Introduction to Stress-Strain Diagram Flashcards
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.
stiffness
______ is the extent
to which it resists ______ in response to an
applied force.
Stiffness ; deformation
The rigidity of an object
Stiffness
To a lesser degree, mechanical properties such as
_______ determine the
selection of a material.
hardness, toughness, and ductility
Is a measure
of how resistant solid
matter is to various
kinds of permanent
shape change when a
compressive force is
applied.
Hardness
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.
Ductility
Is the ability of a
material to absorb energy
when impacted.
Toughness
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.
Tension & Compression Test
A ______ is obtained by plotting the
various values of the stress and corresponding strain in the
specimen.
stress-strain diagram
Is is used to express the
loading in terms of force
applied to a certain cross-sectional area of an object
Stress
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.
Strain
From the origin (say point O) to a point called the ______ ,
the figure shows the stress-strain diagram to be straight line.
proportional limit
first postulated by _____ in ______ ,
that stress is proportional to strain.
Robert Hooke ; 1678
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
ends ; no longer proportional
The proportional limit is important because all subsequent theory
involving the behavior of elastic bodies is based on a ______ .
stress-strain
proportionality
This is also our first indication that the _______ ,
and not the ultimate strength is the _______ to which a material
may be subjected.
proportional limit ; maximum stress
______ is the stress beyond which the material will not return to its
original shape when unloaded but will retain a permanent deformation
called ______ .
Elastic Limit
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.
Yield point
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.
Yield Strength
_____ - 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)
Yield Strength ; tangent of
the stress-strain curve ;
Is the highest ordinate on the stress-strain curve.
Ultimate Stress or Ultimate Strength
Stress at failure
Rupture Strength
