Tissue properties
Lakes lecture
Viscoelastic and Microelastic Properties of Tissue
Title Bio,
Viscoelasticity
Bone Galen View
Bone hierarchy
View of bone
Bone frequency and time dependence
Spring back
Bone hierarchy
Spring damper model which gives single exponential relaxation.
Single exponential relaxation E(t) on a log scale.
Phase delta. Stress vs. strain in sinusoidal loading. Meaning of the loss tangent.
Bone relaxation and damping plot.
Viscoelasticity due to fluid flow.
Heart muscle relaxation.
Heart muscle relaxation time related to size.
Interpretation via Biot theory.
BVS Instrument diagram
slow
fast
BVS Instrument functions
Bone axial damping summary plot .
Bone shear damping summary plot .
Stiffness / loss plot: comparison of materials.
Bone torsion damping summary plot .
Bovine bone
Bone long creep
Cement line displacement in bone under prolonged load.
Slow waves
Size effect in damping
Damping via FEM
Fluid pressure via FEM
Misshapen head reshaped
Baby helmet for head reshaping
Baby heads improper treatment.
2,
3;
head deformation
skeleton
Summary
Ape-men
Ligament and tendon
Stretching
Spring back
Tendon hierarchical structure diagram.
Ligament structure.
Ligament structure. Scanning electron micrographs of a normal rat medial collateral ligament (A)
Ligament structure. Normal (top) and scar (bottom) tissues of a healing medial collateral ligament (MCL) in slack configuration.
Ligament structure. Bifurcation/Fusion of collagen fibrils in normal MCL tissue at 20,000X (arrow). Note the collagen fibril overlap and interweaving.
Ligament structure. Ligament in which a single tensile overload produced microstructural damage but not ligament rupture (B).
Ligament overload damage image
Ligament overload damage graph
Ligament stress-strain curves
Creep and relaxation
Constitutive equations. Linear and nonlinear viscoelasticity
Superposition in viscoelasticity
Prediction of nonlinear viscoelasticity
Ligament relaxation.
Ligament creep and relaxation.
Ligament rate effect.
Tendon relaxation
Cornea creep
Tendon recovery does not follow QLV
QLV; experiment.
Conclusion
Summary
isthmus view
isthmus and campus
Bone as a generalized continuum
Material freedom
Composite Structure.
Rationale: structure
Osteon
Cosserat equations
characteristic lengths
measuring properties, torsion
measuring properties, bending
Size effect, Rohacell foam
Size effect, dense foam
Elastic constants, dense foam
Size effect, bone
Size effect, osteons
Elastic constants, bone
Strain concentration reduction
Strain distribution
Corner element: why spill over
Warp in fibrous medium
Cement line displacement in bone under prolonged load.
Corner element in rubber
Corner element in foam
Warp in foam by holography
Warp by theory
Chiral structure
Chiral equations
Chiral stretching
Holography PMMA,
dense foam,
dry bone,
wet bone
Summary
isthmus view
isthmus and campus