Rayleigh wave propagation in human skin: A multiphysics model of a natural fibrous composite incorporating nonlocal, micropolar, and thermal-memory effects

Khan M. A., Abualnaja K. M., Riaz U., Mahmoud E. E., Jahangir A., YAYLACI M.

Composites Part C: Open Access, cilt.20, 2026 (ESCI, Scopus) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 20
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1016/j.jcomc.2026.100738
  • Dergi Adı: Composites Part C: Open Access
  • Derginin Tarandığı İndeksler: Emerging Sources Citation Index (ESCI), Scopus
  • Anahtar Kelimeler: Biocomposite, Fibrous composites, Fractional thermoelasticity, Global sensitivity analysis, Micropolar continuum, Multiphysics modeling, Non-destructive evaluation (NDE), Nonlocal elasticity, Rayleigh wave, Three-phase-lag model, Wave propagation
  • Recep Tayyip Erdoğan Üniversitesi Adresli: Evet

Özet

This work develops and validates a unified multiphysics framework for Rayleigh wave propagation in human skin, treating the dermis as a functionally graded fibrous composite of collagen fibrils in a viscoelastic proteoglycan matrix. For the first time, we simultaneously incorporate nonlocal elasticity (capturing scale-dependent stress interactions), micropolar (Cosserat) theory (accounting for fiber–matrix rotational coupling), fractional-order thermoelasticity (describing power-law thermal memory), and the three-phase-lag bioheat equation (encompassing non-Fourier heat transfer). The governing equations are derived for a graded half-space and solved analytically. Results show that local continuum theories are inadequate: nonlocal and micropolar effects significantly alter dispersion, attenuation, penetration depth, and specific heat loss, while the fractional order α(0<α≤1) quantifies sub-diffusive thermal transport arising from the tissue's multiple relaxation scales. A global sensitivity analysis identifies the dominant parameters—elastic nonlocality ϵ1, fractional order α, vortex viscosity κ, and inhomogeneity α∗- providing a roadmap for model reduction. The study offers (i) a physically realistic foundation for non-destructive skin diagnosis and thermal therapy planning, and (ii) establishes skin as a paradigm fibrous composite whose wave dynamics inform the design of biomimetic materials.