium manufactures a range of transport aircraft for which Aerospatiale supplies the wings and associated structure and Alenia of Italy manufactures the…

Abstract

THE ATR consortium manufactures a range of transport aircraft for which Aerospatiale supplies the wings and associated structure and Alenia of Italy manufactures the fuselage and empennage. Engines, propellers and landing gear are supplied by Pratt & Whitney of Canada, Hamilton Standard and Messier‐Bugatti, respectively. At Le Bourget this year, the opportunity was taken to introduce new models together with plans for the future.

Details

Aircraft Engineering and Aerospace Technology, vol. 65 no. 9/10
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 2 March 2012

Adam Mather, Raymond Cipra and Thomas Siegmund

Topologically interlocked materials are a class of materials in which individual unit elements interact with each other through contact only. Cracks and other defects…

Abstract

Purpose

Topologically interlocked materials are a class of materials in which individual unit elements interact with each other through contact only. Cracks and other defects occurring due to external loading are contained in the individual unit elements. Thus, topologically interlocked materials are damage tolerant and provide high structural integrity. The purpose of this paper is to investigate the concepts of remanufacturing in the context of a material for which the intended use is structural such that the material's structural integrity is of concern. In particular, the study is concerned with the mechanical behavior of a topologically interlocked material.

Design/methodology/approach

A topologically interlocked material based on tetrahedron unit elements is investigated experimentally. Manufacturing with aid of a robotically controlled end‐effector is demonstrated, and mechanical properties are determined for a plate configuration. A conceptual mechanical model for failure of topologically interlocked materials is developed and used to interpret the experimental results.

Findings

It is demonstrated that remanufacturing of the topologically interlocked material is possible with only a limited loss of material performance. The proposed model predicts trends in agreement with the experimental findings.

Research limitations/implications

While the model predictions are qualitatively in agreement with experiments, more detailed finite element models are needed to predict the material performance accurately. Experiments were conducted on a model material obtained from a 3D printer and should be verified on other solids.

Practical implications

The authors demonstrate that damage containment together with the absence of binders or adhesives enables reuse through remanufacturing without loss of structural integrity.

Social implications

Topologically interlocked materials emerge as attractive materials for sustainable engineering once their material performance are weighted with an environmental impact factor.

Originality/value

Remanufacturing experiments on a novel class of materials were conducted and a new model for the characterization of the structural integrity of topologically interlocked materials is proposed and successfully evaluated against experiments in at least qualitative form.

Details

International Journal of Structural Integrity, vol. 3 no. 1
Type: Research Article
ISSN: 1757-9864

Keywords

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Article
Publication date: 1 August 1997

Terry Ford

Details the development of composites, in particular carbon fibre reinforced plastics, for use in aerospace structures. Describes a wide range of products manufactured by…

Abstract

Details the development of composites, in particular carbon fibre reinforced plastics, for use in aerospace structures. Describes a wide range of products manufactured by various companies. Looks at the integrity of these materials and the testing methods used to ensure this. In particular, discusses metal matrix composites, aluminium/silicon carbide particulate MMCs and fibre‐metal laminates. Finally looks at advanced composites’ promise of being able to meet the needs of high specific properties and enhanced temperature capability required for future engines.

Details

Aircraft Engineering and Aerospace Technology, vol. 69 no. 4
Type: Research Article
ISSN: 0002-2667

Keywords

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Article
Publication date: 1 January 1992

Mayday

THE problems peculiar to the operation of rotating wing aircraft have always posed additional tasks related to control, vibration and the difficulties of ensuring adequate…

Abstract

THE problems peculiar to the operation of rotating wing aircraft have always posed additional tasks related to control, vibration and the difficulties of ensuring adequate load paths in the event of a failure. Issues related to these topics in both the civil and military field were addressed at a recent Royal Aeronautical Society Conference which outlined the various factors in helicopter flight safety together with progress in the last few years and the outlook for the future.

Details

Aircraft Engineering and Aerospace Technology, vol. 64 no. 1
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 7 December 2015

Paulo J Tavares, Tiago Ramos, Daniel Braga, Mario A P Vaz and Pedro Miguel Guimarães Pires Moreira

Hybrid methods, wherefore numerical and experimental data are used to calculate a critical parameter, have been used for several years with great success in Experimental…

Abstract

Purpose

Hybrid methods, wherefore numerical and experimental data are used to calculate a critical parameter, have been used for several years with great success in Experimental Mechanics and, in particular, in fracture mechanics. The purpose of this paper is to report on the comparison of the strain field from numerical modelling forecasts against the experimental data obtained with the digital image correlation method under Mode II loading in fatigue testing. The numerical dual boundary element method has been established in the past as a very reliable method near singular regions where stresses tend to grow abruptly. The results obtained from the strain data near the crack tip were used in Williams expansion and agree fairly well with both the numerical results and the analytical solution proposed for pure Mode II testing.

Design/methodology/approach

The work presented in this note is experimental. The proposed methodology is of an hybrid experimental/numerical nature in that a numerical stress intensity factor calculation hinges upon a stress field obtained with an image method.

Findings

The obtained results are an important step towards the development of a practical tool for crack behaviour prediction in fatigue dominated events.

Research limitations/implications

The results also stress the necessity of improving the experimental techniques to a point where the methods can be applied in real-life solicitations outside of laboratory premises.

Originality/value

Although several research teams around the globe are presently working in this field, the present research topic is original and the proposed methodology has been presented initially by the research team years ago.

Details

International Journal of Structural Integrity, vol. 6 no. 6
Type: Research Article
ISSN: 1757-9864

Keywords

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Article
Publication date: 1 February 2001

Aydin Akdeniz

Economic and market conditions have resulted in the use of commercial jet transport airplanes well beyond their design service objective (DSO). Air transport industry…

Abstract

Economic and market conditions have resulted in the use of commercial jet transport airplanes well beyond their design service objective (DSO). Air transport industry consensus is that older jet transport airplanes will continue to be in service despite an anticipated substantial increase in the required maintenance. Based on economical considerations, established operators may replace their airplanes beyond DSO with new ones. At the same time these older airplanes are sold to operators with little or no knowledge and experience of the aging airplane maintenance programs. Discusses the damage tolerance concept, its relation to airplane age and its evolution that is fail‐safe to damage tolerance based maintenance certification for jet transport airplanes. Also, this paper will discuss a process for upgrading structural inspection programs for older airplanes to damage tolerance standard per MSG‐3 Rev. 2 analysis. Finally, sub‐surface corrosion on principal airplane structures and its effect on airplane safety will be discussed.

Details

Aircraft Engineering and Aerospace Technology, vol. 73 no. 1
Type: Research Article
ISSN: 0002-2667

Keywords

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Article
Publication date: 7 December 2015

Peter Horst

In general two main types of criteria are essential for the sizing of aircraft structural panels, namely, stability and damage tolerance. The way these criteria act and…

Abstract

Purpose

In general two main types of criteria are essential for the sizing of aircraft structural panels, namely, stability and damage tolerance. The way these criteria act and interact is very different for metallic and composite building blocks. While interaction of both types of criteria is relatively clear for composite parts, this is normally not the case for metallic ones. What is common for both is the fact that, if an interaction occurs, the impact is essential. The paper aims to discuss these issues.

Design/methodology/approach

This is a survey paper.

Findings

There is a strong mutual influence of buckling and damage in many cases.

Originality/value

It shows the significance of both, buckling and damage as a combined phenomenon.

Details

International Journal of Structural Integrity, vol. 6 no. 6
Type: Research Article
ISSN: 1757-9864

Keywords

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Article
Publication date: 1 July 2014

Patryk Jakubczak, Jaroslaw Bieniaś, Krzysztof Majerski, Monika Ostapiuk and Barbara Surowska

The purpose of this study was to carry out the analysis of impact resistance for aluminum hybrid laminates and polymer matrix composites reinforced with glass and carbon…

Abstract

Purpose

The purpose of this study was to carry out the analysis of impact resistance for aluminum hybrid laminates and polymer matrix composites reinforced with glass and carbon fibers. Damage modes and damages process under varied impact energies are also presented and discussed.

Design/methodology/approach

The subject of examination were fiber metal laminates – FMLs (Al/CFRP and Al/GFRP). The samples were subjected to low-velocity impact by using a drop-weight impact tester. The specimens after impact were examined using non-destructive and destructive inspection techniques.

Findings

The hybrid laminates are characterized by higher resistance to impact in comparison to the conventional laminates. The delaminations between composite layers as well as the delaminations on metal/composite interface and lateral cracks are the prevailing type of destruction mechanisms. No significant relationships between metal volume friction coefficient vs response to the impact were recorded for the hybrid laminates under tests.

Practical implications

The understanding of impact behavior of FMLs is particularly important for selecting these materials and their designing, in damage tolerance philosophy aspect in aerospace industry as well as in searching the methods of predicting of FML hybrid materials resistance to impact. The test results might be useful for the validation of simulations using numerical methods.

Originality/value

The paper presents the impact resistance of new hybrid laminates for aerospace applications. The identification of damage character and failure mechanisms as well as the relationships between damage and impact responses of aluminum/carbon and aluminum/glass hybrid laminates were estimated.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 86 no. 4
Type: Research Article
ISSN: 0002-2667

Keywords

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