Lecture 8 (BME 296)

Mechanical Properties of Biomaterials

Characteristics that determine how biomaterials respond to various forces and deformations.

Stress Shielding

The process where the stresses placed on tissues are reduced, potentially leading to bone loss or weakening.

Viscoelastic Behavior

Materials that exhibit both viscous and elastic characteristics when undergoing deformation.

Hooke’s Law

States that stress is directly proportional to strain in the elastic region of a material.

Tensile Testing

A method used to determine the behavior of materials under tensile (stretching) forces.

Poisson's Ratio

The ratio of the strain in the transverse direction to the strain in the axial direction when loaded.

Yield Strength

The stress level at which a material begins to deform plastically.

Ductility

A material's ability to deform plastically before rupture.

Brittleness

The tendency of a material to fracture without considerable deformation.

Compression Test

A test to measure the behavior of a material under compressive (squeezing) loads.

Shear Testing

A method to measure how a material responds to forces that cause it to deform along a plane.

Fracture Strength

The stress at which a material fails and breaks due to applied forces.

Plastic Deformation

Permanent deformation of a material when the stress exceeds the yield strength.

Amorphous Polymers

Materials that lack a definite shape or crystalline structure, deforming through viscous flow.

Semi-Crystalline Polymers

Polymers characterized by both crystalline and amorphous regions, affecting their mechanical properties.

Strain

The amount of deformation experienced by a body in the direction of the applied force, normalized to its original length.

Shear Modulus

A measure of a material's response to shear stress, defined as the ratio of shear stress to shear strain.

Elastic Deformation

Temporary deformation where the material returns to its original shape once the load is removed.

Tensile Strength

The maximum stress a material can withstand while being stretched or pulled before necking.

Viscous Flow

The flow of a material that occurs when it deforms under stress, exhibiting time-dependent characteristics.