Computational Mechanics and Design Group

Department of Civil & Structural Engineering

Dr Jack Hetherington

Research Associate

Contact

j.hetherington@sheffield.ac.uk
+44 (0) 114 222 5724

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

Profile

Jack graduated from the University of Sheffield in 2009 with a first-class honours degree in Civil Engineering.  During the fourth year of his undergraduate course he completed a dissertation on the transmission of impact noise at UPC in Barcelona, before returning to Sheffield to begin a PhD in the department the following year.  He is currently investigating the use of penalty methods in the field of computational structural dynamics, a topic which has allowed him to return to UPC for further collaboration thanks to a travel grant from the Royal Society.

Qualifications

MEng, Civil & Structural Engineering, University of Sheffield, 2009

Research project(s)

Dynamic constraint modelling

In this project, we develop new penalty methods for use in fast transient dynamic problems, simulated with time-domain integrators. A problem that has plagued the community for many decades is that the usual stiffness-type penalties tend to decrease the critical time step of conditionally stable time integrators such as the...

Publication(s)

(2015). The effects of element shape on the critical time step in explicit time integrators for elasto-dynamics. International Journal for Numerical Methods in Engineering, 101 (11), pp. 809-824. (Full Text).
(2014). A mass matrix formulation for cohesive surface elements. Theoretical and Applied Fracture Mechanics, 69 (6), pp. 110-117. (Full Text).
(2013). The bipenalty method for arbitrary multipoint constraints. International Journal for Numerical Methods in Engineering, 93 (5), pp. 465-482, Abstract: In finite element (FE) analysis, traditional penalty methods impose constraints by adding virtual stiffness to the FE system. In dynamics, this can decrease the critical time step of the system when conditionally stable time integration schemes are used by introducing spurious modes with high...
(2011). Controlling the critical time step with the bi-penalty method. In ECCOMAS Thematic Conference - COMPDYN 2011: 3rd International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering: An IACM Special Interest Conference, Programme.
(2011). A new bipenalty formulation for ensuring time step stability in time domain computational dynamics. International Journal for Numerical Methods in Engineering, 90 (3), pp. 269-286.
Díaz-Cereceda C, Hetherington J, Poblet-Puig J, Rodríguez-Ferran A (2011). A deterministic model of impact noise transmission through structural connections based on modal analysis. Journal of Sound and Vibration, 330 (12), pp. 2801-2817, Abstract: Vibration transmission through structural connections is modelled in a deterministic way by means of modal analysis. This model is used first to study the effect of elastic joints across the floor in the transmission of impact noise. They are an effective means of reducing impact noise propagation...
Hetherington J, Askes H, Rodríguez-Ferran A (2011). Controlling the critical time step with the bi-penalty method. In ECCOMAS Thematic Conference - COMPDYN 2011: 3rd International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering: An IACM Special Interest Conference, Programme , Abstract: Penalty functions are a popular tool to add constraints to a system of equations, such as for instance Dirichlet boundary conditions or setting a relation between different degrees of freedom. Although implementation of the penalty method is simple, the commonly used stiffnesstype penalties have a...