Stavros for RReport CU

Dr Stavros Syngellakis is Adjunct Professor of Materials and Structures at the Wessex Institute of Technology (WIT), Ashurst, Southampton, UK.

Major contributions to WIT activities
Dr Syngellakis served as an external member of the joint WIT/University of Wales Research Committee from 1995 to 2011 and has been a member of WIT Board of Directors since 2009.

Short courses
Lectures in Continuum Mechanics, Mechanics of Solids, Offshore Collisions, Finite Element Method.

Conferences
Contributions as author, co-author, session chair and member of the International Scientific & Advisory Committee to conferences on Boundary Element Method, Computational Methods & Experimental Measurements, Design in Nature, Heat Transfer, Tribology & Design, Fluid Structure Interaction, Surface Effects & Contact Mechanics, Material Characterisation, Structures under Shock & Impact.

Journal editing
International Journal of Computational Methods and Experimental Measurements (member of editorial board)
International Journal of Energy Production and Management (co-editor)

Book editing
Editor of 9 volumes comprising articles from the Transactions of Wessex Institute on special topics in the areas of Earthquake Engineering, Blast & Impact, Heritage Structures and Renewable Energy.

Summary of significant personal achievements in research and scholarship

Research work can be broadly described as mathematical modelling applied to a wide range of engineering applications of solids and structures. The analytical work included
• the application of rigorous mathematical reasoning for the generation of theoretical solutions from first principles;
• formulations, algorithm development and computer programming for numerical analysis using the boundary element method (BEM) and the transfer matrix method (TMM);
• advanced finite element (FE) simulations based on general purpose codes for the assessment and characterisation of complex material or structural behaviour under conditions leading to failure.
In particular, personal research has led to
• a new, validated and widely used theory for piezoelectric plate vibrations1,2,3;
• the discovery of a new buckling mode for stiffened cylindrical shells and insight into their respective post-buckling behaviour4,5;
• new, efficient TMM-based formulations for analysing material non-linearity, stability and dynamics of high-rise structures incorporating shear walls6,7,8,9,10;
• greater understanding of the intensity and criticality of thermal stresses arising during solid plug-forming by freezing in fluid-transporting pipes11,12;
• new BEM-based algorithms and codes for analysing flexure as well as linear and non-linear buckling of isotropic and anisotropic plates13,14,15,16,17;
• a new BEM formulation for the coupled flexure-extension analysis of laminated plates18
• reliable assessment of the stiffness characteristics of ankle foot orthoses based on experimentally validated FE simulations19 ;
• improved elasto-plastic characterisation methodology for steels and coatings based on indentation experiments20 ,21 ,22 ,23 ;
• a new approach, based on metamodelling, to the mechanical characterisation of composites from dynamic test data24 ;
• new BEM formulations for analysing the non-linear and fracture behaviour of polymers25,26,27 ;
• greater insight into the mechanical behaviour and fatigue performance of aluminium alloys used in plain bearing linings with outcomes of direct relevance to design practices28,29 ,30 ,31 ,32 ,33 ,34 ,35 .
• the determination of stress amplification in narrow zones produced by cavities36 
• a new approach to special cases of longitudinal pressurised tube buckling37 
Critical complementary role in investigating
• numerical solution issues and strategies for problems governed by the Laplace equation (ill-posed problems, conformal mapping)38 ,39 
• the response of offshore and defense structures to impulsive loads40 ,41 ,42 ;
• the ‘convolver’ effect in non-linear piezoelectric surface wave propagation43 ;
• piezo-optical coupling in optical fibre pressure sensors44 ;
• predictive models for the stiffness and strength of metal matrix composites45 ;
• the role of roughness and plasticity in fatigue crack closure46 
• the stiffness and strength of welded joints47 .
• numerical modelling of indentation fracture of brittle materials48 
• high strain rate deformation of composites49

Supervision of 20 PhD theses to completion

External examiner of advanced degrees for NCAA, Portsmouth, Warwick, Wales, London

Education

Diploma in Civil Engineering, National Technical University of Athens
Master of Science in Engineering, Princeton University
Doctor of Philosophy, Princeton University

[1] Lee, P.C.Y., Syngellakis, S. and Hou, J.P. A two‑dimensional theory for high‑frequency vibrations of piezoelectric crystal plates with or without electrodes. J. Appl. Phys., 61(4), 1987, 1249‑1262.

[2]Syngellakis, S. and Lee, P. C. Y. Piezoelectric wave dispersion curves for infinite anisotropic plates. Journal of Applied Physics, 73(11), 1993, 7152-7161.

[3] Lee, P.C.Y., Edwards, N. P., Lin, W.-S. and Syngellakis, S. Second-order theories for extensional vibrations of piezoelectric crystal plates and strips. IEEE Trans. Ultras. Ferroel. Freq. Control, 49(11), 2002, 1497‑1506.

[4] Syngellakis, S. and Walker, A.C. Elastic local buckling of longitudinally stiffened cylinders. In: T.H. Richards and P. Stanley eds  Stability problems in Engineering Structures and Components, Essex, Applied Science Publishers, 1979, 159-178.

[5] Syngellakis, S. and Walker, A.C. Elastic buckling of cylinders with widely spaced stiffeners. In: W.T. Koiter and G.K. Mikhailov eds  Theory of Shells, Amsterdam, North Holland, 1980, 553-574.

[6] Syngellakis, S. and Papoulia, K.D. A transfer matrix approach to free vibrations of coupled shear walls. Engng Structures, 9(4), 1987, 265‑271.

[7] Syngellakis, S. and Akintilo, I.A. Nonlinear dynamic analysis of coupled shear walls by the transfer matrix method. J. Struct. Engng, ASCE, 117(4), 1991, 1003-1016.

[8] Syngellakis, S. and Younes, I. The transfer matrix method applied to frame‑shear wall systems. Computers and Structures, 41(2), 1991, 197-206.

[9] Syngellakis, S. and Chan, A. K. L. Free vibrations of coupled walls by transfer matrices and finite element modelling of joints. Computers and Structures, 44(6), 1992, 1239-1247.

[10] Syngellakis, S. and Kameshki, E. S. Elastic critical loads for plane frames by the transfer matrix method. J. of Structural Engineering, ASCE, 120(4), 1994, 1140-1157.

[11] Syngellakis, S., Keary, A. C. and Bowen, R. J. On the prediction of stresses in pipes caused by ice plug formation. Proc. IMechE Part E, J. Process Mech. Eng., 210, 1996, 151-158.

[12] Keary, A., Syngellakis, S. and Bowen, R. J. Experimental and analytical study of thermal stresses during pipe freezing. Proc. IMechE Part E, J. Process Mech. Engng., 215, 2001, 63-78.

[13] Syngellakis, S. and Kang, M. A boundary element solution to the plate buckling problem. Engng Analysis, 4(2), 1987, 75‑81.

[14] Elzein, A. and Syngellakis, S. Dual reciprocity in boundary element formulations of the plate buckling problem. Engineering Analysis with Boundary Elements, 9(2), 1992, 175-184.

[15]Syngellakis, S. and Bai, C.-X. On the application of the boundary element method to plate-half space interaction. Engineering Analysis with Boundary Elements, 12(2), 1993, 119-125.

[16] Syngellakis, S. and Elzein, A. Plate buckling loads by the boundary element method. Int. J. for Numerical Methods in Engineering, 37(10), 1994, 1763-1778.

[17] Syngellakis, S. and Cherukunnath, N. Boundary element analysis of symmetrically laminated plates.  Engineering Analysis with Boundary Elements, 28, 2004, 1005-1016.

[18] Syngellakis, S. Stability analysis for laminates with general anisotropy using boundary elements. Boundary Elements and other Mesh Reduction Methods XXXV (35th International Conference on Boundary Elements and other Mesh Reduction Methods), C. A. Brebbia and A. H.-D. Cheng, eds, 2013, WIT Press, Southampton, 133-144.

[19] Syngellakis, S., Arnold, M. A. and Rassoulian, H. Assessment of the non-linear behaviour of plastic ankle foot orthoses by the finite element method. Proc. IMechE Part H, J. Engng. Medicine, 214, 2000, 527-539.

[20] De Fazio, L., Syngellakis, S., Wood, R. J. K., Fugiuele, F. and Sciume, G. Nanoindentation of CVD diamond: comparison of an FE model with analytical and experimental data. Diamond and Related Materials, 10, 2001, 765-769.

[21] Liu, J., Christensen, S. W., Reed, P. A. S. and Syngellakis, S. Elastic-plastic characterisation of aluminium bearing alloys. Aluminium Alloys: Their Physical and Mechanical Properties (Proc. ICAA-8), P. J. Gregson and S. J. Harris, eds, Mater. Sci. Forum, 2002, 396-402, 1091-1096.

[22] Habbab, H., Mellor, B. G. and Syngellakis, S. Post-yield characterisation of metals with significant pile up through spherical indentations. Acta. Mater., 54, 2006, 1965-1973.

[23]Syngellakis, S. and Summerfield, O. C. Vickers micro-indentation for the elasto-plastic characterisation of thin layers. Surface Effects and Contact Mechanics XI, WIT Transactions on Engineering Sciences, Vol. 78, J. Th. M. De Hosson and C. A. Brebbia, eds, 2013, WIT Press, Southampton, 157-168.

[24] Setiawan, R., Syngellakis, S. and Hill, M. A metamodelling approach to mechanical characterisation of anisotropic plates. Journal of Composite Materials, 43(21), 2009, 2333-2349, doi:10.1177/0021998308099008.

[25] Syngellakis, S. and Wu, J. Evaluation of various schemes for quasi-static boundary element analysis of polymers. Engineering Analysis with Boundary Elements, 28, 2004, 733-745.

[26] Syngellakis, S. and Wu, J. Evaluation of polymer fracture parameters by the boundary element method. Engineering Fracture Mechanics, 75(5), 2008, 1251-1265.

[27] Syngellakis, S. and Wu, J. Nonlinear viscoelastic fracture mechanics using boundary elements. Key Engineering Materials, 454(2011) 2010, 137-148.

[28]Joyce, M. R., Reed, P. A. S. and Syngellakis, S. Numerical modelling of crack shielding and deflection in plain bearing materials, Mat. Sci. Eng A, 342, 2003, 11-22.

[29] Mwanza, M.C., Joyce, M. R., Lee, K. K., Syngellakis, S. and Reed, P. A. S. Microstructural  characterisation of fatigue crack initiation in Al based plain bearing  alloys. Int. J. Fatigue, 25, 2003, 1135-1145.

[30] Joyce, M.R., Lee, K.K., Syngellakis, S. and Reed, P.A.S. Quantitative assessment of preferential fatigue initiation sites in a multi-phase aluminium alloy. Fat. Fract. Engng Mater. Struct., 27, 2004, 1025-1036.

[31] Ali, M.S., Reed, P. A. S. and Syngellakis, S. Comparison of fatigue performance of HVOF spray coated and conventional roll bonded aluminium bearing alloys. Mater. Sci. Technol, 25(5), 2009, 575-581.

[32] Burke-Veliz, A., Reed, P. A. S. and Syngellakis, S. A numerical study of crack shielding and deflection under extensive plasticity. Engineering Fracture Mechanics, 76(9), 2009, 1345-1356.

[33] Burke-Veliz, A., Reed, P. A. S. and Syngellakis, S. Assessment of three-dimensional crack growth in ductile layered material systems. Engineering Fracture Mechanics, 88, 2012, 15-27.

[34] Syngellakis, S., Ali, M. S. and Reed, P. A. S., Microstructural modelling of fatigue initiation in aluminium bearing alloys, International Journal of Computational Methods and Experimental Measurements, 1(3), 2013, 249-264.

[35]Syngellakis, S. and Burke-Veliz, A. Residual and cyclic stresses in automotive plain bearings. Tribology and Design II, M. Hadfield and C.A. Brebbia, eds, WIT Press, Southampton, 189-200.

[36]Syngellakis, S. Stress concentrations in narrow zones produced by cavities, Theoretical & Applied Mechanics, 39(1), 2012, 71-97.

[37]Syngellakis, S. Longitudinal buckling of slender pressurised tubes. Fluid Structure Interaction VII, C. A. Brebbia and G. R. Rodriguez, eds, 2013, WIT Press, Southampton, 133-144.

[38] Li, B. C. and Syngellakis, S. On improperly posed boundary value problems and their approximate solution. IMA Journal of Applied Mathematics, 55, 1995, 85-95.

[39] Li, B. C. and Syngellakis, S. Numerical conformal mapping based on the generalised conjugation operator. Mathematics of Computation, 67(222), 1998, 619-639.

[40] Syngellakis, S. and Balaji, R. Tension leg platform response to impact forces. Marine Structures, 2(2), 1989, 151‑171.

[41] Zintilis, G.M., Reynolds, P. and Syngellakis, S. Design of buried blast-resistant RC structures. In: J.L. Clarke, F.K. Garas and G.S.T. Armer, eds  Structural Design for Hazardous Loads, London, E & F N Spon, 1992, 216-226.

[42]Syngellakis, S. Simple models for penetration of thick targets by rigid projectiles. Structures under Shock and Impact XII, G. Schleyer and C. A. Brebbia, eds, WIT Press, Southampton, 63-74.

[43] Harvey, A.P., Craine, R.E. and Syngellakis, S. Propagation of nonlinear surface acoustic waves on elastic and piezoelectric solids. Journal of the Mechanics and Physics of Solids, 40(7), 1992, 1529-1542.

[44] Clowes, J. R., Syngellakis, S. and Zervas, M. N. Pressure sensitivity of side-hole optical fiber sensors. IEEE Photonics Technology Letters, 10(6), 1998, 857-859.

[45] Starink, M. J. and Syngellakis, S. Shear lag models for discontinuous composites: fibre end stresses and weak interface layers. Materials Science and Engineering A, A270, 1999, 270-277.

[46]Parry, M. R., Syngellakis, S. and Sinclair, I. Numerical modelling of combined roughness and plasticity induced crack closure effects in fatigue. Materials Science and Engineering A, 291, 2000, 224-234.

[47] Wu, A., Mellor, B. and Syngellakis, S. Experimental and finite element study of welded T-joints. Advances in Experimental Mechanics IV, J. M. Dulieu-Barton and S. Quinn, eds, 2005, Trans Tech Publications, Switzerland, 117-124.

[48]Leonardi, A., Furgiuele, F., Wood, R. J. K. and Syngellakis, S. Numerical analysis of brittle materials fractured by sharp indenters. Engineering Fracture Mechanics, 77(2) 2010, 264-276.

[49]Longana, M. L., Dulieu-Barton, J. M. and Syngellakis, S. Application of optical measurement techniques to high strain rate deformations in composite materials. CD-Rom Proceedings of the 7th Asian-Australasian Conference on Composites Materials, Taipei, Taiwan, November 2010.