Computational Mechanics and Design Group

Department of Civil & Structural Engineering

Prof. Andy Tyas


0114 222 5735

Department of Civil and Structural Engineering
Sir Frederick Mappin Building
Mappin Street,
S1 3JD


Andrew Tyas is a graduate of Loughborough University of Technology, who spent five years working in civil engineering design practice before returning to academia. He received his PhD in for University of Sheffield for a DERA sponsored study of impact dynamics and was appointed Lecturer in Structural Design in 1997.

His teaching interests include structural analysis, design and blast and impact dynamics. He is particularly interested in helping students develop the confidence and maturity to produce suitable design ideas at the initial concept stage. He has been closely involved with the growth of the innovative MEng degree in Structural Engineering and Architecture, accredited by both the IStructE and RIBA, and has developed close links with the School of Architecture at Sheffield, leading to a number of teaching publications. He is currently First and Second Year Undergraduate Tutor.

Dr Tyas is head of the blast and impact research group in the Department of Civil and Structural Engineering, managing the testing laboratory at Harpur Hill, Buxton where research into blast physics and the response of structures to rapid dynamic loading is conducted. He is also a Director of Blastech Ltd, a University spin-out company offering consultancy and commercial testing services to industry in the field of blast and impact loading of structures. Additionally, he collaborates with Matthew Gilbert in the development of computational optimisation-based methods for the design of structures.


PhD (University of Sheffield)


MatLab script for generating LS-DYNA mesh file for spherical expansion of a blast wave

When modelling explosive detonations and blast wave propagation it is important that material movement is aligned with the elements. If a spherical charge is modelled in a rectangular mesh, an advection error is introduced. By modelling the blast wave in a radially symmetric mesh, this problem can be avoided. This...

Research project(s)

Dynamics of micro-trusses

We study the mechanical behaviour of micro lattices (also known as micro-trusses) under a range of loading conditions. Where applicable, we apply homogenisation and continualisation principles to derive higher-order gradient theories with a transparent interpretation of the emerging internal length scales. Under elastic loading conditions, the emergence of stop bands...


Rigby SE, Fay SD, Clarke SD, Tyas A, Reay JJ, Warren JA, Gant M, Elgy I (2016). Measuring spatial pressure distribution from explosives buried in dry Leighton Buzzard sand. International Journal of Impact Engineering, 96 (2), pp. 89-104.
Rigby SE, Fay SD, Warren JA, Tyas A, Clarke SD (2016). CoBL End of Year 3 Report.
Ozdemir Z, Hernandez-Nava E, Tyas A, Warren JA, Fay SD, Goodall R, Todd I, Askes H (2016). Energy absorption in lattice structures in dynamics: Experiments. International Journal of Impact Engineering, 89 (6), pp. 49-61. (Full Text).
Barr AD, Clarke SD, Rigby SE, Petkovski M, Tyas A (2015). Finite element modelling of split-Hopkinson pressure bar experiments on sand. (Full Text)., Abstract: Finite element modelling of confined split Hopkinson pressure bar (SHPB) tests on dry quartz sand have been carried out using LS-DYNA to assess the suitability of models *MAT_SOIL_AND_FOAM and *MAT_MOHR_COULOMB for simulating high-pressure transient events in soils. Both models were defined using...
Clarke SD, Rigby SE, Fay SD, Tyas A, Reay JJ, Warren JA, Gant M, Livesey R, Elgy I (2015). Bubble-type' vs 'shock-type' loading from buried explosives. (Full Text)., Abstract: The detonation of a buried explosive is known to be highly influenced by the conditions of the surrounding soil. Depending on the moisture content this leads to two distinct loading mechanisms being generated, that of bubble-type loading in saturated soils and shock-type loading in low moisture...
Yin T, Tyas A, Plekhov O, Terekhina A, Susmel L (2015). A novel reformulation of the Theory of Critical Distances to design notched metals against dynamic loading. Materials and Design, 69 (1), pp. 197-212. (Full Text).
Rigby SE, Tyas A, Clarke SD, Fay SD, Reay JJ, Warren JA, Pope DJ (2015). A Review of UFC-3-340-02 Blast Wave Clearing Predictions. (Full Text)., Abstract: When a blast wave impinges on a target of finite lateral or vertical dimension, diffraction of the blast wave around the target edge causes a relief wave to propagate inwards along the face of the target. This relief wave reduces the pressure acting at any point it passes over as the higher...
Rigby S, Fay S, Tyas A, Warren J, Clarke S (2015). Angle of Incidence Effects on Far-Field Positive and Negative Phase Blast Parameters. International Journal of Protective Structures, 6 (1), pp. 23-42. (Full Text).
Tyas A, Reay J, Warren JA, Rigby SE, Clarke SD, Fay SD, Pope DJ (2015). Experimental Studies of Blast Wave Development and Target Loading from Near-Field Spherical PETN Explosive Charges. (Full Text)., Abstract: A detailed understanding the features associated with the development of blast waves in the near-field following a HE detonation, and the loading generated when these waves impinge upon a target is essential if analysts and designers are to be able to validate numerical modelling approaches to near...
Barr AD, Clarke SD, Petkovski M, Tyas A, Warren J, Kerr S (2015). Strain-rate effects in dry and partially-saturated sand under one-dimensional compression at high pressures. In Geomechanics from Micro to Macro - Proceedings of the TC105 ISSMGE International Symposium on Geomechanics from Micro to Macro, IS-Cambridge 2014 (pp. 1397-1402). (Full Text)., Abstract: This paper investigates the effect of strain rate on the behaviour of dry and partially-saturated sand at very high stresses, seeking to clarify the existence of a strain-rate dependence and how this is affected by changes in moisture content. Quasi-static one-dimensional compression tests on a...