In steel building construction, various beam shapes and
profiles are used to support structural loads and distribute them efficiently.
The choice of beam shape depends on factors such as the span of the beam, the
load it needs to carry, and architectural considerations. Here are some common
beam shapes used in steel building works:
- I-Beams
(Wide Flange Beams): I-beams are one of the most common and versatile
beam shapes. They have a horizontal top and bottom flange connected by a
vertical web. I-beams are efficient in carrying both bending and shear
loads and are used in a wide range of applications.
- W-Beams
(Wide Flange Beams): W-beams are similar to I-beams but have a wider
flange, which provides better stability and load-bearing capacity. They
are often used in large-span structures such as bridges and skyscrapers.
- HSS
(Hollow Structural Section) Beams: These beams are typically square or
rectangular in shape and have a hollow cross-section. HSS beams are lightweight,
which makes them suitable for applications where weight is a concern. They
are commonly used in residential and commercial construction.
- C-Channel
Beams: C-channel beams have a shape resembling the letter
"C" and are used when the load primarily requires vertical
strength, such as in purlins and framing for metal buildings.
- T-Beams:
T-beams have a T-shaped cross-section with a horizontal top flange and a
vertical stem. They are often used in composite construction with concrete
slabs to create efficient and strong floor systems.
- Box
Beams: Box beams are made by welding or bolting together two or more
I-beams or HSS sections to create a rectangular or square shape. They are
used for heavy-duty applications, such as bridge construction.
- Angle
Beams (L-Beams): Angle beams are L-shaped and are often used for
bracing or as support members in structures. They are particularly useful
in situations where the load is primarily in one direction.
- Single
and Double Channels: These beams are essentially C-channels and
U-channels, respectively, used for various purposes, including bracing and
supporting loads in lighter structural applications.
- Custom
Fabricated Beams: In some cases, custom-designed beams are fabricated
to meet specific project requirements. These beams can have unique shapes
and dimensions tailored to the needs of the structure.
The choice of beam shape also depends on the design
specifications, including factors like moment of inertia, deflection limits,
and the allowable stress. Engineers and architects work together to determine
the most suitable beam shape for a given project to ensure structural stability
and efficiency.
- The portion that connects the flanges is referred to as the web.
In steel building construction, various terminologies are
used to describe different components, processes, and aspects of the structural
framework. Here are some common beam-related terminologies:
- Beam:
A horizontal structural member that carries loads primarily by flexure.
Beams are typically supported by columns and are essential for
transferring loads and supporting the building's structure.
- I-Beam:
Also known as an "I-section" or "Universal Beam" (UB),
it is a steel beam with an "I" shape when viewed in
cross-section. This shape provides excellent strength-to-weight ratios and
is commonly used in building construction.
- H-Beam:
An "H" shaped steel beam, also known as an "H-section"
or "Wide Flange Beam" (W), which offers greater strength and
load-bearing capacity than I-beams. H-beams are often used in larger and
heavier structures.
- Flange:
The top and bottom horizontal parts of an I-beam or H-beam. The flanges
carry most of the load, while the web connects the flanges and provides
stability.
- Web:
The vertical, or nearly vertical, component connecting the top and bottom
flanges of an I-beam or H-beam. The web provides lateral support and helps
resist shear forces.
- Beam
Size: Refers to the dimensions and specifications of a steel beam,
including its depth, width, and weight per unit length. Common sizes are
specified by design engineers based on structural requirements.
- Beam
Span: The distance between two points of support (e.g., columns or
walls) where the beam is resting. The span affects the beam's size and
load-carrying capacity.
- Clear
Span: The distance between supports along the beam, excluding any
additional supports or obstructions. Clear span is essential for designing
open spaces without the need for intermediate columns or supports.
- Beam
Flange Width: The width of the horizontal top and bottom flanges of
the beam, typically measured in inches or millimeters.
- Beam
Depth: The vertical distance from the top flange to the bottom flange
of the beam, often referred to as the beam's height.
- Beam
Camber: A slight upward curvature intentionally added to a beam during
fabrication to compensate for anticipated deflection under load, ensuring
that the beam remains level when in use.
- Beam
Connection: The method used to connect beams to other structural
elements, such as columns or other beams. Common types include bolted
connections, welded connections, and moment connections.
- Beam
Deflection: The amount by which a beam sags or bends under the
influence of loads. Engineers calculate and consider deflection when
designing beams to ensure structural integrity and user comfort.
- Lateral
Bracing: Additional diagonal or horizontal members are added to beams to
prevent buckling or excessive lateral movement under load.
- Beam
Reinforcement: The use of additional steel plates or sections to
strengthen a beam in areas of high stress or to enhance its load-carrying
capacity.
These are some of the key terminologies related to beams in
steel building construction. Understanding these terms is crucial for
architects, engineers, and construction professionals involved in designing and
erecting steel structures.
Beam support configurations refer to the various ways in
which beams, which are horizontal structural members that support loads, can be
supported or held in place. The choice of beam support configuration depends on
the specific requirements of a structural design and the loads the beam needs
to carry. There are several common beam support configurations, including:
- Simply
Supported Beam: In this configuration, a beam is supported at its ends,
creating a scenario where it can rotate freely at the supports. This is
the most basic and common type of beam support.
- Cantilever
Beam: A cantilever beam is supported at one end while the other end is
left free. This configuration allows for overhanging structures and is
often used in situations where a beam needs to extend beyond a support.
- Fixed
Beam: A fixed beam is rigidly connected or fixed at both ends, preventing
any rotation or translation at the supports. This configuration provides
the highest level of support and is used when stability and rigidity are
critical.
- Continuous
Beam: Continuous beams are supported at multiple points along their
length, creating a series of spans. This configuration is used when a
longer beam needs to distribute loads evenly or when there are multiple
points of support.
- Propped
Cantilever Beam: This is a combination of a cantilever and a simply
supported beam. One end of the beam is fixed or supported, while the other
end is supported by a column or post. It provides more support than a pure
cantilever but still allows for overhangs.
- Fixed-Fixed
Beam: In this configuration, both ends of the beam are fixed, preventing
any movement or rotation. It is similar to the fixed beam but may have
different applications in structural design.
- Roller
Support Beam: A beam supported by rollers at one or both ends, allowing
for horizontal movement but preventing vertical movement or rotation at
the supports. Roller supports are often used when beams need to expand or
contract due to temperature changes.
- Hinged
Support Beam: Hinged supports allow for rotation at the supports but
restrict horizontal and vertical movement. They are often used in
situations where thermal expansion or contraction is anticipated.
The choice of beam support configuration depends on factors
such as the span of the beam, the type and magnitude of the loads it will
carry, and the structural requirements of the project. Engineers and architects
carefully consider these factors when designing structures to ensure that beams
are adequately supported to withstand the intended loads and maintain
structural integrity.
Beam load and force configurations refer to how external
forces and loads are applied to a beam structure. Beams are structural elements
designed to carry loads primarily by resisting bending. Understanding the
different load and force configurations is essential in structural engineering
and civil engineering to ensure that beams can safely support the applied
loads. Here are some common beam load and force configurations:
- Uniformly
Distributed Load (UDL):
- In
this configuration, the load is distributed evenly along the length of
the beam.
- It
creates a constant load per unit length.
- Example:
The weight of a slab or a uniform snow load on a roof.
- Concentrated
Load:
- A
concentrated load is applied at a specific point along the beam.
- It
can be a single point load or multiple-point loads applied at different
locations.
- Example:
A person standing at a specific point on a bridge.
- Point
Load:
- A
point load is a concentrated force applied at a single point on the beam.
- It
represents a non-uniform force acting on the beam.
- Example:
A heavy piece of machinery placed on a beam.
- Cantilevered
Load:
- A
cantilevered load is applied at the free end of a cantilever beam.
- It
creates a bending moment at the fixed support.
- Example:
A diving board with a person jumping off the free end.
- Distributed
Load:
- In
this case, the load is distributed non-uniformly along the beam's length.
- The
load intensity can vary along the beam's span.
- Example:
Wind pressure on the side of a building.
- Moment
Load:
- A
moment load, also known as a couple moment, creates a twisting effect on
the beam without any translational motion.
- It's
represented by two equal and opposite forces applied at a distance from
each other.
- Example:
Torque applied to a shaft supported by a beam.
- Torsional
Load:
- Torsional
loads are twisting forces that cause the beam to rotate.
- They
can occur when beams are subjected to torques.
- Example:
Twisting of a beam due to the action of a motor.
- Temperature
Load:
- Temperature
changes can cause beams to expand or contract, leading to thermal
stresses.
- These
thermal loads are usually non-uniform and can result in bending or
buckling.
- Example:
A metal beam expanding or contracting due to temperature fluctuations.
- Dead
Load and Live Load:
- Dead
load refers to the permanent, constant weight of the structure and any
immovable components.
- Live
load refers to variable, transient loads such as people, furniture, or
vehicles.
- Engineers
consider both types of loads when designing structures.
- Dynamic
Loads:
- Dynamic
loads are loads that vary with time, such as those caused by earthquakes,
wind gusts, or moving vehicles.
- Engineers
use dynamic analysis to account for these loads.
Understanding these load and force configurations is crucial
for designing beams and other structural elements to ensure they can safely
support the anticipated loads and forces while maintaining structural
integrity. Engineers use mathematical and computational methods to analyze and
design beams for specific load scenarios.
