The combination of an electric arc with the laser beam in the same weld pool in a hybrid process (Fig.4) can significantly improve the gap-bridging capability and tolerance to misalignment of the laser process alone. (W 131) (1)

Gap-bridging capability = Capacidade de ligação de lacunas

Notably over the past 40 years, electron beam welding has been taken from a very thin section welding process to the point where joints in even 300mm thick material can be attempted in a single pass. Similarly laser welding has advanced in leaps and bounds; numerous types of laser have been developed and although currently lacking the ultimate thick section welding capability of the electron beam welding process the penetration performance is advancing at a substantial pace. (W 507) (2)

Welding capability = Capacidade de soldagem

The results of tensile testing on Comeld specimens between stainless steel and GFRP demonstrated that, in comparison to control specimens they withstood loads 75% higher, the displacement before failure was three times higher and the energy absorbed was five times higher.

The crucial difference between these Comeld and control specimens was the failure mode. The control specimens failed without warning at the interface between the metal and the composite whereas the Comeld specimens prevented interfacial failure, initially exhibited damage without losing load-carrying capability and final failure occurred within the composite material. (W 241) (3)

Load-carrying capability = Capacidade de transporte de carga

(1) The importance of welding quality in ship construction

P.L. Moore 

Paper presented at Analysis and design of Marine Structures 2nd International Conference on Marine Structures (MARSTRUCT 2009) March 16- 18, 2009 Lisbon, Portugal.

(2) Advanced welding processes for fusion reactor fabrication

By A Sanderson, C S Punshon and J D Russell 

Paper presented at the 5th International Symposium of Fusion Nuclear Technologies, ISFNT-5, Rome, September 1999 and published in Fusion Engineering and Design, 49-50, 2000, pp. 77 – 87.

(3) Energy absorbing joints between fibre reinforced plastics and metals

Faye Smith

Paper presented at Joining Plastics 2006, London, National Physical Laboratory (NPL), 25-26 April 2006.

Low C-steels (typically up to 0.3%C) can be satisfactorily laser welded and it has been reported that a sintered steel-part can be acceptably laser welded to a wrought counterpart, as long as both components have low carbon content. (W 141) (1)

Low carbon = Baixo carbono

Steel A had a high carbon equivalent and showed high weld/parent hardness overmatching. This is due to the formation of hard metastable phases such as bainite in the weld microstructure. (W 417) (2)

High carbon = Alto carbono

Just as with other microalloying routes vanadium-microalloying, by facilitating reductions in steel carbon content, can provide improvements in steel weldability. Moreover, there is now clear evidence that vanadium-microalloying canbring additional benefits, especially to weld joint toughness, by virtue of its influence on microstructural development. (W 427) (3)

Steel carbon = Carbono de aço

(1) Critical review of joining processes for powder metallurgy parts

C. Selcuk, S. Bond and P. Woollin

Metallurgy, Corrosion & Surfacing Technology Group, TWI Ltd, Granta Park, Great Abington, Cambridge, CB21 6AL, UK. T: +44 (0) 1223 899 000, F: +44 (0) 1223 894 717.

Paper presented at Euro PM 2008 Congress and Exhibition, Mannheim, Germany, 29 Sept – 1 Oct 2008.

(2) Microstructure & properties of autogenous high-power Nd:YAG laser welds in C-Mn steels

P L Moore 

University of Cambridge and TWI Ltd . D S Howse . TWI Ltd 

E R Wallach 

University of Cambridge 

Paper presented at 6th International Conference on Trends in Welding Research, 15 – 19 April 2002, Callaway Gardens Resort, Pine Mountain, Georgia.

(3) The influence of vanadium-microalloying on the weldability of steels

P H M Hart

Paper presented at Vanadium 2001. Vanadium Application Technology. International Symposium, Beijing, China, 12-14 Oct 2001.

The control system was also upgraded and substantial fume extraction and vacuum chamber cleaning equipment was installed. (W 220) (1)

Vacuum chamber = Câmara de vácuo

The work involved the design and manufacture of a pressure chamber equipped with access, via a sapphire window, for the laser beam. To simulate the welding process, material samples in the form of small diameter discs, were rotated inside a chamber under the focussed laser beam, to perform a series of melt runs in high pressure gaseous atmospheres of helium and argon. (W 346) (2)

Pressure chamber =  Câmara de pressão

The tests in hydrogen were carried out in an environmental chamber at ambient temperature. It was reported that the crack growth rates in dry hydrogen were accelerated, when compared with the data obtained in air. (W 94) (3)

Environmental chamber = Câmara ambiental

(1) Four decades of electron beam development at TWI

Allan Sanderson

Paper presented at IIW ASSEMBLY Quebec, Canada, August 2006, IIW Doc. IV-913-06. 

(2) An exploratory investigation of Nd:YAG laser welding in high pressure gaseous environments

Paul Hilton, Martin Ogle, David Taylor*, TWI Ltd. * now at JCB;

Paul Lurie and Roger D Howard, BP Exploration Operating Company Ltd

Paper presented at ICALEO 2003 Conference, 13-16 October 2003, Jacksonville, Florida, USA.

(3) Review of the effect of hydrogen gas on fatigue performance of steels

Yan Hui Zhang 

Structural Integrity Technology Group

TWI Ltd

Granta Park, Great Abington, Cambridge CB21 6AL, United Kingdom

Paper presented at 29th International Conference on Offshore Mechanics and Arctic Engineering (OMAE 2010), Shanghai, China, 6-11 June 2010.

LLLLLLL

The tolerance of high brightness hybrid laser-arc butt welding to joint gap and mismatch in 6-8mm plate, whilst still producing the most stringent class of welds to ISO 13919-1:1997, is ~0.3-0.5mm and ~0.5-0.6mm, respectively, if fixed conditions are used. (W 68) (1)

Stringent class = Classe de rigor

Target failure probability and calibration with failure data- two basic factors were considered in setting the target annual failure probability levels for determining the end of life and hence the pipeline remaining lives. Firstly, the target values recommended in offshore codes, standards and other published documents [10-12] were reviewed. In most cases these are based on safety classification, which for pipelines, is mainly related to the fluids transported and the pipeline location. Typically, three safety classes of ‘low’, ‘normal’ and ‘high’ are defined. (W 402) (2)

Safety class = Classe de segurança

As Fig.9 shows, the hybrid welded simple butt joints in 8mm plate are of similar fatigue-endurance class at low stress ranges. A slight deterioration in performance was observed at higher stress ranges, yielding consequently shorter fatigue lives. (W 138) (3)

Fatigue-endurance class = Classe de resistência à fadiga

(1) Adaptively controlled high brightness laser-arc hybrid welding

Chris Allen, Steve Shi and Paul Hilton 

TWI Ltd., Granta Park, Gt. Abington, Cambridge, CB21 6AL, United Kingdom.

Paper published in ILAS Supplement to AILU magazine, Issue 63, July 2011.

(2) Probabilistic remnant life assessment of corroding pipelines within a risk-based framework

Dr A Muhammed and Mr J B Speck 

Paper presented at ASRANet International Colloquium 2002, 8 -10 July 2002, University of Glasgow, Scotland.

(3) Hybrid laser-MAG welding procedures and weld properties in 4mm, 6mm and 8mm thickness C-Mn steels

C M Allen 1 , C H J Gerritsen 2 , Y Zhang 1 , J Mawella 3

1 TWI Ltd., Granta Park, Gt. Abington, Cambridge CB21 6AL, United Kingdom.

2 Formerly at TWI Ltd., now at OCAS NV (Arcelor), Industry Research Centre, Arcelor Innovation – R&Dmp;D, OCAS NV, John Kennedylaan 3, 9060 Zelzate, Belgium.

3 Defence Procurement Agency, Ministry of Defence, Abbeywood, Bristol BS34 8JH, United Kingdom.

Paper presented at the IIW Commission IV / XII, Intermediate Meeting, Vigo, Spain, 11 – 13 April 2007.

Vacuum-fused coating displayed an inter-diffusion (mixing white) layer, where coating and substrate constituents have been mixed to a large extent. (W 420) (1)

Vacuum-fused coating = Revestimento a vácuo

The images of the cross sections clearly show layered structures of the impacted molten particles or lamella, with different amounts of coating porosity and oxide stringers typical for thermal sprayed coatings. (W 262) (2)

Sprayed coating = Revestimento pulverizado

Further salt spray exposure tests were undertaken for the coated specimens sealed with sol-gel, which displayed significant improvement in the corrosion resistance afforded by the sealed coating to the underlying aluminium substrate. (W 363) (3)

Sealed coating = Revestimento selado

(1) The corrosion behaviour of high velocity oxy-fuel (HVOF) sprayed Ni-Cr-Si-B coatings

S Shrestha and A Sturgeon, Cambridge, UK; T Hodgkiess, Glasgow, UK; A Neville, Edinburgh, UK

Paper 95 presented at ITSC 2002 International Thermal Spray Conference, 4-6 March 2002, Essen, Germany.

(2) Characteristics and electrochemical corrosion behaviour of thermal sprayed aluminium (TSA) coatings prepared by various wire thermal spray processes.

S. Shrestha and A. Sturgeon

TWI Ltd

E-mail: suman.shrestha@twi.co.uk

Paper published in EUROCORR 2005 Lisbon, Portugal, 4-8 September 2005.

(3) Some preliminary evaluations of black coating on aluminium AA2219 alloy produced by plasma electrolytic oxidation (PEO) process for space applications.

S. Shrestha (1), A. Merstallinger (2), D. Sickert (3) and B. D. Dunn (4)

(1) TWI Ltd, Cambridge, United Kingdom, 

Email: suman.shrestha@twi.co.uk 

(2) ARC Seibersdorf research GmbH, Austria, 

Email: andreas.merstallinger@arcs.ac.at 

(3) Dresden University of Technology, Germany, 

Email: Daniel.Sickert@mailbox.tu-dresden.de 

(4) European Space Agency, Noordwijk ZH, The Netherlands, 

Email: Barrie.Dunn@esa.int

Paper presented at 9th International Symposium on Materials in a Space Environment, 16-20 June 2003, ESTEC, Noordwijk, The Netherlands.

Barkston Plastics Engineering, based in Leeds, UK, produces a range of structural components from plastics. (W 243) (1)

Structural component = Componente estrutural

The three stress components acting in hoop, axial and radial directions were calculated from the obtainable, associated strain components. (W 36) (2)

Stress component = Componente de tensão

…The next generation of ultrasonic procedures can inspect the welds in critical components with reduced errors and greater confidence. (W 102) (3)

Critical component = Componente crítico

(1) Application studies using through-transmission laser welding of polymers

Marcus Warwick and Marcus Gordon 

TWI Ltd, Granta Park, Great Abington, Cambridge, CB1 6AL, UK

Paper presented at Joining Plastics 2006, London, National Physical Laboratory (NPL), 25-26 April 2006.

(2) Evaluation of residual stresses in steel-to-nickel dissimilar joints.

K. Sotoudeh, S. E. Eren, M.F. Gittos and M. Milititsky 

TWI Ltd,

Cambridge, UK..

S. Kabra and S.Y. Zhang 

ISIS Facility 

STFC Rutherford Appleton Laboratory 

Harwell Oxford, Didcot, UK.

Paper presented at OMAE 2013 – Proceedings of the ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering, Nantes, France. 9-14 June 2013.

(3) Microstructural quantification, modeling and array ultrasonics to improve the inspection of austenitic welds

Channa Nageswaran and Capucine Carpentier 

TWI Ltd

Yau Yau Tse 

University of Birmingham

Edgbaston, Birmingham, UK, B15 2TT

Paper published in Insight vol.51. no.12. Dec. 2009, pp. 600-660.

Among the materials which can be deposited by this process are tool steels, aluminium alloys, stainless steels, nickel super alloys, hard-facing materials and metal-matrix composites. (W 436) (1)

Metal-matrix composite = Compósito com matriz de metal

The process of internal bagging for thermoplastic composite consolidation, using the laser welding process to seal the bags, has been demonstrated and the technique has been shown to produce a completely closed hollow composite component. (Welding 519) (2)

Thermoplastic composite = Compósito termoplástico

Finite Element Analysis, provided under the Joining Forces Wales programme, has enabled the company to proceed with confidence in the design of its carbon-fibre composite version. (Welding 85) (3)

Carbon-fibre composite = Compósito de fibra de carbono

(1) Friction based technologies for joining and processing

W M Thomas, E D Nicholas, and S W Kallee 

TWI Ltd

Paper presented at TMS Friction Stir Welding and Processing Conference, November 2001, Indianapolis.

(2) Case Study

www.twi-global.com/…/case-studies/laser-welding-of-peek-for-inflatable-bag-manufacture-513/ – 2014-05-06.

(3) Case study

www.twi-global.com/news-events/case-studies/fea-aids-design-of-climbers-snow-safety-device-086/ – 2015-07-29.

A number of researchers have attempted to produce methods of calculating a local stress that takes account of this behaviour by assuming that the apparent increase in strength for small notches is due to the fact that the stress concentration occurs over only a small volume of material. (W 16) (1)

Stress concentration = Concentração de stress

Precise computation of hydrogen concentration (even assuming totally uniform initial distribution) from effusion rate and temperature under dynamic cooling conditions is a very challenging concept. (W 62) (2)

Hydrogen concentration = Concentração de hidrogênio

Plastic strain in ligament – in order to enable an assessment of strains in the ligament adjacent to embedded flaws, data on strain concentrations in the smaller of the two ligaments (below and above the flaw) were obtained for all cases. (W 105) (3)

Strain concentration = Concentração de tensão

(1) Estimating long-endurance fatigue strength of girth-welded pipes using local stress approach

Yanhui Zhang and Steve J Maddox 

TWI Ltd, Granta Park, Great Abington, Cambridge CB21 6AL, UK

Paper presented at Proceedings 33rd International Conference on Ocean, Offshore and Arctic Engineering (OMAE 2014) June 8-13, 2014, San Francisco, USA.

(2) Novel Control of Weld Metal Hydrogen Cracking in the Welding of Thick Steels

Joanna Nicholas and Richard Pargeter

TWI Ltd, Granta Park, Great Abington, Cambridge, CB21 6AL

Paper presented at the International Steel and Hydrogen Conference

28 September 2011.

(3) Approaches for Determining Limit Load and Reference Stress for Circumferential Embedded Flaws in Pipe Girth Welds

Mohamad J Cheaitani 

TWI Ltd Granta Park, Great Abington, Cambridge CB21 6AL, UK

Pipeline Technology Conference, Ostend, Belgium 2009.

Generally the quality of lap welds can be more difficult to optimise than butt welds, but good quality lap welds can readily be reproduced when the correct tool design, welding procedure and joint configuration is implemented. (W 158) (1)

Joint configuration = Configuração conjunta

This paper describes the influence of rotation speed; lap configuration; probe length and tool motion on fatigue performance in Friction stir welded lap joints. (W 334) (2)

Lap configuration = Configuração sobreposta

For hybrid welding the effect of the laser/arc configuration, such as laser pulling or laser pushing and the separation between the two processes, on the gap bridging capability of hybrid welding were examined. The results indicate that the hybrid laser-arc process shows very good potential for welding with both fixed and varying gaps, so much so that use of this process with adaptive on-line feedback control, to account for changing gap, is recommended. (W 259) (3)

Laser/arc configuration = Configuração do laser/arco

(1) Friction stir weld integrity and its importance to the rolling stock industry

Blignault C1, Kallee S W1, Thomas W M1, Russell M J1

Author details

1Friction and Forge Processes Department, TWI, Ltd., UK.

Paper presented at Southern African Institute of Welding (SAIW) conference, Integrity of Welded Structures in the Energy, Processing and Transport Industries in Southern Africa, Gold Reef City, 28-29 May 2008.

(2) FSW Process Variants and Mechanical Properties

by W. Thomas, D. Nicholas, D. Staines, P J Tubby and M F Gittos

TWI Ltd 

(III-1293-04)

Published on the Internet June 17, 2004 

Presented at the IIW Meeting on FSW in Nagoya 2004, Nagoya University, Japan, 9th July 2004.

(3) Laser and hybrid laser MAG welding of thick section C-MN steel

Steve Shi

Paper presented at 2005 International Forum on Welding Technologies in Energy Engineering, 21-23 September 2005, Shanghai, China.

Welding is one of the most critical operations within ship construction. When welds fail, often the whole structure fails. Fortunately, over sixty years of research and development in the field of welding has provided current ship builders with fabrication processes that are readily automated, can produce consistent welds reliably…(W 132) (1)

Ship construction = Construção naval

The allowable thickness in millimetres was equal to twice the Charpy energy in Joules at the minimum design temperature for Grade 355 steel for welded construction and punched holes; otherwise the factor was four times. (W 361) (2)

Welded construction = Construção soldada

The most common welding process used for hull construction is GSFCAW. This process deposits the largest volume of weld metal in the vessel hull. (W 317) (3)

Hull construction = Construção do casco

(1) The importance of welding quality in ship construction

P.L. Moore 

Paper presented at Analysis and design of Marine Structures 2nd International Conference on Marine Structures (MARSTRUCT 2009) March 16- 18, 2009 Lisbon, Portugal.

(2) Material selection requirements for civil structures

M H Ogle (1) , F M Burdekin (2) and I Hadley (3)

(1,3) TWI

(2) Formerly Dept of Civil and Structural Engineering, UMIST

Paper presented at Materials selection requirements for Civil Structures, 56th IIW Annual Assembly 6-11 July 2003, Bucharest, Romania.

(3) Quality requirements for an FPSO hull and marine piping fabrication

John Still, Lochead Still Associates (formerly of Amerada Hess London), Julian Speck, TWI and Marcos Pereira, TWI

OMAE-FPSO’04-0088.

Proceedings of OMAE-FPSO 2004, OMAE Specialty Symposium on FPSO Integrity, Houston, USA, 30 Aug – 2 Sept 2004.

Adaptive control is more useful in avoiding lack of fusion defects in aluminium butt joints with mismatch, but does not improve the weld root profiles achieved in those cases. (W 46) (1)

Adaptive control = Controle adaptativo

…in some cases, the plasma control obtained using a coaxial gas flow is not satisfactory as the weld penetration and quality may be adversely affected, particularly for high aspect ratio, partial penetration welds. (W 509) (2)

Plasma control = Controle de plasma

Dual and triple focus beam welding was originally intended as a porosity control mechanism, although it was found that this could also benefit plume control. (W 343) (3)

Plume control = Controle de pluma

(1) Increasing the tolerance to fit-up gap using hybrid laser-arc welding and adaptive control of welding parameters

C M Allen, P A Hilton and J Blackburn

TWI Ltd, Granta Park, Gt. Abington, Cambridge, CB21 6AL, United Kingdom

Copyright © TWI Ltd 2012

Paper presented at 37th International MATADOR Conference, Manchester, England, 25-27 July 2012.

(2) Optimisation of plasma control parameters for Nd:YAG laser welding of stainless steel enclosures

S Fisher, BNFL, Dr C A Olivier, TWI and S T Riches, TWI

Presented at 7th NOLAMP Conference (Nordic Conference in Laser Processing of Materials),

Lappeenranta, Finland, August 23-25, 1999.

(3) Dual and triple focus beam welding was originally intended as a porosity control mechanism, although it was found that this could also benefit plume control. (W 343) (3)

Laser-Vapour Interaction in High-Power cw Nd:YAG Laser Welding

J Greses, P A Hilton, TWI, Granta Park, Great Abington, Cambridge, UK; C Y Barlow, Engineering Department, University of Cambridge, Cambridge, UK; W M Steen, Material Science Department, University of Cambridge, Cambridge, UK and Laser Group, University of Liverpool, Liverpool, L69 3GH, UK

Paper 1607 presented at ICALEO 2003 Conference, 13-16 October 2003, Jacksonville, Florida, USA.

Initial studies showed that there was no good correlation between the results of non-destructive tests on the welds and their performance. It was therefore decided that there was little to be gained by a rush programme of inspection. Instead, a statistical approach was adopted. (Welding 175) (1)

Good correlation = Boa correlação

To measure directly residual stresses by digital-image correlation using hole-drilling, the deformation pattern which is governed by the residual stresses is used to affine transform the image captured after the object is deformed. If the values of trial residual stress components are properly chosen, the image after affine transformation will have a maximum similarity to the original image. (W 115) (2)

Digital-image correlation = Correlação de imagens digitais

A full comparison between Pollitt theory and the experimental detectability of real welding flaws was performed as part of this current study. The results show a strong correlation between experiment and theory. In over 89% of the cases considered, basic Pollitt theory correctly predicted the response of one or both of the radiographers. (W 511) (3)

Strong correlation = Correlação forte

(1) Motorway safety fences – welded barriers in the spotlight

Case Study

www.twi-global.com/news-events/case-studies/motorway-safety-fences-099/ – 2014-05-06.

(2) Deformation pattern based digital image correlation method and its application to residual stress measurement

Jianxin Gao* and Haixia Shang 

*Corresponding author

Paper published in Applied Optics, vol.48. issue 7, 2009. pp.1371 – 1381.

(3) The Reliability of Radiography of Thick Section Welds

I. J. Munns and C. R. A. Schneider

Presented at conference on ‘Review of Progress in Quantitative Nondestructive Evaluation’, Montreal, Canada, 26-30 July 1999.

The process of inserting a fatigue pre-crack can present difficulties, as it is important that the fatigue crack grows in a uniform fashion. If pre-cracking is performed at too high a stress intensity range then a large plastic zone can form at the pre-crack tip which may mask the behaviour of the actual material during the test. (W 17) (1)

Fatigue crack = Ruptura por fadiga

…The rate of change in the load line displacement and creep crack length at the end of the test depends on the point at which the test is interrupted. (W 29) (2)

Creep crack = Ruptura por fluência

During the tests, each replica was examined in an optical microscope to check crack initiation, or, if it had occurred, to measure the surface crack length. To determine the size of small cracks more accurately, some replicas were examined in a scanning electron microscope (SEM). (W 114) (3)

Surface crack =Ruptura na superfície

(1) The Effect of Notch Sharpness on the Fracture Toughness Determined from SENT Specimens

Philippa Moore 

TWI Ltd, Granta Park Great Abington, Cambridge, CB21 6AL, UK 

Paper presented at Proceedings of the ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering OMAE2014 June 8-13, 2014, San Francisco, California, USA. 

(2) Specimen geometry and size effects on the creep crack growth behaviour of P91 weldments

S. Maleki 

TWI Ltd

A. Mehmanparast, K. M. Nikbin 

Imperial College London

M. Yatomi 

IHI Corporation

Paper presented at 2013 ASME Pressure Vessels and Piping Conference. Paris, France, 14-18 July 2013. 

(3) Fatigue life prediction for toe ground welded joints

Yan-Hui Zhang and Stephen J Maddox

Structural Integrity Technology Group

TWI Limited

Granta Park

Great Abington

Cambridge

CB1 6AL, UK

Paper published in International Journal of Fatigue, Vol. 31, Issue 7, July 2009, 1124-1136. 

The morphology of the interface is central to the susceptibility of the fusion zone, to hydrogen-assisted cracking. (W 18) (1)

Hydrogen-assisted cracking = Rachamento assistido por hidrogênio

Welding thick walled components generates residual stresses which can be the cause of brittle fracture or corrosion cracking. (W 32) (2)

Corrosion cracking = Rachadura por corrosão

A drawback to processing at very high speeds with hybrid Nd:YAG laser/MAG processes is the propensity of the laser process to solidification cracking when welding structural steel grades. (W 355) (3)

Solidification cracking = Fissura / trinca por solidificação

(1) Fusion Zone Microstructure Associated With Embrittlement Of Subsea Dissimilar Joints.

M. F. Dodge, H. B. Dong 

Department of Engineering, University of Leicester, Leicester, UK.

M. F. Gittos, T. Mobberley 

TWI Ltd. Great Abington, Cambridge, UK

Presented at Proceedings of the 33rd International Conference on Ocean, Offshore and Arctic Engineering OMAE2014 June 8-13, 2014, San Francisco, CA, USA.

(2) Finite Element Prediction of the Residual Stresses in a Branch-Pipe Connection after Local Post-Weld Heat-Treatment

Philippe Bastid 

TWI Ltd, Granta Park, Great Abington, Cambridge CB21 6AL, UK

NAFEMS conference. July 2013.

(3) Welding of Structural Steel Components with High Power, Fibre Delivered Nd:YAG Lasers

D S Howse and C H J Gerritsen

Paper presented at 2nd International Conference on Recent Developments and Future Trends in Welding Technology, Cranfield University, UK, 3-5 September 2003.

..Currently, there are no acceptance criteria for flaws in butt fusion joints in PE pipes. (W 3) (1)

Acceptance criteria = Critérios de aceitação

When compared to the quality criteria for sub-surface porosity given in Table 1, all of the butt welds and all of the bead on plate runs made at a power of 4.8kW, plus three of the bead on plate runs made at 3.8kW, met the acceptance criteria. (W 170) (2)

Quality criteria = Critérios de qualidade

This paper aims to summarise and explain the evolution of the flaw characterisation step central to which are the interaction criteria. (W 66) (3)

Interaction criteria = Critérios de interação

(1) Short-term And Long-term Mechanical Testing To Evaluate The Effect Of Flaws In Butt Fusion Joints In Polyethylene Pipes

Mike Troughton and Amir Khamsehnezhad 

TWI Ltd, Granta Park Great Abington, Cambridge, CB21 6AL, UK

Paper presented at the ASME 2016 Pressure Vessels & Piping Division Conference, PVP2016, July 17-21, 2016, Vancouver, BC, Canada.

(2) Welding of Ti-6Al-4V with fibre delivered laser beams

Paul Hilton1 , Jonathan Blackburn2 , and Pak Chong3

1 TWI Ltd, Cambridge

2 Laser Processing Research Centre, Department of Mechanical, Aerospace and Civil Engineering, University of Manchester

3 Welding and Materials, Subsea7, Aberdeen

Paper presented at ICALEO 2007, Orlando, FL. USA, 29 Oct – 1 Nov. 2007. Paper #1607.

(3) The history of BS 7910 flaw interaction

Bostjan Bezensek

Hunting Energy Services (UK) Ltd

John Sharples 

Serco Technical Consultancy Services

Isabel Hadley, Henryk Pisarski 

TWI Ltd

Paper presented at ASME 2011 Pressure Vessels & Piping Division Conference – PVP 2011 – July 17-21 2011, Baltimore, Maryland, USA. 

The aim of the interaction criterion is to find a balance between the inherent pessimism involved with such simplifications and the evidence from experimental test data and, more recently, finite element analyses. The basis for interaction criterion used in the 1980 version of PD 6493 was a 20% increase in the stress intensity factor on the first flaw by the second flaw. (W 63) (1)

Interaction criterion = Critério de interação

A new statistical local criterion for cleavage is proposed, which expresses the necessity of maintaining a critical dynamic connectivity between micro-crack nucleation and unstable propagation in order for cleavage fracture to occur. (W 299) (2)

Local criterion = Critério local

Further research is required to produce guidance on strain concentrations in the ligament in the presence of axial misalignment and strength mismatch. Such guidance can be used to assess the possibility of ligament failure due to excessive straining. This would be a separate failure criterion to J-based fracture associated with extension of the flaw. (W 105) (3)

Failure criterion = Critério de falha

(1) > Technical Knowledge > Published Papers > The History of BS 7910 Flaw Interaction Criteria

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The History of BS 7910 Flaw Interaction Criteria

Bostjan Bezensek* 

Hunting Energy Services (UK) Ltd

Badentoy Park, Portlethen, Aberdeen AB12 4YB

John Sharples 

Serco Technical Consultancy Services,

Birchwood park, Warrington, Cheshire WA3 6GA

Isabel Hadley (TWI Ltd) 

Henryk Pisarski (TWI Ltd) 

Paper presented at ASME 2011 Pressure Vessels and Piping Division Conference, Baltimore, Maryland USA, 17-21 July 2011. Paper PVP2011-57857.

(2) A new statistical local criterion for cleavage fracture in steel. Part I – Model presentation

S R Bordet a , A D Karstensen a , D M Knowles b , C S Wiesner a ,*

a TWI, Granta Park, Great Abington, Cambridge, CB1 6AL, U.K. 

b Gracefield Research Centre, Gracefield Road, PO Box 31-310, Lower Hutt 6009, New Zealand 

* Corresponding author.

Paper published in Engineering Fracture Mechanics, vol.72. issue 3. February 2005. pp.435 – 452.

(3) Approaches for Determining Limit Load and Reference Stress for Circumferential Embedded Flaws in Pipe Girth Welds

Mohamad J Cheaitani 

TWI Ltd Granta Park, Great Abington, Cambridge CB21 6AL, UK

Pipeline Technology Conference, Ostend, Belgium 2009.

Welding conditions affect the fume formation rate and welding current is considered to be the most important parameter. (W 55) (1)

Welding current = Corrente de soldagem

In induction welding, heat is generated through Joule losses from the induced eddy currents in response to the applied alternating magnetic field. (W 20) (2)

Eddy current = Corrente parasita

A rapid increase in anodic current during the test is often associated with the initiation and propagation of localised corrosion due to the formation of pits, the presence of crevices or a breakdown of the oxide film. (W 373) (3)

Anodic current = Corrente anódica

(1) The Effect Of Metal Transfer Modes On Welding Fume Emission In MIG/MAG Welding

Eur Ing Geoff Melton 

TWI Ltd., Granta Park, Abington, Cambridge, UK.

Eighth European Conference on Joining Technology, Eurojoin 8, Pula, Croatia, 24 – 26 May 2012.

Welding current = corrente de soldagem.

In induction welding, heat is generated through Joule losses from the induced eddy currents in response to the applied alternating magnetic field. (W 20) (2)

Novel Induction Heating Technique for Joining of Carbon Fibre Composites

Chris Worrall and Roger Wise 

TWI Ltd, Granta Park Great Abington, Cambridge, CB21 6AL, UK

Paper presented at SEICO 14: 35th International Technical Conference & Forum “Low Cost Composite Processing, from Aerospace OOA to Automotive Thermoplastic”, 2014.

(2) Novel Induction Heating Technique for Joining of Carbon Fibre Composites

Chris Worrall and Roger Wise 

TWI Ltd, Granta Park Great Abington, Cambridge, CB21 6AL, UK

Paper presented at SEICO 14: 35th International Technical Conference & Forum “Low Cost Composite Processing, from Aerospace OOA to Automotive Thermoplastic”, 2014.

(3) The corrosion behaviour of HVOF sprayed stainless steel and nickel alloy coatings in artificial seawater

A J Sturgeon 

Paper No.03245 presented at CORROSION 2003, NACE Conference, 16-21 March 2003, San Diego, CA, USA.

The engineering stress-strain curves obtained from a series of specimens taken around the circumference of the pipe are shown in Figure 1. (W 31) (1)

Stress-strain curve = Curvatura da tensão-deformação

Fracture toughness test results on parent steels and welds revealed that an increase in loading rate causes a shift in the fracture toughness transition curve. (Welding 380) (2)

Transition curve = Curvatura de transição

The dispersion curves for a rail are discussed and modelling results of the variation of reflection coefficient with defect depth is presented for aBS113A type rail. (W 401) (3)

Dispersion curve = Curvatura de dispersão

(1) Flaw Tolerance of Pipelines Containing Circumferential Flaws Subjected to Axial Straining and Internal Pressure – Tests and Analyses.

H. Pisarski, S. Smith and T. London 

TWI Ltd, 

Cambridge, UK. 

Paper presented at ISOPE Conference July 2013, Anchorage, Alaska, USA.

(2) Design advice at 30 mph

Case Study

www.twi-global.com/news-events/case-studies/design-advice-at-30-mph-335/ – 2014-05-06.

(3) The application of finite element modelling to guided wave testing systems

R M Sanderson and S D Smith, TWI

Paper presented at QNDE Conference 2002, Western Washington University, 14-19 July 2002.