Dr Siegkas is a senior Lecturer at the Engineering Department. He has been involved in curriculum development with modules such as ENGG10111 Innovation and Engineering Solutions, ENGG20091 Sports Technology, ENGG20071 Industrial design and Product Case Studies, ENGG30061 Mechanical Engineering in Sport, ENGG40091 Optimising Sport Equipment
- Postdoctoral Researcher : Dyson School of Design Engineering, Faculty of Engineering, Imperial College London
- Postdoctoral Researcher: Impact Laboratory, Department of Engineering Science, University of Oxford
- DPhil: University of Oxford (Department of Engineering Science, Solid Mechanics group, Worcester College)
- GDL (Graduate Diploma in Law): BPP University London
- Dipl. Eng. (5 year Degree): National Technical University of Athens (Mechanical Engineering-Aeronautics)
- Chartered Engineer Member of the Institution of Mechanical Engineers (CEng MIMechE)
- Associate Fellow of the Higher Education Academy
Dr Siegkas’ research within the field of solid mechanics includes developing and implementing experiment and modelling techniques related to material behavior and impact energy management in biomechanics and aerospace applications. Projects involved close collaboration with both industrial and academic partners of various fields. Current research interests include 3D printing, personalised protective equipment, and engineered meta-materials.
Dr Siegkas’ DPhil was focused on developing experiments and modeling techniques to characterise and model the static and dynamic performance of porous- cellular materials for use as biocompatible bone implants, and applications within the aerospace industry. Experiments involved mechanical testing at various strain rates and included the use of high speed photography, in-situ SEM, X-ray micro-tomography and image analysis.
A computational method was developed for virtually generating porous material prototypes and capturing their mechanical behavior at different scales thus providing a tool for virtual prototyping and characterisation, based on application requirements. The foam geometries were generated in Matlab using a method based on Voronoi polyhedrals, that could either mimic geometrical features (e.g. pore size distribution) obtained by X-ray tomography analysis or generate new prototype geometries. The geometries were then subjected to uniaxial and multiaxial mechanical loading at the mesoscale level from which the macroscale properties were obtained. The virtual specimens were simulated using finite element techniques (Abaqus) at different strain rates. The project was partially funded by Rolls Royce, EPSRC and in collaboration with the IMI Canada.
Metal Alloys-Ballistics-Aerospace Components
Dr Siegkas worked on the ballistic performance of granular materials (including Nickel at temperatures up to 800 degrees Celsius and Titanium alloys at room temperature) and jet engine components. The research was related to the aviation safety and impact energy management (i.e. jet engine fan blade off e.t.c.).
The projects were focused in designing experiments to generate data for material model calibration and validation or used for the development and optimisation of new materials. The aim was to capture the material mechanisms involved in managing energy dissipation and related to application requirements. The work was done in collaboration with industrial partners (Rolls Royce, TIMET) and has received a departmental award under the University of Oxford departmental recognition scheme. Results were subject to publishing restrictions.
Traumatic Brain Injury and Protective Equipment
During a PDRA position at Imperial College London, Dr Siegkas worked on projects related to understanding and preventing traumatic brain injury. The work involved implementing finite element models and extracting information as to regions of the brain that were mechanically affected by impact loading.
One of the projects was funded by the ‘’Welcome trust network of excellence’’ and was carried by a multidisciplinary team of experts from the fields of biology, neuroscience and solid mechanics. The second project was funded by the Welsh Government and was a collaboration between Imperial College and industrial partners (Dainese-AGV manufacturer of motorcycle helmets, Armougel manufacturer of liner add-on material). Dr Siegkas' role involved both experiments and computational modelling. Experiments included liner material characterisation (polymer), drop tower experiments on helmets (with and without added liner) and fitted on an instrumented head form. Modelling included using a head and brain model to extract information regarding potential injury and a full helmet-head form (Hybrid III) model of the drop tower tests aiming to extract information for further liner design and optimisation.
Sponsors and collaborators
Undertaken projects were funded and in collaboration with industrial, public and academic partners with expertise from multiple disciplines including: Rolls Royce, TIMET, Bridgestone, Division of Brain sciences Imperial College London and funding bodies such as EPSRC, Welsh Government and Welcome Trust Network of Excellence.
- Iizuka, M.; Goto, R.; Siegkas, P.; Simpson, B.; Mansfield, N. Large Deformation Finite Element Analyses for 3D X-ray CT Scanned Microscopic Structures of Polyurethane Foams. Materials 2021, 14, 949. https://doi.org/10.3390/ma14040949
- Cornelius K Donat, Maria Yanez Lopez, Magdalena Sastre, Nicoleta Baxan, Marc Goldfinger, Reneira Seeamber, Franziska Müller, Polly Davies, Peter Hellyer, Petros Siegkas, Steve Gentleman, David J Sharp, Mazdak Ghajari, From biomechanics to pathology: predicting axonal injury from patterns of strain after traumatic brain injury, Brain (2021)
- Melia, G., Siegkas, P., Levick, J. and Apps, C., 2020. Insoles of uniform softer material reduced plantar pressure compared to dual-material insoles during regular and loaded gait. Applied Ergonomics, 91, p.103298.
- Elmrabet, Nabila, and Petros Siegkas. "Dimensional considerations on the mechanical properties of 3D printed polymer parts." Polymer Testing (2020): 106656.
- Siegkas, Petros, David J. Sharp, and Mazdak Ghajari. "The traumatic brain injury mitigation effects of a new viscoelastic add-on liner." Scientific reports 9.1 (2019): 1-10.
- Pedrazzini, S., Galano, M., Audebert, F., Siegkas, P., Gerlach, R., Tagarielli, V. L., & Smith, G. D. W. (2019). High strain rate behaviour of nano-quasicrystalline Al93Fe3Cr2Ti2 alloy and composites. Materials Science and Engineering: A, 764, 138201.
- Siegkas P, Petrinic N and Tagarielli VL. Measurements and micro-mechanical modelling of the response of sintered titanium foams, Journal of the Mechanical Behavior of Biomedical Materials, 2016, 57: 365-375
- Siegkas P, Tagarielli VL, Petrinic N and Lefebvre LP. The compressive response of a titanium foam at low and high strain rates, 2011, J Mater Sci, 46: 2741–2747
- Siegkas P, Tagarielli VL, Petrinic N and Lefebvre LP. Rate Dependence of the Compressive Response of Ti Foams. Metals (special issue), 2012, 2: 229-237.
- Simone F, Siegkas P, Barbieri E and Petrinic N. A new method for the generation of arbitrarily shaped 3D random polycrystalline domains J. Computational Mechanics, 2014
Dr Siegkas research expertise includes porous-cellular materials, metal alloys, ballistics, aerospace components, protective equipment and traumatic brain injury (TBI).