1. BEAMS
Overview
• Introduction
• Types of sections
• Behavior
• laterally supported and unsupported Beams
• Design of laterally supported and unsupported
Beams
• built up beams/compound beams using flange
plates.
• curtailment of flange plates
• Design for strength and serviceability
• Web buckling & web crippling.
2.
3.
4.
5. Various terms used for Beam members
• Joist: Structural member provided in the building to
support roof also know as beam
• Girder: large beam which supports a number of Joists.
It is basically built-up section.
• Purlin: is beam which supports roofing material is
roof trusses. Angle and channel section are used.
• Lintel: it is beam which supports load of masonry
over openings.
• Plate girder: it is built up flexure member made up of
plates provided when Rolled I section are insufficient
to catty load.
• Gantry Girder: Steel Built-up section provided in the
industry to carry moving loads.
18. Classification of Cross sections
• In Beam design it is necessary to see that plate element should
not buckle locally due to compressive stresses before beam can
develop its full flexure capacity.
• The Critical buckling stress plate element is inversely
proportional to the width to thickness ratio. Hence suitably
reducing slenderness ratio of the plate element its buckling
resistance can be increased.
• Hence depend upon width to thickness ration of plate element
following classification of section is performed:
• Class 1: Plastic
• Class 2: Compact
• Class 3: Semi-Compact
• Class 4: Slender
19.
20.
21. • Identify Class of following sections section
• ISLB 450 @65.3Kg/m
• ISLB 600 @ 99.5Kg/m
• ISWB 600 @1311.6N/m
• ISMC 300@ 351.2N/m
• ISWB 550 @1103.6N/m
27. DESIGN CONSIDERATION FOR BEAM
• Bending moment
• Shear Force
• Deflection
• Bearing Stress
• Buckling
28. Web Buckling and Crippling
Due to high vertical stresses directly over a support or under
a concentrated load, the beam web may actually crush or
buckle as a result of these stresses.
