Introduction to Stress-Strain Diagram

Question 1

The strength of a material is not the only criterion
that must be considered in designing structures. The
_______ of a material is frequently of equal importance.

Answer 1

stiffness

Question 2

______ is the extent
to which it resists ______ in response to an
applied force.

Answer 2

Stiffness ; deformation

Question 3

The rigidity of an object

Answer 3

Stiffness

Question 4

To a lesser degree, mechanical properties such as
_______ determine the
selection of a material.

Answer 4

hardness, toughness, and ductility

Question 5

Is a measure
of how resistant solid
matter is to various
kinds of permanent
shape change when a
compressive force is
applied.

Answer 5

Hardness

Question 6

Is a solid material’s ability to
deform under tensile stress; this is often
characterized by the material’s ability to
be stretched into a wire.

Answer 6

Ductility

Question 7

Is the ability of a
material to absorb energy
when impacted.

Answer 7

Toughness

Question 8

This test is used primarily to determine the relationship
between the average normal stress and average normal strain in
common engineering materials, such as metals, ceramics, polymers
and composites.

Answer 8

Tension & Compression Test

Question 9

A ______ is obtained by plotting the
various values of the stress and corresponding strain in the
specimen.

Answer 9

stress-strain diagram

Question 10

Is is used to express the
loading in terms of force
applied to a certain cross-sectional area of an object

Answer 10

Stress

Question 11

Is the response of a system to an
applied stress. When a material is loaded
with a force, it produces a stress, which
then caused a material to deform.

Answer 11

Strain

Question 12

From the origin (say point O) to a point called the ______ ,
the figure shows the stress-strain diagram to be straight line.

Answer 12

proportional limit

Question 13

first postulated by _____ in ______ ,
that stress is proportional to strain.

Answer 13

Robert Hooke ; 1678

Question 14

Notice carefully that this proportionality
does not extend throughout the diagram; it ____ at the proportional limit.
Beyond this point, the stress is _______ to the strain

Answer 14

ends ; no longer proportional

Question 15

The proportional limit is important because all subsequent theory
involving the behavior of elastic bodies is based on a ______ .

Answer 15

stress-strain
proportionality

Question 16

This is also our first indication that the _______ ,
and not the ultimate strength is the _______ to which a material
may be subjected.

Answer 16

proportional limit ; maximum stress

Question 17

______ is the stress beyond which the material will not return to its
original shape when unloaded but will retain a permanent deformation
called ______ .

Answer 17

Elastic Limit

Question 18

Is the point at which there is an appreciable elongation or
yielding of the material without any corresponding increase of load;
indeed, the load may actually decrease while the yielding occurs.

Answer 18

Yield point

Question 19

Is closely associated with the yield point. For materials that do
not have a well-defined yield point, yield strength is determined by
the offset method.

Answer 19

Yield Strength

Question 20

_____ - This consists of drawing a line parallel to the initial _______ , this line being started at an arbitrary offset
strain, usually 0.2% (0.002 m/m or 0.002 in/in)

Answer 20

Yield Strength ; tangent of
the stress-strain curve ;

Question 21

Is the highest ordinate on the stress-strain curve.

Answer 21

Ultimate Stress or Ultimate Strength

Question 22

Stress at failure

Answer 22

Rupture Strength