TY - JOUR

T1 - Finite-wavelength surface-tension-driven instabilities in soft solids, including instability in a cylindrical channel through an elastic solid

AU - Xuan, Chen

AU - Biggins, John

N1 - Publisher Copyright:
© 2016 American Physical Society.

PY - 2016/8/15

Y1 - 2016/8/15

N2 - We deploy linear stability analysis to find the threshold wavelength (λ) and surface tension (γ) of Rayleigh-Plateau type "peristaltic" instabilities in incompressible neo-Hookean solids in a range of cylindrical geometries with radius R0. First we consider a solid cylinder, and recover the well-known, infinite-wavelength instability for γ≥6μR0, where μ is the solid's shear modulus. Second, we consider a volume-conserving (e.g., fluid filled and sealed) cylindrical cavity through an infinite solid, and demonstrate infinite-wavelength instability for γ≥2μR0. Third, we consider a solid cylinder embedded in a different infinite solid, and find a finite-wavelength instability with λ R0, at surface tension γ μR0, where the constants depend on the two solids' modulus ratio. Finally, we consider an empty cylindrical channel (or filled with expellable fluid) through an infinite solid, and find an instability with finite wavelength, λ≈2R0, for γ≥2.543⋯μR0. Using finite-strain numerics, we show such a channel jumps at instability to a highly peristaltic state, likely precipitating it's blockage or failure. We argue that finite wavelengths are generic for elastocapillary instabilities, with the simple cylinder's infinite wavelength being the exception rather than the rule.

AB - We deploy linear stability analysis to find the threshold wavelength (λ) and surface tension (γ) of Rayleigh-Plateau type "peristaltic" instabilities in incompressible neo-Hookean solids in a range of cylindrical geometries with radius R0. First we consider a solid cylinder, and recover the well-known, infinite-wavelength instability for γ≥6μR0, where μ is the solid's shear modulus. Second, we consider a volume-conserving (e.g., fluid filled and sealed) cylindrical cavity through an infinite solid, and demonstrate infinite-wavelength instability for γ≥2μR0. Third, we consider a solid cylinder embedded in a different infinite solid, and find a finite-wavelength instability with λ R0, at surface tension γ μR0, where the constants depend on the two solids' modulus ratio. Finally, we consider an empty cylindrical channel (or filled with expellable fluid) through an infinite solid, and find an instability with finite wavelength, λ≈2R0, for γ≥2.543⋯μR0. Using finite-strain numerics, we show such a channel jumps at instability to a highly peristaltic state, likely precipitating it's blockage or failure. We argue that finite wavelengths are generic for elastocapillary instabilities, with the simple cylinder's infinite wavelength being the exception rather than the rule.

UR - http://www.scopus.com/inward/record.url?scp=84983509295&partnerID=8YFLogxK

U2 - 10.1103/PhysRevE.94.023107

DO - 10.1103/PhysRevE.94.023107

M3 - Article

AN - SCOPUS:84983509295

SN - 1539-3755

VL - 94

JO - Physical Review E - Statistical, Nonlinear, and Soft Matter Physics

JF - Physical Review E - Statistical, Nonlinear, and Soft Matter Physics

IS - 2

M1 - 023107

ER -