Stress concentration factor of foamed materials used for cores of sandwich composites

Abstract

The numerical finite element method was used to identify the stress concentration factor of the structure of foamed polymer material under tensile loading by constant strain and depending on cell form, orientation, and geometrical parameters. It was determined that the value of the stress concentration factor depends upon both the form and the orientation of the cell with respect to the loading direction. It was also determined that the higher ratio of the thickness to the length of the edge of the cell is, the higher the stress concentration factor is. The low stress concentration factor is when the angle between edges is approximately 90° and the rounding radius of this angle is from 0.25R to 0.4R (R is maximal rounding radius), angle between cell edges, and the direction of loading is equal to 45°.

First Published Online: 14 Oct 2010

Keyword : stress concentration factor, foamed material, structure, cell geometry, finite element modelling, sandwich composites, core, matrix