Creep-buckling of open-cell foams

✍ Scribed by Ting-Jung Chen; Jong-Shin Huang

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 362 KB
• Volume: 57
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/j.actamat.2008.11.038

✦ Synopsis

A repeating element composed of four cell struts in a pentagonal dodecahedron model is used to analyze the creep-buckling of opencell foams. The solid making up the cell struts is assumed to follow power-law creep. As a result, the theoretical expression for describing the failure time for the onset of creep-buckling of open-cell foams under uniaxial compression is obtained. Theoretical results indicate that the creep-buckling of open-cell foams depends on their relative density and microstructural imperfection and the creep parameters of solid cell struts. Furthermore, a simple relationship between creep strain rate and failure time is proposed for the creep-buckling of opencell foams and then compared to the existing experimental results; they agree well. In addition, cell-strut creep-buckling is the dominant failure mechanism when the imposed compressive stress is close to the elastic buckling strength of open-cell foams. However, cell-strut creep-rupturing is more likely to occur when the imposed compressive stress becomes smaller. Moreover, the transition of failure mechanism from cell-strut creep-buckling to cell-strut creep-rupturing is discussed.