cold formed steel
TRANSCRIPT
CONTENTS
• DEFINITION• PROPERTIES AND DESCRIPTION • CHARACTERISTICS• FABRICATION• APPLICATIONS• CONNECTIONS• YIELD ANALYSIS• INDUSTRIAL STRUCTURES• DESIGN
• DEFINITION• PROPERTIES AND DESCRIPTION • CHARACTERISTICS• FABRICATION• APPLICATIONS• CONNECTIONS• YIELD ANALYSIS• INDUSTRIAL STRUCTURES• DESIGN
• ALLOY OF IRON AND CARBON IN WHICH THE CARBON CONTENT RANGES UP TO 2 PERCENT .
• BY FAR THE MOST WIDELY USED MATERIAL FOR BUILDING THE WORLD'S INFRASTRUCTURE AND INDUSTRIES, IT IS USED TO FABRICATE EVERYTHING FROM SEWING NEEDLES TO OIL TANKERS.
• ALLOY OF IRON AND CARBON IN WHICH THE CARBON CONTENT RANGES UP TO 2 PERCENT .
• BY FAR THE MOST WIDELY USED MATERIAL FOR BUILDING THE WORLD'S INFRASTRUCTURE AND INDUSTRIES, IT IS USED TO FABRICATE EVERYTHING FROM SEWING NEEDLES TO OIL TANKERS.
STEELSTEEL
HOT ROLLED STEEL• THE ROLLING OF HOT STRIP BEGINS WITH A SLAB,
WHICH IS INSPECTED AND, IF NECESSARY, SURFACE CLEANED EITHER MANUALLY OR BY SCARFING MACHINES WITH OXYACETYLENE TORCHES. THE SLABS ARE THEN PUSHED, OR WALKED ON THEIR BROADSIDE, THROUGH GAS-FIRED FURNACES THAT HAVE A HEARTH DIMENSION OF ABOUT 13 METRES BY 30 METRES. IN A PUSHER-TYPE FURNACE, THE SLABS SLIDE ON WATER-COOLED SKIDS, AND, EACH TIME A NEW SLAB IS CHARGED, A HEATED SLAB DROPS THROUGH A DISCHARGE DOOR ONTO A ROLLER TABLE. IN WALKING-BEAM FURNACES, SEVERAL WALKING BEAMS LIFT THE WORKPIECES FROM THE HEARTH, MOVE THEM FORWARD, AND SET THEM BACK DOWN IN A SERIES OF RECTANGULAR MOVEMENTS. PREHEATING TEMPERATURE, AS WITH SLABS AND PLATES, IS ABOUT 1,250° C.
• THE ROLLING OF HOT STRIP BEGINS WITH A SLAB, WHICH IS INSPECTED AND, IF NECESSARY, SURFACE CLEANED EITHER MANUALLY OR BY SCARFING MACHINES WITH OXYACETYLENE TORCHES. THE SLABS ARE THEN PUSHED, OR WALKED ON THEIR BROADSIDE, THROUGH GAS-FIRED FURNACES THAT HAVE A HEARTH DIMENSION OF ABOUT 13 METRES BY 30 METRES. IN A PUSHER-TYPE FURNACE, THE SLABS SLIDE ON WATER-COOLED SKIDS, AND, EACH TIME A NEW SLAB IS CHARGED, A HEATED SLAB DROPS THROUGH A DISCHARGE DOOR ONTO A ROLLER TABLE. IN WALKING-BEAM FURNACES, SEVERAL WALKING BEAMS LIFT THE WORKPIECES FROM THE HEARTH, MOVE THEM FORWARD, AND SET THEM BACK DOWN IN A SERIES OF RECTANGULAR MOVEMENTS. PREHEATING TEMPERATURE, AS WITH SLABS AND PLATES, IS ABOUT 1,250° C.
COLD ROLLED STEEL
• THE ROLLING OF COLD STRIP BEGINS WITH THE RETRIEVAL OF HOT-ROLLED STRIP FROM A COIL STORAGE YARD, WHICH OFTEN USES FULLY AUTOMATED CRANES FOR SETTING AND RETRIEVING COILS ACCORDING TO ROLLING SCHEDULES. THE COILS ARE FIRST DESCALED IN CONTINUOUS PICKLE LINES, WHICH ARE DISCUSSED BELOW (SEE TREATING OF STEEL: SURFACE TREATING: PICKLING). THE CLEANED AND OILED COILS ARE FED INTO A COLD-REDUCTION MILL, WHICH IS USUALLY A TANDEM MILL OF FOUR TO SIX FOUR-HIGH STANDS WITH AN UNCOILING REEL AT THE ENTRY AND A RECOILING REEL AT THE EXIT.
• THE ROLLING OF COLD STRIP BEGINS WITH THE RETRIEVAL OF HOT-ROLLED STRIP FROM A COIL STORAGE YARD, WHICH OFTEN USES FULLY AUTOMATED CRANES FOR SETTING AND RETRIEVING COILS ACCORDING TO ROLLING SCHEDULES. THE COILS ARE FIRST DESCALED IN CONTINUOUS PICKLE LINES, WHICH ARE DISCUSSED BELOW (SEE TREATING OF STEEL: SURFACE TREATING: PICKLING). THE CLEANED AND OILED COILS ARE FED INTO A COLD-REDUCTION MILL, WHICH IS USUALLY A TANDEM MILL OF FOUR TO SIX FOUR-HIGH STANDS WITH AN UNCOILING REEL AT THE ENTRY AND A RECOILING REEL AT THE EXIT.
• WHEN ROLLING FROM, FOR EXAMPLE, 2 MILLIMETRES TO 0.3 MILLIMETRE, THE COLD REDUCTION IS USUALLY 35 PERCENT ON THE FIRST STANDS AND 15 PERCENT ON THE FINAL STAND. THE EXIT SPEED IS NORMALLY HIGH, OFTEN 100 KILOMETRES (60 MILES) PER HOUR, IN ORDER TO ACHIEVE PROPER PRODUCTION RATES WITH SUCH SMALL CROSS SECTIONS. SINCE THE STRIP TEMPERATURE MAY GO AS HIGH AS 200° C (390° F), PROPER COOLING OF STRIP AND ROLLS IS ESSENTIAL. HEAVY-DUTY LUBRICANTS ARE ALSO USED TO MINIMIZE FRICTION IN THE ROLL GAP.
• WHEN ROLLING FROM, FOR EXAMPLE, 2 MILLIMETRES TO 0.3 MILLIMETRE, THE COLD REDUCTION IS USUALLY 35 PERCENT ON THE FIRST STANDS AND 15 PERCENT ON THE FINAL STAND. THE EXIT SPEED IS NORMALLY HIGH, OFTEN 100 KILOMETRES (60 MILES) PER HOUR, IN ORDER TO ACHIEVE PROPER PRODUCTION RATES WITH SUCH SMALL CROSS SECTIONS. SINCE THE STRIP TEMPERATURE MAY GO AS HIGH AS 200° C (390° F), PROPER COOLING OF STRIP AND ROLLS IS ESSENTIAL. HEAVY-DUTY LUBRICANTS ARE ALSO USED TO MINIMIZE FRICTION IN THE ROLL GAP.
Cold roll forming machine.Cold roll forming machine.
METHODS OF FORMINGMETHODS OF FORMING
• 1. Cold roll forming
• 2. Press brake operation
• 3. Bending brake operation
• 1. Cold roll forming
• 2. Press brake operation
• 3. Bending brake operation
Size ranges of typical roll-formed structural shapes.
Size ranges of typical roll-formed structural shapes.
DESCRIPTION AND PROPERTIES OF HOT ROLLED STEEL AND
COLD ROLLED STEEL ACCORDING TO IISI
DESCRIPTION AND PROPERTIES OF HOT ROLLED STEEL AND
COLD ROLLED STEEL ACCORDING TO IISI
VARIOUS SECTIONS OF COLD FORMED STEEL VARIOUS SECTIONS OF COLD FORMED STEEL
• As compared with thicker hot-rolled shapes, cold-formed light members can be manufactured for relatively light loads and/or short spans.
• Unusual sectional configurations can be produced economically by cold-forming operations and consequently favorable strengthto- weight ratios can be obtained.
• Nestable sections can be produced, allowing for compact packaging and shipping.
• Load-carrying panels and decks can provide useful surfaces for floor,roof, and wall construction, and in other cases they can also provide enclosed cells for electrical and other conduits.
• As compared with thicker hot-rolled shapes, cold-formed light members can be manufactured for relatively light loads and/or short spans.
• Unusual sectional configurations can be produced economically by cold-forming operations and consequently favorable strengthto- weight ratios can be obtained.
• Nestable sections can be produced, allowing for compact packaging and shipping.
• Load-carrying panels and decks can provide useful surfaces for floor,roof, and wall construction, and in other cases they can also provide enclosed cells for electrical and other conduits.
• Load-carrying panels and decks not only withstand loads normal to their surfaces, but they can also act as shear diaphragms to resist force in their own planes if they are adequately interconnected to each other and to supporting members.
• Load-carrying panels and decks not only withstand loads normal to their surfaces, but they can also act as shear diaphragms to resist force in their own planes if they are adequately interconnected to each other and to supporting members.
Compared with other materials such as timber and concrete, the
followingqualities can be realized for cold-formed steel structural members
Compared with other materials such as timber and concrete, the
followingqualities can be realized for cold-formed steel structural members.
• 1. Lightness
• 2. High strength and stiffness
• 3. Ease of prefabrication and mass production
• 4. Fast and easy erection and installation
• 5. Substantial elimination of delays due to weather
• 6. More accurate detailing
• 1. Lightness
• 2. High strength and stiffness
• 3. Ease of prefabrication and mass production
• 4. Fast and easy erection and installation
• 5. Substantial elimination of delays due to weather
• 6. More accurate detailing
• 7. Nonshrinking and noncreeping at ambient temperatures
• 8. Formwork unneeded• 9. Termite-proof and rotproof• 10. Uniform quality• 11. Economy in transportation and handling• 12. Noncombustibility• 13. Recyclable material
• 7. Nonshrinking and noncreeping at ambient temperatures
• 8. Formwork unneeded• 9. Termite-proof and rotproof• 10. Uniform quality• 11. Economy in transportation and handling• 12. Noncombustibility• 13. Recyclable material
Composite truss-panel system used in World Trade Center
Building,
Composite truss-panel system used in World Trade Center
Building,
Placement of prefabricatedcomposite floor panel section in World
Trade Center Building.
Placement of prefabricatedcomposite floor panel section in World
Trade Center Building.
Cold-formed steel joists used together with hot-rolled shapesCold-formed steel joists used
together with hot-rolled shapes
Cold-formed steel sections used in space frames
Cold-formed steel sections used in space frames
Cold-formed steel sections used in space frames
Cold-formed steel sections used in space frames
TYPES OF COLD-FORMED STEEL SECTIONS AND THEIR
APPLICATIONS
TYPES OF COLD-FORMED STEEL SECTIONS AND THEIR
APPLICATIONS
• 1. Individual structural framing members
• 2. Panels and decks
• 1. Individual structural framing members
• 2. Panels and decks
Cold-formed sections used in structural framing
Cold-formed sections used in structural framing
Building composed entirely of cold-formed steel sections.
Building composed entirely of cold-formed steel sections.
Decks, panels and corrugated sheets.
Decks, panels and corrugated sheets.
Numerical and experimental investigation on bolted moment connections in cold-
formed steel sections
Numerical and experimental investigation on bolted moment connections in cold-
formed steel sections
Investigation on efficient beam-column connections in cold-formed
steel structures scaffolds
Investigation on efficient beam-column connections in cold-formed
steel structures scaffolds
Experimental investigationon lapped moment
Experimental investigationon lapped moment
Self-piercing Rivet (SPR) Connections:
Self-piercing Rivet (SPR) Connections:
• SPR connections consist of the joining of two or more sheets of cold-formed steel with a rivet that is installed with proprietary tools, without a drilled or punched hole in the steel. The connection is formed by driving the rivet into the steel sheets, piercing the top layer or layers of steel sheets, with the rivet flaring, under the influence of a die under the of sheets, into the bottom layer without penetrating through the bottom layer.
• SPR connections consist of the joining of two or more sheets of cold-formed steel with a rivet that is installed with proprietary tools, without a drilled or punched hole in the steel. The connection is formed by driving the rivet into the steel sheets, piercing the top layer or layers of steel sheets, with the rivet flaring, under the influence of a die under the of sheets, into the bottom layer without penetrating through the bottom layer.
SEQUENTIAL FORMATION OF A TYPICAL SPR CONNECTION
SEQUENTIAL FORMATION OF A TYPICAL SPR CONNECTION
CLINCHED CONNECTIONSCLINCHED CONNECTIONS
Cold-formed steel members used in space grid system.
Cold-formed steel members used in space grid system.
Cold-formed steel members used in a 100 3 220 3 30-ft (30.5 3 67.1
3 9.2-m) triodetic arch.
Cold-formed steel members used in a 100 3 220 3 30-ft (30.5 3 67.1
3 9.2-m) triodetic arch.
Hangar-type arch structures using cold-formed steel sections.
Hangar-type arch structures using cold-formed steel sections.
Rack Structures.Rack Structures.
Cold-formed steel panels used in folded-plate roof.
Cold-formed steel panels used in folded-plate roof.
Superbay hangar for American Airlines Boeing 747s in Los
Angeles.
Superbay hangar for American Airlines Boeing 747s in Los
Angeles.
Arched roof curved at job site.Arched roof curved at job site.
METHODS OF FORMINGMETHODS OF FORMING