Skip to main content

Advertisement

Log in

Rate-dependent electromechanical behavior of anisotropic fiber-reinforced dielectric elastomer based on a nonlinear continuum approach: modeling and implementation

  • Regular Article
  • Published:
The European Physical Journal Plus Aims and scope Submit manuscript

Abstract

Dielectric elastomer (DE) characteristics and potentials have led to more efficient actuators in soft robots. Meanwhile, more possibilities could be explored by incorporating other properties, including viscoelasticity and anisotropy. The present study focuses on establishing constitutive laws to capture the electromechanical coupled behavior of anisotropic viscoelastic fiber-reinforced DEs. The proposed model is presented in the framework of the strain energy function, nonlinear electro-elasticity, and nonlinear continuum mechanics approach. The derived model has been calibrated and validated using available experimental results. An Abaqus subroutine has also been developed and used for finite element simulation. Rate-dependent governing equations of a fiber-reinforced layered DE have also been considered as well as the effects of fibers direction and actuating electric field. Obtained results indicate the efficiency of the suggested model and developed subroutine in describing rate-dependency, electro-elasticity, and anisotropy. According to the findings, stiffening the bending actuator with fibers can drastically affect the deflection and force of the sample under different loading conditions.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16
Fig. 17
Fig. 18
Fig. 19
Fig. 20
Fig. 21
Fig. 22
Fig. 23
Fig. 24
Fig. 25
Fig. 26
Fig. 27
Fig. 28
Fig. 29

Similar content being viewed by others

Data Availability Statement

All data generated or analyzed during this study are included in this published article.

References

  1. R. Pelrine, R. Kornbluh, Q. Pei, J. Joseph, High-speed electrically actuated elastomers with strain greater than 100%. Science 287(5454), 836–839 (2000)

    Article  ADS  Google Scholar 

  2. S. Bauer, S. Bauer-Gogonea, I. Graz, M. Kaltenbrunner, C. Keplinger, R. Schwödiauer, 25th anniversary article: a soft future: from robots and sensor skin to energy harvesters. Adv. Mater. 26(1), 149–162 (2014)

    Article  Google Scholar 

  3. Q. Pei, M. Rosenthal, S. Stanford, H. Prahlad, R. Pelrine, Multiple-degrees-of-freedom electroelastomer roll actuators. Smart Mater. Struct. 13(5), N86 (2004)

    Article  Google Scholar 

  4. F. Carpi, A. Mannini, D. De Rossi, in Elastomeric contractile actuators for hand rehabilitation splints. Electroactive Polymer Actuators and Devices (EAPAD) 2008 (2008), pp. 37–46. SPIE

  5. Y. Qiu, E. Zhang, R. Plamthottam, Q. Pei, Dielectric elastomer artificial muscle: materials innovations and device explorations. Acc. Chem. Res. 52(2), 316–325 (2019)

    Article  Google Scholar 

  6. A. Dorfmann, R.W. Ogden, Nonlinear electroelasticity. Acta Mech. 174(3), 167–183 (2005)

    Article  MATH  Google Scholar 

  7. Z. Suo, X. Zhao, W.H. Greene, A nonlinear field theory of deformable dielectrics. J. Mech. Phys. Solids 56(2), 467–486 (2008)

    Article  ADS  MATH  Google Scholar 

  8. E. Hansy-Staudigl, M. Krommer, A. Humer, A complete direct approach to nonlinear modeling of dielectric elastomer plates. Acta Mech. 230(11), 3923–3943 (2019)

    Article  MATH  Google Scholar 

  9. J. Zhang, J. Chen, Z. Ren, Mechanical behavior of a circular dielectric elastomer membrane under out-of-plane deformation. J. Mech. 37, 184–191 (2021)

    Article  Google Scholar 

  10. A.K. Sharma, M.M. Joglekar, Effect of anisotropy on the dynamic electromechanical instability of a dielectric elastomer actuator. Smart Mater. Struct. 28(1), 015006 (2018)

    Article  ADS  Google Scholar 

  11. A.K. Sharma, M.M. Joglekar, A numerical framework for modeling anisotropic dielectric elastomers. Comput. Methods Appl. Mech. Eng. 344, 402–420 (2019)

    Article  ADS  MATH  Google Scholar 

  12. K.B. Subramani, R.J. Spontak, T.K. Ghosh, Influence of fiber characteristics on directed electroactuation of anisotropic dielectric electroactive polymers with tunability. Compos. Sci. Technol. 154, 187–193 (2018)

    Article  Google Scholar 

  13. C. Zeng, X. Gao, Stability of an anisotropic dielectric elastomer plate. Int. J. Non Linear Mech. 124, 103510 (2020)

    Article  ADS  Google Scholar 

  14. A. Moss, M. Krieg, K. Mohseni, Modeling and characterizing a fiber-reinforced dielectric elastomer tension actuator. IEEE Robot. Autom. Lett. 6(2), 1264–1271 (2021)

    Article  Google Scholar 

  15. E. Allahyari, M. Asgari, Nonlinear dynamic analysis of anisotropic fiber-reinforced dielectric elastomers: a mathematical approach. J. Intell. Mater. Syst. Struct. 32(18–19), 2300–2324 (2021)

    Article  Google Scholar 

  16. E. Allahyari, M. Asgari, Fiber reinforcement characteristics of anisotropic dielectric elastomers: a constitutive modeling development. Mech. Adv. Mater. Struct. (2021). https://doi.org/10.1080/15376494.2021.1958275

    Article  Google Scholar 

  17. A. Ahmadi, M. Asgari, Nonlinear coupled electro-mechanical behavior of a novel anisotropic fiber-reinforced dielectric elastomer. Int. J. Non Linear Mech. 119, 103364 (2020)

    Article  ADS  Google Scholar 

  18. A. Ahmadi, M. Asgari, Novel bio-inspired variable stiffness soft actuator via fiber-reinforced dielectric elastomer, inspired by Octopus bimaculoides. Intel. Serv. Robot. 14(5), 691–705 (2021)

    Article  Google Scholar 

  19. S. Wang, M. Decker, D.L. Henann, S.A. Chester, Modeling of dielectric viscoelastomers with application to electromechanical instabilities. J. Mech. Phys. Solids 95, 213–229 (2016)

    Article  ADS  Google Scholar 

  20. S. Qu, K. Li, T. Li, H. Jiang, M. Wang, Z. Li, Rate dependent stress-stretch relation of dielectric elastomers subjected to pure shear like loading and electric field. Acta Mech. Solida Sin. 25(5), 542–549 (2012)

    Article  Google Scholar 

  21. M. Shariff, R. Bustamante, J. Merodio, A nonlinear spectral rate-dependent constitutive equation for electro-viscoelastic solids. Z. Angew. Math. Phys. 71(4), 1–22 (2020)

    Article  MATH  Google Scholar 

  22. S.K. Behera, D. Kumar, S. Sarangi, Modeling of electro–viscoelastic dielectric elastomer: a continuum mechanics approach. Eur. J. Mech. A Solids 90, 104369 (2021)

    Article  ADS  MATH  Google Scholar 

  23. K.A. Khan, H. Wafai, T.E. Sayed, A variational constitutive framework for the nonlinear viscoelastic response of a dielectric elastomer. Comput. Mech. 52(2), 345–360 (2013)

    Article  MATH  Google Scholar 

  24. N. Kumar, V.V. Rao, Hyperelastic Mooney-Rivlin model: determination and physical interpretation of material constants. Parameters 2(10), 01 (2016)

    Google Scholar 

  25. D.P. Pioletti, L. Rakotomanana, J.-F. Benvenuti, P.-F. Leyvraz, Viscoelastic constitutive law in large deformations: application to human knee ligaments and tendons. J. Biomech. 31(8), 753–757 (1998)

    Article  Google Scholar 

  26. Z.M. Ghahfarokhi, M. Salmani-Tehrani, M.M. Zand, S. Esmaeilian, A new viscous potential function for developing the viscohyperelastic constitutive model for bovine liver tissue: continuum formulation and finite element implementation. Int. J. Appl. Mech. 12(03), 2050029 (2020)

    Article  Google Scholar 

  27. A. Tayeb, M. Arfaoui, A. Zine, M. Ichchou, A. Hamdi, J. Ben Abdallah, Investigation of the nonlinear hyper-viscoelastic behavior of elastomers at finite strain: implementation and numerical validation. Eur. Phys. J. Plus 137(5), 1–18 (2022)

    Article  Google Scholar 

  28. J. Simo, R. Taylor, Penalty function formulations for incompressible nonlinear elastostatics. Comput. Methods Appl. Mech. Eng. 35(1), 107–118 (1982)

    Article  ADS  MATH  Google Scholar 

  29. A. Büschel, S. Klinkel, W. Wagner, Dielectric elastomers–numerical modeling of nonlinear visco-electroelasticity. Int. J. Numer. Methods Eng. 93(8), 834–856 (2013)

    MATH  Google Scholar 

  30. G.A. Holzapfel, T.C. Gasser, R.W. Ogden, A new constitutive framework for arterial wall mechanics and a comparative study of material models. J. Elast. Phys. Sci. Solids 61(1), 1–48 (2000)

    MATH  Google Scholar 

  31. D.R. Nolan, A.L. Gower, M. Destrade, R.W. Ogden, J.P. McGarry, A robust anisotropic hyperelastic formulation for the modelling of soft tissue. J. Mech. Behav. Biomed. Mater. 39, 48–60 (2014)

    Article  Google Scholar 

  32. L.D. Peel, Fabrication and mechanics of fiber-reinforced elastomers, Brigham Young University, 1998

  33. J. Mehta, Y. Chandra, R. Tewari, The use of dielectric elastomer actuators for prosthetic, orthotic and bio-robotic applications. Procedia Comput. Sci. 133, 569–575 (2018)

    Article  Google Scholar 

  34. S. Son, N. Goulbourne, Dynamic response of tubular dielectric elastomer transducers. Int. J. Solids Struct. 47(20), 2672–2679 (2010)

    Article  MATH  Google Scholar 

  35. Y. Wang, B. Chen, Y. Bai, H. Wang, J. Zhou, Actuating dielectric elastomers in pure shear deformation by elastomeric conductors. Appl. Phys. Lett. 104(6), 064101 (2014)

    Article  ADS  Google Scholar 

  36. T. Vu-Cong, C. Jean-Mistral, A. Sylvestre, Impact of the nature of the compliant electrodes on the dielectric constant of acrylic and silicone electroactive polymers. Smart Mater. Struct. 21(10), 105036 (2012)

    Article  ADS  Google Scholar 

  37. M. Hossain, D.K. Vu, P. Steinmann, Experimental study and numerical modelling of VHB 4910 polymer. Comput. Mater. Sci. 59, 65–74 (2012)

    Article  Google Scholar 

  38. G. Kofod, P. Sommer-Larsen, R. Kornbluh, R. Pelrine, Actuation response of polyacrylate dielectric elastomers. J. Intell. Mater. Syst. Struct. 14(12), 787–793 (2003)

    Article  Google Scholar 

  39. F.S.C. Mustata, A. Mustata, Dielectric behaviour of some woven fabrics on the basis of natural cellulosic fibers. Adv. Mater. Sci. Eng. (2014). https://doi.org/10.1155/2014/216548

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Masoud Asgari.

Appendix

Appendix

This section is aimed to provide a detailed presentation of the derivation processes of involved parameters and the tangent moduli. It should be noted that if the definition of the Cauchy stress is showed to be correct, the final FEM result obtained using the Cauchy stress and extracted tangent moduli would be correct because the tangent modulus serves as an iterative operator. In this research work, all the stress terms are evaluated using analytical results and appropriate experimental data.

1.1 Hyperelastic terms

$${\overline{W} }^{hyperelastic}={C}_{10}\left({\overline{I} }_{1}-3\right)+{C}_{01}\left({\overline{I} }_{2}-3\right)$$
(91)
$$\frac{\partial {\overline{W} }^{hyperelastic}}{\partial {{\varvec{C}}}_{ij}}={C}_{10}\left(\frac{\partial {\overline{I} }_{1}}{\partial {{\varvec{C}}}_{ij}}\right)+{C}_{01}\left(\frac{\partial {\overline{I} }_{2}}{\partial {{\varvec{C}}}_{ij}}\right)={C}_{10}\frac{\partial \left({J}^{-\frac{2}{3}}{I}_{1}\right)}{\partial {{\varvec{C}}}_{ij}}+{C}_{01}\frac{\partial \left({J}^{-\frac{4}{3}}{I}_{2}\right)}{\partial {{\varvec{C}}}_{ij}}={C}_{10}\left(\frac{\partial {J}^{-\frac{2}{3}}}{\partial {{\varvec{C}}}_{ij}}{I}_{1}+\frac{\partial {I}_{1}}{\partial {{\varvec{C}}}_{ij}}{J}^{-\frac{2}{3}}\right)+{C}_{01}\left(\frac{\partial {J}^{-\frac{4}{3}}}{\partial {{\varvec{C}}}_{ij}}{I}_{2}+\frac{\partial {I}_{2}}{\partial {{\varvec{C}}}_{ij}}{J}^{-\frac{4}{3}}\right)={C}_{10}\left(\left(-\frac{1}{3}{J}^{-\frac{2}{3}}{{\varvec{C}}}_{ij}^{-1}\right){I}_{1}+{\delta }_{ij}{J}^{-\frac{2}{3}}\right)+{C}_{01}\left(\left(-\frac{2}{3}{J}^{-\frac{4}{3}}{{\varvec{C}}}_{ij}^{-1}\right){I}_{2}+\left({I}_{1}{\delta }_{ij}-{{\varvec{C}}}_{ij}\right){J}^{-\frac{4}{3}}\right)={C}_{10}{J}^{-\frac{2}{3}}\left(-\frac{1}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{1}+{\delta }_{ij}\right)+{C}_{01}{J}^{-\frac{4}{3}}\left(-\frac{2}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{2}+\left({I}_{1}{\delta }_{ij}-{{\varvec{C}}}_{ij}\right)\right)$$
(92)
$${{\varvec{S}}}_{ij}^{hyperelastic}=2{C}_{10}{J}^{-\frac{2}{3}}\left(-\frac{1}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{1}+{\delta }_{ij}\right)+2{C}_{01}{J}^{-\frac{4}{3}}\left(-\frac{2}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{2}+\left({I}_{1}{\delta }_{ij}-{{\varvec{C}}}_{ij}\right)\right)$$
(93)
$${{\varvec{\sigma}}}_{mn}^{hyperelastic}=\frac{1}{J}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{S}}}_{ij}^{e}=\frac{2}{J}\left({C}_{10}{J}^{-\frac{2}{3}}\left(-\frac{1}{3}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{C}}}_{ij}^{-1}{I}_{1}+{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{\delta }_{ij}\right)+{C}_{01}{J}^{-\frac{4}{3}}\left(-\frac{2}{3}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{C}}}_{ij}^{-1}{I}_{2}+\left({I}_{1}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{\delta }_{ij}-{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{C}}}_{ij}\right)\right)\right)=\frac{2}{J}\left({C}_{10}{J}^{-\frac{2}{3}}\left(-\frac{1}{3}{\delta }_{mn}{I}_{1}+{{\varvec{B}}}_{mn}\right)+{C}_{01}{J}^{-\frac{4}{3}}\left(-\frac{2}{3}{\delta }_{mn}{I}_{2}+\left({I}_{1}{{\varvec{B}}}_{mn}-{{\varvec{B}}}_{mk}{{\varvec{B}}}_{nk}\right)\right)\right)$$
(94)
$$\frac{\partial {{\varvec{S}}}_{ij}^{hyperelastic}}{\partial {{\varvec{C}}}_{kl}}=2{C}_{10}\frac{\partial \left({J}^{-\frac{2}{3}}\left(-\frac{1}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{1}+{\delta }_{ij}\right)\right)}{\partial {{\varvec{C}}}_{kl}}+2{C}_{01}\frac{\partial \left({J}^{-\frac{4}{3}}\left(-\frac{2}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{2}+\left({I}_{1}{\delta }_{ij}-{{\varvec{C}}}_{ij}\right)\right)\right)}{\partial {{\varvec{C}}}_{kl}}=2{C}_{10}\left(\frac{\partial {J}^{-\frac{2}{3}}}{\partial {{\varvec{C}}}_{kl}}\left(-\frac{1}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{1}+{\delta }_{ij}\right)+{J}^{-\frac{2}{3}}\frac{\partial \left(-\frac{1}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{1}+{\delta }_{ij}\right)}{\partial {{\varvec{C}}}_{kl}}\right)+2{C}_{01}\left(\frac{\partial {J}^{-\frac{4}{3}}}{\partial {{\varvec{C}}}_{kl}}\left(-\frac{2}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{2}+\left({I}_{1}{\delta }_{ij}-{{\varvec{C}}}_{ij}\right)\right)+{J}^{-\frac{4}{3}}\frac{\partial \left(-\frac{2}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{2}+\left({I}_{1}{\delta }_{ij}-{{\varvec{C}}}_{ij}\right)\right)}{\partial {{\varvec{C}}}_{kl}}\right)=2{C}_{10}{J}^{-\frac{2}{3}}\left(-\frac{1}{3}{{\varvec{C}}}_{kl}^{-1}\left(-\frac{1}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{1}+{\delta }_{ij}\right)+\frac{\partial \left(-\frac{1}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{1}+{\delta }_{ij}\right)}{\partial {{\varvec{C}}}_{kl}}\right)+2{C}_{01}{J}^{-\frac{4}{3}}\left(-\frac{2}{3}{{\varvec{C}}}_{kl}^{-1}\left(-\frac{2}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{2}+\left({I}_{1}{\delta }_{ij}-{{\varvec{C}}}_{ij}\right)\right)+\frac{\partial \left(-\frac{2}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{2}+\left({I}_{1}{\delta }_{ij}-{{\varvec{C}}}_{ij}\right)\right)}{\partial {{\varvec{C}}}_{kl}}\right)=2{C}_{10}{J}^{-\frac{2}{3}}\left(-\frac{1}{3}{{\varvec{C}}}_{kl}^{-1}\left(-\frac{1}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{1}+{\delta }_{ij}\right)-\frac{1}{3}\left(\frac{\partial {{\varvec{C}}}_{ij}^{-1}}{\partial {{\varvec{C}}}_{kl}}{I}_{1}+\frac{\partial {I}_{1}}{\partial {{\varvec{C}}}_{kl}}{{\varvec{C}}}_{ij}^{-1}\right)\right)+2{C}_{01}{J}^{-\frac{4}{3}}\left(-\frac{2}{3}{{\varvec{C}}}_{kl}^{-1}\left(-\frac{2}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{2}+\left({I}_{1}{\delta }_{ij}-{{\varvec{C}}}_{ij}\right)\right)-\frac{2}{3}\left(\frac{\partial {{\varvec{C}}}_{ij}^{-1}}{\partial {{\varvec{C}}}_{kl}}{I}_{2}+\frac{\partial {I}_{2}}{\partial {{\varvec{C}}}_{kl}}{{\varvec{C}}}_{ij}^{-1}\right)+\frac{\partial \left({I}_{1}{\delta }_{ij}-{{\varvec{C}}}_{ij}^{-1}\right)}{{{\varvec{C}}}_{ij}^{-1}}\right)=2{C}_{10}{J}^{-\frac{2}{3}}\left(-\frac{1}{3}{{\varvec{C}}}_{kl}^{-1}\left(-\frac{1}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{1}+{\delta }_{ij}\right)-\frac{1}{3}\left(-\frac{1}{2}\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{jl}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{jk}^{-1}\right){I}_{1}+{\delta }_{kl}{{\varvec{C}}}_{ij}^{-1}\right)\right)+2{C}_{01}{J}^{-\frac{4}{3}}\left(-\frac{2}{3}{{\varvec{C}}}_{kl}^{-1}\left(-\frac{2}{3}{{\varvec{C}}}_{ij}^{-1}{I}_{2}+\left({I}_{1}{\delta }_{ij}-{{\varvec{C}}}_{ij}\right)\right)-\frac{2}{3}\left(-\frac{1}{2}\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{jl}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{jk}^{-1}\right){I}_{2}+\left({I}_{1}{\delta }_{kl}-{{\varvec{C}}}_{kl}\right){{\varvec{C}}}_{ij}^{-1}\right)+{\delta }_{ij}{\delta }_{kl}-\frac{1}{2}\left({\delta }_{ik}{\delta }_{jl}+{\delta }_{il}{\delta }_{jk}\right)\right)=2{C}_{10}{J}^{-\frac{2}{3}}\left(\left(\frac{1}{9}{{\varvec{C}}}_{ij}^{-1}{{\varvec{C}}}_{kl}^{-1}{I}_{1}-\frac{1}{3}{{\varvec{C}}}_{kl}^{-1}{\delta }_{ij}\right)+\left(\frac{1}{6}\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{jl}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{jk}^{-1}\right){I}_{1}-\frac{1}{3}{\delta }_{kl}{{\varvec{C}}}_{ij}^{-1}\right)\right)+2{C}_{01}{J}^{-\frac{4}{3}}\left(\left(\frac{4}{9}{{\varvec{C}}}_{ij}^{-1}{{\varvec{C}}}_{kl}^{-1}{I}_{2}-\frac{2}{3}{{\varvec{C}}}_{kl}^{-1}\left({I}_{1}{\delta }_{ij}-{{\varvec{C}}}_{ij}\right)\right)+\left(\frac{1}{3}\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{jl}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{jk}^{-1}\right){I}_{2}-\frac{2}{3}\left({I}_{1}{\delta }_{kl}-{{\varvec{C}}}_{kl}\right){{\varvec{C}}}_{ij}^{-1}\right)+{\delta }_{ij}{\delta }_{kl}-\frac{1}{2}\left({\delta }_{ik}{\delta }_{jl}+{\delta }_{il}{\delta }_{jk}\right)\right)=2{C}_{10}{J}^{-\frac{2}{3}}\left(\frac{1}{9}{{\varvec{C}}}_{ij}^{-1}{{\varvec{C}}}_{kl}^{-1}{I}_{1}-\frac{1}{3}\left({{\varvec{C}}}_{kl}^{-1}{\delta }_{ij}+{\delta }_{kl}{{\varvec{C}}}_{ij}^{-1}\right)+\frac{1}{6}{I}_{1}\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{jl}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{jk}^{-1}\right)\right)+2{C}_{01}{J}^{-\frac{4}{3}}\left(\frac{4}{9}{{\varvec{C}}}_{ij}^{-1}{{\varvec{C}}}_{kl}^{-1}{I}_{2}+\frac{2}{3}\left({{\varvec{C}}}_{ij}{{\varvec{C}}}_{kl}^{-1}+{{\varvec{C}}}_{kl}{{\varvec{C}}}_{ij}^{-1}\right)-\frac{2}{3}{I}_{1}\left({\delta }_{ij}{{\varvec{C}}}_{kl}^{-1}+{\delta }_{kl}{{\varvec{C}}}_{ij}^{-1}\right)+\frac{1}{3}{I}_{2}\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{jl}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{jk}^{-1}\right)-\frac{1}{2}\left({\delta }_{ik}{\delta }_{jl}+{\delta }_{il}{\delta }_{jk}\right)+{\delta }_{ij}{\delta }_{kl}\right)$$
(95)
$$ \begin{gathered} \mathbb{C}_{{mnrs}}^{{hyperelastic}} = \frac{2}{J}{\varvec{F}}_{{mi}} {\varvec{F}}_{{nj}} {\varvec{F}}_{{rk}} {\varvec{F}}_{{sl}} \frac{{\partial {\varvec{S}}_{{ij}}^{{hyperelastic}} }}{{\partial {\varvec{C}}_{{kl}} }} = \frac{2}{J}\left( {2C_{{10}} J^{{ - \frac{2}{3}}} \left( {\frac{1}{9}\delta _{{mn}} \delta _{{rs}} I_{1} - \frac{1}{3}\left( {\delta _{{rs}} {\varvec{B}}_{{mn}} + \delta _{{mn}} {\varvec{B}}_{{rs}} } \right) + \frac{1}{6}I_{1} \left( {\delta _{{mr}} \delta _{{ns}} + \delta _{{ms}} \delta _{{nr}} } \right)} \right)} \right. \hfill \\ \quad \quad \quad \quad \quad + 2C_{{01}} J^{{ - \frac{4}{3}}} \left( {\frac{4}{9}\delta _{{mn}} \delta _{{rs}} I_{2} + \frac{2}{3}\left( {{\varvec{B}}_{{mk}} {\varvec{B}}_{{nk}} \delta _{{rs}} + {\varvec{B}}_{{rk}} {\varvec{B}}_{{sk}} \delta _{{mn}} } \right) - \frac{2}{3}I_{1} \left( {{\varvec{B}}_{{mn}} \delta _{{rs}} + {\varvec{B}}_{{rs}} \delta _{{mn}} } \right) + \frac{1}{3}I_{2} \left( {\delta _{{mr}} \delta _{{ns}} + \delta _{{ms}} \delta _{{nr}} } \right)} \right. \hfill \\ \left. {\left. {\quad \quad \quad \quad \quad \quad \quad \quad \quad - \frac{1}{2}\left( {{\varvec{B}}_{{mr}} {\varvec{B}}_{{ns}} + {\varvec{B}}_{{nr}} {\varvec{B}}_{{ms}} } \right) + {\varvec{B}}_{{mn}} B_{{rs}} } \right)} \right) = \frac{2}{J}\left( {2C_{{10}} \left( {\frac{1}{9}\delta _{{mn}} \delta _{{rs}} \bar{I}_{1} - \frac{1}{3}\left( {\delta _{{rs}} \overline{{\varvec{B}}} _{{mn}} + \delta _{{mn}} \overline{{\varvec{B}}} _{{rs}} } \right) + \frac{1}{6}\bar{I}_{1} \left( {\delta _{{mr}} \delta _{{ns}} + \delta _{{ms}} \delta _{{nr}} } \right)} \right)} \right. \hfill \\ \quad \quad \quad \quad \quad + 2C_{{01}} \left( {\frac{4}{9}\delta _{{mn}} \delta _{{rs}} \bar{I}_{2} + \frac{2}{3}\left( {\overline{{\varvec{B}}} _{{mk}} \overline{{\varvec{B}}} _{{nk}} \delta _{{rs}} + \overline{{\varvec{B}}} _{{rk}} \overline{{\varvec{B}}} _{{sk}} \delta _{{mn}} } \right) - \frac{2}{3}\bar{I}_{1} \left( {\overline{{\varvec{B}}} _{{mn}} \delta _{{rs}} + \overline{{\varvec{B}}} _{{rs}} \delta _{{mn}} } \right) + \frac{1}{3}\bar{I}_{2} \left( {\delta _{{mr}} \delta _{{ns}} + \delta _{{ms}} \delta _{{nr}} } \right)} \right. \hfill \\ \left. {\left. {\quad \quad \quad \quad \quad \quad \quad \quad \quad \; - \frac{1}{2}\left( {\overline{{\varvec{B}}} _{{mr}} \overline{{\varvec{B}}} _{{ns}} + \overline{{\varvec{B}}} _{{nr}} \overline{{\varvec{B}}} _{{ms}} } \right) + \overline{{\varvec{B}}} _{{mn}} \overline{{\varvec{B}}} _{{rs}} } \right)} \right) = \frac{1}{J}\left( \begin{gathered} \frac{4}{9}\left( {C_{{10}} \bar{I}_{1} + 4C_{{01}} \bar{I}_{2} } \right)\delta _{{mn}} \delta _{{rs}} - \frac{4}{3}\left( {C_{{10}} + 2C_{{01}} \bar{I}_{1} } \right)\left( {\delta _{{rs}} \overline{{\varvec{B}}} _{{mn}} + \delta _{{mn}} \overline{{\varvec{B}}} _{{rs}} } \right) \hfill \\ \hfill \\ \end{gathered} \right. \hfill \\ \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad + \frac{2}{3}\left( {C_{{10}} \bar{I}_{1} + 2C_{{01}} \bar{I}_{2} } \right)\left( {\delta _{{mr}} \delta _{{ns}} + \delta _{{ms}} \delta _{{nr}} } \right) + \frac{8}{3}C_{{01}} \left( {\overline{{\varvec{B}}} _{{mk}} \overline{{\varvec{B}}} _{{nk}} \delta _{{rs}} + \overline{{\varvec{B}}} _{{rk}} \overline{{\varvec{B}}} _{{sk}} \delta _{{mn}} } \right)\left. { + 4C_{{01}} \left( {\overline{{\varvec{B}}} _{{mn}} \overline{{\varvec{B}}} _{{rs}} - \frac{1}{2}\left( {\overline{{\varvec{B}}} _{{mr}} \overline{{\varvec{B}}} _{{ns}} + \overline{{\varvec{B}}} _{{nr}} \overline{{\varvec{B}}} _{{ms}} } \right)} \right)} \right) \hfill \\ \end{gathered} $$
(96)

1.2 Viscoelastic terms

$${\overline{W} }^{viscoelastic}=\frac{1}{4}\left({\overline{I} }_{1}-3\right)\left({\eta }_{1}{\overline{J} }_{2}+{\eta }_{2}{\overline{J} }_{4}^{2}\right)$$
(97)
$$ \begin{gathered} \frac{{\partial \bar{W}^{{viscoelastic}} }}{{\partial \mathop {\varvec{C}}\limits^{.} _{{ij}} }} = \frac{1}{4}\left( {\bar{I}_{1} - 3} \right)\left[ {\eta _{1} \frac{{\partial \bar{J}_{2} }}{{\partial \mathop {\varvec{C}}\limits^{.} _{{ij}} }} + 2\eta _{2} \bar{J}_{4} \frac{{\partial \bar{J}_{4} }}{{\partial \mathop {\varvec{C}}\limits^{.} _{{ij}} }}} \right]\frac{1}{4}\left( {\bar{I}_{1} - 3} \right)\left[ {\eta _{1} \left( {\left( {J^{{ - \frac{2}{3}}} \left( {\frac{1}{2}\left( {\delta _{{ai}} \delta _{{bj}} + \delta _{{bi}} \delta _{{aj}} } \right)\dot{\bar{C}}_{{ab}} } \right) - \frac{1}{3}J^{{ - \frac{2}{3}}} {\varvec{C}}_{{ij}}^{{ - 1}} {\varvec{C}}_{{ab}} \mathop {\overline{{\varvec{C}}} }\limits^{.} _{{ab}} } \right)} \right)} \right. \hfill \\ \left. {\quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad + 2\eta _{2} \bar{J}_{4} \left( {J^{{ - \frac{4}{3}}} {\varvec{C}}_{{ij}} - \frac{1}{3}J^{{ - \frac{4}{3}}} {\varvec{C}}_{{ij}}^{{ - 1}} \left( {I_{1}^{2} - 2I_{2} } \right)} \right)} \right] = \frac{1}{4}\left( {\bar{I}_{1} - 3} \right)\left[ {\eta _{1} \left( {J^{{ - \frac{2}{3}}} \mathop {\overline{{\varvec{C}}} }\limits^{.} _{{ij}} - \frac{1}{3}{\varvec{C}}_{{ij}}^{{ - 1}} \overline{{\varvec{C}}} _{{ab}} \mathop {\overline{{\varvec{C}}} }\limits^{.} _{{ab}} } \right)} \right.\left. { + 2\eta _{2} \bar{J}_{4} J^{{ - \frac{4}{3}}} \left( {{\varvec{C}}_{{ij}} - \frac{1}{3}{\varvec{C}}_{{ij}}^{{ - 1}} \left( {I_{1}^{2} - 2I_{2} } \right)} \right)} \right] \hfill \\ \end{gathered} $$
(98)
$${{\varvec{S}}}_{ij}^{viscoelastic}=\frac{1}{2}\left({\overline{I} }_{1}-3\right)\left[{\eta }_{1}\left({J}^{-\frac{2}{3}}{\dot{\overline{{\varvec{C}}}} }_{ij}-\frac{1}{3}{{\varvec{C}}}_{ij}^{-1}{\overline{{\varvec{C}}} }_{ab}{\dot{\overline{{\varvec{C}}}} }_{ab}\right)+2{\eta }_{2}{\overline{J} }_{4}{J}^{-\frac{4}{3}}\left({{\varvec{C}}}_{ij}-\frac{1}{3}{{\varvec{C}}}_{ij}^{-1}\left({I}_{1}^{2}-2{I}_{2}\right)\right)\right]$$
(99)
$${{\varvec{\sigma}}}_{mn}^{viscoelastic}=\frac{1}{J}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{S}}}_{ij}^{viscoelastic}=\frac{1}{2J}\left({\overline{I} }_{1}-3\right)\left[{\eta }_{1}\left({{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{J}^{-\frac{2}{3}}{\dot{\overline{{\varvec{C}}}} }_{ij}-\frac{1}{3}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{C}}}_{ij}^{-1}{\overline{{\varvec{C}}} }_{ab}{\dot{\overline{{\varvec{C}}}} }_{ab}\right)+2{\eta }_{2}{\overline{J} }_{4}{J}^{-\frac{4}{3}}\left({{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{C}}}_{ij}-\frac{1}{3}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{C}}}_{ij}^{-1}\left(1:\left(C.C\right)\right)\right)\right]=\frac{1}{2J}\left({\overline{I} }_{1}-3\right)\left[{\eta }_{1}\left({{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{J}^{-\frac{2}{3}}\left({J}^{-\frac{2}{3}}{\dot{{\varvec{C}}}}_{ij}-\frac{2}{3}{J}^{-\frac{5}{3}}\dot{J}{{\varvec{C}}}_{ij}\right)-\frac{1}{3}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{C}}}_{ij}^{-1}{\overline{{\varvec{C}}} }_{ab}{\dot{\overline{{\varvec{C}}}} }_{ab}\right)+2{\eta }_{2}{\overline{J} }_{4}{J}^{-\frac{4}{3}}\left({{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{C}}}_{ij}-\frac{1}{3}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{C}}}_{ij}^{-1}\left(1:\left(C.C\right)\right)\right)\right]=\frac{1}{2J}\left({\overline{I} }_{1}-3\right)\left[{\eta }_{1}\left(\left(2{\overline{{\varvec{B}}} }_{mi}{{\varvec{D}}}_{ij}{\overline{{\varvec{B}}} }_{jn}-\frac{2}{3}{J}^{-1}\dot{J}{\overline{{\varvec{B}}} }_{mk}{\overline{{\varvec{B}}} }_{nk}\right)-\frac{1}{3}{\delta }_{mn}{\overline{J} }_{4}\right)+2{\eta }_{2}{\overline{J} }_{4}\left({\overline{{\varvec{B}}} }_{mk}{\overline{{\varvec{B}}} }_{nk}-\frac{1}{3}{\delta }_{mn}\left(\left({\overline{I} }_{1}^{2}-2{\overline{I} }_{2}\right)\right)\right)\right]$$
(100)
$$\frac{\partial {{\varvec{S}}}_{ij}^{viscoelastic}}{\partial {\dot{{\varvec{C}}}}_{kl}}=\frac{1}{2}\left({\overline{I} }_{1}-3\right)\left[{\eta }_{1}\left({J}^{-\frac{2}{3}}\frac{\partial {\dot{\overline{C}} }_{ij}}{\partial {\dot{{\varvec{C}}}}_{kl}}-\frac{1}{3}{C}_{ij}^{-1}\frac{\partial \left({\overline{C} }_{ab}{\dot{\overline{C}} }_{ab}\right)}{\partial {\dot{{\varvec{C}}}}_{kl}}\right)+2{\eta }_{2}{J}^{-\frac{4}{3}}\frac{\partial {\overline{J} }_{4}}{\partial {\dot{{\varvec{C}}}}_{kl}}\left({C}_{ij}-\frac{1}{3}{C}_{ij}^{-1}\left({I}_{1}^{2}-2{I}_{2}\right)\right)\right]=\frac{1}{2}\left({\overline{I} }_{1}-3\right)\left[{\eta }_{1}\left({J}^{-\frac{2}{3}}\frac{\partial {\dot{\overline{C}} }_{ij}}{\partial {\dot{{\varvec{C}}}}_{kl}}-\frac{1}{3}{C}_{ij}^{-1}{J}^{-\frac{4}{3}}\left({C}_{kl}-\frac{1}{3}{C}_{kl}^{-1}\left({I}_{1}^{2}-2{I}_{2}\right)\right)\right)+2{\eta }_{2}{J}^{-\frac{4}{3}}\left({C}_{kl}-\frac{1}{3}{C}_{kl}^{-1}\left(1:\left(C.C\right)\right)\right)\left({C}_{ij}-\frac{1}{3}{C}_{ij}^{-1}\left(1:\left(C.C\right)\right)\right)\right]=\frac{1}{2}\left({\overline{I} }_{1}-3\right)\left[{\eta }_{1}\left({J}^{-\frac{4}{3}}\frac{1}{2}\left({\delta }_{ik}{\delta }_{jl}+{\delta }_{il}{\delta }_{jk}\right)-\frac{1}{3}{J}^{-\frac{4}{3}}\left({C}_{kl}^{-1}{C}_{ij}+{C}_{ij}^{-1}{C}_{kl}\right)+\frac{1}{9}{{C}_{ij}^{-1}C}_{kl}^{-1}\left({\overline{I} }_{1}^{2}-2{\overline{I} }_{2}\right)\right)+2{\eta }_{2}{J}^{-\frac{8}{3}}\left({C}_{ij}{C}_{kl}-\frac{1}{3}\left({C}_{ij}{C}_{kl}^{-1}+{{C}_{ij}^{-1}C}_{kl}\right)\left({I}_{1}^{2}-2{I}_{2}\right)+\frac{1}{9}{{C}_{ij}^{-1}C}_{kl}^{-1}{\left({I}_{1}^{2}-2{I}_{2}\right)}^{2}\right)\right]$$
(101)
$$ \begin{gathered} \mathbb{C}_{{mnrs}}^{{viscoelastic}} = \frac{2}{J}{\varvec{F}}_{{mi}} {\varvec{F}}_{{nj}} {\varvec{F}}_{{rk}} {\varvec{F}}_{{sl}} \frac{{\partial {\varvec{S}}_{{ij}}^{{viscoelastic}} }}{{\partial {\varvec{C}}_{{kl}} }} = \frac{1}{J}\left( {\bar{I}_{1} - 3} \right)\left[ {\eta _{1} \left( {J^{{ - \frac{4}{3}}} \frac{1}{2}\left( {{\varvec{F}}_{{mi}} {\varvec{F}}_{{nj}} {\varvec{F}}_{{rk}} {\varvec{F}}_{{sl}} \delta _{{ik}} \delta _{{jl}} + {\varvec{F}}_{{mi}} {\varvec{F}}_{{nj}} {\varvec{F}}_{{rk}} {\varvec{F}}_{{sl}} \delta _{{il}} \delta _{{jk}} } \right)} \right.} \right. \hfill \\ \quad\quad\quad\quad\quad\quad\quad \left. { - \frac{1}{3}J^{{ - \frac{4}{3}}} \left( {{\varvec{F}}_{{mi}} {\varvec{F}}_{{nj}} {\varvec{F}}_{{rk}} {\varvec{F}}_{{sl}} C_{{kl}}^{{ - 1}} C_{{ij}} + {\varvec{F}}_{{mi}} {\varvec{F}}_{{nj}} {\varvec{F}}_{{rk}} {\varvec{F}}_{{sl}} C_{{ij}}^{{ - 1}} C_{{kl}} } \right) + \frac{1}{9}{\varvec{F}}_{{mi}} {\varvec{F}}_{{nj}} {\varvec{F}}_{{rk}} {\varvec{F}}_{{sl}} C_{{ij}}^{{ - 1}} C_{{kl}}^{{ - 1}} \left( {1:\left( {\bar{C}.\bar{C}} \right)} \right)} \right) \hfill \\ \quad\quad\quad\quad\quad\quad\quad + 2\eta _{2} J^{{ - \frac{8}{3}}} \left( {{\varvec{F}}_{{mi}} {\varvec{F}}_{{nj}} {\varvec{F}}_{{rk}} {\varvec{F}}_{{sl}} C_{{ij}} C_{{kl}} - \frac{1}{3}\left( {{\varvec{F}}_{{mi}} {\varvec{F}}_{{nj}} {\varvec{F}}_{{rk}} {\varvec{F}}_{{sl}} C_{{ij}} C_{{kl}}^{{ - 1}} + {\varvec{F}}_{{mi}} {\varvec{F}}_{{nj}} {\varvec{F}}_{{rk}} {\varvec{F}}_{{sl}} C_{{ij}}^{{ - 1}} C_{{kl}} } \right)\left( {1:\left( {C.C} \right)} \right)} \right. \hfill \\ \quad\quad\quad\quad\quad\quad\quad \left. {\left. { + \frac{1}{9}{\varvec{F}}_{{mi}} {\varvec{F}}_{{nj}} {\varvec{F}}_{{rk}} {\varvec{F}}_{{sl}} C_{{ij}}^{{ - 1}} C_{{kl}}^{{ - 1}} \left( {1:\left( {C.C} \right)} \right)^{2} } \right)} \right] = \frac{1}{J}\left( {\bar{I}_{1} - 3} \right)\left[ {\eta _{1} \left( {J^{{ - \frac{4}{3}}} \frac{1}{2}\left( {{\varvec{B}}_{{mr}} {\varvec{B}}_{{ns}} + {\varvec{B}}_{{ms}} {\varvec{B}}_{{nr}} } \right)} \right)} \right. \hfill \\ \quad\quad\quad\quad\quad\quad\quad \left. { - \frac{1}{3}J^{{ - \frac{4}{3}}} \left( {{\varvec{B}}_{{mk}} {\varvec{B}}_{{nk}} \delta _{{rs}} + {\varvec{B}}_{{rk}} {\varvec{B}}_{{sk}} \delta _{{mn}} } \right) + \frac{1}{9}\delta _{{mn}} \delta _{{rs}} \left( {1:\left( {\bar{C}.\bar{C}} \right)} \right)} \right) \hfill \\ \quad\quad\quad\quad\quad\quad\quad \left. { + 2\eta _{2} J^{{ - \frac{8}{3}}} \left( {{\varvec{B}}_{{mk}} {\varvec{B}}_{{nk}} {\varvec{B}}_{{rl}} {\varvec{B}}_{{sl}} - \frac{1}{3}\left( {{\varvec{B}}_{{mk}} {\varvec{B}}_{{nk}} \delta _{{rs}} + \delta _{{mn}} {\varvec{B}}_{{rk}} {\varvec{B}}_{{sk}} } \right)\left( {1:\left( {C.C} \right)} \right) + \frac{1}{9}\delta _{{mn}} \delta _{{rs}} \left( {1:\left( {C.C} \right)} \right)^{2} } \right)} \right] \hfill \\ \quad\quad\quad\quad = \frac{1}{J}\left( {\bar{I}_{1} - 3} \right)\left( {\frac{{\eta _{1} }}{2}} \right.\left. {\left( {\overline{{\varvec{B}}} _{{mr}} \overline{{\varvec{B}}} _{{ns}} } \right. + \overline{{\varvec{B}}} _{{ms}} \overline{{\varvec{B}}} _{{nr}} } \right) + 2\eta _{2} \overline{{\varvec{B}}} _{{mk}} \overline{{\varvec{B}}} _{{nk}} \overline{{\varvec{B}}} _{{rl}} \overline{{\varvec{B}}} _{{sl}} - \frac{1}{3}\left( {\overline{{\varvec{B}}} _{{mk}} \overline{{\varvec{B}}} _{{nk}} \delta _{{rs}} } \right. \hfill \\ \quad\quad\quad\quad\quad\quad\quad \left. { + \overline{{\varvec{B}}} _{{rk}} \overline{{\varvec{B}}} _{{sk}} \delta _{{mn}} } \right)\left( {\eta _{1} + 2\eta _{2} \left( {\bar{I}_{1}^{2} - 2\bar{I}_{2} } \right)} \right)\left. { + \frac{1}{9}\delta _{{mn}} \delta _{{rs}} \left( {\bar{I}_{1}^{2} - 2\bar{I}_{2} + 2\eta _{2} \left( {\bar{I}_{1}^{2} - 2\bar{I}_{2} } \right)^{2} } \right)} \right) \hfill \\ \end{gathered} $$
(102)

1.3 Volumetric terms

$${W}^{vol}=\frac{K}{2}{\left(J-1\right)}^{2}$$
(103)
$$\frac{\partial {W}^{vol}}{\partial {{\varvec{C}}}_{ij}}=K\left(J-1\right)J{{\varvec{C}}}_{ij}^{-1}$$
(104)
$${{\varvec{S}}}_{ij}^{vol}=K\left(J-1\right)J{{\varvec{C}}}_{ij}^{-1}$$
(105)
$${{\varvec{\sigma}}}_{mn}^{vol}=\frac{1}{J}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{S}}}_{ij}^{vol}={{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}K\left(J-1\right){{\varvec{C}}}_{ij}^{-1}=K\left(J-1\right){\delta }_{mn}$$
(106)
$$\frac{\partial {{\varvec{S}}}_{ij}^{vol}}{\partial {{\varvec{C}}}_{kl}}=\frac{\partial \left(K\left(J-1\right)J{{\varvec{C}}}_{ij}^{-1}\right)}{\partial {{\varvec{C}}}_{kl}}=K\left(\left(2J-1\right){{\varvec{C}}}_{ij}^{-1}\frac{\partial J}{\partial {{\varvec{C}}}_{kl}}+\left(J-1\right)J\frac{\partial {{\varvec{C}}}_{ij}^{-1}}{\partial {{\varvec{C}}}_{kl}}\right)=\frac{KJ}{2}\left(\left(2J-1\right){{\varvec{C}}}_{ij}^{-1}{{\varvec{C}}}_{kl}^{-1}-\left(J-1\right)\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{jl}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{jk}^{-1}\right)\right)$$
(107)
$${\mathbb{C}}_{mnrs}^{vol}=\frac{2}{J}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{F}}}_{rk}{{\varvec{F}}}_{sl}\left(\frac{KJ}{2}\left(\left(2J-1\right){{\varvec{C}}}_{ij}^{-1}{{\varvec{C}}}_{kl}^{-1}-\left(J-1\right)\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{jl}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{jk}^{-1}\right)\right)\right)=K\left(\left(2J-1\right){\delta }_{mn}{\delta }_{rs}-\left(J-1\right)\left({\delta }_{mr}{\delta }_{ns}+{\delta }_{ms}{\delta }_{nr}\right)\right)$$
(108)

1.4 Anisotropic terms

$${W}^{anisotropic}=\frac{{k}_{1}^{\left(1\right)}}{2{k}_{2}^{\left(1\right)}}\left\{exp \left[{k}_{2}^{\left(1\right)}{\left({I}_{4}-1\right)}^{2}\right]-1\right\}+\frac{{k}_{1}^{\left(2\right)}}{2{k}_{2}^{\left(2\right)}}\left\{exp \left[{k}_{2}^{\left(2\right)}{\left({I}_{6}-1\right)}^{2}\right]-1\right\}$$
(109)
$$\frac{\partial {W}^{anisotropic}}{\partial {{\varvec{C}}}_{ij}}=\frac{{k}_{1}^{\left(1\right)}}{2{k}_{2}^{\left(1\right)}}\frac{2\left({I}_{4}-1\right){k}_{2}^{\left(1\right)}\partial \left({I}_{4}-1\right)}{\partial {{\varvec{C}}}_{ij}}\left\{exp \left[{k}_{2}^{\left(1\right)}{\left({I}_{4}-1\right)}^{2}\right]\right\}+\frac{{k}_{1}^{\left(2\right)}}{2{k}_{2}^{\left(2\right)}}\frac{2\left({I}_{6}-1\right){k}_{2}^{\left(1\right)}\partial \left({I}_{6}-1\right)}{\partial {{\varvec{C}}}_{ij}}\left\{exp \left[{k}_{2}^{\left(2\right)}{\left({I}_{6}-1\right)}^{2}\right]\right\}={k}_{1}^{\left(1\right)}{{\varvec{A}}}_{i}^{(1)}{{\varvec{A}}}_{j}^{(1)}\left({I}_{4}-1\right)\left\{exp \left[{k}_{2}^{\left(1\right)}{\left({I}_{4}-1\right)}^{2}\right]\right\}+{k}_{1}^{\left(2\right)}{{\varvec{A}}}_{i}^{(2)}{{\varvec{A}}}_{j}^{(2)}\left({I}_{6}-1\right)\left\{exp \left[{k}_{2}^{\left(2\right)}{\left({I}_{6}-1\right)}^{2}\right]\right\}$$
(110)
$${{\varvec{S}}}_{ij}^{anisotropic}=2{k}_{1}^{\left(1\right)}{{\varvec{A}}}_{i}^{(1)}{{\varvec{A}}}_{j}^{(1)}\left({I}_{4}-1\right)\left\{exp \left[{k}_{2}^{\left(1\right)}{\left({I}_{4}-1\right)}^{2}\right]\right\}+2{k}_{1}^{\left(2\right)}{{\varvec{A}}}_{i}^{(2)}{{\varvec{A}}}_{j}^{(2)}\left({I}_{6}-1\right)\left\{exp \left[{k}_{2}^{\left(2\right)}{\left({I}_{6}-1\right)}^{2}\right]\right\}$$
(111)
$${{\varvec{\sigma}}}_{mn}^{anisotropic}=\frac{1}{J}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{S}}}_{ij}^{anisotropic}=\frac{2}{J}\left({k}_{1}^{\left(1\right)}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{A}}}_{i}^{(1)}{{\varvec{A}}}_{j}^{(1)}\left({I}_{4}-1\right)\left\{exp \left[{k}_{2}^{\left(1\right)}{\left({I}_{4}-1\right)}^{2}\right]\right\}+{k}_{1}^{\left(2\right)}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{A}}}_{i}^{(2)}{{\varvec{A}}}_{j}^{(2)}\left({I}_{6}-1\right)\left\{exp \left[{k}_{2}^{\left(2\right)}{\left({I}_{6}-1\right)}^{2}\right]\right\}\right)=\frac{2}{J}\left({k}_{1}^{\left(1\right)}{{\varvec{a}}}_{m}^{(1)}{{\varvec{a}}}_{n}^{(1)}\left({I}_{4}-1\right)\left\{exp \left[{k}_{2}^{\left(1\right)}{\left({I}_{4}-1\right)}^{2}\right]\right\}+{k}_{1}^{\left(2\right)}{{\varvec{a}}}_{m}^{(2)}{{\varvec{a}}}_{n}^{(2)}\left({I}_{6}-1\right)\left\{exp \left[{k}_{2}^{\left(2\right)}{\left({I}_{6}-1\right)}^{2}\right]\right\}\right)$$
(112)
$$\frac{\partial {{\varvec{S}}}_{ij}^{anisotropic}}{\partial {{\varvec{C}}}_{kl}}=2{k}_{1}^{\left(1\right)}{{\varvec{A}}}_{i}^{(1)}{{\varvec{A}}}_{j}^{(1)}\left(\left({I}_{4}-1\right)\frac{\partial \left\{exp \left[{k}_{2}^{\left(1\right)}{\left({I}_{4}-1\right)}^{2}\right]\right\}}{\partial {{\varvec{C}}}_{kl}}+\frac{\partial {I}_{4}}{\partial {{\varvec{C}}}_{kl}}\left\{exp \left[{k}_{2}^{\left(1\right)}{\left({I}_{4}-1\right)}^{2}\right]\right\}\right)+2{k}_{1}^{\left(2\right)}{{\varvec{A}}}_{i}^{(2)}{{\varvec{A}}}_{j}^{(2)}\left(\left({I}_{6}-1\right)\frac{\partial \left\{exp \left[{k}_{2}^{\left(2\right)}{\left({I}_{6}-1\right)}^{2}\right]\right\}}{\partial {{\varvec{C}}}_{kl}}+\frac{\partial {I}_{6}}{\partial {{\varvec{C}}}_{kl}}\left\{exp \left[{k}_{2}^{\left(2\right)}{\left({I}_{6}-1\right)}^{2}\right]\right\}\right)=2{k}_{1}^{\left(1\right)}{{\varvec{A}}}_{i}^{(1)}{{\varvec{A}}}_{j}^{(1)}\left((2{k}_{2}^{\left(1\right)}{\left({I}_{4}-1\right)}^{2}+1)\frac{\partial {I}_{4}}{\partial {{\varvec{C}}}_{kl}}exp \left[{k}_{2}^{\left(1\right)}{\left({I}_{4}-1\right)}^{2}\right]\right)+2{k}_{1}^{\left(2\right)}{{\varvec{A}}}_{i}^{(2)}{{\varvec{A}}}_{j}^{(2)}\left((2{k}_{2}^{\left(2\right)}{\left({I}_{6}-1\right)}^{2}+1)\frac{\partial {I}_{6}}{\partial {{\varvec{C}}}_{kl}}exp \left[{k}_{2}^{\left(2\right)}{\left({I}_{6}-1\right)}^{2}\right]\right)=2{k}_{1}^{\left(1\right)}{{\varvec{A}}}_{i}^{(1)}{{\varvec{A}}}_{j}^{(1)}{{\varvec{A}}}_{k}^{(1)}{{\varvec{A}}}_{l}^{(1)}\left((2{k}_{2}^{\left(1\right)}{\left({I}_{4}-1\right)}^{2}+1)exp \left[{k}_{2}^{\left(1\right)}{\left({I}_{4}-1\right)}^{2}\right]\right)+2{k}_{1}^{\left(2\right)}{{\varvec{A}}}_{i}^{(2)}{{\varvec{A}}}_{j}^{(2)}{{\varvec{A}}}_{k}^{(2)}{{\varvec{A}}}_{l}^{(2)}\left((2{k}_{2}^{\left(2\right)}{\left({I}_{6}-1\right)}^{2}+1)exp \left[{k}_{2}^{\left(2\right)}{\left({I}_{6}-1\right)}^{2}\right]\right)$$
(113)
$${\mathbb{C}}_{mnrs}^{anisotropic}=\frac{2}{J}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{F}}}_{rk}{{\varvec{F}}}_{sl}\left(2{k}_{1}^{\left(1\right)}{{\varvec{A}}}_{i}^{(1)}{{\varvec{A}}}_{j}^{(1)}{{\varvec{A}}}_{k}^{(1)}{{\varvec{A}}}_{l}^{(1)}\left((2{k}_{2}^{\left(1\right)}{\left({I}_{4}-1\right)}^{2}+1)exp \left[{k}_{2}^{\left(1\right)}{\left({I}_{4}-1\right)}^{2}\right]\right)+2{k}_{1}^{\left(2\right)}{{\varvec{A}}}_{i}^{(2)}{{\varvec{A}}}_{j}^{(2)}{{\varvec{A}}}_{k}^{(2)}{{\varvec{A}}}_{l}^{(2)}\left((2{k}_{2}^{\left(2\right)}{\left({I}_{6}-1\right)}^{2}+1)exp \left[{k}_{2}^{\left(2\right)}{\left({I}_{6}-1\right)}^{2}\right]\right)\right)=\frac{4}{J}\left({k}_{1}^{\left(1\right)}{{\varvec{a}}}_{m}^{(1)}{{\varvec{a}}}_{n}^{(1)}{{\varvec{a}}}_{r}^{(1)}{{\varvec{a}}}_{s}^{(1)}\left((2{k}_{2}^{\left(1\right)}{\left({I}_{4}-1\right)}^{2}+1)exp \left[{k}_{2}^{\left(1\right)}{\left({I}_{4}-1\right)}^{2}\right]\right)+{k}_{1}^{\left(2\right)}{{\varvec{a}}}_{r}^{(2)}{{\varvec{a}}}_{s}^{(2)}{{\varvec{a}}}_{m}^{(2)}{{\varvec{a}}}_{n}^{(2)}\left((2{k}_{2}^{\left(2\right)}{\left({I}_{6}-1\right)}^{2}+1)exp \left[{k}_{2}^{\left(2\right)}{\left({I}_{6}-1\right)}^{2}\right]\right)\right)$$
(114)

1.5 Dielectric terms

$${W}^{electric}=-\frac{1}{2}\varepsilon J{{\varvec{C}}}_{pq}^{-1}{\mathbb{E}}_{p}{\mathbb{E}}_{q}$$
(115)
$$\frac{\partial {W}^{electric}}{\partial {{\varvec{C}}}_{ij}}=-\frac{1}{2}\varepsilon {\mathbb{E}}_{p}{\mathbb{E}}_{q}\frac{\partial \left(J{{\varvec{C}}}_{pq}^{-1}\right)}{\partial {{\varvec{C}}}_{ij}}=-\frac{1}{2}\varepsilon {\mathbb{E}}_{p}{\mathbb{E}}_{q}\left(J\frac{\partial {{\varvec{C}}}_{pq}^{-1}}{\partial {{\varvec{C}}}_{ij}}+{{\varvec{C}}}_{pq}^{-1}\frac{\partial J}{\partial {{\varvec{C}}}_{ij}}\right)=-\frac{1}{2}\varepsilon {\mathbb{E}}_{p}{\mathbb{E}}_{q}\left(-\frac{1}{2}J\left({{\varvec{C}}}_{ip}^{-1}{{\varvec{C}}}_{jq}^{-1}+{{\varvec{C}}}_{iq}^{-1}{{\varvec{C}}}_{jp}^{-1}\right)+\frac{1}{2}J{{\varvec{C}}}_{pq}^{-1}{{\varvec{C}}}_{ij}^{-1}\right)=-\frac{1}{4}\varepsilon J{\mathbb{E}}_{p}{\mathbb{E}}_{q}\left({{\varvec{C}}}_{pq}^{-1}{{\varvec{C}}}_{ij}^{-1}-\left({{\varvec{C}}}_{ip}^{-1}{{\varvec{C}}}_{jq}^{-1}+{{\varvec{C}}}_{iq}^{-1}{{\varvec{C}}}_{jp}^{-1}\right)\right)$$
(116)
$${{\varvec{S}}}_{ij}^{electric}=-\frac{1}{2}\varepsilon J{\mathbb{E}}_{p}{\mathbb{E}}_{q}\left({{\varvec{C}}}_{pq}^{-1}{{\varvec{C}}}_{ij}^{-1}-\left({{\varvec{C}}}_{ip}^{-1}{{\varvec{C}}}_{jq}^{-1}+{{\varvec{C}}}_{iq}^{-1}{{\varvec{C}}}_{jp}^{-1}\right)\right)$$
(117)
$${{\varvec{\sigma}}}_{mn}^{electric}=\frac{1}{J}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{S}}}_{ij}^{electric}=-\frac{1}{2}\varepsilon {\mathbb{E}}_{p}{\mathbb{E}}_{q}\left({{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{C}}}_{pq}^{-1}{{\varvec{C}}}_{ij}^{-1}-\left({{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{C}}}_{ip}^{-1}{{\varvec{C}}}_{jq}^{-1}+{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{C}}}_{iq}^{-1}{{\varvec{C}}}_{jp}^{-1}\right)\right)=-\frac{1}{2}\varepsilon \left({\delta }_{mn}{{\varvec{C}}}_{pq}^{-1}{\mathbb{E}}_{p}{\mathbb{E}}_{q}-\left({{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{C}}}_{ip}^{-1}{{\varvec{C}}}_{jq}^{-1}{\mathbb{E}}_{p}{\mathbb{E}}_{q}+{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{C}}}_{iq}^{-1}{{\varvec{C}}}_{jp}^{-1}{\mathbb{E}}_{p}{\mathbb{E}}_{q}\right)\right)=-\frac{1}{2}\varepsilon \left({\delta }_{mn}{\mathbbm{e}}_{l}{\mathbbm{e}}_{l}-2{\mathbbm{e}}_{m}{\mathbbm{e}}_{n}\right)=\varepsilon \left({\mathbbm{e}}_{m}{\mathbbm{e}}_{n}-\frac{1}{2}{\delta }_{mn}{\mathbbm{e}}_{l}{\mathbbm{e}}_{l}\right)$$
(118)
$$\frac{\partial {{\varvec{S}}}_{ij}^{electric}}{\partial {{\varvec{C}}}_{kl}}=-\frac{1}{2}\varepsilon J{\mathbb{E}}_{p}{\mathbb{E}}_{q}\left(\frac{\partial \left({{\varvec{C}}}_{pq}^{-1}{{\varvec{C}}}_{ij}^{-1}\right)}{\partial {{\varvec{C}}}_{kl}}-\left(\frac{\partial \left({{\varvec{C}}}_{ip}^{-1}{{\varvec{C}}}_{jq}^{-1}\right)}{\partial {{\varvec{C}}}_{kl}}+\frac{\partial \left({{\varvec{C}}}_{iq}^{-1}{{\varvec{C}}}_{jp}^{-1}\right)}{\partial {{\varvec{C}}}_{kl}}\right)\right)=-\frac{1}{2}\varepsilon J{\mathbb{E}}_{p}{\mathbb{E}}_{q}\left(\frac{\partial {{\varvec{C}}}_{pq}^{-1}}{\partial {{\varvec{C}}}_{kl}}{{\varvec{C}}}_{ij}^{-1}+\frac{\partial {{\varvec{C}}}_{ij}^{-1}}{\partial {{\varvec{C}}}_{kl}}{{\varvec{C}}}_{pq}^{-1}-\left(\frac{\partial {{\varvec{C}}}_{ip}^{-1}}{\partial {{\varvec{C}}}_{kl}}{{\varvec{C}}}_{jq}^{-1}+\frac{\partial {{\varvec{C}}}_{jq}^{-1}}{\partial {{\varvec{C}}}_{kl}}{{\varvec{C}}}_{ip}^{-1}+\frac{\partial {{\varvec{C}}}_{iq}^{-1}}{\partial {{\varvec{C}}}_{kl}}{{\varvec{C}}}_{jp}^{-1}+\frac{\partial {{\varvec{C}}}_{jp}^{-1}}{\partial {{\varvec{C}}}_{kl}}{{\varvec{C}}}_{iq}^{-1}\right)\right)=\frac{1}{4}\varepsilon J{\mathbb{E}}_{p}{\mathbb{E}}_{q}\left({{\varvec{C}}}_{ij}^{-1}\left({{\varvec{C}}}_{pk}^{-1}{{\varvec{C}}}_{ql}^{-1}+{{\varvec{C}}}_{pl}^{-1}{{\varvec{C}}}_{qk}^{-1}\right)+{{\varvec{C}}}_{pq}^{-1}\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{jl}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{jk}^{-1}\right)-\left({{\varvec{C}}}_{jq}^{-1}\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{pl}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{pk}^{-1}\right)+{{\varvec{C}}}_{ip}^{-1}\left({{\varvec{C}}}_{jk}^{-1}{{\varvec{C}}}_{ql}^{-1}+{{\varvec{C}}}_{jl}^{-1}{{\varvec{C}}}_{qk}^{-1}\right)+{{\varvec{C}}}_{jp}^{-1}\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{ql}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{qk}^{-1}\right)+{{\varvec{C}}}_{iq}^{-1}\left({{\varvec{C}}}_{jk}^{-1}{{\varvec{C}}}_{pl}^{-1}+{{\varvec{C}}}_{jl}^{-1}{{\varvec{C}}}_{pk}^{-1}\right)\right)\right)$$
(119)
$${\mathbb{C}}_{mnrs}^{electric}=\frac{2}{J}{{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{F}}}_{rk}{{\varvec{F}}}_{sl}\left(\frac{1}{4}\varepsilon J{\mathbb{E}}_{p}{\mathbb{E}}_{q}\left({{\varvec{C}}}_{ij}^{-1}\left({{\varvec{C}}}_{pk}^{-1}{{\varvec{C}}}_{ql}^{-1}+{{\varvec{C}}}_{pl}^{-1}{{\varvec{C}}}_{qk}^{-1}\right)+{{\varvec{C}}}_{pq}^{-1}\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{jl}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{jk}^{-1}\right)-\left({{\varvec{C}}}_{jq}^{-1}\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{pl}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{pk}^{-1}\right)+{{\varvec{C}}}_{ip}^{-1}\left({{\varvec{C}}}_{jk}^{-1}{{\varvec{C}}}_{ql}^{-1}+{{\varvec{C}}}_{jl}^{-1}{{\varvec{C}}}_{qk}^{-1}\right)+{{\varvec{C}}}_{jp}^{-1}\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{ql}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{qk}^{-1}\right)+{{\varvec{C}}}_{iq}^{-1}\left({{\varvec{C}}}_{jk}^{-1}{{\varvec{C}}}_{pl}^{-1}+{{\varvec{C}}}_{jl}^{-1}{{\varvec{C}}}_{pk}^{-1}\right)\right)\right)\right)=\frac{1}{2}\varepsilon {{\varvec{F}}}_{mi}{{\varvec{F}}}_{nj}{{\varvec{F}}}_{rk}{{\varvec{F}}}_{sl}\left({\mathbb{E}}_{p}{\mathbb{E}}_{q}\left({{\varvec{C}}}_{ij}^{-1}\left({{\varvec{C}}}_{pk}^{-1}{{\varvec{C}}}_{ql}^{-1}+{{\varvec{C}}}_{pl}^{-1}{{\varvec{C}}}_{qk}^{-1}\right)+{{\varvec{C}}}_{pq}^{-1}\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{jl}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{jk}^{-1}\right)-\left({{\varvec{C}}}_{jq}^{-1}\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{pl}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{pk}^{-1}\right)+{{\varvec{C}}}_{ip}^{-1}\left({{\varvec{C}}}_{jk}^{-1}{{\varvec{C}}}_{ql}^{-1}+{{\varvec{C}}}_{jl}^{-1}{{\varvec{C}}}_{qk}^{-1}\right)+{{\varvec{C}}}_{jp}^{-1}\left({{\varvec{C}}}_{ik}^{-1}{{\varvec{C}}}_{ql}^{-1}+{{\varvec{C}}}_{il}^{-1}{{\varvec{C}}}_{qk}^{-1}\right)+{{\varvec{C}}}_{iq}^{-1}\left({{\varvec{C}}}_{jk}^{-1}{{\varvec{C}}}_{pl}^{-1}+{{\varvec{C}}}_{jl}^{-1}{{\varvec{C}}}_{pk}^{-1}\right)\right)\right)\right)=\varepsilon \left({\mathbbm{e}}_{r}{\mathbbm{e}}_{s}{\delta }_{mn}+{\mathbbm{e}}_{m}{\mathbbm{e}}_{n}{\delta }_{rs}-\left({\mathbbm{e}}_{r}{\mathbbm{e}}_{n}{\delta }_{ms}+{\mathbbm{e}}_{n}{\mathbbm{e}}_{s}{\delta }_{mr}+{\mathbbm{e}}_{m}{\mathbbm{e}}_{r}{\delta }_{ns}+{\mathbbm{e}}_{m}{\mathbbm{e}}_{s}{\delta }_{nr}\right)\right)$$
(120)

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Majidi, M., Asgari, M. Rate-dependent electromechanical behavior of anisotropic fiber-reinforced dielectric elastomer based on a nonlinear continuum approach: modeling and implementation. Eur. Phys. J. Plus 138, 73 (2023). https://doi.org/10.1140/epjp/s13360-023-03688-w

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1140/epjp/s13360-023-03688-w

Navigation