Impact response of high density flexible polyurethane foam(7)

The dynamic tensile(spall)strength of the studied foam was found to be very low,w0.3MPa,some10times lower than expected for such foam under quasi-static tension.Such low resistance of the foam to the tensile stress may be caused by the considerable damage suffered by the foam under shock compression.

To summarize,the VISAR-instrumented gun-driven planar impact experiment is a useful tool for obtaining constitutive information about low-impedance materials under strain rates ranging from103to106sÀ1.

References

[1]Gibson LJ,Ashby MF.Cellular solids,structure and properties.2nd ed.Cam-

bridge:Cambridge University Press;1999.

[2]Kraynik AM,Nielsen MK,Reinelt DA,Warren WE.Foam micromechanics.In:

Sadoc JF,River N,editors.Foams and herlands:Kluwer Academic Publishers;1999.

[3]Lankford J,Dannemann KA.Strain rate effects in porous materials.In:

Schwartz DS,Shih DS,Evans AG,Wadley HNG,editors.Porous and cellular materials for structural applications.Warrendale,PA:Materials Research Society;1998.p.103e8.

[4]Progelhof RC.Impact measurement of low-pressure thermoplastic structural

foam.In:Kessler SL,Adams GC,Driscoll SB,Ireland DR,editors.Proceedings of instrumented impact testing of plastics and composite materials.Houston (TX):ASTM STP936;1986.p.105e16.

[5]Shim VPW,Tu ZH,Lim CT.Two-dimensional response of crushable poly-

urethane foam to low velocity impact.Int Journ.of Impact Eng2000;24: 703e31.

[6]Ramon O,Miltz J.Prediction of dynamic properties of plastic foams from

constant-strain rate measurements.Journ Appl Polym Sci1990;40:1683e92.

[7]Sounik DF,Gansen P,Clemons JL,Liddle JW.Head-impact testing of polyurethane

energy-absorbing(EA)foams.J Mater Manufacturing1997;106(5):211e20.

[8]Chen W,Lu F,Winfree N.High-strain-rate compressive behavior of a rigid

polyurethane foam with various densities.Exp Mech2002;42:65e73.

[9]Song B,Chen W,Dou S,Winfree N,Kang J.Strain-rate effects on elastic and

early cell-collapse responses of a polystyrene foam.Int Journ Impact Eng 2005;31:509e21.

[10]Song B,Lu W-Y,Chen W.Strain-rate e temperature superposition behavior of

Polymethylene Diisocyanate(PMDI)based rigid polyurethane foams with different densities.DYMAT2009;2009:1251e6.

[11]Chen W,Song B,Frew DJ,Forrestal MJ.Dynamic small strain measurements of

a metal specimen with a split Hopkinson pressure bar.Exp Mech2003;43:

20e3.

[12]Kanel G,Razorenov SV,Fortov VE.Shock wave phenomena and the properties

of condensed matter.New-York,Berlin,Heidelberg:Springer;2004.p.33. [13]Barker LM,Hollenbach ser interferometer for measuring high velocities

of any reflecting surface.J Appl Phys1972;43(11):4669e75.

[14]Grady DE.Structured shock waves and the fourth-power law.J Appl Phys

2010;107:013506.

[15]Duval GE,Graham RA.Phase transitions under shock-wave loading.Rev Mod

Phys1977;49(3):523e79.

[16]Mateen A,Shamim A.Thermal expansion of rigid polyurethane,reinforced by

hammer-milled glassfibre.J Mater Sci Lett1989;8:927e30.

[17]Maw JR,Whitworth NJ,Holland RB.Multiple shock compression of poly-

urethane and syntactic foams.In:Schmidt SC,Tao WC,editors.Shock compression of condensed matter-1995;AIP Conference Proceedings270.

Woodberry,NY:American Institute of Physics;1996.p.133e6.

[18]Liao SK,Jang SC,Lin MF.Phase behavior and mechanical properties of

siloxane-urethane copolymer.J Polymer Res2005;12(2):103e12.

[19]Antoun T,Seaman L,Curran D,Kanel GI,Razorenov SV,Utkin AV.Spall frac-

ture.New-York,Berlin,Heidelberg:Springer;2002.pp.90,99.

[20]Datta J,Kacprzy M.Thermal analysis and static strength of polyurethanes

obtained from glycolisates.J Thermal Anal Calorimetry2008;93(3):753e7. [21]Smith TL.Tensile strength of polyurethane and other elastomeric block

copolymers.J Polymer Science:Polymer Physics Edition1974;12: 1825e48.

[22]Jellinek HHG,Martin F,Wegener H.Tensile strength of polyurethane exposed

to nitrogen dioxide.J Applied Polymer Science1974;18:1773e8.

E.Zaretsky et al./International Journal of Impact Engineering39(2012)1e77