Colloquium Vikram Deshpande
Size Effects in Discrete Dislocation Plasticity
When: Monday 11 February 2013
Where: Ceres building, CE0.31, TU/e campus
DisPlastic flow in crystalline materials is size dependent over length scales of the order of tens of microns and smaller. This size dependence arises in a variety of contexts; e.g. the grain size dependence of the flow strength, the indentation size effect and bending of thin films. One well appreciated origin of size effects is associated with imposed plastic strain gradient and geometrically necessary dislocations.
In addition, size-dependent response can occur in circumstances where, at least in principle, a more or less homogeneous response is possible. Discrete dislocation plasticity analyses of various plastic flow processes will be used to illustrate a range of size effects including size effects in bending, uniaxial compression/tension and grain size effects in polycrystals in order to illustrate the range of different physical phenomena that can give rise to plastic size effects. The seminar will not only focus on the scaling of plastic properties with size but also discuss the effect of temperature on size effects in crystalline metals.
After a PhD at Cambridge Engineering Department and a Maudslay Research Fellow at Pembroke College, Cambridge he held a Lindemann Research Fellowship at Brown University, USA. Vikram Deshpande is currently Professor of Materials Engineering at the Department of Engineering at the University of Cambridge and visiting Professor in at TU/e in the Department of Mechanical Engineering. He has previously held positions of lecturer and Reader at Cambridge and Associate Professor at Department of Mechanical Engineering at the University of California, Santa Barbara. His current research interests include: mechanics of foams and lattice materials, dynamic behaviour of structures, plasticity at the micron length scale, and mechano-biology of cells and tissues. He has published over 150 international journal articles in the field of experimental and theoretical Solid Mechanics and was awarded the Philip Leverhulme Prize in 2003.