Page 49 - Modern Steel Construction (April 2019)

Powerful,

where deformations are controlled by DOWNLOAD
tensioning along the member axis. Rotary 90-DAY TRIAL
VERSION
draw bending is commonly used to form Easy, and
small-radius bends in smaller-size round,
square and rectangular HSS members. Spe- Intuitive

ci c tooling is required for each member
size, shape and bend radius; therefore, this
method is best suited for projects requiring
many identical bends. Some bender-roller
companies have hundreds of die sets, likely
eliminating any initial tooling costs for
common geometries.
This bending method is primarily used
in the machine and parts industry and for
piping. The maximum degree of bend is
180°, but the minimum bend radii of round
HSS is approximately 50% smaller than
that of other cold-bending methods. RFEM 5 © www.novumstructures.com
Other methods can be used to bend The 3D FEA Structural
members, including ram bending gag Analysis Software
pressing and hot bending.
Ram bending. Ram bending is Nonlinear Analysis Steel Concrete
a cold-bending method that uses a Timber / CLT Aluminum Glass
Dynamic Analysis
Form-Finding
BIM Integration
hydraulic ram to apply a force near the
mid-span of two widely spaced supports.
The member is moved through the
machine so the force can be applied at E-mail: info-us@dlubal.com www.dlubal.com
discrete locations as required to produce Phone: (267) 702-2815
the desired curvature.
Gag pressing. Gag pressing, also
known as point bending or cold cam-
bering, is a bending method that uses
hydraulic rams to simultaneously apply Can’t make it to St. Louis?
forces at discrete locations along the
member to produce large-radii bends. Watch 13 sessions live from the 2019
This is the most common method for NASCC: The Steel Conference!
cambering beams to offset a portion of

the service-load de ections; therefore,
the hydraulic rams are located approxi-
mately at one-third points to produce NASCC LIVE
a curved shape approximating a typical

beam de ection curve. The supports for
most cambering machines are between 20 For more information, visit
ft and 28 ft apart. www.aisc.org/nascclive
Beams are usually cambered in a
custom-built machine at the fabricator’s
shop; however, members can also be
cambered by a bender-roller company.
Because beam lines can be used only with
straight members, beams are usually cam-

bered after they are cut to the nal length
and holes are punched or drilled. If the
machine capacity is exceeded, heat can
be applied to the member to reduce the
yield stress. Because many bender-roller
companies have specialized, high-capacity
equipment, it can be more economical for
the fabricator to sublet the cambering of
large beams.

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