γij- shear strain component in Green's strain tensor η- coordinate in non inertial system λ(s,t)- Lagrange multiplier ν- non dimensional time coordinate θ- error in the displacement θ- Euler angle θ- the product βl θr- rth value of θ ρ- density ρ(s,t)- curvature vector ρα (α= ξ, η, ζ)- component of the curvature vector σij- component of stress tensor τ- integration variable in convolution integral ω- frequency of vibration ω(s,t)- angular velocity vector ω(t)- weighting function ωr- rth natural frequency ωα (α= ξ, η, ζ)- component of angular velocity vector ξ- coordinate in non inertial system ξr- rth modal damping ratio ξηζ- non inertial coordinate system ψ- Euler angle ψα ( α= 1,2,3,4)- shape functions for discretization in the spatial coordinate ζ- coordinate in non inertial system
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