Research Interests

Polymer Processing Simulation and Design

The ADOPT research group carries out research in the areas of structural shape and topology optimisation employing automatic mesh generation tools and adaptive finite element analysis. The research is directed at producing methods for the systematic design of lightweight, stiff structures as for instance needed in the aerospace industry. Ongoing work with collaborating companies include structural design optimization for (i) non-load carrying acoustic panels for aircraft, and (ii) buried PE pipes. Other work looks at developing specialist optimization tools, such as particle swarm optimization applied to jetty scheduling optimization.

Structural topology and shape optimization

The research work in this area deals mainly with simulation and optimisation of advanced injection moulding (e.g. fluid assisted injection moulding), and profile extrusion processes for highly non-linear materials exhibiting complex behaviour, such as visco-elasticity, wall-slip, etc. This work – carried out in collaboration with UK and overseas companies – resulted in several prize winning publications.

Biomedical applications 

Working with colleagues from the medical/life/health science groups within the university several MSc/MRes projects have been carried out, such as patient specific multi-body biomechanical modelling of the skeleton and muscle movement, and modelling the middle ear transfer function for a computational tool for diagnostics and prediction of hearing for pathological cases.

Academic Qualifications

• Diplom-Ingenieur (FH), FH Augsburg, Germany, 1989
• BEng (Hons), University of Central Lancashire, 1989
• MSc, University of Wales Swansea, 1990
• PhD, University of Wales Swansea, 1994

Professional Qualifications

• Fellow of the Institution of Mechanical Engineers (FIMechE)
• Fellow of the Royal Aeronatical Society (FRAeS)
• Member of the Institute of Mathematics and its Applications
• Member of the Verein Deutscher Ingenieure
• Chartered Engineer
• Chartered Mathematician

Employment History

• Academic
  • Senior/ Research Assistant, University of Wales Swansea, 1992 - 1996
  • Senior Research Assistant/Honorary Lecturer, University of Wales Swansea, 1996 - 1999
  • Lecturer, University of Wales Swansea, 1999 - 2001
  • Senior Lecturer, University of Wales Swansea, 2001 – 2007
  • Reader, University of Wales Swansea, 2007 -
• Industrial and Industrial Work Experience
  • MAN Roland, Germany, 1987
  • MAN Technologie, Germany, 1988
  • Company Director Diktyon Ltd, UK, 1998 - 1999
  • MBB (now EADS), Germany, 1981, 1985.
  • MAN, Germany, 1987, 1988.

Prize Winning Applications and Awards

• Publications
  • Best Paper Presentation Prize in the design engineering section of the 45th AIAA/ASME/ASCE/ AHS/ASC, 2004.
  • Best Poster Prize in the category: ‘Best Materials and Design Innovation’ awarded by Materials KTN: ‘3D simulation of water assisted injection Moulding’, 2007
  • Alan Glanvill Award for published work of particular merit in the field of polymers as awarded by the Institute of Materials, Minerals and Mining, 2007.
• Academic
  • 4 year academic scholarship, Government of Federal State Bavaria, 1984
  • 2 year academic scholarship, DAAD (German Academic Exchange Service), 1990

Most Recent Invited Lectures

• ‘Fluid Assisted Injection Moulding Simulation: Virtual Prototyping for Complex Parts’, 8th CST/5th  ECT International Conference, Las Palmas de Gran Canaria, Spain. 2006.
• ‘Gas Assisted Injection Moulding: 3-D Simulation and Industrial Case Studies’, PPE 05 International Conference, Bradford, 2005.
• ‘Simulation and Optimization for Polymer Processing’, 7th CST/4th ECT International Conference, Lisbon, Portugal, 2004.
• ‘Gas assisted injection moulding of a handle: three dimensional simulation and comparison with moulding trials and moldflow simulation’, 6th ESAFORM International Conference, Italy, 2003.
• ‘Automated Optimization of Extrusion Die Design for PVC Profiles’, 6th ESAFORM International Conference, Italy, 2003.
• ‘Parameterization techniques for two- and three-dimensional automated optimisation of PVC extrusion dies’, 18th Annual Polymer Processing Society Meeting, Guimarães, Portugal, 2002.
• ‘Optimization of thermoplastics extrusion die design: parameterization, algorithms and strategies’, 5th ESAFORM 2002 International Conference, Cracow, Poland, 2002.
• ‘Optimisation strategies for extrusion die design’, 4th ESAFORM  2001 International Conference,  Liege, Belgium, 2001.
• ‘3-D Simulation of Advanced Injection Moulding Technologies’, 4th ESAFORM  2001 International Conference,  Liege, Belgium, 2001.
• ‘Engineering design optimization within the FIDO environment’, 1º Workshop em Mecânica Computacional, UFPE, Recife, Brazil, 2000.

Editorship or Editorial Board Membership

• Review Editor: Structural and Multidisciplinary Optimization, International Journal published by Springer
• Edited/Co-edited works: 3 Proceedings of theASMO UK / ISSMO Conference on Engineering Design Optimization
• Reviewer of papers for 15 international journals

Recent Research Grants

• ‘Advanced Injection Moulding Technologies for Plastics, Simulation and Validation’, 1999 – 2002 (EPSRC).
• ‘Computer Aided Optimisation of Extrusion Die Design’, 2000 – 2004 (EPSRC).
• ‘Central Parallel Computing Facility For the Department of Mechanical Engineering’, 2001 – 2004 (EPSRC).
• ‘The Calibration Process In Thermoplastics Extrusion: Computer Simulation And Optimisation With Experimental Trials’, 2002 – 2005 (EPRSC).
• ‘Injection Moulding Process Intensification’, 2004 – 2005 (Carbontrust).
• ’Development of 3D simulation of water assisted injection moulding of polymers guided and validated by experimentation using an instrumented process’, 2006 – 2008 (EPRSC).

Research Centre/Consortia Leadership

• Director: Centre for Polymer Processing Simulation and Design.
• Director: ADOPT Research Group
• Director: Welsh Composites Consortium

Conference Activities

• Organiser/Co-organiser of 3 international conferences
• Session/Track organiser at 5 international conferences
• Member of the scientific committee of 8 international conferences

Selected Publications

Research Monograph

• E. Hinton, J. Sienz and M. Özakça, ‘Analysis and Optimization of Prismatic and Axisymmetric Shell Structures: Theory, Practice and Software’, Springer Verlag, 2003, ISBN: 1852334215. 528 pages, 247 illustrations, CD-Rom with ~ 60,000 lines of source code.

Refereed Journal Papers (IF = impact factor)

• E. Hinton, N.V.R. Rao and J. Sienz, ‘Finite element structural shape and thickness optimisation of axisymmetric shells’, Engineering Computations (IF 0.54), Pineridge Press, Swansea, UK, 9, 499-527, 1992.
• E. Hinton, M. Özakça and J. Sienz, ‘Optimum shapes of vibrating axisymmetric plates and shells’, Journal of Sound and Vibration (IF 0.83), Academic Press Ltd, UK, 167, 511-528, 1993.
• E. Hinton and J. Sienz, ‘Fully stressed topological design of structures using an evolutionary procedure’, Engineering Computations (IF 0.54), Pineridge Press, Swansea, UK, 12, 229-244, 1995.
• M. Papadrakakis, Y. Tsompanakis, E. Hinton and J. Sienz, ‘Advanced solution methods in topology optimisation and shape sensitivity analysis’, Engineering Computations (IF 0.54), MCB University Press, UK, 13(5), 57 - 90, 1996.
• J. Sienz and E. Hinton, ‘Reliable structural optimisation with error estimation, adaptivity and robust sensitivity analysis’, Computers and Structures (IF 0.74), 64(1-4), 31-63, 1997.
• J. Sienz, I. Szarvasy, E. Hinton and M.L. Andrade, ‘Computational modelling of 3D objects by using fitting techniques and subsequent mesh generation’, Computers and Structures (IF 0.74), 78(1-3), 397-413, 2000.
• I. Szarvasy, J. Sienz, J.F.T. Pittman and E. Hinton, ‘Computer aided optimisation of profile extrusion dies: definition and assessment of the objective function’, International Polymer Processing (IF 0.69), XV (2000) 1, 28 – 39, 2000.
• S. Bulman, J. Sienz and E. Hinton, ‘Comparisons between algorithms for structural topology optimization using a series of benchmark studies’, Computers and Structures (IF 0.74), 79, 1203-1218, 2001.
• J. Sienz and S. Bulman, ‘Adaptivity and optimisation – ADOPT’, Engineering Computations (IF 0.54), 18 (1/2), pp 10 – 47, 2001. ISSN 0264-4401.
• S.J. Bates, J.F.T. Pittman, J. Sienz and D.S. Langley, ‘Enhancing Slit Die Performance by Optimization of Restrictor Profiles’, Polymer Engineering & Science (IF 1.22), 43(8), 1500-1511, 2003.
• S.J. Bates, J. Sienz and D.S. Langley, ‘Formulation of the Audze-Eglais Design of Experiments using a Genetic Algorithm’, Advances in Engineering Software (IF 0.37), 34(8), 493-506, 2003, 2003.
• A. Polynkin, J.F.T. Pittman and J. Sienz, ‘Gas displacing liquids from tubes: high capillary number power law flow including inertia effects’, Chemical Engineering Science (IF 1.66), 59(14), pp 2969-2982, 2004.
• H. Ettinger, J. Sienz, J.F.T. Pittman and A. Polynkin, ‘Parameterization and optimization strategies for the automated design of uPVC profile extrusion dies’, Structural and Multidisciplinary Optimization (IF 0.81), 28(2-3), pp 180 - 194,  2004.
• A. Polynkin, J.F.T. Pittman and J. Sienz, ‘Modelling of cyclic 3-dimensional heat transfer in injection moulding’, International Polymer Processing (IF 0.69), XIX (2004) 4, 408 - 418, 2004.
• A. Polynkin, J.F.T. Pittman and J. Sienz, ‘Gas displacing liquids from non-axisymmetric tubes: high capillary number shear thinning fluids’, Chemical Engineering Science (IF 1.66), 60, 1591 – 1602, 2005.
• A. Polynkin, J.F.T. Pittman and J. Sienz, ‘3D-simulation of primary and secondary gas penetration in injection moulding: comparison with experimental results’, International Polymer Processing (IF 0.69), XX (2005) 2, 191 – 201, 2005.
• F. Belblidia, J.F.T. Pittman, A. Polynkin and J. Sienz, ‘Gas displacing viscous shear thinning liquids from tubes: effects of cooling before gas injection’, Chemical Engineering Science (IF 1.66), 60 (2005), 4953 – 4956, 2005.
• S.M.B. Afonso, J. Sienz and F. Belblidia, ‘Structural optimisation strategies for simple and integrally stiffened plates and shells’, Engineering Computations (IF 0.54), 22(4), 429 – 452, 2005.
• A. Polynkin, J.F.T. Pittman and J. Sienz, ‘Gas assisted injection molding of a handle: three dimensional simulation and experimental verification’, Polymer Engineering & Science (IF 1.22), 45(8), 1049 – 1058, 2005.
• A. Polynkin, J.F.T. Pittman and J. Sienz, ‘Industrial application of gas assisted moulding: numerical predictions and experimental trials’, Plastics, Rubbers & Composites (IF 0.41), 34(5/6),  236 – 246, 2005.
• J. Sienz, S.J. Bates and J.F.T. Pittman, ‘Flow restrictor design for extrusion slit dies for a range of materials: simulation and comparison of optimization techniques’, Finite Elements in Analysis and Design (IF 0.84), 42, 430 - 453, 2006.
• A. Polynkin, J.F.T. Pittman and J. Sienz, ‘prediction of gas core geometry in gas assisted injection molding using a short cut method', Polymer Engineering & Science (IF 1.22), 42(5), 713 – 720, 2007.
• [AR = PhD, JFTP, AP = co-workers. JS: 15% contribution to all aspects of the work, including leadership of the project.]
• A. Polynkin, J.F.T. Pittman and J. Sienz, ‘Gas assisted injection molding of an industrial part: 3-d simulation provides virtual molding trials’, International Polymer Processing (IF 0.69), XXII (2007) 2, 173 - 178, 2007.
• A. Rippl, J.F.T. Pittman, A. Polynkin and J. Sienz, ‘Simultaneous determination of shear and extensional viscosities and wall slip by on-line rheometry with parameter fitting: an application to EPDM rubber’, Rheologica Acta (IF=1.43), 46, 847 – 860, 2007.

Chapters in Books

• J. Sienz and E. Hinton, ‘Chapter 13: Integrated design and analysis modelling in structural shape optimisation’, in M. Papadrakakis and G. Bugeda, (eds), Advanced computational methods in structural mechanics, pp 235 - 265, CIMNE, Barcelona, 1996. ISBN 84-87867-75-8.
• J. Sienz and E. Hinton, ‘Chapter 12: Sensitivity analysis for shape optimisation’, in M. Papadrakakis and G. Bugeda, (eds), Advanced computational methods in structural mechanics, pp 216 - 234, CIMNE, Barcelona, 1996. ISBN 84-87867-75-8.
• J. Sienz, B. Hassani and E. Hinton, ‘Chapter 11: Structural optimisation’, in M. Papadrakakis and G. Bugeda, (eds), Advanced computational methods in structural mechanics, pp 185 - 215, CIMNE, Barcelona, 1996. ISBN 84-87867-75-8.
• J. Sienz, C. Silva, E. Hinton and I. Szarvasy, ‘Chapter 13: Computer aided design of extrusion dies’, in M. Papadrakakis and B.H.V. Topping (eds), Innovative computational methods for structural mechanics, Saxe-Coburg Publications, pp 271 - 303, Edinburgh, 1999. ISBN 1-874672-05-9.
• J. Sienz, E. Hinton, G. Bugeda, and S. Bulman, ‘Chapter 11: Some studies on integrating topology and shape optimization’, in M. Papadrakakis and B.H.V. Topping (eds), Innovative computational methods for structural mechanics, Saxe-Coburg Publications, pp 223 - 256, Edinburgh, 1999. ISBN 1-874672-05-9.
• M. Papadrakakis, Y. Tsompanakis, N.D. Lagaros, E. Hinton, J. Sienz, G. Thierauf and J. Cai, ‘Chapter 10: Innovative computational methods for structural optimization’, in M. Papadrakakis and B.H.V. Topping (eds), Innovative computational methods for structural mechanics, Saxe-Coburg Publications, pp 195 - 222, Edinburgh, 1999. ISBN 1-874672-05-9.
• J. Sienz, J.F.T. Pittman and A. Polynkin, ‘Simulation and Optimization for Polymer Processing’, Invited Lecture, in B.H.V. Topping and C.A. Moares (eds), Progress in Engineering Computational Technology, Saxe-Coburg Publications, pp 189 – 218, Edinburgh, UK. 2004. ISBN 1-874672-22-9.
• A. Polynkin, J.F.T. Pittman and J. Sienz, ‘Gas Assisted Injection Moulding: 3D Simulation and Industrial Case Studies’, Invited Lecture, in P.D. Coates (ed), Polymer Process Engineering 05: Enhanced Polymer Processing, pp 288 – 325, Bradford, UK, 2005.
• J. Sienz, J.F.T. Pittman and A. Polynkin, ‘Fluid Assisted Injection Moulding Simulation: Virtual Prototyping for Complex Parts’,  Invited Lecture, in B.H.V. Topping, G. Montero and R. Montenegro (eds), Innovation in Engineering Computational Technology, pp 287 - 308, Saxe-Coburg Publications, Edinburgh,  UK. 2006.
• J.F.T. Pittman, A. Polynkin, J. Sienz, L. Mulvaney-Johnson, E. Brown, A. Dawson, P.D. Coates, K. Vinning, J. Butler, ‘Water assisted injection moulding: development of insights and predictive capabilities though experiments on an instrumented process in parallel with computer simulations’, in P.D. Coates (ed), Polymer Process Engineering 05: Enhanced Polymer Processing, pp 323 – 358, Bradford, UK, 2007. ISBN 13-978-1-85143-248-6.

Edited Works

• J. Sienz (ed), Proceedings of the 2nd ASMO UK / ISSMO Conference on Engineering Design Optimization, University of Wales Swansea, Swansea, SA2 8PP, UK, July 2000, ISBN: 0-86076-168-1.
• O.M. Querin, J. Sienz, V.V. Toropov and P.D. Gosling (eds), Proceedings of the 5th ASMO UK / ISSMO Conference on Engineering Design Optimization, Stratford-upon-Avon, July 2004, CD-ROM, ISBN: 0-85316-246-8.
• J. Sienz, V.V. Toropov and O.M. Querin (eds), Proceedings of the 6th ASMO UK / ISSMO Conference on Engineering Design Optimization, Oxford, July 2006, CD-ROM.