A NUMERICAL STUDY ON CAVITATION IN NONLINEAR ELASTICITY — DEFECTS AND CONFIGURATIONAL FORCES

An iso-parametric finite element method is introduced in this paper to study cavitations and configurational forces in nonlinear elasticity. The method is shown to be highly efficient in capturing the cavitation phenomenon, especially in dealing with multiple cavities of various sizes and shapes. Our numerical experiments verified and extended, for a class of nonlinear elasticity materials, the theory of Sivaloganathan and Spector on the configurational forces of cavities, as well as justified a crucial hypothesis of the theory on the cavities. Numerical experiments on configurational forces indicate that, in the case of a round reference configuration with radially symmetric stretch on the boundary, the cavitation centered at the origin is the unique energy minimizer. Numerical experiments also reveal an interesting size effect phenomenon: for macro-scale pre-existing-defects, the cavitation process is dominated by the relatively larger pre-existing-defects, and the cavitation tendency of much smaller pre-existing-defects is significantly suppressed.

Thermodynamic Calculations on Vapour Phase Species in Halogen Doped CDTE

ABSTRACTA thermodynamic analysis of the vapour phase species occurring in the undoped CdTe and doped CdTe:X (X = Cl, Br, I) systems is given. Calculations are performed using a Gibbs energy minimizer software (EPC), which offers the possibility of receiving relativly prompt results allowing for the change in experimental conditions as well as the consideration of even spurious species.In each system, the dopant - transporting species are the cadmiumdihalogenides CdX2. Contrary, in the CdTe:I vapour phase two more species (Tel and I) have to be considered at the growing phase boundary afffecting transport and interface kinetics.

Structure Analysis of Catechol-Like Molecular Fragments

A system of rigid benzene ring and two variable torsion angles ϕ(C-C-OH) in catechol-like molecular fragments was studied. A scattergam of the two torsion angles taken from the Cambridge Structural Databank is in a good agreement with the potential energy map calculated with the AMBER compatible energy minimizer ORAL. Symmetry operations and point symmetry domains used during the analysis are described in detail. Results are interpreted in accord with the catchment region theory and the structure-correlation principle.