Chapter 11 Design of Beams (Sections 1 and 2)

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Chapter 11 Design of Beams (Sections 1 and 2)
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Recall, with beams we have two stresses to deal
with, normal stress, s, and shear stress, t
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How are the design of these beams different???
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Beam Recap

• Beams are structural members designed to support
  loads applied perpendicular to longitudinal axis.
• Must be sized adequatly to reduce both shear
  stress and bending stress as well as shear flow
  if beam fabricated with fasteners!
• Shear stress issue with wooden beams, short
  beams, beams with narrow sections (small t) or
  glued beams.

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Beam Recap Contd

• Bending stress generally the stress designed
  to. Especially for long beams, steel beams, etc.
• Recall

Let S section modulus I/c, then
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Beam Design Summary

• Find shear and moment diagram get Vmax and
  Mmax. Determine material and type of beam.
• Calculate required section modulus using
• Calculate max shear stress to make sure ok

Design Cross-Section!!!!
Optional If fabricated with fasteners determine
fastener spacing S Fsd/q If glued, calculate
shear stress at glue joint to make sure ok!
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EXAMPLES
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