Modeling microcellular models

Ramesh, N. S., Rasmussen, D. H., and Campbell, G. A., The Heterogeneous Nucleation of Microcellular Foams Assisted by the Survival of Microvoids in Polymers Containing Low Glass Transition Particles. Part 1 Mathematical Modeling and Numerical Simulation, Polym. Eng. ScL, 34, 1685 (1994)... 

Ramesh NS, Rasmussen DH, Campbell GA (1994) The heterogeneous nucleation of microcellular foams assisted by the survival of microvoids in polymers containing low glass-transition particles. 1. Mathematical-modeling and numerical-simulation. Polym Eng Sci 34 1685-1697... 

A further study of the microcellular structure of oligon ric foams and the development of models taking into account both mararo- and microcells are equally important. 

Open-pore microcellular aluminium foams can be produced by a process known as replication . This consists in infiltration of NaCl powder preforms by a melt, which is then solidified to form a composite. The NaCl is subsequently leached out with water, to leave a network of open pores, of volume fraction roughly varying between 65 and 90% [15], The foams can be produced to feature good microstructural homogeneity over a comparatively wide range of metal alloy compositions, pore size and component shape. They furthermore serve as attractive model materials for the investigation of microstructure/property relations in metal foams because of their macroscopically uniform and fine-scale microstructure, and because the metal making the foam can be varied with relatively wide latitude and produced free of internal defects. 

Wright et al. (23-24) discussed the elastic response of TPV using the micro-cellular modeling, in which three types of deformation such as elastic and plastic deformation of PP, elastic deformation of EPDM, and localized elastic and plastic rotation about PP junction points were considered. Their microcellular model suggests that EPDM domains are surrounded by the PP struts and the struts are connected with hinges. They were successful to elucidate the permanent deformation and stiffness and stress-strain relation of TPV. 

Alavi, S. H., Rizvi, S. S. H., and Harriott, P. 2003b. Process-dynamics of starch-based microcellular foams produced by supercritical fluid extrusion. I Model development FoodRes Int 36 309-19. 

Kumar V., Wella- J. E., A Model for the Unfoamed Skin on Microcellular Foams, Polymer Engineering and Science, 34 (3) 169-173 (1994). 

As a first step, in the present work, the microcellular poroelastic foams under study are considered as rigid and their acoustics described by the JCA model. That is, the mechanical properties are not considered in this initial study. The approach that is taken to characterize the acoustical performance is as follow. First a morphological characterization of the microcellular stracture will be performed using the Scanning Electron Microscope in order to determine average cell (pore) dimensions. Then, basic acoustical measmements (mainly, porosity, flow... 

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