University:
Boston University
Course:
ENG ME 303 | Fluid Mechanics
Academic year:

2021
Views:

84

Pages:

24
Author:

shokoa5oyn

Swelling of Elastic Materials Fluids Deforming Solids Geometric Non-linearities: • Buckling • Wrinkling • Folding • Creasing • Snapping How do objects change shape? How do you “grow” a structure into a desired shape? Thin Structures Bending vs. Stretching Thin structures deform by bending & avoid stretching Swelling Dynamics Diffusive-like Dynamics Beam Bending Beam Bending Dynamics of bending : Diffusion of temperature Diffusion • Thermal diffusion through the beam thickness. • Shape obtained by minimizing the bending moment in the beam. • Beam curvature as temperature diffuses. Beam curvature as solvent diffuses: Poroelastic time scale: μ = Solvent viscosity h = Thickness k = Permeability (k ≈ 10-18 m2/s) E = Elastic modulus (E = 106 Pa) Swelling Nonlinear Swelling Nonlinear Swelling What happens when you swell a thicker beam? Mechanical Instability Mechanical Instability Bending and Buckling Bending and Buckling No Structural Deformation Surface Deformation Bending and Buckling Structural Deformation No Surface Deformation No Structural Deformation Surface Deformation Bending vs. Swelling Can the fluid bend the structure? Bending Swelling Length scale: Thin structures bend… Thick structures stay flat, while their surface creases… “Elastoswelling” length Deformation Transition Structural Deformation (Bending/Buckling) Surface Deformation (Creasing) , е е ' ( Н<•>. е, а -;; , • )- ----.J,. • Controlling Shape Microfluidic Swelling Controlling Shape