Mechanical Properties of Metals

Question 1

Key mechanical
design properties

Answer 1

stiffness, strength, hardness, ductility, and toughness

Question 2

Factors to be considered in performing designed laboratory experiments that replicate as nearly as possible the service conditions.

Answer 2

nature of the
applied load and its duration, environmental conditions

Question 3

It can be used to ascertain
several mechanical properties of materials that are important in design.

Answer 3

Tension Test

Question 4

conducted in a manner
similar to the tensile test, except that the force is compressive and the
specimen contracts along the direction of the stress

Answer 4

Compression Test

Question 5

more common because they are easier to perform; also, for most
materials used in structural applications, very little additional
information is obtained from compressive tests

Answer 5

Tensile tests

Question 6

used when a material’s behavior under large and permanent (i.e.,
plastic) strains is desired, as in manufacturing applications, or when the
material is brittle in tension.

Answer 6

s. Compressive tests

Question 7

computed as Ƭ = F/A

Answer 7

shear stress

Question 8

is the load or
force imposed parallel to the upper and lower faces, each of which has
an area of A

Answer 8

F in the formula

Question 9

defined as the tangent of the strain
angle.

Answer 9

shear strain

Question 10

units of stress

Answer 10

N/m2 or lb/in2

Question 11

Stresses that are
computed from the tensile, compressive, shear, and torsional force
states.

Answer 11

Geometric Consideration of the Stress State

Question 12

The degree to which a structure deforms
or strains depends on the magnitude of an
imposed stress

Answer 12

Elastic Deformation

Question 13

For most metals that are
stressed in tension and at relatively low levels,
stress and strain are __________ to each other
through the relationship

Answer 13

proportional

Question 14

For most typical metals
the magnitude of this modulus ranges between ___________ for magnesium and ___________

Answer 14

45 GPa (6.5x106
psi), 407 GPa (59x106
psi)

Question 15

Deformation in which stress and strain are proportional

Answer 15

elastic
deformation

Question 16

elastic means

Answer 16

reversible

Question 17

plastic means

Answer 17

permanent

Question 18

time-dependent elastic behavior

Answer 18

anelasticity

Question 19

Maximum stress on engineering stress-strain curve

Answer 19

Tensile Strength, TS

Question 20

It is a measure of
the degree of plastic deformation that has been sustained at fracture.

Answer 20

Ductility

Question 21

A metal
that experiences very little or no plastic deformation upon fracture

Answer 21

brittle

Question 22

capacity of a material to absorb energy when it is
deformed elastically and then, upon unloading, to have this energy recovered.

Answer 22

Resilience

Question 23

the strain
energy per unit volume required to stress a material from an unloaded state
up to the point of yielding.

Answer 23

modulus of resilience

Question 24

the ability of a material to absorb energy and
plastically deform before fracturing

Answer 24

Toughness

Question 25

a property
that is indicative of a material’s resistance to fracture when a crack

Answer 25

Toughness

Question 26

a measure of a material’s resistance to localized plastic
deformation (e.g., a small dent or a scratch)

Answer 26

hardness

Question 27

material property and Critical properties depend
largely on sample flaws (defects, etc.)

Answer 27

Elastic modulus

Question 28

the instantaneous applied load divided by the
instantaneous cross-sectional area.

Answer 28

True stress