Chapter 9 Mechanics of Biological Materials

Question 1

anisotropic

Answer 1

material properties dependent on direction of load

Question 2

bending load

Answer 2

nonaxial load where tensile and compressive stresses result in force couples at opposite ends of the object causing the body to deform by curving

Question 3

cancellous/spongy bone

Answer 3

porous, less dense bone tissue found deep to cortical bone near the ends of long bones

Question 4

combined load

Answer 4

combination of tension, compression, simple shear loads, bending, and torsion

Question 5

cortical/compact bone

Answer 5

solid, dense bone tissue found in the outer layer of bones

Question 6

compression

Answer 6

axial stress due to a load squeezing molecules together causing the body to deform by shortening

Question 7

creep

Answer 7

progressive increase in strain or deformation of a structure over time under a constant stress or load

Question 8

elastic

Answer 8

deformed material able to return to original length when load is removed

Question 9

elastic cartilage

Answer 9

cartilage with more elastic than fibrous cartilage

Question 10

elastic limit

Answer 10

yield point for a material on the stress-strain curve, stress above this point causes permanent deformation

Question 11

elastic modulus

Answer 11

ratio of stress to strain, slope of the stress-strain curve (youngs modulus)

Question 12

failure strain

Answer 12

strain at which total failure occurs

Question 13

failure strength

Answer 13

stress at which total failure occurs

Question 14

fibrous cartilage

Answer 14

cartilage with heavier collagen fibers than hyaline cartilage

Question 15

hyaline cartilage

Answer 15

shiny, white, smooth cartilage that makes up articular cartilage covering bone ends at joints

Question 16

isotropic

Answer 16

material properties that are the same in all directions

Question 17

plastic

Answer 17

deformed material unable to return to original shape resulting in permanent deformation

Question 18

poissons ratio

Answer 18

ratio between transverse strain and axial strain, width of an object changes as it lengthens or shortens

Question 19

shear

Answer 19

transverse stress that acts parallel due to non-colinear forces sliding molecules causing the body to deform by skewing

Question 20

stress

Answer 20

external applied load

Question 21

tensile stress

Answer 21

axial stress due to a force or load pulling molecules apart causing the body to deform by stretching

Question 22

torsion load

Answer 22

nonaxial load where shear stress results in opposing torques at either end of the body causing the body to deform by twisting

Question 23

toughness

Answer 23

ability of a material to absorb energy before failing

Question 24

ultimate strength

Answer 24

maximum stress a material can withstand

Question 25

yield strength

Answer 25

stress above which plastic deformation will occur at the elastic limit

Question 26

mechanical stress

Answer 26

internal force divided by the cross-sectional area of the surface on which the internal force acts