FEA OF SOFT TISSUE

Question 1

What counts as SOFT TISSUE?

Answer 1

• Cartilage
• Ligaments
• Skin
• Tendons
• Fibrous Tissues
• Muscles
• Nerves
• Blood Vessels

Question 2

What is CARTILAGE AND WHAT ARE ITS PROPERTIES?

Answer 2

A natural shock absorber found in joints

• Multiphasic (fluid and solid) - mostly water with collagen and other solid proteins
• Viscoelastic
• Non-uniform structure
• High shock absorbance
• Low Friction

Question 3

What are LIGAMENTS?

Answer 3

• Covers a variety of constituents: collagen, elastin, glycoproteins, protein-polysaccharide, glycolipids, water and cells
• Made of tightly packed COLLAGEN FIBRES
• Time-dependent & history-dependent viscoelastic behaviour
• Temperature effect

Question 4

What is the makeup OF SKIN?

Answer 4

• Three layers - EPIDERMIS, DERMIS, HYPODERMIS
• Extracellular matrix contains;
  - Structural proteins (collagen/elastin)
  - Specialised proteins (fibronectins)
  - Proteoglycans
• Viscoelastic, anisotropic, non-linear

Question 5

What is HYPERELASTICITY?

Answer 5

Low elastic modulus with high bulk modulus

Question 6

What is VISCOELASTIC?

Answer 6

When something is VISCOUS and ELASTIC
Time-dependent strain

Question 7

What are the TWO TYPES OF FIBRE REINFORCEMENT AND HOW ARE THEY DIFFERENT?

Answer 7

DISCRETE MODELLING - fibres with non-uniform material in arbitrary orientations.
SMEARED MODELLING - fibres with identical materials and orientations