Characterisation and Modelling of a Melt-Extruded LDPE Closed Cell Foam

Abstract:

This paper describes uniaxial compression tests on a melt-extruded closed-cell Low-Density Polyethylene (LDPE) foam. The stress-strain response shows the mechanical behaviour of the foam is predominantly transversely isotropic viscoelastic and compressible. Images analysis is used to estimate the Poisson’s ratio under large strains. When the deformation is less than 5 percent, the kinematics and mechanical response of the polymer foam can be well-described by a linear compressible transversely isotropic elastic model. For large strain, a method of manipulating experimental data obtained from testing in the principal and transverse directions (stress vs strain and Poisson’s ratio) in order to estimate the uniaxial compression response of the foam at any arbitrary orientation is proposed. An isotropic compressible hyperfoam model is then used to implement this behaviour in a finite element code.

• Periodical: Applied Mechanics and Materials (Volume 70)
• Pages: 105-110
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.70.105
• Online since: August 2011
• Authors: Qusai Hatem Jebur, Philip Harrrison, Zao Yang Guo, Gerlind Schubert, Vincent Navez
• Keywords: Closed-Cell Compressible Foam, Poisson's Ratio, Transverse Isotropy, Uniaxial Compression

References

[1] L.G. Gibson and M.F. Ashby: Cellular solids structure and properties, Cambridge University press, 2nd edition, (1997).

[2] N.J. Mills: engineering and biomechanics applications and design guide, Butterworth- Heinemann, (2007).

[3] M.D. Isac and I. Ori: Engineering mechanics of composite materials, Oxford University press, (1994).

[4] X.X. Wei and K.T. Chau: Finite and transversely isotropic elastic cylinders under compression with end constraint induced by friction, International Journal of Solids and Structures, Vol 46(9), (2009), p.1953-(1965).

DOI: 10.1016/j.ijsolstr.2009.01.007

[5] R.W. Ogden: Large deformation isotropic elasticity correlation of theory and experiment for in compressible rubber like solids, Proceedings of the Royal Society of London Series a-Mathematical and Physical Sciences, Vol 326(1573), (1972).

DOI: 10.1098/rspa.1972.0096

[6] R.W. Ogden: Non-linear elastic deformations, Dover, New York (1997).

[7] R.D. Widdle, A.K. Bajaj and P. Davies: Measurement of the Poisson's ratio of flexible polyurethane foam and its influence on a uniaxial compression model, International Journal of Engineering Science, Vol 46(1), (2008), pp.31-49.

DOI: 10.1016/j.ijengsci.2007.09.002

[8] S. Jemiolo and J.J. Telega: Transversely isotropic materials undergoing large deformations and application to modelling of soft tissues, Mechanics Research Communications, Vol 28(4), (2001), pp.397-404.

DOI: 10.1016/s0093-6413(01)00189-6

[9] V.L. Tagarielli, V.S. Deshpande, N.A. Fleck and N.A. Chen: A constitutive model for transversely isotropic foams, and its application to the indentation of balsa wood, International Journal of Mechanical Sciences, Vol 47(4-5), (2005), pp.666-686.

DOI: 10.1016/j.ijmecsci.2004.11.010

[10] British Standard: BS ISO 844 Cellular plastics – Compression test for rigid materials – Specifications, (1998).

[11] D. Haojiang, C. Weiqiu and Z. Liangchi: Elasticity of transversely isotropic Materials, Springer, (2006).

[12] E.H. Twizell and R.W. Ogden: Non-Linear optimization of the material constants in Ogden's stress-deformation function for incompressible isotropic elastic materials, Austral. Math. Soc. Ser. B, Vol 24, (1983), p.424–434.

DOI: 10.1017/s0334270000003787

[13] G. A. Holzapfel: Nonlinear solid mechanics, John Wiley and Sons, (2000).

[14] Information on http: http: /rsbweb. nih. gov/ij/index. html.

[15] ABAQUS User manual version 6. 8 Section 18. 2. 1: Linear elastic behaviour, (2008).

[16] British Standard: BS ISO 1922 Rigid cellular plastics — Determination of shear strength, (2001).

[17] ABAQUS User manual version 6. 8 Section 3. 1. 5: Fitting of elastomeric foam test data, (2008).