## Past research interests

Between 1997 and 2001, I was a PhD student in the Deployable Structures Laboratory of the Engineering Department at the University of Cambridge. My supervisor was Simon Guest. The project I worked on concerned composite ribs with a circular arc as cross-section. These ribs, which have a novel composite layup, appear to have two equilibrium states, an extended form and a coiled form. They are hence similar to the well-known tape-measure, apart from the fact that the composite structures are stable at both equilibrium states, whereas tape-measures are stable only in the extended form and require a spindle or casing to hold them in the coiled form.

The reseach I did derived several analytical models of the rib (as a beam, allowing linear deformations only, or both linear and non-linear, or as a shell), and
investigated possible modes of deformation. This allowed me to determine the precise location
of the second equilibrium state. The
work then continued by investigating the stability of this
second equilibrium state. These stability expressions also
provided an explanation for the *lack* of stability of the standard
tape measure (and other isotropic materials) in the coiled form.

Prior to that, I studied Engineering at the University of Cambridge graduating with a Masters of Engineering with Distinction in 1997. The first two years of this course are in General Engineering: the subjects studied are Mechanics, Materials, Structural Mechanics, Fluid Dynamics and Thermodynamics, Linear Circuits, Electrical Power, Digital Circuits, Linear Systems and Control and Mathematics. At the end of the second year one begins to specialise by choosing two elective courses; I chose to do mine in Civil Engineering and Information Engineering.

In the third year I studied Soil Mechanics, Structures, Solid Mechanics, Materials and Management Science. At the end of the third year, there are two small projects; mine were in Structural Modelling (where one learns to use analysis packages such as Oasys, ABAQUS and Masterseries) and French (where I produced a report on the use of numerical analysis techniques such as Finite Element Analysis and Computational Fluid Dynamics in the design of the Airbus).

In the fourth year, half the year is spent studying modules, and half the year working on a major project. The modules I studied were Geotechnical Engineering, Structural Dynamics and Earthquake Engineering, Thinwalled Structures, Structural Steel, Designing with Composites, Finite Elements, French and Linear Algebra and Optimisation.

My fourth year project was done in collaboration with the Ecole des Mines Materials' Centre, in Evry, and consisted of introducing shell elements (axisymmetric and 3 dimensional) into their finite element program, ZeBuLoN, and also implementing the Riks' algorithm, thus permitting the analysis of, amongst other things, shell buckling problems. My final report on the project is available in pdf format. One of the problems that can thus be studied is that of a spherical cap under uniform pressure. Note that the buckling mode shown is not the most likely to occur; an anti-symmetrical mode is much more likely, but the axisymmetric shell element implementation did not contain the ability to use Fourier series, as there was insufficient time, and the 3D shell elements were less convincing in their correctness.

For work experience, I worked at the CEA at Saclay, in the Service d'Etudes Mecaniques et Thermiques, in the summer between my first two years at university, and at the Ecole des Mines in Paris, in the Centre des Materiaux in Evry, between my second and third year, and between my third and fourth year. At the CEA, I used the INCA module of the finite element analysis package, CASTEM, to investigate the failure of cracked cylindrical tubes subjected to an applied couple. At the Ecole des Mines, I worked initially on validating the new C++ version of their finite element code, ZeBuLoN, and (whilst working for a small spin-off company for a month) developed code in C to model spring and beam elements in the post-processor. The second summer I was there, I started work on my fourth year project.

Please consult my CV for further information.

Content and design by

Diana Galletly

Last updated January 2005.