Mechanical Properties Of Metals

Question 1

The mechanical behavior of a material refects its______________ in relation to an applied load or force.

Answer 1

response or deformation

Question 2

mechanical design properties are

Answer 2

stiffness, strength, hardness, ductility, and
toughness

Question 3

ascertained by perorming carefully designed laborator experiments that replicate as nearly as possible the seice conditions.

Answer 3

Mechanical Properties

Question 4

three principal ways in which a load
may be applied:

Answer 4

tension, compression, and shear

Question 5

is designed to elongate the specimen at a constant rate and to continuously and simultaneously measure the instantaneous
applied load and the resulting elongation.

Answer 5

tensile testing machine

Question 6

is used in ductility computations

Answer 6

Gauge length

Question 7

typically takes several minutes to perform and is destructive;

Answer 7

stress–strain test

Question 8

the test specimen is permanently deformed and usually fractured.

Answer 8

stress–strain test

Question 9

strain tests may be conducted if in-service forces are of this type.

Answer 9

Compression stress

Question 10

conducted in a manner that the force is compressive and the specimen contracts
along the direction of the stress.

Answer 10

Compression stress

Question 11

is taken to be negative, which yields a negative stress.

Answer 11

compressive force

Question 12

are used when a material’s behavior under large and permanent (i.e., plastic) strains is desired

Answer 12

Compressive tests

Question 13

is a variation of pure shear, wherein a structural
member is twisted

Answer 13

Torsion

Question 14

produce a rotational motion about the longitudinal axis of one end of the member relative to the other end.

Answer 14

Torsional forces

Question 15

Stresses that are computed from the tensile,
compressive, shear, and torsional force states act either ________________ to planar faces of the bodies.

Answer 15

parallel or perpendicular

Question 16

Torsional tests are normally performed on

Answer 16

cylindrical solid shafts or tubes

Question 17

function of the orientations of the planes upon which the stresses are taken to act

Answer 17

Stress state

Question 18

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

Answer 18

False (dependent)

Question 19

Deformation in which stress and strain are proportional

Answer 19

elastic deformation

Question 20

This modulus may be thought of as sti‡ness, or a material’s resistance to elastic deformation.

Answer 20

Modulus of elasticity

Question 21

an
important design parameter for computing elastic deflections

Answer 21

Modulus

Question 22

Elastic deformation is

Answer 22

nonpermanent

Question 23

timedependent elastic strain

Answer 23

anelasticity

Question 24

due to time-dependent microscopic and atomistic processes that are attendant to the deformation

Answer 24

anelasticity

Question 25

parameter termed _____________ is defined as the ratio of the lateral and axial strains

Answer 25

Poisson’s ratio

Question 26

elastic deformation persists only to strains of about ______.

Answer 26

0.005

Question 27

stress corresponding to the intersection of this line and the stress–strain cue as it bends over in the plastic region

Answer 27

yield strength

Question 28

the stress at the maximum on the engineering stress–strain curve

Answer 28

tensile strength

Question 29

corresponds to the maximum stress that can be sustained by a structure in tension

Answer 29

tensile strength

Question 30

measure of the degree of plastic deformation that has been sustained at fracture

Answer 30

Ductility

Question 31

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

Answer 31

Resilience

Question 32

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

Answer 32

Toughness

Question 33

defined as the load divided by the instantaneous cross-sectional area over which deformation is occurring

Answer 33

True stress

Question 34

measure of a material’s resistance to localized plastic deformation

Answer 34

hardness

Question 35

constitute the most common method used to measure hardness because they are so simple to perform and require no special skills.

Answer 35

Rockwell Hardness Tests

Question 36

hard, spherical indenter is forced into the surface of the metal to be tested.

Answer 36

Brinell Hardness Tests

Question 37

For each test a very small diamond indenter having pyramidal geometry is forced into the surface of the specimen.

Answer 37

Knoop and Vickers Microindentation Hardness Tests

Question 38

Is based on the yield strength of the material and is defined as the yield strength divided by a factor of safety

Answer 38

safe stress