Chapter 1: Introduction Flashcards
It is a property of steel that is of great importance for long-span bridge, tall building, and structures situated on poor foundations.
High Strength
A property of steel where in it does not change appreciably with time.
Uniformity
A property of steel which shows its closeness to design assumptions than most materials because it follows Hooke’s Law up to fairly high stresses.
Elasticity
Steel frames that are properly maintained will last indefinitely.
Permanence
A property of steel by which it can withstand extensive deformation without failure under high tensile stresses.
Ductility
This is the ability of steel to absorb energy in large amounts.
Toughness
Other advantages of steel includes addition to existing structures.
TRUE
Steels can be fastened together through what?
Bolts, rivets, welds and nails
Steel aren’t useful once it is disassembled.
FALSE
Steel can’t be rolled into variety of sizes and shapes.
FALSE
Steel’s advantage is it can be easily erected and it can adapt prefabrication.
TRUE
Steels are susceptible to corrosion when freely exposed to _______ and _______.
Air and water
What must be done to steel when it is exposed to air and water?
Must be painted periodically.
What do you call the anti-corrosion component used in steels?
Copper
Structural members are incombustible, their strength is tremendously reduced at high temperatures.
Fireproofing Costs
As the length and slenderness of a compression member is increased, its danger to ______ also increases.
Buckling
This is a disadvantage of steel where in it occurs when the steel is subjected to a large number of stress reversals or even to a large number of variations of tensile stress.
Fatigue
This problem is led by fatigue; type loading, very low temperatures, and tri-axial stress conditions.
Brittle Fracture
This is a test performed to illustrate the property of steel through a stress-strain diagram.
Tensile Test
This is the relationship between stress and strain.
Proportional Limit
It is the stress that lies betwen the proportional limit and the upper yield point.
Elastic Limit
The linear portion of the stress-strain diagram, the specimen can be unloaded without permanent deformation.
Elastic Range
The stress remains constant, even though the strain continues to increase.
Plastic Range
Additional load (and stress) is required to cause additional elongation (and strain).
Strain Hardening
When the specimen begins to neck down as the stress decreases with increasing strain followed by fracture.
Necking and Failure
The yield point or yield strength is the combination of what several points on the stress-strain diagram?
Elastic Limit
Proportional Limit
Upper and lower yield point
It is the maxium value of stress that can be attained in a stress-strain diagram.
Ultimate Tensile Strength
This is the ratio of stress to strain within the elastic range.
Modulus of Elasticity
These are types of structural steels made up of mostly iron and carbon, with less than 1% carbon.
Plain Carbon Steels
These are types of structural steels made up of iron and carbon plus other components (usually less than 5%) primarily for increasing strength, which is accomplished at the expense of a reduction in ductility
Low Alloy Steels
These are types of structural steels made up of iron and carbon plus other components (usually greater than 5%). They have high strength and have some special quality such as resistance to corrosion.
High Alloy or Specialty Steels
The manufacturing process of these types of structural shapes takes place in mill, molten steel is taken from an electric arc furnace and poured into a continuous casting system where the steel solidifies but is never allowed to cool completely, and then passes through a series of rollers that squeeze the material into the desired cross-sectional shape.
Hot Rolled Shapes
A steel shape where it has two parallel flanges separated by a single web and has two axes of symmetry.
W-shaped (wide-flanged shape)
A shape formerly called an I-Beam. Similar to W shape but flanges has sloping inside face
American Standard (S-Shape)
This shape is available either equal or unequal leg and do not provide the weight per foot.
Angle Shapes (L-Shape)
2 flanges and a web with 1 AOS, inside faces of flanges are sloping.
American Standard Channel ( C-Shape)
This is referred to as Split-Tee. Abbreviated as WT,ST or MT depending on which shape is the parent.
Structural Tee
HP shape is used for
Bearing piles
This can be of circular, square or rectagular shape.
Rectangular= width is less than 8 inches
Bars
Rectangular = width is greater than 8 inches.
Abbreviation is PL
Plate
What is HSS?
Hollow Structural Sections
This shapes are produced either by bending pate material into the desired shape or welding the seam or by hot-working to produce a seamless shape In addition this is also categorized as “Steel pipes, round HSS, square and rectangular HSS”.
Hollow Shapes
Formula for stress
f=P/A ;
Formula for strain
E= delta L/L
these types of shapes are made by bending thin sheets of carbon or low-alloy steels into almost any desired cross section. There is a reduction in ductility but there is a significant increase in strength.
Cold Formed Shapes
What serves as economical forms for the wet concrete and are left in place after the concrete hardens.
Concrete floor slabs cast on formed steel decks
Types of CFS
Channel
Stiffened Channel
Zee
Stiffened Zee
Hat
Sigma
Angle
These shapes are made when there is a special condition such as the need for heavier members of particular cross sectional geometries.
Built-Up Sections
Types of BUS which are welded or bolted
Welded Plate Girder
Cover Plated W-shape
W-shape with shelf angle
deflections and vibrations are not so great as to frighten the occupants or to cause unsightly cracks.
Safety
keep in mind factors that lower costs can without sacrifice of strength
Cost
Can be fabricated and erected without great problems arising
Constructability
3 regions of a stress strain diagram for low-carbon structural steel
Elastic Strain Region, Plastic Strain Region, Strain Hardening Region
This is the largest stress for which Hooke’s Law applies, or the highest point on the linear portion of the stress strain diagram.
Proportional Limit
The largest stress that a material can withstand without being permanently deformed.
Elastic Limit
The stress where in there is a significant increase in the elongation, or strain, without corresponding increase in stress.
Yield Stress
What is ASTM?
American Society for Testing and Materials
