The Influence of the Microstructural Shape on the Mechanical Behaviour of Interpenetrating Phase Composites
To study the complex response of the IPC microstructure under load, a numerical modelling analysis using the finite element method (FEM) was undertaken. Two three-dimensional models of IPCs were created, the first consisting of an interconnected spherical phase with the interstitial space forming the other interconnected phase, and the second replacing the spherical phase with an interconnected cylindrical phase. With the simulation of a uniaxial tension test under elastic and plastic conditions, these two models exhibited different responses based on the shape of the phases.
Results from an analysis of the macroscopic behaviour identified that the cylindrical model produced greater effective properties than the spherical model at the same volume fraction. The influence of phase shape was connected to the increased contiguity of the superior phase within the IPC for the cylindrical model, which allowed similar levels of long-range continuity with smaller amounts of the superior phase (compared to the spherical model).
An examination of microstructural stress distributions showed that preferential stress transfer occurred along paths of low compliance. This provided an explanation of how the improved contiguity of the stiffer (or stronger) phase could enhance the macroscopic effective properties of an IPC. Contiguity of the stronger phase was particularly important for plastic behaviour, where early yielding of the weaker phase requires the stronger phase to carry nearly all the load within itself.
Advisor:Yannacopoulos, Spiro; Wegner, Leon D.; Sparling, Bruce F.; Peng, Jian; Boulfiza, Mohamed
School:University of Saskatchewan
School Location:Canada - Saskatchewan
Source Type:Master's Thesis
Keywords:continuity contiguity behaviour mechanical finite element method co continuous interpenetrating phase composites microstructural shape elastic plastic
Date of Publication:03/24/2005