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Article
Publication date: 18 March 2021

Miroslaw Rodzewicz

The purpose of this paper is to present the concept of the author’s method of fatigue properties assessment of polymer composite structures, especially structures having…

Abstract

Purpose

The purpose of this paper is to present the concept of the author’s method of fatigue properties assessment of polymer composite structures, especially structures having nodes of concentrated force introduction (NCFI) using fatigue test data of coupons of similar composites and the ratio of their structural stress rate factors.

Design/methodology/approach

Basing on fatigue properties of pure composite shells coupons subjected to cyclic loads, and basing on the static strength difference between pure composite shells and shells having the structure affected by NCFI – (considered here as not only a manner of load introduction but also a kind of structural discontinuity), a method of relative fatigue properties reduction (RFPR) was developed. In the RFPR evaluation process, the author used the results of experiments on a special type of an NCFI named “a labyrinth non-adhesive node of concentrated force introduction” (LNA-NCFI) applied in certain composite gliders for fitting glider wings with the fuselage and also referred to design directives relating to primary structure of composite gliders, which are presented in the form of lightness factors linking stress with a structural mass.

Findings

The result of RFPR method application matched well with the results of fatigue tests of the LNA-NCFI type of a NCFI. The RFPR method may significantly facilitate the estimation of fatigue life of a structure with a structural discontinuity or an NCFI.

Practical implications

The RFPR method may significantly facilitate the estimation of fatigue life of a structure with a structural discontinuity or an NCFI.

Originality/value

The paper presents a proposal of a novel simplified method for fatigue life estimation of composite structures having a kind of structural discontinuity or an NCFI.

Details

Aircraft Engineering and Aerospace Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 1 June 1997

Jaroslav Mackerle

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the…

Abstract

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the theoretical as well as practical points of view. The range of applications of FEMs in this area is wide and cannot be presented in a single paper; therefore aims to give the reader an encyclopaedic view on the subject. The bibliography at the end of the paper contains 2,025 references to papers, conference proceedings and theses/dissertations dealing with the analysis of beams, columns, rods, bars, cables, discs, blades, shafts, membranes, plates and shells that were published in 1992‐1995.

Details

Engineering Computations, vol. 14 no. 4
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 20 December 2018

Shalini Saha, Amares Chattopadhyay and Abhishek Kumar Singh

The purpose of this paper is to develop a numerical (finite-difference) model exploring phase and group velocities of SH-wave propagation in initially stressed…

Abstract

Purpose

The purpose of this paper is to develop a numerical (finite-difference) model exploring phase and group velocities of SH-wave propagation in initially stressed transversely isotropic poroelastic multi-layered composite structures and initially stressed viscoelastic-dry-sandy multi-layered composite structures in two distinct cases.

Design/methodology/approach

With the aid of relevant constitutive relations, the non-vanishing equations of motions for the propagation SH-wave in the considered composite structures have been derived. Haskell matrix method and finite-difference scheme are adopted to deduce velocity equation for both the cases. Stability analysis for the adopted finite-difference scheme has been carried out and the expressions for phase as well as group velocity in terms of dispersion-parameter and stability-ratio have been deduced.

Findings

Velocity equations are derived for the propagation of SH-wave in both the composite structures. The obtained results are matched with the classical results for the case of double and triple-layered composite structure along with comparative analysis. Stability analysis have been carried out to develop expressions of phase as well as group velocity in terms of dispersion-parameter and stability-ratio. The effect of wavenumber, dispersion parameter along with initial-stress, porosity, sandiness, viscoelasticity, stability ratio, associated with the said composite structures on phase, damped and group velocities of SH-wave has been unveiled.

Originality/value

To the best of authors’ knowledge, numerical modelling and analysis of propagation characteristics of SH-wave in multi-layered initially stressed composite structures composed of transversely isotropic poroelastic materials and viscoelastic-dry-sandy materials remain unattempted inspite of its importance and relevance in many branches of science and engineering.

Details

Engineering Computations, vol. 36 no. 1
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 11 March 2014

Aaron Warren, Rikard Heslehurst and Eric Wilson

The purpose of this paper is to discuss changes to MIL-STD-1530C “Aircraft Structural Integrity Program” to account for the increased usage of composites in aircraft…

Abstract

Purpose

The purpose of this paper is to discuss changes to MIL-STD-1530C “Aircraft Structural Integrity Program” to account for the increased usage of composites in aircraft structures.

Design/methodology/approach

The evolution of the Aircraft Structural Integrity Program is presented and the five tasks that comprise the program are assessed for compatibility with composite aircraft structures.

Findings

This paper identifies a number of recommended changes to MIL-STD-1530C to ensure that the unique behaviour of composites is considered within the Aircraft Structural Integrity Program.

Originality/value

This paper recommends changes to MIL-STD-1530C to account for composite aircraft structures, thus providing assurance compatibility of the Aircraft Structural Integrity Program with composite materials.

Details

International Journal of Structural Integrity, vol. 5 no. 1
Type: Research Article
ISSN: 1757-9864

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Article
Publication date: 8 March 2011

Richard R. Williams, William E. Howard and Scott M. Martin

The purpose of this paper is to investigate the feasibility of using rapid prototyping (RP) technologies (stereolithography (SLA), fused deposition modeling (FDM), and…

Abstract

Purpose

The purpose of this paper is to investigate the feasibility of using rapid prototyping (RP) technologies (stereolithography (SLA), fused deposition modeling (FDM), and three‐dimensional printing (3DP)) for fabrication of the core of a composite sandwich structure.

Design/methodology/approach

Control cores of a flat geometry were fabricated from epoxy using SLA and from acrylonitrile butadiene styrene (ABS) plastic using FDM. Corrugated geometry cores were fabricated using SLA, FDM, and 3DP. Carbon‐epoxy composite sandwich structures were fabricated from all cores using a wet‐hand layup process with vacuum cure. The performance of each core was measured using a bend test to determine bending stiffness and failure load.

Findings

Based upon bending stiffness and failure load, composite sandwich structures utilizing epoxy cores fabricated via SLA outperformed composite sandwich structures utilizing plaster powder and ABS plastic cores. Composite sandwich structures with corrugated ABS plastic cores outperformed those with flat ABS plastic cores by a margin well beyond that predicted by theory in both bending stiffness and failure load.

Research limitations/implications

The marked improvement in stiffness and failure load of the composite sandwich structures with corrugated ABS plastic cores over those with flat ABS cores is not explained by the theoretical improvement due to an increased area moment of inertia and increased surface area. Additional research in the failure mechanism is warranted.

Practical implications

The ability to easily create complex core geometries will allow for the ability to place enhanced structural features in the regions of high stress.

Originality/value

This paper demonstrates that cores fabricated via RP technology and containing enhanced structural features are suitable for carbon‐epoxy composite sandwich structures.

Details

Rapid Prototyping Journal, vol. 17 no. 2
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 9 July 2020

Mohammad Amin Rahiminia, Masoud Latifi and Mojtaba Sadighi

The purpose of this paper is to introduce an innovative transversal tubular braid texture and to study the elastic behavior of its 3 D printed structure comparatively to…

Abstract

Purpose

The purpose of this paper is to introduce an innovative transversal tubular braid texture and to study the elastic behavior of its 3 D printed structure comparatively to 3 D printed longitudinal tubular braid texture (maypole) to be used as reinforcement.

Design/methodology/approach

Regarding the lack of proper machines for the production of the proposed texture, the structure of samples was produced as a tubular lattice braid texture using a 3 D printer with the fused deposition modeling method subsequent to simulation by Rhinoceros software. The produced specimens were composited by polyurethane resin. The composite samples were evaluated by the split disk mechanical test to obtain their hoop stress. The structures of the reinforced composites were theoretically analyzed by ANSYS software.

Findings

The results of the mechanical test and theoretical analysis showed that the composites reinforced with transversal tubular lattice braid have higher strength compared to the composites reinforced with longitudinal ones. This assured that the composite reinforced by transversal tubular lattice braid is reliable to be used as high-performance tube for different applications.

Originality/value

Further work is carried out to produce the innovated complex structure continuously by a specially designed machine and fibrous materials to reinforce tubular composites in an industrial continual process to be applied for high-pressure fluids flows.

Details

Rapid Prototyping Journal, vol. 26 no. 7
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 17 October 2018

Jiang Xie, Haolei Mou, Xuan Su and Zhenyu Feng

This paper aims to present an evaluation method for energy-absorption characteristics of thin-walled composite structures with random uncertain parameters.

Abstract

Purpose

This paper aims to present an evaluation method for energy-absorption characteristics of thin-walled composite structures with random uncertain parameters.

Design/methodology/approach

The mechanical properties of T700/3234 are obtained by material performance tests and energy-absorption results are obtained by quasi-static crushing tests of thin-walled composite circular tubes. The indicators of triggering specific load (TSL) and specific energy absorption (SEA) are introduced and calculated to determine the energy-absorption characteristics and validate the probability finite element analysis model. The uncertainty in the parameters contain the machining tolerance for the thickness and inner diameter of composite circular tubes and are associated with the composite material system. The Plackett–Burman method is used to choose the measurement parameters. Then, the response surface method is used to build a second-order function of random uncertain parameters versus TSL/SEA, and the Monte Carlo method is finally used to obtain the probabilities of TSL and SEA.

Findings

The finite element models can accurately simulate the initial peak load, load-displacement curve and SEA value. The random uncertain parameter method can be used to evaluate the energy-absorption characteristics of thin-walled composite circular tubes.

Practical implications

The presented evaluation method for energy-absorption characteristics of thin-walled composite structures is an approach that considers uncertain parameters to increase the simulation accuracy and decrease the computational burden.

Originality/value

This methodology considers uncertain parameters in evaluating the energy-absorption characteristics of thin-walled composite structures, and this methodology can be applied to other thin-walled composite structures.

Details

Aircraft Engineering and Aerospace Technology, vol. 90 no. 8
Type: Research Article
ISSN: 1748-8842

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Book part
Publication date: 21 November 2018

Jun Xiu Low, Poi Ngian Shek and Mahmood Md Tahir

Composite slabs are gaining wide acceptance in many countries as they lend themselves to faster, lighter and more economic in construction buildings. The strength of…

Abstract

Composite slabs are gaining wide acceptance in many countries as they lend themselves to faster, lighter and more economic in construction buildings. The strength of composite slabs system relies on the bonding action between the concrete and the steel deck, the shear connections and the cross-sectional resistance of steel beam. However, structural behaviour of composite slab is a complex phenomenon and therefore experimental study is often conducted to establish the actual strength of the structure under ultimate load capacity. The main objective of this study is to determine the structural behaviour of composite slab system until ultimate limit state. Total of two specimens are examined in order to obtain failure mechanism of the composite structure under full load capacity. A new design approach of composite slab for roofing system are proposed in this study to construct a composite slab system that can float in the water but not wash away by flood. The lightweight materials in this composite construction are cold-formed steel and foam concrete. The system focuses on the concept of Industrialised building system (IBS) to reduce the cost and construction time.

Details

Improving Flood Management, Prediction and Monitoring
Type: Book
ISBN: 978-1-78756-552-4

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Article
Publication date: 1 March 2006

Carroll Grant

This paper provides a general review of automated processing methods currently being used to fabricate aircraft composite structure.

Abstract

Purpose

This paper provides a general review of automated processing methods currently being used to fabricate aircraft composite structure.

Design/methodology/approach

Presents a description of the Automated Tape Layer (ATL) process and the Fiber Placement (FP) process. These processes are the most “automated” of all processes being used to fabricate composite aircraft structure. Fiber Placement machines and Automated Tape Layers are composites machine tools and they are the closest comparison the composites industry has to metals machining equipment.

Findings

There is a need for more variety of composites automation and more affordable machines in the aerospace composites industry. The limited variety of automation and the cost of equipment tend to limit the spread of automation throughout the aerospace composites industry. ATL and FP are composites laminating technologies that could be adapted to a wide range of machine sizes, configurations, and price ranges.

Originality/value

More widespread use of automated processes in composites would tend to lower the cost of composite aircraft structure on a global basis.

Details

Industrial Robot: An International Journal, vol. 33 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

Content available
Article
Publication date: 4 December 2017

Natalie Ishmael, Anura Fernando, Sonja Andrew and Lindsey Waterton Taylor

This paper aims to provide an overview of the current manufacturing methods for three-dimensional textile preforms while providing experimental data on the emerging…

Abstract

Purpose

This paper aims to provide an overview of the current manufacturing methods for three-dimensional textile preforms while providing experimental data on the emerging techniques of combining yarn interlocking with yarn interlooping.

Design/methodology/approach

The paper describes the key textile technologies used for composite manufacture: braiding, weaving and knitting. The various textile preforming methods are suited to different applications; their capabilities and end performance characteristics are analysed.

Findings

Such preforms are used in composites in a wide range of industries, from aerospace to medical and automotive to civil engineering. The paper highlights how the use of knitting technology for preform manufacture has gained wider acceptance due to its flexibility in design and shaping capabilities. The tensile properties of glass fibre knit structures containing inlay yarns interlocked between knitted loops are given, highlighting the importance of reinforcement yarns.

Originality/value

The future trends of reinforcement yarns in knitted structures for improved tensile properties are discussed, with initial experimental data.

Details

Research Journal of Textile and Apparel, vol. 21 no. 4
Type: Research Article
ISSN: 1560-6074

Keywords

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