Experimental Mechanics

, Volume 58, Issue 8, pp 1311–1324 | Cite as

A New Technique for Characterization of Low Impedance Materials at Acoustic Frequencies

  • W. Nantasetphong
  • Z. Jia
  • M.A. Hasan
  • A.V. Amirkhizi
  • S. Nemat-Nasser


Measuring the mechanical properties of low impedance rubbery polymers at acoustic frequencies is a challenging problem due to the small signal amplitudes, relatively high loss, and the long wavelength of stress waves. One such material is solid polyurea (PU), an elastomeric copolymer, which has excellent chemical, thermal, and mechanical properties and is widely used as a coating (e.g. in truck bed lining) or blast protection (advanced helmet designs and concrete structures) material. Moreover, due to its heterogeneous structure, PU has a wide transition of thermo-mechanical behavior from rubber-like to glassy compared to most engineering polymers, which translates to a broader loss spectrum in frequency domain. In this study, we have developed a new test technique by modifying the split Hopkinson pressure bar and using ball impact to measure Young’s storage and loss moduli of polyurea at kHz frequencies. This will therefore fill the frequency gap between the dynamic mechanical analysis (DMA) and ultrasonic (US) wave measurement. The measured Young’s storage and loss moduli from this technique are compared with the master curves of the moduli developed using experimental data of dynamic mechanical analysis and ultrasonic wave measurements. This technique is a direct measurement which provides more reliable data in the kHz frequency range and can be used to evaluate the reliability of other indirect estimations including master curves. The utility of this technique is not limited to polyurea and it can be used to characterize other low impedance materials at kHz frequencies.


Low impedance materials Polyurea Low frequency wave propagation Modified Hopkinson bar Impact 



The experiments described in this paper were conducted at the Center of Excellence for Advanced Materials (CEAM) at the University of California, San Diego. The work was supported through ONR Grant N00014-09-1-1126 and DARPA Grant RDECOM W91CRB-10-1-0006 to University of California, San Diego and ONR Grants N00014-13-1-0392 and N00014-16-1-2458 to University of Massachusetts, Lowell.


  1. 1.
    Brinson J (2013) Ultra-violet radiation effect on the mechanical properties polyurea. PhD thesis, California State University, NorthridgeGoogle Scholar
  2. 2.
    Davidson JS, Fisher JW, Hammons MI, Porter JR, Dinan RJ (2005) Failure mechanisms of polymer-reinforced concrete masonry walls subjected to blast. J Struct Eng 131(8): 1194–1205CrossRefGoogle Scholar
  3. 3.
    Tekalur SA, Shukla A, Shivakumar K (2008) Blast resistance of polyurea based layered composite materials. Compos Struct 84(3):271–281CrossRefGoogle Scholar
  4. 4.
    Amini MR, Isaacs J B, Nemat-Nasser S (2010) Experimental investigation of response of monolithic and bilayer plates to impulsive loads. Int J Impact Eng 37(1):82–89CrossRefGoogle Scholar
  5. 5.
    Mohotti D, Ngo T, Mendis P, Raman SN (2013) Polyurea coated composite aluminium plates subjected to high velocity projectile impact. Mater Des 52:1–16CrossRefGoogle Scholar
  6. 6.
    Barsoum RGS (2015) Elastomeric polymers with high rate sensitivity: applications in blast, shockwave, and penetration mechanics. William Andrew, OxfordGoogle Scholar
  7. 7.
    Jia Z, Amirkhizi AV, Nantasetphong W, Nemat-Nasser S (2016) Experimentally-based relaxation modulus of polyurea and its composites. In: Mechanics of time-dependent materials, pp 1–20Google Scholar
  8. 8.
    TA Instruments (1997) DMA 2980: dynamic mechanical analyzer operator’s manualGoogle Scholar
  9. 9.
    Ultran Laboratories Inc. Modern ultrasonic transducers including phenomenally high sensitivity and high frequency non-contact transducersGoogle Scholar
  10. 10.
    Truell R, Elbaum C, Chick BB (2013) Ultrasonic methods in solid state physics. Academic, New YorkGoogle Scholar
  11. 11.
    Krautkrämer J, Krautkrämer H (2013) Ultrasonic testing of materials. Springer Science & Business MediaGoogle Scholar
  12. 12.
    Nemat-Nasser S, Sadeghi H, Amirkhizi AV, Srivastava A (2015) Phononic layered composites for stress-wave attenuation. Mech Res Commun 68:65–69CrossRefGoogle Scholar
  13. 13.
    Hopkinson B (1914) A method of measuring the pressure produced in the detonation of high explosives or by the impact of bullets. Philos Trans R Soc Lond Ser A, Containing Papers of a Mathematical or Physical Character 213:437–456CrossRefGoogle Scholar
  14. 14.
    Kolsky H (1949) An investigation of the mechanical properties of materials at very high rates of loading. Proc Phys Soc London, Sect B 62(11):676CrossRefGoogle Scholar
  15. 15.
    Harding J, Wood EO, Campbell JD (1960) Tensile testing of materials at impact rates of strain. J Mech Eng Sci 2(2):88–96CrossRefGoogle Scholar
  16. 16.
    Duffy J, Campbell JD, Hawley RH (1971) On the use of a torsional split hopkinson bar to study rate effects in 1100-0 aluminum. J Appl Mech 38(1):83–91CrossRefGoogle Scholar
  17. 17.
    Nemat-Nasser S, Isaacs JB, Starrett JE (1991) Hopkinson techniques for dynamic recovery experiments. Proc R Soc Lond A: Math Phys Eng Sci 435:371–391CrossRefGoogle Scholar
  18. 18.
    Nesterenko V (2013) Dynamics of heterogeneous materials. Springer Science & Business MediaGoogle Scholar
  19. 19.
    Starosvetsky Y, Vakakis AF (2011) Primary wave transmission in systems of elastic rods with granular interfaces. Wave Motion 48(7):568–585CrossRefzbMATHGoogle Scholar
  20. 20.
    Sachse W, Pao Y-H (1978) On the determination of phase and group velocities of dispersive waves in solids. J Appl Phys 49(8):4320–4327CrossRefGoogle Scholar
  21. 21.
    Kline RA (1984) Measurement of attenuation and dispersion using an ultrasonic spectroscopy technique. J Acoust Soc Am 76(2):498–504CrossRefGoogle Scholar
  22. 22.
    Pialucha T, Guyott CCH, Cawley P (1989) Amplitude spectrum method for the measurement of phase velocity. Ultrasonics 27(5):270–279CrossRefGoogle Scholar
  23. 23.
    Kinra VK, Ker E (1982) Effective elastic moduli of a thin-walled glass microsphere/pmma composite. J Compos Mater 16(2):117–138CrossRefGoogle Scholar
  24. 24.
    Chen W, Zhang B, Forrestal MJ (1999) A split hopkinson bar technique for low-impedance materials. Exp Mech 39(2):81–85CrossRefGoogle Scholar
  25. 25.
    Zhao H, Gary G (1995) A three dimensional analytical solution of the longitudinal wave propagation in an infinite linear viscoelastic cylindrical bar. application to experimental techniques. J Mech Phys Solids 43(8):1335–1348MathSciNetCrossRefzbMATHGoogle Scholar
  26. 26.
    Zhao H, Gary G, Klepaczko JR (1997) On the use of a viscoelastic split hopkinson pressure bar. Int J Impact Eng 19(4):319–330CrossRefGoogle Scholar
  27. 27.
    Sawas O, Singh Brar N, Brockman RA (1998) Dynamic characterization of compliant materials using an all-polymeric split hopkinson bar. Exp Mech 38(3):204–210CrossRefGoogle Scholar
  28. 28.
    Bacon C (1998) An experimental method for considering dispersion and attenuation in a viscoelastic hopkinson bar. Exp Mech 38(4):242–249CrossRefGoogle Scholar
  29. 29.
    Kulite Semiconductor Products Inc (2012) Kulite Strain Gage ManualGoogle Scholar
  30. 30.
    Jayaprakash KR, Starosvetsky Y, Vakakis AF, Gendelman OV (2013) Nonlinear resonances leading to strong pulse attenuation in granular dimer chains. J Nonlinear Sci 23(3):363–392MathSciNetCrossRefzbMATHGoogle Scholar
  31. 31.
    Hasan MA, Cho S, Remick K, Vakakis AF, McFarland DM, Kriven WM (2013) Primary pulse transmission in coupled steel granular chains embedded in pdms matrix: experiment and modeling. Int J Solids Struct 50(20):3207–3224CrossRefGoogle Scholar
  32. 32.
    Potekin R, Jayaprakash KR, McFarland DM, Remick K, Bergman LA, Vakakis AF (2013) Experimental study of strongly nonlinear resonances and anti-resonances in granular dimer chains. Exp Mech 53(5):861–870CrossRefGoogle Scholar
  33. 33.
    Wang E, Geubelle P, Lambros J (2013) An experimental study of the dynamic elasto-plastic contact behavior of metallic granules. J Appl Mech 80(2):021009CrossRefGoogle Scholar
  34. 34.
    Herbold EB, Nesterenko VF (2007) Shock wave structure in a strongly nonlinear lattice with viscous dissipation. Phys Rev E 75(2):021304CrossRefGoogle Scholar
  35. 35.
    Lifshitz JM, Leber H (1994) Data processing in the split hopkinson pressure bar tests. Int J Impact Eng 15(6):723–733CrossRefGoogle Scholar
  36. 36.
    Randall D, Lee S (2002) The polyurethanes book. Wiley, New YorkGoogle Scholar
  37. 37.
    Qiao J, Amirkhizi AV, Schaaf K, Nemat-Nasser S, Wu G (2011) Dynamic mechanical and ultrasonic properties of polyurea. Mech Mater 43(10):598–607CrossRefGoogle Scholar
  38. 38.
    Esquivel-Sirvent R, Cocoletzi GH (1994) Band structure for the propagation of elastic waves in superlattices. J Acoust Soc Am 95(1):86–90CrossRefGoogle Scholar
  39. 39.
    Cai C, Liu GR, Lam KY (2001) A transfer matrix approach for acoustic analysis of a multilayered active acoustic coating. J Sound Vib 248(1):71–89CrossRefGoogle Scholar
  40. 40.
    Nantasetphong W, Jia Z, Amirkhizi AV, Nemat-Nasser S (2016) Dynamic properties of polyurea-milled glass composites part i: experimental characterization. Mech Mater 98:142–153CrossRefGoogle Scholar
  41. 41.
    Qiao J, Nantasetphong W, Amirkhizi AV, Nemat-Nasser S (2016) Ultrasonic properties of fly ash/polyurea composites. Mater Des 89:264–272. CrossRefGoogle Scholar
  42. 42.
    Williams ML, Landel RF, Ferry JD (1955) The temperature dependence of relaxation mechanisms in amorphous polymers and other glass-forming liquids. J Am Chem Soc 77(14): 3701–3707CrossRefGoogle Scholar

Copyright information

© Society for Experimental Mechanics 2018

Authors and Affiliations

  • W. Nantasetphong
    • 1
  • Z. Jia
    • 2
  • M.A. Hasan
    • 3
  • A.V. Amirkhizi
    • 4
  • S. Nemat-Nasser
    • 3
  1. 1.SCG Chemicals Co., Ltd.BangkokThailand
  2. 2.Department of Mechanical EngineeringThe University of ConnecticutStorrsUSA
  3. 3.Center of Excellence for Advanced Materials, Department of Mechanical and Aerospace EngineeringUniversity of California, San DiegoLa JollaUSA
  4. 4.Department of Mechanical EngineeringUniversity of Massachusetts, LowellLowellUSA

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