Interface Chemistry Dependent Mechanical Properties in Energetic Materials Using Nano-Scale Impact Experiment

  • Ayotomi Olokun
  • Chandra Prakash
  • I. Emre Gunduz
  • Vikas TomarEmail author
Conference paper
Part of the Conference Proceedings of the Society for Experimental Mechanics Series book series (CPSEMS)


Energetic materials are sensitive to mechanical shock and defects caused by a high velocity impact, which may result in unwanted detonation due to hot-spot formation. In order to understand the underlying mechanism, characterization of high strain rate mechanical properties needs to be studied. One of the key factors that can contribute to this type of defect is the failure initiated at the interfaces such as those between Hydroxyl-terminated polybutadiene (HTPB)-HMX (or HTPB-Ammonium Perchlorate (AP)). In this work, interface mechanical properties of HTPB-HMX (and HTPB-AP) interfaces are characterized using nano-scale impact experiments at strain rates up to 100 s−1. The experiments were conducted with impactor of radius 1 μm on the interfaces with varying amount of binding agent. For HTPB-AP samples, Tepanol is used as the binding agent. The impact response is determined in the bulk HTPB, HMX, and AP as well as at the HTPB-HMX and HTPB-AP interfaces. A power law viscoplastic constitutive model is fitted to experimental stress-strain-strain rate data which can be used in Finite Element Model simulation to predict the shock behavior of energetic materials. An in-situ mechanical Raman spectroscopy (MRS) setup was used to analyze the effect of interface chemistry on interface level stress variation. The stress distribution near the interface captures the effect of interface chemistry variation.


Energetic material MRS HTPB HMX AP 



This research was supported by US-AFoSR Grant FA9550-15-1-0202 (Program Manager Dr. Martin Schmidt).


  1. 1.
    Benson, D.J., Conley, P.: Eulerian finite-element simulations of experimentally acquired HMX microstructures. Modelling Simul. Mater. Sci. Eng. 7, 333–354 (1999)CrossRefGoogle Scholar
  2. 2.
    Palmer, S.J.P., Field, J.E., Huntley, J.M.: Deformation, strengths and strains to failure of polymer bonded explosives. Proc. R. Soc. A: Math.. Phys. Eng. Sci. 440, 399–419 (1993)CrossRefGoogle Scholar
  3. 3.
    Tan, H., Huang, Y., Liu, C.: The viscoelastic composite with interface debonding. Compos. Sci. Technol. 68(15–16), 3145–3149 (2008)CrossRefGoogle Scholar
  4. 4.
    Verma, D., Prakash, C., Tomar, V.: Properties of material interfaces: dynamic local versus nonlocal. In: Voyiadjis, G. (ed.) Handbook of Nonlocal Continuum Mechanics for Materials and Structures, pp. 1–16. Springer, Cham (2017)Google Scholar
  5. 5.
    Verma, D., Prakash, C., Tomar, V.: Interface mechanics and its correlation with plasticity in polycrystalline metals, polymer composites, and natural materials. Procedia Eng. 173, 1266–1274 (2017)CrossRefGoogle Scholar
  6. 6.
    Prakash, C., et al.: Strain rate dependent failure of interfaces examined via nanoimpact experiments. Challenges in Mechanics of Time Dependent Materials, 2017. 2: p. Conference Proceedings of the Society for Experimental Mechanics SeriesGoogle Scholar
  7. 7.
    Prakash, C., et al.: Effect of interface chemistry and strain rate on particle-matrix delamination in an energetic material. Eng. Fract. Mech. 191C, 46–64 (2018)CrossRefGoogle Scholar
  8. 8.
    Verma, D., Exner, M., Tomar, V.: An investigation into strain rate dependent constitutive properties of a sandwiched epoxy interface. Mater. Des. 112, 345–356 (2016)CrossRefGoogle Scholar
  9. 9.
    Tsai, J., Sun, C.T.: Constitutive model for high strain rate response of polymeric composites. Compos. Sci. Technol. 62, 1289–1297 (2002)CrossRefGoogle Scholar
  10. 10.
    Prakash, C., et al.: Effect of interface chemistry and strain rate on particle-matrix delamination in an energetic material. Eng. Fract. Mech. 191, 46–64 (2018)CrossRefGoogle Scholar

Copyright information

© The Society for Experimental Mechanics, Inc. 2019

Authors and Affiliations

  • Ayotomi Olokun
    • 1
  • Chandra Prakash
    • 1
  • I. Emre Gunduz
    • 2
  • Vikas Tomar
    • 1
    Email author
  1. 1.School of Aeronautics and AstronauticsPurdue UniversityWest LafayetteUSA
  2. 2.School of Mechanical EngineeringPurdue UniversityWest LafayetteUSA

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