Lesson 4

• mainly used to connect or support building components made of other material

  Metals
• Metals were mainly used for connecting stones

  Late 1800's
• Years when Bessemer proccess (air was blown into vessel of melton iron to burn out the impuritires

  1850
• Year open hearth method

  1868
• Year steel framed skyscraper existed in US

  1889
• numerous uses throughout a variety of industries. commonly utilized in the construction industry for producing a variety of products such as girders, bars, pipes, plates, sheets, rods, and beams. Bridges, road barriers, electrical pylons, and trains

  STEEL ALLOY
• Every steel can be considered an alloy as it is made through the combination of

  
  

  
  

  iron and carbon.
• The purpose of alloy steels is to

  increase the mechanical or physical properties of the metal
• are solid, strong beams that may be distinguished from I-beams by their wide flanges, which are positioned perpendicular to the material's surface to give them their distinctive shape.

  WIDE FLANGE
• is a length of steel that comes in a variety of shapes and sizes. It is used for attaching wall ties and masonry supports to the building's framework.

  CHANNEL
• These bars have legs that are vertical and at a right angle. Depending on the project, they could have equal or uneven lengths.

  ANGLE
• type of cold-formed, welded steel tube that is used in the construction of bridges, buildings, as well as other manufactured products. It can also be bolted to one another.

  HSS (HOLLOW STRUCTURAL SECTION)
• TYPES JOINTING STEEL MEMBERS

  Rivets, Bolts,Welding
• is a steel fastener consisting of a cylindrical body and formed head

  Rivets
•   used in steel frame construction may be high-strength bolts.

  Bolts
• offers a unique and valuable capability of structural designer it can join the members of a steel frame as if they were a monolithic whole

  Welding
• THREE BASIC STABILIZING MECHANISMS

  BRACED FRAMES, SHEAR WALLS, MOMENT-RESISTING FRAMES
• works through the integration of diagonal bracing, or stable triangular configurations, to stabilize the alternatively unstable rectilinear geometry of a steel building frame.

  BRACED FRAMES
• A specialized kind of braced frame in which the diagonal braces' two ends are spaced apart by a particular distance.

  ECCENTRICALLY BRACED FRAME
• are stiff walls composed of standard components such as steel, concrete, or reinforced concrete masonry. It serves the same purpose as braced frames in stabilizing the steel building frame's irregularities

  SHEAR WALLS
• comprise neither of the aforementioned approaches, but rather rely on moment connections between columns and beams that can withstand rotation and stabilize the frame against lateral forces.

  MOMENT-RESISTING FRAMES
• -          The elevator, stairs, mechanical chases, restrooms, and other areas of the building's center, or the "core, " are arranged using various approaches to form a rigid core.

  -          Following the construction of the rigid core, the remaining building frame will be assembled using shear connections and stabilized through the use of diaphragm action.

  Providing a Rigid Core
• -          Following application of each approach, the interior of the structure can now be formed with shear connections, with the floor and roof plates providing stability through diaphragm action

  Providing a Rigid Perimeter
• dependent mostly on the web of a section, moment connections add to that by strengthening the connectivity of the flanges .most commonly used connections.

  SHEAR CONNECTION
• TYPES OF SHEAR CONNECTIONS

  
  

  
  

  ANGLE CONNECTION, SINGLE PLATE CONNECTION,WT CONNECTION, SEATED CONNECTION
• are L-shaped brackets that hold the parent and child members together. The connection can have either one L-shaped bracket on one side or two brackets on both sides.

  ANGLE CONNECTION
• uses a single plate to hold together the two members. It can be welded or bolted to the child member but is welded to the parent member. As it is welded to the parent member, it normally is more costly to use a single plate connection than an angle connection.

  SINGLE PLATE CONNECTION
• This connection uses a T-shaped section to join the parent and child member. This greatly increases its strength towards shear and moment loads. As such, the bearing strength of the connection becomes important.

  WT CONNECTION
• use L-shaped brackets to connect the parent and child members together. They differ from angle connections as they connect at the flange of both the parent and child members.

  SEATED CONNECTION
• structural engineering is a joint that allows the transfer of bending moment forces between a column and beam If a child member has some internal moment, the connection should be able to transmit the load due to that moment.

  Moment Connection
• While shear connections are dependent mostly on the web of a section, moment connections add to that by strengthening the connectivity of the flanges.

  dependent , strengthening
• TYPES OF MOMENT CONNECTIONS

  FLANGE PLATE, THROUGH PLATE, COLLARED PLATE, DIRECTLY WELDED CONNECTION
• connects the flange of the column to the web of the beam member. A plate is either belted and/or welded to join the members to form a rigid fixture.

  FLANGE PLATE
• transfer moment between members through the use of a rigid plate that is either bolted or welded to the members. If the HSS column undergoes a bending force then intuitively it will transfer to the beam due to the yellow plate.

  THROUGH PLATE
• fairly similar to through plates; however, the plate does not extend through the HSS section. Rather the plate sits comfortably around the HSS section and is then secured to the child (beam) members.

  COLLARED PLATE
• a connection in every direction creates a very strong, rigid connection. By welding a plate between the beam and column (welding around all edges) means that movement and rotation is completely restricted and a moment connection is formed.

  DIRECTLY WELDED CONNECTION
• Advantages of Metal and Steel Frames

  STRENGTH AND DURABILITY, SPEED OF CONSTRUCTION, DESIGN FLEXIBILITY, SUSTAINABILITY, DIMENSIONAL STABILITY, PEST AND WEATHER RESISTANCE
• Steel offers exceptional strength-to-weight ratio. It can withstand heavy loads and harsh weather conditions, leading to long-lasting structures.

  STRENGTH AND DURABILITY
• Steel components are prefabricated off-site, allowing for faster assembly compared to on-site concrete pouring. This reduces construction time and labor cost.

  SPEED OF CONSTRUCTION
• Steel is highly versatile and can be formed into various shapes and sizes. This flexibility allows for innovative and complex architectural designs.

  DESIGN FLEXIBILITY