Abstract
Epoxy is a widely used thermosetting polymer in various engineering fields to develop composites. Studying its damage and fracture behaviour under various loading conditions is highly important. In this work, a micromechanics-based damage model is developed for understanding the damage initiation and growth in epoxy. To support this damage model, tests are performed for obtaining mechanical properties and to study the damage behaviour of epoxy. Diglycidyl ether of bisphenol A (DGEBA) resin with triethylenetetramine (TETA) hardener in 10:1 ratio are mixed and cured to make the epoxy. To give a physical meaning to damage, the model quantifies the damage as volume fraction of a spherical void in a unit representative volume element (RVE) of epoxy material. Degraded effective properties are computed for damaged RVE using standard mechanics-based micromechanical approach. A second-degree polynomial is established for effective stiffness with damage at any loading instance. This functional form of degraded stiffness in terms of damage is used in constitutive relations. A strain energy- based approach is used to compute thermodynamic forces, a state variable used for the evolution of damage. A damage evolution model is proposed with two material-specific parameters which are determined using experimental tests. The model is implemented by user material subroutine (UMAT) in commercial finite element software, Abaqus/Standard. The proposed model accurately captures the tensile behaviour of the epoxy material and gives capability to simulate an epoxy material’s damage behaviour from its initiation till failure or macrolevel rupture under uniaxial tensile loading. The developed model predicts the behaviour of the material in agreement with experimental results.
Similar content being viewed by others
References
Kachanov, L.: Time of the rupture process under creep conditions. Isv. Akad. Nauk. SSR. Otd Tekh. Nauk 8, 26–31 (1958)
Rabotnov, Y.N.: Creep Rupture, in: Applied mechanics, pp. 342–349. Springer, Berlin (1969)
Chaboche, J.-L.: Continuous damage mechanics—a tool to describe phenomena before crack initiation. Nuclear Eng. Des. 64(2), 233–247 (1981)
Janson, J.: Damage model of crack growth and instability. Eng. Fract. Mech. 10(4), 795–806 (1978)
Mazars, J., Pijaudier-Cabot, G.: From damage to fracture mechanics and conversely: a combined approach. Int. J. Solids Struct. 33(20), 3327–3342 (1996)
Daudeville, L., Allix, O., Ladeveze, P.: Delamination analysis by damage mechanics: some applications. Compos. Eng. 5(1), 17–24 (1995)
Allix, O., Leveque, D., Perret, L.: Identification and forecast of delamination in composite laminates by an interlaminar interface model. Compos. Sci. Technol. 58(5), 671–678 (1998)
Ladevèze, P., Allix, O., Gornet, L., Lévêque, D., Perret, L.: A computational damage mechanics approach for laminates: identification and comparison with experimental results. Stud. Appl. Mech. 46, 481–500 (1998)
Ladeveze, P., Allix, O., Daudeville, L.: Mesomodeling of Damage for Laminate Composites: Application to Delamination, in: Inelastic Deformation of Composite Materials. Springer, New York (1991)
Ladevèze, P., Lubineau, G.: On a damage mesomodel for laminates: micro–meso relationships, possibilities and limits. Compos. Sci. Technol. 61(15), 2149–2158 (2001)
Hill, R.: Elastic properties of reinforced solids: some theoretical principles. J. Mech. Phys. Solids 11(5), 357–372 (1963)
Hill, R.: Theory of mechanical properties of fibre-strengthened materials: I. Elastic behaviour. J. Mech. Phys. Solids 12(4), 199–212 (1964)
Dassault Systèmes.: Abaqus 6.10 online documentation. Dassault Systèmes, Providence, Rhode Island (2010)
Hibbitte, K.: Abaqus user subroutines reference manual. HKS INC (2005)
Allaoui, A., Bai, S., Cheng, H.-M., Bai, J.: Mechanical and electrical properties of a MWNT/epoxy composite. Compos. Sci. Technol. 62(15), 1993–1998 (2002)
Schadler, L.S., Giannaris, S.C., Ajayan, P.M.: Load transfer in carbon nanotube epoxy composites. Appl. Phys. Lett. 73(26), 3842–3844 (1998). doi:10.1063/1.122911. http://scitation.aip.org/content/aip/journal/apl/73/26/10.1063/1.122911
Gojny, F.H., Wichmann, M.H.G., Köpke, U., Fiedler, B., Schulte, K.: Carbon nanotube-reinforced epoxy-composites: enhanced stiffness and fracture toughness at low nanotube content. Compos. Sci. Technol. 64(15) 2363–2371 (2004)
Alvarez, V., Valdez, M., Vzquez, A.: Dynamic mechanical properties and interphase fiber/matrix evaluation of unidirectional glass fiber/epoxy composites. Polym. Test.22(6), 611–615 (2003). doi:10.1016/S0142-9418(02)00164-2. http://www.sciencedirect.com/science/article/pii/S0142941802001642
Yang, B., Kozey, V., Adanur, S., Kumar, S.: Bending, compression, and shear behavior of woven glass fiber–epoxy composites. Compos. Part B Eng. 31(8), 715–721 (2000). doi:10.1016/S1359-8368(99)00052-9. http://www.sciencedirect.com/science/article/pii/S1359836899000529
W. Goertzen, M. Kessler, Creep behavior of carbon fiber/epoxy matrix composites. Mater. Sci. Eng. A 421(12) (2006) 217–225. In: Internal Stress and Thermo-Mechanical Behavior in Multi-component Materials Systems, (TMS) Annual Meeting, 2004. doi:10.1016/j.msea.2006.01.063. http://www.sciencedirect.com/science/article/pii/S0921509306001390
Dong, S., Gauvin, R.: Application of dynamic mechanical analysis for the study of the interfacial region in carbon fiber/epoxy composite materials. Polym. Compos. 14(5), 414–420 (1993). doi:10.1002/pc.750140508
Choi, N., Kinloch, A., Williams, J.: Delamination fracture of multidirectional carbon-fiber/epoxy composites under mode i, mode ii and mixed-mode i/ii loading. J. Compos. Mater. 33(1), 73–100 (1999)
Yokozeki, T., Aoki, Y., Ogasawara, T.: Experimental characterization of strength and damage resistance properties of thin-ply carbon fiber/toughened epoxy laminates. Compos. Struct. 82(3), 382–389 (2008). doi:10.1016/j.compstruct.2007.01.015. http://www.sciencedirect.com/science/article/pii/S0263822307000219
Wang, X., Chung, D.D.L.: Short-carbon-fiber-reinforced epoxy as a piezoresistive strain sensor. Smart Mater. Struct. 4(4), 363 (1995). http://stacks.iop.org/0964-1726/4/i=4/a=017
Wang, X., Chung, D.D.L.: Real-time monitoring of fatigue damage and dynamic strain in carbon fiber polymer-matrix composite by electrical resistance measurement. Smart Mater. Struct. 6(4), 504 (1997). http://stacks.iop.org/0964-1726/6/i=4/a=017
Chevalier, J., Morelle, X., Bailly, C., Camanho, P., Pardoen, T., Lani, F.: Micro-mechanics based pressure dependent failure model for highly cross-linked epoxy resins. Eng. Fract. Mech. 158, 1–12 (2016)
Thomas, G.K.: Progressive delamination in unidirectional composites. unpublished M.Tech. thesis (2013)
Suquet, P.: Elements of homogenization for inelastic solid mechanics. Homog. Tech. Compos. Media 272, 193–278 (1987)
Herakovich, C.T.: Mechanics of fibrous composites. Wiley, New York (1998)
Ward, I.M., Sweeney, J.: Mechanical Properties of Solid Polymers. Wiley, Hoboken (2012)
Li, F., Pan, J.: Plane-stress crack-tip fields for pressure-sensitive dilatant materials. Eng. Fract. Mech. 35(6), 1105–1116 (1990)
Chang, W., Pan, J.: Effects of yield surface shape and round-off vertex on crack-tip fields for pressure-sensitive materials. Int. J. Solids Struct. 34(25), 3291–3320 (1997)
Hsu, S.-Y., Vogler, T., Kyriakides, S.: Inelastic behavior of an AS4/PEEK composite under combined transverse compression and shear. part ii: modeling. Int. J. Plast. 15(8), 807–836 (1999)
Khan, A.S., Huang, S.: Continuum Theory of Plasticity. Wiley, Hoboken (1995)
Montazeri, A., Khavandi, A., Javadpour, J., Tcharkhtchi, A.: Viscoelastic properties of multi-walled carbon nanotube/epoxy composites using two different curing cycles. Mater. Des. 31(7), 3383–3388 (2010)
ASTM D638: Standard Test Method for Tensile Properties of Plastics. American Society for Testing and Materials, Philadelphia (1998)
Davis, J.R.: Tensile Testing. ASM International, Ohino (2004)
Gilat, A., Goldberg, R.K., Roberts, G.D.: Strain rate sensitivity of epoxy resin in tensile and shear loading. J. Aerosp. Eng. 20(2), 75–89 (2007)
Acknowledgements
Authors thank technical staff of Aeromodeling Lab and Structures lab from Department of Aerospace Engineering, Indian Institute of Technology Kanpur, India for helping in the development of molds and materials.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Singh, G., Kumar, D. & Mohite, P.M. Damage modelling of epoxy material under uniaxial tension based on micromechanics and experimental analysis. Arch Appl Mech 87, 721–736 (2017). https://doi.org/10.1007/s00419-016-1219-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00419-016-1219-4