Mechanics of Advanced Materials

   

 

Ian Ashcroft

Senior Lecturer

i.a.ashcroft@lboro.ac.uk
+44-1509-227535

BSc  DPhil (Oxon)  CEng   MIM


Background

Born in Lancashire. B.Sc. at Loughborough University. Graduated 1985. Graduate trainee British Steel 1985-1987. Postgraduate studies at Oxford University. Awarded D.Phil. in 1991. Postdoctoral positions in UK and Australia 1991-1995. Senior scientist at DERA Farnborough 1995-2000. Lecturer at Loughborough University since 2000.

Professional Affiliations

Chartered Engineer
Member of Institution of Materials
Member of the Society for Adhesion and Adhesives

External Activities

Consultant to MOD and Industry in the analysis of bonded joints
DERA MSS Fellow
Visiting Fellow at University of Surrey
Referee for various publications including Composites A, Journal of Strain Analysis and Journal of Adhesion.

Broad Interests and Expertise

Adhesive bonding for structural applications
Strength and lifetime prediction
Environmental degradation
Stress analysis and finite element analysis
Mechanical testing
Depth-sensing indentation

Research Interests and Activities

Design and analysis of composite joints for aerospace applications
Modelling environmental degradation in bonded joints
Lifetime prediction for joints subjected to variable amplitude fatigue
In-service monitoring of bonded joints
Indentation of viscoelastic materials
Hybrid joining techniques

School Research Groups

Publications

Conference Contributions - Refereed
Ashcroft, I.A., Gilmore, R.B. and Shaw, S.J., ''Cyclic fatigue and environmental effects with adhesively bonded joints'', AGARD Conference Proceedings 590, Bolted/Bonded Joints in Polymeric Composites, NATO, Florence, Italy, 1997, pp 14.1 - 14.9, ISBN 92-836-1046-6. SFX
Ashcroft, I.A., Hughes, D. and Shaw, S.J., ''The effect of temperature on the fatigue of bonded composite joints'', 1st World Congress on Adhesion and Related Phenomena, Dechema e. V., Garmisch-PartenKirchen, Germany, 1998, p 1.53.
Ashcroft, I.A., Digby, R. and Shaw, S.J., ''Accelerated ageing and life prediction of adhesively bonded joints'', Proc. 1st World Congress on Adhesion and Related Phenomena, Dechema e. V., Garmisch-PartenKirchen, Germany, 1998, p 285.
Ashcroft, I.A., Hughes, D. and Shaw, S.J., ''Mixed mode fatigue testing of bonded composite joints'', Structural Adhesives in Engineering V, Institute of Materials, Bristol, UK, 1998, pp 86-91, ISBN 1-86125-066-5. SFX
Ashcroft, I.A., Digby, R., Hughes, D.J., O'Gara, P. and Shaw, S., ''Durability aspects of high temperature adhesives'', Proc. 36th Annual Conference on Adhesion and Adhesives, Oxford, 1998, pp.
Ashcroft, I.A., Hughes, D.J. and Shaw, S.J., ''The effect of test environment on the fatigue life of mixed-mode composite joints'', Proc. ACS Polymeric Materials Science and Engineering Division, 81, American Chemical Society, New Orleans, USA, 1999, p 422, ISBN 0-8412-3683. SFX
Ashcroft, I.A., Nelson, L. and Shaw, S.J., ''The effect of the environment and loading rate on the mechanical properties of an epoxy film adhesive'', Proc. 7th Int. Conf. on Adhesion and Adhesives, IOM Communications, Cambridge, UK, 1999, pp 211-216.
Ashcroft, I.A., Hughes, D.J. and Shaw, S.J., ''Analysis methods for the design of bonded composite joints'', Proc. 7th Int. Conf. on Adhesion and Adhesives, IOM Communications, Cambridge, UK, 1999, pp 277-282.
Ashcroft, I.A., Digby, R.P. and Shaw, S.J., ''The effect of environment on the performance of bonded composite joints'', I.Mech.E. Conf. Trans. Joining and Repair of Plastics and Composites, Professional Engineering Publishing, London, UK, 1999, pp 73-85, ISBN 1 86058 198 6. SFX
Ashcroft, I.A., Abdel Wahab, M.M., Crocombe, A.D., Hughes, D.J. and Shaw, S.J., ''Adhesive bonding of CFRP for aerospace applications'', ECCM9: Proceedings of 9th European Conference on Composite Materials, IOM Communications Ltd, Brighton, UK, 2000, pp, [CD-ROM].
Abdel Wahab, M.M., Ashcroft, I.A., Crocombe, A.D., Hughes, D.J. and Shaw, S.J., ''Prediction of fatigue strength of adhesively bonded composite joints in hostile environment using a fracture mechanics approach'', Proc. 4th International Conference on Modern Practice in Stress and Vibration Analysis, Nottingham, UK, 2000, pp 297-307.
Loh, W.K., Crocombe, A.D., Abdel Wahab, M.M., Watts, J.F. and Ashcroft, I.A., ''Investigating the degradation of an epoxy-steel interphase'', Proc. 6th International Conference on Structural Adhesives in Engineering, IOM Communications Ltd, Bristol, UK, 2001, pp 107-110.
Crocombe, A.D., Ong, C.Y. and Ashcroft, I.A., ''Measurement of fatigue crack initiation in adhesive bonds'', Proc. 6th International Conference on Structural Adhesives in Engineering, IOM Communications Ltd, Bristol, UK, 2001, pp 149-152.
Abdel Wahab, M.M., Ashcroft, I.A., Crocombe, A.D., Shaw, S.J. and Loh, W.K., ''A damage model for fatigue crack initiation threshold prediction in adhesively bonded joints'', Proc. 6th International Conference on Structural Adhesives in Engineering, IOM Communications Ltd, Bristol, UK, 2001, pp 187-190.
Erpolat, S., Ashcroft, I.A. and Crocombe, A.D., ''Variable amplitude fatigue loading of adhesively bonded joints'', Proc. 6th International Conference on Structural Adhesives in Engineering, IOM Communications Ltd, Bristol, UK, 2001, pp 215-220.
Ashcroft, I.A. and Shaw, S.J., ''The effect of temperature on the mode I fracture of CFRP joints tested quasi-statically and in fatigue'', Proc. 6th International Conference on Structural Adhesives in Engineering, IOM Communications Ltd, Bristol, UK, 2001, pp 97-102.
Abdel Wahab, M.M. and Ashcroft, I.A., ''Failure Prediction using FEA and Analytical Solutions for Adhesively Bonded Composite Beams'', Proc. Euradh 2002/Adhesion'02, IOM Communications Ltd, Glasgow, UK, 2002, pp 137-140.
Zheng, S. and Ashcroft, I.A., ''Nano-scale Mechanical Characterization of Adhesives'', Proc. Euradh 2002/Adhesion'02, IOM Communications Ltd, Glasgow, UK, 2002, pp 153-156.
Erpolat, S., Ashcroft, I.A. and Crocombe, A.D., ''Variable Amplitude Fatigue of Bonded DCB Joints'', Proc. Euradh 2002/Adhesion'02, IOM Communications Ltd, Glasgow, UK, 2002, pp 185-189.
Abdel-Wahab, M.M., Ashcroft, I.A. and Crocombe, A.D., ''Crack Growth in Adhesively Bonded Carbon Fibre Composite Joints Subjected to Fatigue and Creep'', Proc. Euradh 2002/Adhesion'02, IOM Communications Ltd, Glasgow, UK, 2002, pp 190-193.
Abdel-Wahab, M.M., Ashcroft, I.A. and Crocombe, A.D., ''Fatigue Lifetime Prediction in Composite Bonded Joints'', Proc. Euradh 2002/Adhesion'02, IOM Communications Ltd, Glasgow, UK, 2002, pp 198-201.
Loh, W.K., Crocombe, A.D., Abdel Wahab, M.M. and Ashcroft, I.A., ''Progressive Damage Modeling as a Predictive Tool for Environmental Degradation'', Proc. Euradh 2002/Adhesion'02, IOM Communications Ltd, Glasgow, UK, 2002, pp 62-65.
Erpolat, S., Ashcroft, I.A., Crocombe, A.D. and Abdel--Wahab, M.M., ''On the Analytical Determination of Strain Energy Release Rate in Bonded DCB Joints'', Proc. 26th Annual Meeting of the Adhesion Society, Ed. G.L. Anderson, Pub. The Adhesion Society, Myrtle Beach, S.C., U.S.A., 2003, pp 246-247, ISSN 1086-9506. SFX
Erpolat, S., Ashcroft, I.A., Crocombe, A.D. and Abdel-Wahab, M.M., ''An Investigation of Crack Growth Acceleration in Bonded Joints Subjected to Variable Amplitude Fatigue Loading'', Proc. 26th Annual Meeting of the Adhesion Society, Ed. G.L. Anderson, Publ. The Adhesion Society, Myrtle Beach, S.C., U.S.A., 2003, pp 74-76, ISSN 1086-9506. SFX
Yu, Y., Ashcroft, I.A. and Swallowe, G,, ''An Experimental Investigation of Residual Stresses in Epoxy-Steel Samples'', Proc. 7th International Conference on Structural Adhesives in Engineering, IOM Communications Ltd, Bristol, UK, 2004, pp 141-144.
Crocombe, A.D., Abdel-Wahab, M.M. and Ashcroft, I.A., ''Modelling the Evolution of Fatigue Cracks in Adhesively Bonded Joints'', Proc. 7th International Conference on Structural Adhesives in Engineering, IOM Communications Ltd., Bristol, UK, 2004, pp 113-117.
Al-Ghamdi, A.H., Ashcroft, I.A., Crocombe, A,D, and Abdel-Wahab, M.M., ''Creep and Fatigue Crack Growth in DCB Joints'', Proc. 7th International Conference on Structural Adhesives in Engineering, IOM Communications Ltd., Bristol, UK, 2004, pp 22-25.
Crocombe, A.D., Loh, W.K., Hua, Y.X., Abdel-Wahab, M.M. and Ashcroft, I.A., ''Progressive Damage Modeling of Environmentally Degraded Adhesively Bonded Lap Joints'', Proc. 7th International Conference on Structural Adhesives in Engineering, IOM Communications Ltd., Bristol, UK, 2004, pp 72-75.
Ashcroft, I.A., ''Depth Sensing Indentation of Epoxy Adhesives'', Proc. 27th Annual Meeting of the Adhesion Society, M.K. Chaudhury (ed), The Adhesion Society, Wilmington, N.C., U.S.A., 2004, pp 36-38, ISSN 1086-9506. SFX
Ashcroft, I.A., ''Fatigue of Adhesively Bonded Joints'', Proc. 27th Annual Meeting of the Adhesion Society, M.K. Chaudhury (ed), The Adhesion Society, Wilmington, N.C., U.S.A., 2004, pp 416-418, ISSN 1086-9506. SFX
Liljedahl, C.D.M., Crocombe, A.D., Wahab, M.A. and Ashcroft, I.A., ''The effect of adhesive joint residual stresses on the predicitve modelling of environmental degradation'', Proceedings of the 7th European Adhesion Conference, Freiburg, Dechema e.V., 2004, pp. 161-166.
Crocombe, A.D., Wahab, M.A. and Ashcroft, I.A., ''Modelling the evolution of fatigue cracks in adhesively bonded joints'', Proceedings of the 7th European Adhesion Conference, Freiburg, Dechema e.V., 2004, pp. 421-426.
Jumbo, F., Ashcroft, I.A., Crocombe, A.D. and Wahab, M.A., ''The analysis of thermal residual stresses in adhesively bonded joints'', Proceeding of the 7th European Adhesion Conference, Freiburg, Dechema e.V., 2004, pp. 532-537.
Liljedahl, C.D.M., Crocombe, A.D., Wahab, M.A., Clough, A.S. and Ashcroft, I.A., ''Interfacial diffusion in adhesively bonded joints'', Proceedings of the 7th European Adhesion Conference, Freiburg, Dechema e.V., 2004, pp. 552-557.
Ashcroft, I.A., Williams, K. and Primartomo, A., ''Laser Transformation Hardening Using Customized Laser Beam Intensity Profiles'', Proceedings of the 1st Int. Pacific International Conference on Applications of Lasers & Optics, LMP-LSIII 29 - 34, Melbourne, Australia, April 2004, pp 29-43, ISBN 0-912035-76-5. SFX
Ruiz, P.D., Yu, Y., Erpolat, S., Huntley, J.M., Swallowe, G.M. and Ashcroft, I.A., ''Numerical and experimental investigation of 3-dimensional strains in adhesively bonded joints'', Proceedings of ICEM12, 12th International Conference on Experimental Mechanics, Politecnico di Bari, Italy, August 2004, pp 190-195.
Lijedahl, C.D.M., Crocombe, A.D., Wahab, M.A. and Ashcroft, I.A., ''The modelling of interfacial degradation in bonded joint durability'', Proceedings of the 9th International Conference on the Sci. and Technol. of Adhesives, IOM Communications, Oxford, 2005, pp. 45-48, ISBN: 1-86125-164-5. SFX
Ashcroft, I.A., Al-Ghamdi, A.H., Crocombe, A.D. and Wahab, M.A., ''Creep-Fatigue Interactions and the Effect of Frequency on Crack Growth in Adhesively Bonded Joints'', Proceedings of the 9th International Conference on the Sci. and Technol. of Adhesives, IOM Communications, Oxford, UK, 2005, pp. 110-113, ISBN: 1-86125-164-5. SFX
Jumbo, F., Ashcroft, I.A., Crocombe, A.D. and Wahab, M.A., ''Modelling of hygro-thermal residual stresses in adhesively bonded joints'', Proceedings of the 9th International Conference on the Sci. and Technol. of Adhesives, IOM Communications, Oxford, UK, 2005, pp. 138-142, ISBN: 1-8125-164-5. SFX
Crocombe, A.D., Wahab, M.A. and Ashcroft, I.A., ''Characterising adhesive joint fatigue damage evolution using multiple backface strain guages'', Proceedings of the 28th Annual Meeting of the Adhesion Society, K. Vorvolakos, The Adhesion Society, Alabama, USA, 2005, pp. 211-213.
Jumbo, F., Ashcroft, I.A., Crocombe, A.D. and Wahab, M.A., ''Investigation of hygrothermal residual stresses in adhesively bonded joints'', Proceedings of the 28th Annual Meeting of the Adhesion Society, K. Vorvolakos, The Adhesion Society, Alabama, USA, 2005, pp. 250.
Crocombe, A.D., Liljedahl, C.D., Hua, Y., Wahab, M.A. and Ashcroft, I.A., ''Extending the application of progressive damage durability modelling of adhesively bonded joints'', Proceedings of the 28th Annual Meeting of the Adhesion Society, K. Vorvolakos, The Adhesion Society, Alabama, USA, 2005, pp. 339-341.

Conference Contributions - Other
Ashcroft, I.A., Digby, R.P., Hughes, D., O'Gara, P. and Shaw, S.J., ''Durability aspects of high temperature adhesives'', Institute of Materials One Day Symposium on Stability of Adhesives, London, December 1998, pp.
Ashcroft, I.A. and Hughes, D.J., ''Finite element analysis of adhesively bonded composite joints'', FEA Composite Workshop, Birmingham, July 1999, pp.
Ashcroft, I.A., Nelson, L.J. and Shaw, S.J., ''Effect of the environment and loading rate on the mechanical properties of an epoxy film adhesive'', Proc. 6th Int. Conf. Adhesion and Surface Analysis, Loughborough University, 2000, pp 91-94.
Ashcroft, I.A., Hughes, D.J. and Shaw, S.J., ''Analysis methods for the design of bonded composite joints'', Proc. 6th Int. Conf. Adhesion and Surface Analysis, Loughborough University, 2000, pp 95-98.
Loh, W.K., Crocombe, A.D., Watts, J.F., Abdel-Wahab, M.M. and Ashcroft, I.A., ''The Effect of Moisture on an Epoxy-Steel Interphase'', Proc. 7th Inst. Conf. Adhesion and Surface Analysis, Loughborough University, Loughborough, UK, 2002, pp 1-4.
Ashcroft, I.A. and Zheng, S., ''Depth Sensing Indentation of Polymers'', Proc. 7th Int. Conf. Adhesion and Surface Analysis, Loughborough University, Loughborough, UK, 2002, pp 2-5.

Edited Works: Contributions
Ashcroft, I.A., ''Adhesive Bonding, Chaper 10: Fatigue'', in Science Technology and Applications, R.D. Adams, Woodhead Publishing, Cambridge, 2005, pp. 209-239, ISBN: 18557-37418. SFX

Journal Papers - Academic Journals
Ashcroft, I.A. and Spinks, G.M., ''Method of monitoring water absorption in polymers using a depth sensing indentation system'', J. Materials Research, 11(2), 1996, pp 529-536.
Abdel Wahab, M.M., Ashcroft, I.A., Crocombe, A.D., Hughes, D.J. and Shaw, S.J., ''Prediction of fatigue threshold in adhesively bonded joints using damage mechanics and fracture mechanics'', Journal of Adhesion Science and Technology, 15, 2000, pp 763-782.
Ashcroft, I.A., Hughes, D.J. and Shaw, S.J., ''Adhesive Bonding of Composite Materials'', Assembly Automation, 20, 2000, pp 150-161, ISSN 0144-5154. SFX
Ashcroft, I.A., Hughes, D.J. and Shaw, S.J., ''Mode I fracture of epoxy bonded composite joints: Part 1: Quasi-static loading'', International Journal of Adhesion and Adhesives, 21, 2001, pp 87-99, ISSN 0143-7496. SFX
Ashcroft, I.A., Abdel-Wahab, M.M. and Crocombe, A.D., ''Predicting Degradation in Bonded Composite Joints Using a Semi-Coupled FEA Method'', Mech. Adv. Matls. & Structs., 10, 2003, pp 227-248.
Abdel-Wahab, M.M., Ashcroft, I.A. and Crocombe, A.D., ''Lifetime Production for Fatigue Damage in Bonded Joints'', Key Engineering Materials, 245, 2003, pp 43-50.
Ashcroft, I.A., Erpolat, S. and Tyrer, J.R., ''Damage Assessment in Bonded Joints'', Key Engineering Materials, 245, 2003, pp 501-508.
Abdel-Wahab, M.M., Ashcroft, I.A., Crocombe, A.D. and Smith, P.A., ''Fatigue Crack Propagation in Adhesively Bonded Joints'', Key Engineering Materials, 251, 2003, pp 229-234.
Loh, W.K., Crocombe, A.D., Abdel-Wahab, M.M. and Ashcroft, I.A., ''Modelling Interfacial Degradation Using Interfacial Rupture Elements'', J. Adhesion, 79, 2003, pp 1135-1160.
Al-Ghamdi, A.H., Ashcroft, I.A., Crocombe, A.D. and Abdel-Wahab, M.M., ''Crack Growth in Adhesively Bonded Joints Subjected to Variable Frequency Fatigue Loading'', Adhesion, 79, 2003, pp 1161-1182.
Erpolat, S., Ashcroft, I.A., Crocombe, A.D. and Abdel-Wahab, M.M., ''A Study of Adhesively Bonded Joints Subjected to Constant and Variable Amplitude Fatigue'', Int. J. Fatigue, 26, 2004, pp 1189-1196.
Erpolat, S., Ashcroft, I.A., Crocombe, A.D. and Abdel-Wahab, M.M., ''Fatigue Crack Growth Acceleration due to Intermittent Overstressing in Adhesively Bonded CFRP Joints'', Comp.A., 35, 2004, pp 1175-1183.
Abdel-Wahab, M.M., Ashcroft, I.A. and Crocombe, A.D., ''A Comparison of Failure Prediction Methods for an Adhesively Bonded Composite Beam'', J. Strain Analysis, 39, 2004, pp 173-185.
Ashcroft, I.A., ''A simple model to predict crack growth in bonded joints and laminates under variable amplitude fatigue'', J. Strain Analysis, 39, 2004, pp 707 - 716, ISSN 0309-3247. SFX
Erpolat, S., Ashcroft, I.A., Crocombe, A. and Abdel-Wahab, M., ''On the Analytical Determination of Strain Energy Release Rate in Bonded DCB Joints'', Eng. Fract. Mech., 71, 2004, pp 1393-1401.
Abdel-Wahab, M.M., Ashcroft, I.A., Crocombe, A.D. and Smith, P.A., ''Finite Element Prediction of Fatigue Crack Propagation Lifetime in Composite Bonded Joints'', Composites, Part A35, 2004, pp 213-222.
Liljedahl, C.D.M., Crocombe, A.D., Wahab, M.A. and Ashcroft, I.A., ''The effect of residual strains on the progressive damage modeling of environmentally degraded joints'', J. Adhesion Sci. Tech., 19, 2005, pp. 525-548.
Loh, W.K., Crocombe, A.D., Abdel Wahab, M.M. and Ashcroft, I.A., ''Modelling anomalous moisture uptake, swelling and thermal characteristics of a rubber toughened epoxy'', International Journal of Adhesion & Adhesives, 25, 2005, pp 1-12, ISSN 0143-7496. SFX
Zheng, S. and Ashcroft, I.A., ''A depth sensing indentation study of adhesive joints'', International Journal of Adhesion & Adhesives, 25, 2005, pp 67-76, ISSN 0143-7496. SFX
Crocombe, A.D., Hua, Y.X., Loh, W.K., Wahab, M.A. and Ashcroft, I.A., ''Predicting the residual strength for environmentally degraded adhesive lap joints'', International Journal of Adhesion & Adhesives, 26, August 2005, pp. 325-336.
Yu, Y., Ashcroft, I.A. and Swallowe, G., ''An experimental investigation of residual stresses in an epoxy-steel laminate'', Int J. Adhesion & Adhesives, 26, 2006, pp. 511-519.
Hua, Y., Crocombe, A.D., Wahab, M.A. and Ashcroft, I.A., ''Modelling environmental degradation in EA9321-bonded joints using a progression damage failure model'', Journal of Adhesion, 82, February 2006, pp. 135-160.

Ashcroft, I.A., Abdel-Wahab, M.M., Crocombe, A.D., Hughes, D.J. and Shaw, S.J., ''The effect of environment on the fatigue of bonded composite joints. Part 1: testing and fractography (Published electronically 27 Nov 2000)'', Composites: Part A, 32(1), 2001, pp 45-58.
Abdel Wahab, M.M., Ashcroft, I.A., Crocombe, A.D., Hughes, D.J. and Shaw, S.J., ''The effect of environment on the fatigue of bonded composite joints. Part 2: fatigue threshold prediction (Published electronically 27 Nov 2000)'', Composites: Part A, 32(1), 2001, pp 59-69.
Ashcroft, I.A., Digby, R.P. and Shaw, S.J., ''A comparison of laboratory conditioned and naturally weathered bonded joints'', Journal of Adhesion, 75, 2001, pp 175-202.
Ashcroft, I.A., Abdel Wahab, M.M., Crocombe, A.D., Hughes, D.J. and Shaw, S.J., ''Effect of temperature on the quasi-static strength and fatigue resistance of bonded composite double lap joints'', Journal of Adhesion, 75, 2001, pp 61-88.
Abdel-Wahab, M.M., Ashcroft, I.A., Crocombe, A.D. and Shaw, S.J., ''Diffusion of Moisture in Adhesively Bonded Joints'', J. Adhesion, 77, 2001, pp 43-80.
Loh, W.K., Crocombe, A.D., Abdel-Wahab, M.M., Watts, J.F. and Ashcroft, I.A., ''The effect of moisture degradation on the failure locus and fracture energy of an epoxy-steel interface'', J.Adhesion Science and Technology, 16, 2002, pp 1407-1429.
Ashcroft, I.A. and Shaw, S.J, ''Mode I Fracture of Epoxy Bonded Composite Joints, Part 2: Fatigue Loading'', Int. J. Adhesion and Adhesives, 22, 2002, pp 151-167.
Abdel-Wahab, M.M., Ashcroft, I.A., Crocombe, A.D. and Smith, P.A., ''Numerical Prediction of Fatigue Crack Propagation Lifetime in Adhesively Bonded Structures'', International Journal of Fatigue, 24(6), 2002, pp 705-709.
Loh, W.K., Crocombe, A.D., Abdel-Wahab, M.M. and Ashcroft, I.A., ''Environmental degradation of the interfacial fracture energy in an adhesively bonded joint'', Eng. Fract. Mech.,, 69, 2002, pp 2113-2128.
Crocombe, A.D., Ong, A.D., Chan, C.Y., Abdel-Wahab, M.M. and Ashcroft, I.A., ''Investigating fatigue damage evolution in adhesively bonded structures using backface strain measurement'', J. Adhesion, 78, 2002, pp 745-778.