ELEMENTS OF STEEL STRUCTUREAniendhita Rizki Amalia, ST. MT.

ELEMENT OF STEEL STRUCTURE Mechanical properties of steel material and LRFD

Tension Member

Compression Member

Beam member

Beam column

Connection – Bolt

Connection – Weld

Time periode : 18 weeks

MID

Books and Code Struktur Baja I – Marwan, Isdarmanu, Soewardojo

Structural Steel Design – Jack C Mc. Cormac

Structural Steel Design and Behavior – Salmon & Johnson

SNI 03-1729-2002

PPIUG 1983 atau R/SNI 03-1727-xx / ASCE 7-05

Tabel Profil Morrisco, Tabel profil khusus, Tabel profil pasaran, Tabel baut

Harus punya dan selalu dibawa saat kuliah !

IntroductionSteel Structures Design and Behavior

Charles G. Salmon & John E. Johnson

Structural Design Structural design may be defined as a mixture of art and science,

combining the experienced engineer’s intuitive feeling for the behavior of the structure with a sound knowledge of the principles of statics, dynamics, mechanics of materials and structural analysis, to produce a safe economical structure.

Principles of Design Certain criteria that must be established to evaluate whether or not

an optimum has been achieved, typical criteria may be :

1. Minimum cost

2. Minimum weight

3. Minimum construction time

4. Minimum labor

5. Minimum cost of manufacture of owner’s product

6. Maximum efficiency of operation to owner

Design Procedure

Functional design1. Adequate working areas and

clearances

2. Proper ventilation and/or air conditioning

3. Adequate transporation facilities, such as elevators, stairways and cranes or material handling equipment

4. Adequate lighting

5. Aesthetics

Structural Framework Design1. Selection of the arrangement

and sizes of structural element so that service loads may be safely carried, and displacement are within acceptable limits.

Design ProcedureGeneral Planning

Preliminary Structural

Configuration

Loading

Preliminary member selection

Analysis

OK

NOT

OK

Final Design

Chapter I - OverviewSteel Structures Design – Jack Mc Cormac

Struktur Baja I – Marwan, Isdarmanu, Soewardojo

Steel as Construction Material

BRIDGE – Blue Water Bridge (St. Claire US – Canada)http://www.midweststeel.com/projects/steel-bridge-structural-steel-contractor.html

ELECTRICAL TRANMISSION TOWER – PLN PURBALINGGAhttp://id.geoview.info/gardu_induk_pln_purbalingga,49441610p

Communication Towerhttp://nangkenne.blogspot.com/2013/02/ciri-ciri-bts-indosat-telkomsel-dan-xl.html

http://www.tempo.co/read/news/2014/10/08/092612849/Desember-Telkomsel-Operasikan-Jaringan-4G

OFFICE - Chinahttp://www.havitsteelstructure.com/steel-structure-office-buildings.html

WAREHOUSEhttp://www.tanuwedsmanu.com/manfaat-menggunakan-baja-untuk-bangunan-gudang/

HOUSE - Chinahttp://www.diytrade.com/china/pd/9606496/Light_steel_house.html

Rail Coal CrusherDokumen pribadi

Roller Coaster – The Swarn - Britain’s Thorpe Parkhttp://www.businessinsider.com.au/a-new-british-roller-coaster-is-so-extreme-that-test-dummies-returned-from-a-practice-run-without-limbs-2012-2

Foundation pilehttp://www.aeyates.co.uk/spi-appleton-ltd/services/steel-piling

STEEL RETAINING WALLhttp://www.aeyates.co.uk/spi-appleton-ltd/harbours-and-waterways-projects/rnli-berth-retaining-wall-hartlepool

Advantages of steel as structural material1. High Strength : The high strength of steel per unit

weight means that structure weights will be small.

2. Uniformity : The property of steel do not change appreciably with times.

3. Elasticity : Steel behave closer to design assumption than most material because it follows Hooke’s law

4. Permanence : Steel frame that are properly maintained will last indefinitely.

5. Ductility : The property of a material by which it can withstand extensive deformation without failure under high tensile stresses is said to be its ductility.

BAB I - OVERVIEW

Advantages of steel as structural material5. Fracture Toughness : the ability of steel absorb

energy in large amounts.

6. Addition to Existing Structure: steel structure are quite well suited to having additions made to them

7. Speed of erection

8. Ability to be rolled into a wide variety of sizes and shapes

9. Possible reuse after a structure is dissambled

10. Scrap value even though not reusable in its existing form

BAB I - OVERVIEW

Disadvantages of steel as structural material1. Maintenance cost : Most steels are susceptible to

corrosion when freely exposed to air and water then must therefore to be periodically painted.

2. Fireproofing cost : Although structural members are incombustible, their strength is tremendously reduced at temperature commonly reached in fires.

3. Susceptibility to Buckling: The longer and slenderer the compression members, the greater and danger of buckling

4. Fatigue: when the tension is involved under a large number variation of cycle tensile stress

BAB I - OVERVIEW

Objectives of the Structural Designer“As a structural designer we learn to control and to balance every part of structure and make them easy and fast to assemble, strength enough and cheap” To get the objectives, we need to be supported

with knowledges about:

1. Fabrication level

2. Standar shapes and dimension of steel frame

3. Transportation ability

4. Erection ability

BAB I - OVERVIEW

Safety Factor : Why do we need it? Deviation from material strength that were calculated.

Deviation will be greater if there are influence from: creep, corrosion and yielding.

Deviation from assumption in calculation Unpredictable load Fabrication and assemble process that cause high :

bent, hammered, sheared, punched, welded Live load assumption based on technology

development Assumption of live load and dead load Variation shapes or dimension of frame

BAB I - OVERVIEW

Safety Factor : What to look forward? Type of load: fix or temporary load. Building function: Public or personal use. Function an element as a primary or secondary

structure.

BAB I - OVERVIEW

Construction Failures Construction failures usually happen because of less of

attention in : connection detail, deflection, foundation and its deformation.

BAB I - OVERVIEW

Stress - Strain Relationship

BAB I - OVERVIEW

Steel Material Properties

BAB I - OVERVIEW

Mechanical properties of structural steel:

Elastic Modulus : E = 200.000 MPa

Shear Modulus : G = 80.000 MPa

Poisson Ratio : ν = 0,3

Jenis Baja Tegangan putus

minimum, fu (MPa)

Tegangan leleh

minimum, fu (MPa)

Peregangan minimum (%)

BJ 34 340 210 22

BJ 37 370 240 20

BJ 41 410 250 18

BJ 50 500 290 16

BJ 55 550 410 13

Steel Material Properties

BAB I - OVERVIEW

ASTM CODE Fy Fu

A36

A529

A441

A572

A242

A588

A852

A514

A53

A500

A992

A913

SPESIFICATION AND CODE The important thing to remember about spesifications, therefore, is

that they are not written for the purpose of restricting engineers but for the purpose of protecting the public.

Example of specification: ASTM, JIS, SNI

Example of code: AISC, ASCE, UBC, SNI

LOAD Dead Load : loads of constant magnitude that remain in one position.

Live Load : loads that may change in position and magnitude.

1. Area loads (due to people or machine)

2. Snow /Ice

3. Rain

4. Traffic

5. Impact load

6. Lateral load : Wind & Earth quake

7. Longitudinal loads: brakes load

8. Other life loads: soil pressures, static pressures, uplift pressures, blast loads, thermal forces

LOAD COMBINATIONUltimate Load Combination

Strength

Sesuaikan dengan SNI yang ada, pada SNI 03-1729-2002 (Baja) ada pada pasal 6.2.2

Service Load Combination

Deflection

1 Dead Load + 1 Live Load

Dimana lendutannya dibatasi sesuai dengan pasal 6.4.3

Calculation Method – Elastic Method

BAB I - OVERVIEW

(ASD – Allowable Stress Design) (WSD – Working Stress Design)

Due to allowable working load that is designed, working stress have to be less than allowable stress.

SF (Safety Factor) = 1,50SFy

Calculation Method – Plastic Method (Collapse Design)

BAB I - OVERVIEW

Formed by : Ductile behavior of steel means that there are reserve strength over the elastic strength .

Design working load will be multiplied by load factor and will be designed based on collapse strength.

Calculation Method – LRFD (Load And Resistance Factor Design)

BAB I - OVERVIEW

Ultimate load (load x load factor) have to be less or equal than ultimate strength structure.

Based on Limit State Condition.

nii RQ