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1 – 10 of 455
Article
Publication date: 7 June 2019

Petr Bělský and Martin Kadlec

Defects can be caused by a number of factors, such as maintenance damage, ground handling and foreign objects thrown up from runways during an in-service use of composite…

360

Abstract

Purpose

Defects can be caused by a number of factors, such as maintenance damage, ground handling and foreign objects thrown up from runways during an in-service use of composite aerospace structures. Sandwich structures are capable of absorbing large amounts of energy under impact loads, resulting in high structural crashworthiness. This situation is one of the many reasons why sandwich structures are extensively used in many aerospace applications nowadays. Their non-destructive inspection is often more complex. Hence, the choice of a suitable non-destructive testing (NDT) method can play a key role in successful damage detection. The paper aims to discuss these issues.

Design/methodology/approach

A comparison of detection capabilities of selected C-scan NDT methods applicable for inspections of sandwich structures was performed using water-squirt, air-coupled and pitch-catch (PC) ultrasonic techniques, supplemented by laser shearography (LS).

Findings

Test results showed that the water-squirt and PC techniques are the most suitable methods for core damage evaluation. Meanwhile, the air-coupled method showed lower sensitivity for the detection of several artificial defects and impact damage in honeycomb sandwiches when unfocussed transducers were used. LS can detect most of the defects in the panels, but it has lower sensitivity and resolution for honeycomb core-type sandwiches.

Originality/value

This study quantitatively compared the damage size indication capabilities of sandwich structures by using various NDT techniques. Results of the realised tests can be used for successful selection of a suitable NDT method. Combinations of the presented methods revealed most defects.

Details

International Journal of Structural Integrity, vol. 10 no. 3
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 1 June 1975

G. Clifton

Non‐destructive testing (NDT) makes use of the controlled application of physical phenomena to materials so that interpretation of signals derived from the materials indicates…

Abstract

Non‐destructive testing (NDT) makes use of the controlled application of physical phenomena to materials so that interpretation of signals derived from the materials indicates their fitness, or otherwise, to perform a design function. The purpose of NDT is to ensure that mainly load carrying components and structures are free from defects. Established non‐destructive testing has become of primary importance in aircraft maintenance and manufacture both as a positive indication for safety and as a method of saving costs. This article written for aircraft engineers is a broad review of the development of NDT in their industry and a brief indication of the status of its various components today.

Details

Aircraft Engineering and Aerospace Technology, vol. 47 no. 6
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 24 August 2010

Robert Bogue

The paper aims to provide a review of the uses of robots in non‐destructive testing (NDT).

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Abstract

Purpose

The paper aims to provide a review of the uses of robots in non‐destructive testing (NDT).

Design/methodology/approach

Following a brief introduction, this paper considers the uses of robotic NDT, with an emphasis on applications in certain key industries. While some development activities are considered, the emphasis is on existing systems rather than research and reference is made to a selection of commercial products.

Findings

It is shown that robotic NDT finds limited uses in most of the industries using conventional NDT methodologies. These include oil and gas, offshore and shipping, petrochemicals, aerospace and power generation. In some instances, financial benefits arise from their use while in other cases the use reflects access difficulties or the hazards associated with testing.

Research limitations/implications

Applications in the nuclear power industry is not considered but will be covered in a subsequent article. Remotely operated vehicles, which are not considered to be true robots, are also excluded.

Originality/value

This paper provides details of NDT robots and their uses in a selection of key industries.

Details

Industrial Robot: An International Journal, vol. 37 no. 5
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 27 July 2012

Robert Bogue

The purpose of this paper is to provide an insight into the techniques used for the non‐destructive testing (NDT) of non‐metallic structural materials, notably polymer and ceramic…

1457

Abstract

Purpose

The purpose of this paper is to provide an insight into the techniques used for the non‐destructive testing (NDT) of non‐metallic structural materials, notably polymer and ceramic composites.

Design/methodology/approach

Following a short introduction, this paper first considers methods for testing carbon fibre‐ and glass fibre‐reinforced polymer composites. It then discusses the role of NDT in wind and wave power systems and some of the techniques used to test ceramics and ceramic composites. Brief conclusions are drawn.

Findings

This shows that the growing use of non‐metallic engineering materials in critical applications has highlighted the need for a range of advanced NDT methods. While some traditional techniques can be adapted to test these materials, in several instances novel methods are required. These include a range of thermal, ultrasonic, electromagnetic, radiographic and laser‐based technologies.

Originality/value

The paper provides a review of the techniques used and being developed for the non‐destructive testing of non‐metallic engineering materials.

Details

Assembly Automation, vol. 32 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 19 June 2009

Tariq P. Sattar and Alina‐Alexandra Brenner

The purpose of this paper is to develop a portable non‐destructive testing (NDT) robotic arm that can be carried by climbing and walking robots (CLAWAR). The arm is required to…

Abstract

Purpose

The purpose of this paper is to develop a portable non‐destructive testing (NDT) robotic arm that can be carried by climbing and walking robots (CLAWAR). The arm is required to maintain, during a scanning trajectory, a desired NDT probe contact force and orientation to evaluate defects in geometrically complex industrial infrastructure and products such as turbine blades.

Design/methodology/approach

A seven‐axis arm transportable by CLAWAR was developed to deploy NDT probes with suitable dexterity. It was equipped with a force sensor to scan a complex shape by keeping the NDT probe normal to the surface while maintaining a constant contact force with it. Two approaches were used. One used permanent magnet adhesion to obtain secure contact while the other used position‐force‐moment (PFM) feedback to adapt the arm.

Findings

Tests were performed on turbine blades with eddy‐current inspection techniques to assess the quality of defect data using manual inspection and automated inspection. Significant improvements in the quality of inspection were observed when using robotic scanning as compared to manual inspection.

Practical implications

The results have practical implications for the remote inspection of very large infrastructures such as petrochemical storage tanks, bridges, pressure vessels, etc. or where the inspection is performed in hazardous environments and the test surface is not known a priori with any accuracy.

Originality/value

The work is a novel application of the PFM control of a seven‐axis robot arm to scan unknown contoured surfaces to ensure reliable NDT data acquisition at scanning speeds of up to 0.5 mm s−1.

Details

Industrial Robot: An International Journal, vol. 36 no. 4
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 17 March 2020

Paschalis Charalampous, Ioannis Kostavelis and Dimitrios Tzovaras

In recent years, additive manufacturing (AM) technology has been acknowledged as an efficient method for producing geometrical complex objects with a wide range of applications…

1631

Abstract

Purpose

In recent years, additive manufacturing (AM) technology has been acknowledged as an efficient method for producing geometrical complex objects with a wide range of applications. However, dimensional inaccuracies and presence of defects hinder the broad adaption of AM procedures. These factors arouse concerns regarding the quality of the products produced with AM and the utilization of quality control (QC) techniques constitutes a must to further support this emerging technology. This paper aims to assist researchers to obtain a clear sight of what are the trends and what has been inspected so far concerning non-destructive testing (NDT) QC methods in AM.

Design/methodology/approach

In this paper, a survey on research advances on non-destructive QC procedures used in AM technology has been conducted. The paper is organized as follows: Section 2 discusses the existing NDT methods applied for the examination of the feedstock material, i.e. incoming quality control (IQC). Section 3 outlines the inspection methods for in situ QC, while Section 4 presents the methods of NDT applied after the manufacturing process i.e. outgoing QC methods. In Section 5, statistical QC methods used in AM technologies are documented. Future trends and challenges are included in Section 6 and conclusions are drawn in Section 7.

Findings

The primary scope of the study is to present the available and reliable NDT methods applied in every AM technology and all stages of the process. Most of the developed techniques so far are concentrated mainly in the inspection of the manufactured part during and post the AM process, compared to prior to the procedure. Moreover, material extrusion, direct energy deposition and powder bed processes are the focal points of the research in NDT methods applied in AM.

Originality/value

This literature review paper is the first to collect the latest and the most compatible techniques to evaluate the quality of parts produced by the main AM processes prior, during and after the manufacturing procedure.

Details

Rapid Prototyping Journal, vol. 26 no. 4
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 1 April 1989

Harold G Bunce

In the “in‐service” maintenance and inspection of aircraft structures, an uneasy alliance exists between corrosion detection and Non‐Destructive Testing. NDT is a widely used and…

Abstract

In the “in‐service” maintenance and inspection of aircraft structures, an uneasy alliance exists between corrosion detection and Non‐Destructive Testing. NDT is a widely used and generally successful way of inspecting for structural defects and as the service life of aircraft is extended and corrosion therefore tends to become a not uncommon structural defect, why should not NDT be as useful in this situation as it often is in detecting cracks occasioned by extended flying hours and increased flight cycles? This paper tries to answer that question by pointing out some of the advantages and disadvantages of NDT applied to corrosion detection in the aviation industry.

Details

Aircraft Engineering and Aerospace Technology, vol. 61 no. 4
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 27 September 2021

Radhia Chabbi, Noureddine Ferhoune and Fouzia Bouabdallah

This research aims to study the materials that compose older reinforced concrete bridges which are damaged and degrading to explain the mechanisms and origins of various…

93

Abstract

Purpose

This research aims to study the materials that compose older reinforced concrete bridges which are damaged and degrading to explain the mechanisms and origins of various disorders. Therefore, this work will contribute to providing answers on the capacity of nondestructive evaluation method during the diagnosis. In addition to the characterization of affected structures, it will aim to provide effective solutions for different serious pathologies.

Design/methodology/approach

In this context, two bridges located on NH16 and NH21, respectively, were studied in Annaba city (north-east Algeria), specifically in El-Hadjar municipality located in the central industrial zone of Pont-Bouchet. This study makes it possible to make conclusions from the in-depth diagnosis based on disorders exposition causes and mechanical characteristics evolution by non-destructive testing (NDT) tools. Furthermore, solutions are proposed, including conservation maintenance of these degraded structures.

Findings

All degradations can be the result of several factors: either human (poor design) or chemical (surface water, wastewater and groundwater quality (acidic or basic)). In addition to other natural causes (geological formations, flood phenomena or climate), NDT tools play a major role in the evaluating mechanical performance of degraded structures (resistance and hardness).

Research limitations/implications

The NDT techniques can be transmitted to civil engineering experts because their training is limited regarding mechanical and structural construction.

Practical implications

NDT tools are the most suitable for in-situ assessing, and the concrete constructions health state, so far from financial problems.

Social implications

Degraded bridge diagnosis by NDT testing is necessary for a thorough safety evaluation (mechanical performance, strength and deformability), to protect human lives and design durability.

Originality/value

This is an original paper which contains new information at different scales and from special fields, based on an evaluation using NDT tools on real degraded structures. It can be used to improve the knowledge of materials employed in a bridge without performing expensive direct tests or the need for destroying it.

Details

International Journal of Building Pathology and Adaptation, vol. 41 no. 4
Type: Research Article
ISSN: 2398-4708

Keywords

Article
Publication date: 9 November 2012

Valdemar Melicher and Peter Sergeant

This paper aims to derive a simple and effective but still a reasonably accurate model for electromagnetic problems with hysteretic magnetic properties and/or induced currents in…

1805

Abstract

Purpose

This paper aims to derive a simple and effective but still a reasonably accurate model for electromagnetic problems with hysteretic magnetic properties and/or induced currents in heterogeneous regions in 2D, meant particularly for non‐destructive testing (NDT) of steel cables by eddy‐currents.

Design/methodology/approach

It is assumed that the diffusion of electromagnetic fields in a heterogeneous cable, which consists of many strands, can be described by the Maxwell equations with periodically oscillating coefficients. A computationally efficient model can then be derived. The idea behind this is to replace the heterogeneous material in the cross‐section by a fictitious homogeneous one, whose behaviour at the macroscopic level is a good approximation of the one of the composite material. Such a homogenized model is obtained by employing the two‐scale convergence.

Findings

The model is validated based on experimental electromagnetic data from a steel cable (measured magnetic hysteresis loops) to show that the model is applicable for NDT of cables. The model is useful for studying NDT of cables, both for excitation at low frequency (where changes in magnetic properties are investigated) and at higher frequency (eddy current testing). It is valid for a wide range of amplitudes and frequencies.

Originality/value

From the mathematical point of view the model incorporated a non‐local boundary condition that has to be included in the analysis. From the engineering point of view, by solving an inverse problem based on this model and on measured hysteresis loops at several frequencies, a broader range of defects in the cable can be detected.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 31 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 7 May 2019

Canzhi Guo, Chunguang Xu, Dingguo Xiao, Hanming Zhang and Juan Hao

With the development of materials science and technology, composite workpieces are increasingly used. This paper aims to discuss a non-destructive testing (NDT) solution for…

Abstract

Purpose

With the development of materials science and technology, composite workpieces are increasingly used. This paper aims to discuss a non-destructive testing (NDT) solution for semi-enclosed composite workpieces. A dual-robot system with one robot that grips an irregular-shaped ultrasonic probe (tool) is established.

Design/methodology/approach

According to robotics, this paper defines the orientations of the discrete points coordinate frames in trajectory and proposes an orientation constraint rule between the tool coordinate frame and the scanning trajectory. A four-posture calibration method for calibrating the transformation relationship of the irregular-shaped tool frame relative to the robot flange frame is presented in detail.

Findings

Calibration and verification experiments were performed, and good-quality C-scan images were obtained by applying the constraint rule and the calibration method. Experimental results show that the calibration method used to determine the tool centre point (TCP) position is correct, effective and efficient; the TCP orientation constraint rule can ensure the extension pole of the irregular-shaped ultrasonic probe is parallel to the axis of the semi-enclosed cylindrical workpieces; and the ultrasonic transducer axis is perpendicular to the surface of the workpiece.

Originality/value

This paper proposes a constraint method for the posture of an irregular-shaped tool in this scheme. Theoretical foundations for the four-posture calibration method of the irregular-shaped tool for dual-robot-assisted ultrasonic NDT are presented in detail. This strategy has been successfully applied in the NDT experiment of semi-enclosed composite workpieces.

Details

Industrial Robot: the international journal of robotics research and application, vol. 46 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

1 – 10 of 455