Material Properties

Load

A force or moment to which a material is subject

Deformation

The change in shape of the material that occurs when a load is applied

Tension

Application of one or more forces that pull apart or separates a material

Compression

Applicaiton of one or more forces that pushes or compressed material together

Bending

The effect of a force that deforms a material at right angles to its long axis. A bent tissue is compressed on its concave side and placed under tension on its convex side

Shear

A force produced as two compressed obhects slide past each other in opposite directions

Torsion

Applicaiton of a force thst twist a material around a longitudinal access

Friction

Is a resisitance to movment between two contacting surfaces (friction forces at parrallel to surfaces)

Stress

Also called pressure, normalized loss: force per unit

Strain

Normalized deformation: change in length relative to original length

Toe- Region

Slightly stretched or elongated ligament produced only a small amount of tension (slack in the tissue)

Elastic Region

Tissue deforms under load but returns to its normal length when load is removed

Elasticity

The abilty os a tissue to return to its resting length after a force has been removed

Plastic region

Material deforms under stress but does not return to its original lenght or shape when load is removed

Plasticity

The ability of a tissue to remain deformed without breaking after a deforming force had been removed

Yeild Strength

The point at which plastic deformation occurs on the stress/strain curve. The transtion from the elastic to plastic regions on the curve

Ultimate strength

Maximum stress or strain, byond whcih tissue failure occurs

Falure strength

stress or strain at which tissue failure occurs

Stiffness

Parmeter which relates stress/load to strain/deformation

Young’s Modulus

change stress/change strain

stiff= large modulus

compliant = small modulus

Stiffness

resistance through the length of change or through the stretch

Fexability

Little resisitance through the length of change or through the stretch

Ductility

The amount of plastic strain a material can undergo before failure

Ductile Vs Brittle

Ductiel is long plastic region while brittle is s ashort plastic region

Viscoelasticity

C

Creep

increase in deformation (strain) of a material when subjected to constant load over time

Stress relaxation

Decrease in load experienced by a material over time when deformed to a constant length