Results for I-beam
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Dictionary:

I-beam

  (ī'bēm')
n.

A steel joist or girder with short flanges and a cross section formed like the letter I.


 
 
Architecture: I-beam

A rolled or extruded structural metal beam having a cross section resembling the letter I.


 
WordNet: I-beam
Note: click on a word meaning below to see its connections and related words.

The noun has one meaning:

Meaning #1: girder having a cross section resembling the letter `I'


 
Wikipedia: I-beam


This I-beam is used to support the first floor of a house.
Enlarge
This I-beam is used to support the first floor of a house.

I-beams (also known as double-T esp. in Polish and German) are beams with an I- or H-shaped cross-section. The horizontal elements are flanges, while the vertical element is the web. The Euler-Bernoulli beam equation shows that this is a very efficient form for carrying both bending and shear in the plane of the web. The cross-section has a reduced capacity in the transverse direction, and is also inefficient in carrying torsion, for which hollow structural sections are often preferred.

There are two standard I-beam forms:

I-beams are commonly made of structural steel but may also be formed from aluminium or other materials. A common type of I-beam is the rolled steel joist (RSJ) - sometimes incorrectly rendered as "reinforced steel joist". British and European standards also specify Universal Beams (UBs) and Universal Columns (UCs). These sections have parallel flanges, as opposed to the varying thickness of RSJ flanges. UCs have equal or near-equal width and depth, while UBs are deeper.

I-beams engineered from wood with fiberboard and/or laminated veneer lumber are also becoming increasingly popular in construction, especially residential, as they are both lighter and less prone to warping than solid wooden joists. However there has been some concern as to their rapid loss of strength in a fire if unprotected.

Design of I-beams

I-beams are widely used in the construction industry and are available in a variety of standard sizes. Tables are available to allow easy selection of a suitable steel I-beam size for a given applied load. I-beams may be used both as beams and as columns.

I-beams may be used both on their own, or acting compositely with another material, typically concrete. Design may be governed by any of the following criteria:

  • deflection - the stiffness of the I-beam will be chosen to minimise deformation
  • vibration - the stiffness and mass are chosen to prevent unacceptable vibrations, particularly in settings sensitive to vibrations, such as offices and libraries
  • bending failure by yielding - where the stress in the cross section exceeds the yield stress
  • bending failure by lateral torsional buckling - where a flange in compression tends to buckle sideways or the entire cross-section buckles torsionally
  • bending failure by local buckling - where the flange or web is so slender as to buckle locally
  • local yield - caused by concentrated loads, such as at the beam's point of support
  • shear failure - where the web fails. Slender webs will fail by buckling, rippling in a phenomenon termed tension field action, but shear failure is also resisted by the stiffness of the flanges
  • buckling or yielding of components - for example, of stiffeners used to provide stability to the I-beam's web

Wide-flange steel materials and rolling processes (U.S.)

In the United States the most commonly referred to I-Beam is primarily now a wide-flange (W) shape. While maintaining the general I-shape, these beams have flanges in which both flange surfaces are nearly parallel. Other I-Beams include American Standard (designated S) shapes, in which flange surfaces are not parallel and H-piles (designated HP) which are typically used as pile foundations. Wide-flange shapes are available primarily in grade ASTM A992[1] which has generally replaced older grades ASTM A572 and A36.

Rusty steel I-beam
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Rusty steel I-beam

Ranges of yield strength:

  • A36 - 36 ksi
  • A572 - 42 ksi to 60 ksi (50 ksi most common)
  • A588 - Similar to A572
  • A992 - 50 ksi to 65 ksi

Wide-flange shapes are produced by the electric arc furnace method and will generally contain more than 95% recycled content.[2]

AISC, or American Institute of Steel Construction, produces a "Steel Construction Manual", that is used to design structures using various steel shapes and documents the common methodologies, ASD and LRFD, (as of 13th ed.) for designing steel structures.

See also

External links and references

  1. ^ ASTM A992 grade steel
  2. ^ Recycled content of steel

 
Translations: Translations for: I-beam

Dansk (Danish)
n. - i-drager, I-markør

idioms:

  • i-beam pointer    I-viser, I-pointer

Français (French)
n. - aiguille (d'une horloge), index (d'une balance), indicateur (d'un baromètre), baguette (d'un tableau noir), pointe (de maçon), (Comput) pointeur

idioms:

  • i-beam pointer    (Comput) pointeur sur l'écran en forme I

Deutsch (German)
n. - (Tech.) I-Träger, Doppel-T-Eisen

idioms:

  • i-beam pointer    I-beam Zeiger

Ελληνική (Greek)
attrib. - δοκός διατομής σχήματος Ι

idioms:

  • i-beam pointer    (Η/Υ) δείκτης σαν Ι

Español (Spanish)
n. - viga I

idioms:

  • i-beam pointer    cursor en forma de "I"

Svenska (Swedish)
attr. - I-balk -

中文(简体) (Chinese (Simplified))
I形金属桁梁

idioms:

  • i-beam pointer    工字钢指针

中文(繁體) (Chinese (Traditional))
n. - I形金屬桁樑

idioms:

  • i-beam pointer    工字鋼指針

한국어 (Korean)
n. - 직광선

العربيه (Arabic)
‏(صفه) دعامه معدنيه تشبه حرف I‏

עברית (Hebrew)
n. - ‮קורת מתכת שחתך הרוחב שלה הוא I‬


 
 

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Copyrights:

Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2007. Published by Houghton Mifflin Company. All rights reserved.  Read more
Architecture. McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc. All rights reserved.  Read more
WordNet. WordNet 1.7.1 Copyright © 2001 by Princeton University. All rights reserved.  Read more
Wikipedia. This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "I-beam" Read more
Translations. Copyright © 2007, WizCom Technologies Ltd. All rights reserved.  Read more

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