Experimental and computation assessment of thermomechanical effects during auxetic foam fabrication

Auxetic foams continue to interest researchers owing to their unique and enhanced properties. Existing studies attest to the importance of fabrication mechanisms and parameters. However, disparity in thermo-mechanical parameters has left much debate as to which factors dominate fabrication output quality. This paper provides experimental, computational, and statistical insights into the mechanisms that enable auxetic foams to be produced, using key parameters reported within the literature: porosity; heating time; and volumetric compression ratio. To advance the considerations on manufacturing parameter dominance, both study design and scale have been optimised to enable statistical inferences to be drawn. Whilst being unusual for a manufacturing domain, such additional analysis provides more conclusive evidence of auxetic properties and highlights the supremacy of volumetric compression ratio in predicting Poisson’s ratio outcomes in the manufacture process. Furthermore statistical results are exploited to formulate key recommendations for those wishing to maximise/optimise auxetic foam production.

[1]  Kenneth E. Evans,et al.  Mass transport properties of auxetic (negative Poisson's ratio) foams , 2007 .

[2]  Peter Cloetens,et al.  In-situ deformation of an open-cell flexible polyurethane foam characterised by 3D computed microtomography , 2002 .

[3]  Sylwester Kłysz,et al.  Tests of polyurethane foams with negative Poisson's ratio , 2013 .

[4]  Fabrizio Scarpa,et al.  Shape memory behaviour in auxetic foams: mechanical properties , 2010 .

[5]  R. Lakes,et al.  Anisotropic polyurethane foam with Poisson'sratio greater than 1 , 1997 .

[6]  Ilaria Corni,et al.  The Preparation of Auxetic Foams by Three‐Dimensional Printing and Their Characteristics , 2013 .

[7]  N. Gaspar.  A granular material with a negative Poisson’s ratio , 2010 .

[8]  R. Lakes.  Foam Structures with a Negative Poisson's Ratio , 1987, Science.

[9]  K. Evans,et al.  Auxetic Materials : Functional Materials and Structures from Lateral Thinking! , 2000 .

[10]  Fabrizio Scarpa,et al.  Dynamic crushing of auxetic open-cell polyurethane foam , 2002 .

[11]  Fabrizio Scarpa,et al.  Dynamic properties of high structural integrity auxetic open cell foam , 2004 .

[12]  Kenneth E. Evans,et al.  Auxetic materials: the positive side of being negative , 2000 .

[13]  A. Bell,et al.  Effects of Heat Exposure and Volumetric Compression on Poisson's Ratios, Young's Moduli, and Polymeric Composition During Thermo‐Mechanical Conversion of Auxetic Open Cell Polyurethane Foam , 2018, physica status solidi (b).

[14]  Yi Min Xie,et al.  Experiments and parametric studies on 3D metallic auxetic metamaterials with tuneable mechanical properties , 2015 .

[15]  P. Withers,et al.  Comparison of the Mechanical Behaviour of Standard and Auxetic Foams by X‐ray Computed Tomography and Digital Volume Correlation , 2013 .

[16]  Ben Wang,et al.  Designable dual-material auxetic metamaterials using three-dimensional printing , 2015 .

[17]  Roderic S. Lakes,et al.  Design Considerations for Materials with Negative Poisson’s Ratios , 1993 .

[18]  M. Wolcott.  Cellular solids: Structure and properties , 1990 .

[19]  F. Scarpa,et al.  Shear Stiffness and Energy Absorption of Auxetic Open Cell Foams as Sandwich Cores , 2018, physica status solidi (b).

[20]  R. Lakes,et al.  Non-linear properties of polymer cellular materials with a negative Poisson's ratio , 1992 .

[21]  Q.M. Li,et al.  Degradation of Elastic Modulus of Progressively Crushable Foams in Uniaxial Compression , 2008 .

[22]  Fabrizio Scarpa,et al.  Novel generation of auxetic open cell foams for curved and arbitrary shapes , 2011 .

[23]  Philip J. Withers,et al.  In situ three-dimensional X-ray microtomography of an auxetic foam under tension , 2009 .

[24]  R. Lakes,et al.  Design of a fastener based on negative Poisson's ratio foam , 1991 .

[25]  Yan Li,et al.  On the successful fabrication of auxetic polyurethane foams: Materials requirement, processing strategy and conversion mechanism , 2016 .

[26]  Fabrizio Scarpa,et al.  Blocked Shape Memory Effect in Negative Poisson's Ratio Polymer Metamaterials. , 2016, ACS applied materials & interfaces.

[27]  Fabrizio Scarpa,et al.  Tensile fatigue of conventional and negative Poisson’s ratio open cell PU foams , 2009 .

[28]  Georgios E. Stavroulakis,et al.  Auxetic behaviour: appearance and engineering applications , 2005 .

[29]  Fabrizio Scarpa,et al.  Stiffness and energy dissipation in polyurethane auxetic foams , 2008 .

[30]  Joseph N. Grima,et al.  A novel mechanism for generating auxetic behaviour in reticulated foams: missing rib foam model , 2000 .

[31]  J. Susan Milton,et al.  Introduction to Probability and Statistics: Principles and Applications for Engineering and the Computing Sciences , 1990 .

[32]  F. Scarpa,et al.  Compressive uniaxial properties of auxetic open cell PU based foams , 2009 .

[33]  Kenneth E. Evans,et al.  The Mechanical Properties of Conventional and Auxetic Foams. Part I: Compression and Tension , 1999 .

[34]  Anna Andersson,et al.  Shear behavior of flexible polyurethane foams under uniaxial compression , 2009 .

[35]  Sylwester Kłysz,et al.  Tomographic examination of auxetic polyurethane foam structures , 2014 .

[36]  A. Alderson,et al.  Interlocking hexagons model for auxetic behaviour , 2007 .

[37]  George Henry Dunteman,et al.  Introduction To Multivariate Analysis , 1984 .

[38]  Fabrizio Scarpa,et al.  Physical and thermal effects on the shape memory behaviour of auxetic open cell foams , 2010 .

[39]  R. H. Myers.  Classical and modern regression with applications , 1986 .

[40]  Ilaria Corni,et al.  A review of the manufacture, mechanical properties and potential applications of auxetic foams , 2013 .

[41]  C. Smith,et al.  Quantitative analysis of the microscale of auxetic foams , 2005 .

[42]  P. Pimienta,et al.  Mechanical Properties , 2018, Bainite in Steels.

[43]  G. M.,et al.  Partial Differential Equations I , 2023, Applied Mathematical Sciences.

[44]  M. Cowles,et al.  On the Origins of the . 05 Level of Statistical Significance , 2005 .

[45]  Kenneth E. Evans,et al.  Fabrication methods for auxetic foams , 1997 .

[46]  A. Alderson,et al.  Manufacture and characterisation of thin flat and curved auxetic foam sheets , 2012 .

[47]  R. S. Lakes,et al.  Non-linear properties of metallic cellular materials with a negative Poisson's ratio , 1992 .

[48]  R. Lakes,et al.  Influence of Cell Size on Re-Entrant Transformation of Negative Poisson's Ratio Reticulated Polyurethane Foams , 2001 .

[49]  J. B. Park,et al.  Negative Poisson's ratio polymeric and metallic foams , 1988 .

[50]  A. Alderson,et al.  Auxetic materials , 2007 .

[51]  Zhong‐Ming Li,et al.  Review on auxetic materials , 2004 .

[52]  R. Lakes,et al.  Poisson's ratio and modern materials , 2011, Nature Materials.

[53]  Massimo Ruzzene,et al.  Auxetic compliant flexible PU foams: static and dynamic properties , 2005 .

[54]  Fabrizio Scarpa,et al.  Density change during the manufacturing process of PU–PE open cell auxetic foams , 2011 .

[55]  F. Pierron.  Identification of Poisson's ratios of standard and auxetic low-density polymeric foams from full-field measurements , 2010 .