R1.3 RESP1.3 RESPONSE OF CIVIL
ENGIONEEONSE OF CIVIL ENGINEERING PROJECT
1.3 RESPONSE OF CIVIL ENGINEERING
PROJECT
1.3 RESPONSE OF CIVIL ENGINEERING
PROJECT
STEELSTEELPREPARED BY :
NOR AZAH BINTI AZIZPREPARED BY :
NOR AZAH BINTI AZIZ
Learning Outcomes:
Identify and describe material response of modes primary failure due to:B) Steel
i. Structure failure● Buckling● Bearing ● Tensile
ii. Performance failure ● Corrosion ● Fatigue
STEEL• It’s included in the term ferrous metal
• It’s a combination of iron & carbon( 0.01 – 1%)
• Contains varying amounts of manganese,
phosphorus, sulfur, silicon & 20 other alloys
• Alloys added to produce steel of different
characteristics.
• To produce useful steel, pig iron need to be
oxidized in another furnace at about 1650°C.
• Most steel is made by the basic oxygen
process, electric-arc process, open-hearth process
or vacuum process.
• Carbon is the key element in controlling
the properties of ordinary steel called
carbon steel.
STEEL
5
STEEL
Steel Structure FailureSteel Structure Failure
● Buckling● Tensile●Bearing
● Buckling● Tensile●Bearing
BucklingBuckling
• In engineering, buckling is a failure mode characterized by a sudden failure of a
structural member subjected to high compressive stresses.
• The actual compressive stress at the point of failure is less than the ultimate
compressive stresses that the material is capable of withstanding.
• This mode of failure is also described as failure due to elastic instability.
• Mathematical analysis of buckling makes useof an axial load eccentricity that introducesa moment, which does not form part of the primary forces to which the member is
subjected.
BucklingBuckling
Column Buckling Column
Buckling (steel plate)
Before After
• Tensile (or tension) is the stress state
leading to expansion; that is, the length
of a material or compression member tends
to increase in the tensile direction.
• Tensile stress is the opposite ofcompressive stress.
• Structural members in direct tension are ropes,
soil anchors and nails, bolts, etc.
• Tensile (or tension) is the stress state
leading to expansion; that is, the length
of a material or compression member tends
to increase in the tensile direction.
• Tensile stress is the opposite ofcompressive stress.
• Structural members in direct tension are ropes,
soil anchors and nails, bolts, etc.
Tensile Tensile
• A tensile test, also known as tension test.
• By pulling on something, you will very quickly
determine how the material will react to
forces being applied in tension .
• As the material is being pulled, you will find its strength
along with how much it will elongate.
• A tensile test, also known as tension test.
• By pulling on something, you will very quickly
determine how the material will react to
forces being applied in tension .
• As the material is being pulled, you will find its strength
along with how much it will elongate.
What is tensile TestWhat is tensile Test
• As continuing to pull on the material until it breaks,
complete tensile profile will be obtained.
• A curve will result showing how it reacted
to the forces being applied.
• The point of failure is of much interest and
is typically called its "Ultimate Strength“
or UTS on the chart.
Why Perform a Tensile TestWhy Perform a Tensile Test
• BEARING STRESS is The surface pressure acting on a joint
face directly as a result of the force applied by a fastener.
• Bearing stress is the contact pressure between the separate
bodies.
• It differs from compressive stress, as it is an internal stress
caused by compressive forces
• BEARING STRESS is The surface pressure acting on a joint
face directly as a result of the force applied by a fastener.
• Bearing stress is the contact pressure between the separate
bodies.
• It differs from compressive stress, as it is an internal stress
caused by compressive forces
Bearing StressBearing Stress
• The equation to determine average bearing stress would be sigmab = P/A
P= force appliedA= contact area of the object resisting the force.
SI unit is Newton/meter2 which equates to Pascals (Pa).
Bearing StressBearing Stress
• Bearing properties are used when designing
mechanically fastened joints.
• The purpose of a bearing test is to
determine the deformation of a hole
as a function of the applied bearing stress.
Bearing PropertiesBearing Properties
Steel Performance FailureSteel Performance Failure
● Corrosion● Fatigue● Corrosion● Fatigue
• Corrosion is oxidation or combining of
the iron with oxygen that occurs in
the presence of moisture.
• Proceeds more rapidly where there is
noticeable dampness but it occurs in
any air with a relative humidity higher
than 70%.
CorrosionCorrosion
• Corrosion occurs more rapidly in salt
air and industrial atmosphere.
• The rust is formed from the solid metal, reducing it
size so that the members
become weaker and loses any decorative finishes it
might have.
• Corrosion occurs more rapidly in salt
air and industrial atmosphere.
• The rust is formed from the solid metal, reducing it
size so that the members
become weaker and loses any decorative finishes it
might have.
Corrosion Corrosion
• A metal component @ structure that is subjected to
repeated or cyclic stresses may eventually fail,
even though the maximum stress in any one
stress cycle is considerably less than the fracture
stress of the material.
• A metal component @ structure that is subjected to
repeated or cyclic stresses may eventually fail,
even though the maximum stress in any one
stress cycle is considerably less than the fracture
stress of the material.
Fatigue Fatigue
• A common occurrence, as components are
subject to alternating @ fluctuating loads during
their service life.
Fatigue Fatigue