Publications > Zentech publications

Technical publications

Technical publications - written by Zentech personnel, or co-authored with other companies, for presentation at various international forums - include those listed below. Abstracts for some papers are included here; for a copy of the full paper please contact Zentech.

Please remember that for older papers that referenece Zencrack there may be improved facilities available in the current version of the software.


Study on application range of SIF calculation method for nozzle corner crack in pressure vessel for ASME XI code
Chao Liu [1], Guang-chen Jiao [2], Ramesh Chandwani [3], Chris Timbrell [3]
[1] School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, PR China
[2] Shanghai Hui Ce Information Technology Co., Ltd, Shanghai, PR China
[3] Zentech International Limited, London, UK
Published in: International Journal of Pressure Vessels and Piping, Volume 193, October 2021.
HTML documentAbstract

Demonstrating Structural Integrity Under Challenging Load And Material Conditions
Chris Timbrell [1], Ramesh Chandwani [1], Ma Chunlei [2]
[1] Zentech International Limited
[2] Consys Group Limited
ISSI 2018 - Nanjing, China, 2-5 November 2018.
PDF documentFull paper - PDF document PDF documentFull paper (extended version) - PDF document

A 3D Crack Evolution In Weld Metal, Base Metal And The Transitional Fusion Line Under A Mixed Fatigue Loading
Mahyar Asadi[1], Majid Tanbakuei Kashani[1], Mathew Smith[1], Chris Timbrell[2], Ramesh Chandwani[2], Arasch Rodbari[2]
[1] SKC Engineering (A division of Applus)
[2] Zentech International Limited
ESIA 14 – ISSI 2017 (Engineering Structural Integrity Assessment 14 in conjunction with the International Symposium on Structural Integrity 2017), Manchester, UK, 16-17 May 2017.
PDF documentFull paper - PDF document

Stress Intensity Factor of Nozzle Corner in Pressure Vessel Under Condition of Thermal and Mechanical Loads
Guang-chen Jiao[1], Ming Cao[2], Rui Shen[2], Zhi-jie Li[1], Chun-lei Ma[1], Chris Timbrell[3]
[1] Consys Group Limited
[2] Shanghai Nuclear Engineering Research & Design Institute
[3] Zentech International Limited
18th National Conference on Fatigue and Fracture (NCFF2016), Zhengzhou, China, April 2016.
HTML documentAbstract (English) PDF documentFull paper (Chinese) - PDF document PDF documentPresentation (Chinese) - PDF document


The Use of Fracture Mechanics for Fatigue Life Assessment
Ramesh Chandwani, Zentech International Ltd.
NAFEMS UK Seminar: Current Best Practices in Fatigue Analysis using FEA, London, UK, 16 September 2014.
PDF documentFull paper - PDF document PDF documentPresentation - PDF document

Comparing Crack Growth Testing and Simulation Results Under Thermo-Mechanical Fatigue Conditions
Chris Timbrell, Ramesh Chandwani, Zentech International Ltd., Steve Jacques, Lee Waterhouse, Andrew Wisbey, Amec Technical Services (was Serco), Steve Williams, Rolls-Royce plc
13th International Conference on Fracture, Beijing, China, 16-21 June 2013.
HTML documentAbstract       PDF documentFull paper - PDF document

Simulation of Complex 3D Non-planar Crack Propagation Using Robust Adaptive Re-meshing and Radial Basis Functions
Chris Timbrell, Angelo Maligno, Zentech International Ltd., David Stevens, BLOS International
NWC 13, Austria, 9-12 June 2013.
HTML documentAbstract       PDF documentFull paper - PDF document

A Time Dependent Crack Growth Law For High Temperature Conditions
Chris Timbrell, Ramesh Chandwani, Zentech International Ltd., Duncan MacLachlan, Steve Williams, Rolls-Royce plc
NAFEMS European Conference: Multiphysics Simulation, Frankfurt, Germany, Oct 16-17 2012.
HTML documentAbstract       PDF documentFull paper - PDF document

A numerical fracture mechanics tool to help assess the structural integrity of nuclear power plant components
Chris Timbrell, Ramesh Chandwani, Angelo Maligno, Zentech International Ltd., Charly Ma, Consys Company Limited
ISSI 2011 - Structural Integrity in Nuclear Engineering, Heifei, China, Oct 27-30 2011.
HTML documentAbstract       PDF documentFull paper - PDF document


Prediction Of Crack Growth In Bridge Roller Bearings
Nawal K. Prinja, Joseph M. Bushell, AMEC Nuclear UK Ltd., R. Chandwani, C. Timbrell, Zentech International Ltd.
NAFEMS World Congress 2009, Crete, Greece, Jun 16-19 2009.
HTML documentAbstract

Numerical Investigations Of Fatigue Crack Growth In Shafts
Angelo R Maligno, University of Nottingham, R. Chandwani, C. Timbrell, Zentech International Ltd.
NAFEMS World Congress 2009, Crete, Greece, Jun 16-19 2009.
HTML documentAbstract

Simulation Of 3D Non-Planar Crack Propagation
R. Chandwani, C. Timbrell
NAFEMS World Congress 2007, Vancouver, Canada, May 22-25 2007.
HTML documentAbstract

Crack Modelling In Power Plant Components
R. Chandwani, C. Timbrell, M. Wiehahn
International Conference On Pressure Vessels And Piping, Chennai, India, Feb 7-9 2006.
HTML documentAbstract

An FE Simulation Tool For Fracture Mechanics
R. Chandwani, C. Timbrell, M. Wiehahn
International Seminar on "Fatigue, Reliability & Performance Considerations In Design", Indian Institute of Science, Bangalore, India, Jul 14-15 2005.
HTML documentAbstract

Stress Intensity Factors For Cracked Plates Under Out-of-plane Bending
M.R. Roy, J.D.G. Sumpter, QinetiQ, Rosyth Business Park, Dunfermline, C. Timbrell, M. Wiehahn, Zentech International Ltd.
Abaqus Users' Conference, Stockholm, Sweden, May 18-20 2005.
HTML documentAbstract


3D Fracture Mechanics In Ansys
R. Chandwani, M. Wiehahn, C. Timbrell
2004 UK Ansys Conference, Stratford-upon-Avon, England, Nov 15-16 2004.
HTML documentAbstract

State Of The Art In Crack Propagation
C. Timbrell, R. Chandwani, G. Cook
Journée Scientifique 2004: Les méthodes de dimensionnement en fatigue, Centre de Compétences Matériaux & Conception (CCM&C), Fribourg, Switzerland, Oct 27 2004.
HTML documentAbstract

Residual Stress in a 3D Finite Element Fracture Mechanics Analysis
C. Timbrell, R. Chandwani
FENET Technology Workshops - Durability and Life Extension, Palma, Majorca, Mar 25-26 2004.

Failure Assessment Diagrams from 3D Finite Element Analysis
M. Wiehahn, C. Timbrell, R. Chandwani
FENET Technology Workshops - Durability and Life Extension, Palma, Majorca, Mar 25-26 2004.

Recent Developments In 3D Fatigue Crack Growth Prediction Using The Finite Element Method
C. Timbrell, R. Chandwani, M. Wiehahn, G. Cook
FENET Technology Workshops - Durability and Life Extension, Noordwijk, The Netherlands, Oct 9-10 2003.

Simulation Of Crack Propagation In Rubber
C. Timbrell, M. Wiehahn & G. Cook, Zentech International Ltd., Camberley, Surrey, UK, A.H. Muhr, TARRC/Rubber Consultants, Hertford, UK
Proceedings of the Third European Conference On Constitutive Models For Rubber, London, England, Sep 15-17 2003.
HTML documentAbstract

Using Abaqus To Analyse Fatigue Crack Growth Under The Combined Influence Of Residual Stress And Cyclic External Load
G. Cook, C. Timbrell, M. Wiehahn
Abaqus UK Users Group Conference, Warrington, England, Nov 12-13 2002.
HTML documentAbstract

The Application of 3D Finite Element Analysis to Engine Life Prediction
G. Cook, C. Timbrell, B. Browning
Symposium on "Turbine Engine and Airframe Sustainment", AeroMat 2001 - 12th Advanced Aerospace Materials & Processes Conference & Exhibition, Long Beach, CA, U.S.A., June 11-14 2001.
HTML documentAbstract

Predicting Large Scale Crack Growth In 3D Finite Element Models
B. Browning, G. Cook, C. Timbrell
Abaqus Users' Conference, Maastricht, The Netherlands, May 30 - June 1 2001.
HTML documentAbstract

3D Crack Analysis Using MSC.Marc
C.Timbrell, G.Cook, R.Chandwani
1st Northern European Technology Conference, Manchester, England, June 7-8 2000.
HTML documentAbstract

Before 2000

Design of Flexible Risers
R.Chandwani, I.Larsen
Proceedings of the "Workshop on Subsea Pipelines", COPPE/UFRJ-Federal University of Brasil, Rio de Janeiro, Brasil, December 8-9 1997.
HTML documentHTML version

3D FE Fracture Mechanics Analysis for Industrial Applications
C.Timbrell, G.Cook
Seminar on "Inelastic Finite Element Analysis", Institute of Mechanical Engineers, London, October 14 1997.
HTML document Abstract

Analysing the Effects of Integrating Riser / Mooring Line Design
P.Chakrabarti, Zentech Inc.; R.Chandwani, I.Larsen, Zentech International
OMAE'96 Conference, Florence, Italy, June 16-20 1996.
HTML documentHTML version

Rapid Application Development in PowerHouse : The Use of Iterative Development Techniques on a Large Project
Cognos North American User Conference, Ottowa, Canada, June 28-30 1995.
HTML documentHTML version

Application of Abaqus to Analysis of 3D Cracks and Fatigue Crack Growth Prediction
C.Timbrell, P.W.Claydon, G.Cook
Abaqus Users' Conference, Rhode Island, U.S.A., June 1-3 1994.
HTML documentAbstract

A Flexible Riser System for Multiple Use on Marginal Fields
R.Chandwani, D.Mahmood, I.Larsen, Zentech International; J.Neffgen, JMN & CEN Consultants, Scotland
Offshore and Arctic Operations - 16th Annual Energy Sources Technology Conference, Houston, February 1993.

Design Life Prediction of Flexible Riser Systems
G.Cook, P.W.Claydon
MARINFLEX 92 Conference on Flexible Pipes, Umbilicals, Marine Cables, London, November 1992
HTML documentHTML version

Maximum Energy Release Rate Distribution From A Generalised 3D Virtual Crack Extension Method
Engineering Fracture Mechanics, 42 (6), 1992.

A Theoretical Approach to Prediction of Service Life of Unbonded Flexible Pipes under Dynamic Loading Conditions
P.W.Claydon, G.Cook, P.A.Brown, R.Chandwani
Marine Structures Journal, October 1991.

The Design of Flexible Marine Risers in Deep and Shallow Water
D.Hoffman, HMC Offshore Corp.; N.M.Ismail, R.Nielsen, Wellstream Corp.; R.Chandwani, Zentech International Ltd.
OTC 6724, OTC Conference, Houston, May 6-9 1991.
HTML documentHTML version

Interaction between Flexible Risers and Mooring Lines within a Floating Production System
P.A.Brown, R.Chandwani, I.Larsen, Zentech Consultants; E.Dasambiagio, Petrobras/Cenpes, Rio de Janeiro, Brazil
Latin American Petroleum Engineering Conference (LAPEC), Rio de Janeiro, Oct. 1990.

Fatigue Crack Growth Prediction in 3D Crack Fronts
G.Cook, P.W.Claydon, C.Timbrell
STRUCENG & FEMCAD Conference, Grenoble, France, 1990.
HTML documentAbstract

Automatic and Adaptive Finite Element Mesh Generation For Full 3D Fatigue Crack Growth
G.Cook, C.Timbrell, P.W.Claydon
STRUCENG & FEMCAD Conference, Grenoble, France, 1990.
HTML documentAbstract

Tools For Predicting Service Life Of Dynamic Flexible Risers
R.Nielsen, R.S.Colquhoun, A.McCone, Wellstream Corp.; J.A.Witz, Univ. College London; R.Chandwani, Zentech, London
Proceedings of Intl. Conf. EUROMS-90, Norway, Aug. 1990.

Investigation into Optimised Design of Flexible Riser Systems
P.A.Brown, A.Soltanahmadi, R.Chandwani, I.Larsen
The Institute of Marine Engineers, London, Oct. 1989.

Application of the Finite Difference Technique to the Analysis of Flexible Riser Systems
P.A.Brown, A.Soltanahmadi, R.Chandwani
CIVIL-COMP 89, Civil & Structural Engineering Conference, City University, London, Sept. 1989.

Transient Analysis of Liquid Pipeline Systems During ESV Trip
M.W.Spiteri, R.Chandwani
Proceedings of Seminar on Subsea Emergency Shutdown Systems, London, 1989.

Problems Encountered in Detailed Design of Flexible Risers
P.A.Brown, A.Soltanahmadi, R.Chandwani
International Seminar on Flexible Risers, University College, London, January 1989.

SIMULUS - Subsea Design Cost and Scheduling System
E.Rasten, Seanor Eng., Oslo; E.Lorentzen, Zentech Consultants; L.Bilstad, Statoil, Stavanger
Proceedings of SUBSEA '88, International Conf., London, December 1988.

Dynamic Analysis of Secondary SubSystems
R.Chandwani, D.Mahmood, Zentech Consultants; J.Colloff & D.Daintith, British Nuclear Fuels, Risley
U.K. Proceedings of Conference held at University Of Bristol, March 1988.

Flexible Riser Dynamics Modelled in 3-Dimensions
P.A.Brown, R.Chandwani, I.Larsen
Proceedings of International Conference on Offshore Structures, City University, London, Sept. 1987.

Precast Prestressed Section Under Axial and Bending
R.Chandwani, N.D.Nathan
Journal Of Prestressed Concrete Institute, USA, May/June 1971.