Characterization and constitutive modeling of polymeric foams under static and dynamic loading

I. M. Daniel*, J. M. Cho, B. T. Werner

*Corresponding author for this work

Research output: Contribution to conferencePaperpeer-review

Abstract

The material investigated was an orthotropic/transversely isotropic polymeric foam commonly used in sandwich structures and exhibiting strain-rate-dependent elastic/viscoplastic behavior. This material was a closed cell PVC foam, (Divinycell H250), having a density of 250 kg/m 3. It was characterized under quasi-static and dynamic loading and a constitutive model was proposed to describe its nonlinear behavior at varying strain rates. Quasi-static (5×10 -4 s -1) and intermediate (3 s -1) strain rate tests were conducted in a servo-hydraulic machine. High strain rate tests (10 3 s -1) were conducted in a split Hopkinson (Kolsky) Pressure Bar (SHPB). This SHPB system was made of polymeric (polycarbonate) bars. The polycarbonate material has an impedance that is closer to that of foam than metals. The stiffness, based on the initial slope of the stress-strain curves, did not vary with strain rate. Four characteristic properties were identified in the compressive stress-strain curves: 1) Yield stress, 2) Peak or "critical" stress corresponding to collapse initiation of the cells, 3) Plateau stress following the initial collapse of the cells, and 4) Strain hardening stress at the end of the plateau region and before the onset of densification. All of the above characteristic stresses vary linearly with the logarithm of strain rate. A nonlinear constitutive model was proposed based on a potential function in the form of a linear combination of deviatoric and dilatational deformation components. A unified (master) constitutive model with built-in strain rate dependence was formulated and was shown to be in very good agreement with experimental results.

Original languageEnglish (US)
StatePublished - Dec 1 2011
Event2nd Joint US-Canada Conference on Composites - American Society for Composites, 26th Annual Technical Conference: Canadian Association for Composite Structures and Materials - Montreal, QC, Canada
Duration: Sep 26 2011Sep 28 2011

Other

Other2nd Joint US-Canada Conference on Composites - American Society for Composites, 26th Annual Technical Conference: Canadian Association for Composite Structures and Materials
CountryCanada
CityMontreal, QC
Period9/26/119/28/11

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Mechanics of Materials
  • Ceramics and Composites

Fingerprint Dive into the research topics of 'Characterization and constitutive modeling of polymeric foams under static and dynamic loading'. Together they form a unique fingerprint.

Cite this