Phenomenological constitutive model for a CNT turf

Tailoring viscoelastic response of carbon nanotubes cellular structure using electric field

“…This suggests that the electric field induced strengthening decreased with the pre-strain value and this may be attributed to the enhanced buckling of the CNT strands and bundles once they are pre-compressed to a high strain. 28 In summary, the stiffness of the CNT samples increased upon the application of the electric field, but the relative increase decreased with the imposed pre-compressive strain. It should be noted that coupling between the strain (or, pre-stress) and the electric field affects the polarization in CNT and hence the actuation strain.…”

“…Various quantitative models describing the viscoelastic response of cellular CNT have been proposed. Mesarovic and co-workers 27,28 modeled CNT turfs as super-compressible foams consisting of sliding CNT nodes and quantified the viscoelastic relaxation response using the Kelvin-Voigt element, i.e., the stress decayed exponentially with time. On the other hand, Xu et al 26 modelled similar CNT structures as non-interacting coils and quantified the creep recovery using a power law: G ∼ ε −2 where G is the stiffness and ε is the strain.…”

Micromechanics of collective buckling in CNT turfs

“…Moreover, while the collective buckling is certainly a structural instability (in the sense that it depends on boundary conditions), the independence of the buckling stress and the buckling wavelength on the turf width (Zbib et al, 2008) indicates a continuum model with an intrinsic material length. A continuum model for stable behavior under non-uniform load has been developed recently in our group (Radhakrishnan et al, 2013).…”

“…6 McCarter et al (2006,Mesarovic et al (2007),Qiu et al (2011a),Radhakrishnan et al (2013).7 Buehler(2006), Volkov et al (2009), Anderson et al (2010).Nonlinear geometry produces torsion-bending coupling at the level of governing equations. Consider an infinitesimal segment ds(Fig.…”

Effect of fluid medium on mechanical behavior of carbon nanotube foam

“…1 Several studies have been carried out to reveal the mechanical properties of bulk CNT foams. [2][3][4][5][6][7][8][9][10][11][12][13][14][15] CNT foams have been shown to combine lightweight, high porosity, and large surface area with relatively high stiffness and tunable energy absorption capacity. 4,16,17 Recently, CNT foams have been assembled into multilayer structures presenting superior energy absorption capability as compared to other conventional layered, metallic and polymeric foams and fibrous cushioning materials.…”