Seminar

> *Subject:* *Applied Maths/Engineering Workshop*
>
> Details of this weeks workshop are:
>
> 26 February 16:10 Applied Maths/Engineering Workshop. *Room S/0.38 ENGIN*
>
> Speaker: Sam Evans (ENGIN)
>
> Title: Errors and Uncertainties in the Identification of Material
> Parameters Using nn Inverse FE Approach
>
>
> Abstract
> Soft materials exhibit complex nonlinear mechanical behaviour which is not
> easily amenable to mathematical modelling. Recently the availability of
> fast computers and medical imaging techniques has allowed considerable
> progress in this area, and there are many interesting applications
> including engineering design, animation and games and medical problems such
> as surgical planning and navigation.
> A major difficulty is the measurement of material properties, which
> typically requires an "inverse finite element" approach in which a model of
> an experiment is adjusted to match the experiment in order to identify the
> material parameters. Often complex material models with many parameters
> are used, making this a very challenging problem with numerous
> uncertainties. Although it may be possible to find a set of parameters
> which matches the experiment reasonably well, it is very difficult to know
> whether these are the best parameters or what range of other values might
> be equally good. Typically there are very large uncertainties which are
> not well understood and cannot easily be quantified. The aim of this study
> was to develop methods to quantify these uncertainties and identify not
> just a plausible set of material parameters but also a confidence space,
> allowing meaningful statistical analysis of the results and a better
> understanding of the experimental design and optimisation process.
> By using Gaussian process models to as emulators for a finite element model
> it is possible to quantify some of these uncertainties and hence to
> estimate the overall uncertainty in the identified parameters. Using a
> Condor network, multiple finite element models were generated and solved in