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