Create
Learn
Share

30. Mechanical Properties of Solids and Tissues

rename
yaboiemil's version from 2016-01-26 12:11

Section

1. Substances can be divided into 5 groups by their reaction to stress (F/A). These are:

 

Question Answer
Elastic SubstancesSubstances that resist a deformative force, returning to original shape. Obey Hooke's Law.
Plastic SubstancesSubstances that deform non-reversibly under stress. (e.g. Piece of metal hammered)
Viscous SubstancesNewtonian and Non-newtonian.
Newtonian SubstancesRate of deformation directly proportional to shear stress.
Non-Newtonian SubstancesRate of deformation not directly proportional to shear stress. Dynamic Viscosity will determine deformation.
Viscoelastic SubstanceAfter stress is released, relaxation occurs and shape returns. Needs force tho. Hysteresis.
Plastic-Viscoelastic SubstanceViscoelastic up to critical value, then deforms like a plastic.
memorize

 

2. In Viscoelastic substances, deformation is stress AND time.
3. Hysteresis is lag in response to a change in force, due to history of other forces on object.

Hooke's Law of Elasticity:

 

 

Question Answer
Weird curly EDeformation
EModus of Elasticity (numerically = tensile strain)
SigmaStress
memorize

Recent badges