PhD opportunity at the University of Southampton on high strain rate material testing

Title: Exploration of novel multiaxial high strain rate tests of materials based on full-field strain measurements and inverse identification

Sponsor: EOARD http://www.wpafb.af.mil/library/factsheets/factsheet.asp?id=16662/

Start of PhD: end of September 2013

Project description:
In the last thirty years, a major revolution has taken place in engineering in the form of numerical simulation, fuelled by the increasing computational power. Computer Aided Design (CAD) coupled to Finite Element Modelling (FEM) has enabled detailed design and optimization of structures. However, this numerical revolution has not yet delivered its full potential mainly because such procedures require input from the real world and in particular, the actual mechanical behaviour of materials. While research in numerical simulation boomed, experimental procedures required to identify the mechanical behaviour of materials lagged behind and failed to reach the expectations of advanced numerical simulations.

Fortunately, the last decade has seen significant technological breakthroughs in the field of digital imaging, enabling to shed a new light on experimental solid mechanics. The availability of inexpensive and good quality digital cameras has led to the fast development of computer vision based techniques to image the deformation of materials subjected to mechanical loads. This has led to a new branch of research trying to make use of this rich experimental information in conjunction with efficient inverse identification techniques to define novel testing procedures to identify more complex models in a more robust way. This area of research in now rapidly expending for quasi-static situations.
However, the very challenging field of rapid dynamics (or high strain rate testing) is still to benefit from this approach. The experimental tools used by the community still heavily rely on technology developed several decades ago, like the Split Hopkinson Pressure Bar, providing very poor experimental information and relying on strong hypotheses (uniaxial and uniform stress fields).

The objective of this project is to contribute to the development of novel mechanical tests at high strain rates based on full-field optical strain measurements using ultra high speed imaging, linked to efficient inverse procedures such as the Virtual Fields Method (www.camfit.fr). The project is rather exploratory in nature and will tackle both numerical and experimental aspects of the problem. The materials to be addressed will be metals and polymers. The project will first use simulated data to design the test configurations and explore the identifiability of different constitutive models at high strain rates. Then, some of these tests will be experimentally set-up, using state of the art ultra-high speed imaging techniques.

If interested, please send email with attached CV to Prof. Fabrice PIERRON f.pierron@soton.ac.uk