Numerical calculations of effective elastic properties of two cellular structures
Abstract
Young's moduli of regular twodimensional trusslike and eyeshaped structures are simulated using the finite element method. The structures are idealizations of soft polymeric materials used in ferroelectret applications. In the simulations, the length scales of the smallest representative units are varied, which changes the dimensions of the cell walls in the structures. A powerlaw expression with a quadratic as the exponent term is proposed for the effective Young's moduli of the systems as a function of the solid volume fraction. The data are divided into three regions with respect to the volume fraction: low, intermediate and high. The parameters of the proposed powerlaw expression in each region are later represented as a function of the structural parameters, the unitcell dimensions. The expression presented can be used to predict a structure/property relationship in materials with similar cellular structures. The contribution of the cellwall thickness to the elastic properties becomes significant at concentrations >0.15. The cellwall thickness is the most significant factor in predicting the effective Young's modulus of regular cellular structures at high volume fractions of solid. At lower concentrations of solid, the eyeshaped structure yields a lower Young's modulus than a trusslike structure with similar anisotropy. Comparison of the numerical results with those of experimental data for poly(propylene) show good aggreement regarding the influence of cellwall thickness on elastic properties of thin cellular films.
 Publication:

Journal of Physics D Applied Physics
 Pub Date:
 February 2005
 DOI:
 10.1088/00223727/38/3/023
 arXiv:
 arXiv:condmat/0404166
 Bibcode:
 2005JPhD...38..497T
 Keywords:

 Condensed Matter  Soft Condensed Matter
 EPrint:
 7 figures and 2 tables