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nick.w
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Homework Statement
Particle board flooring (dead load 8 kg/m2 including joist self-weight) is supported by a series
of Radiata pine VSG8, of call size 150 x 50, timber joists running parallel to one other at 450
mm centers and spanning L=3.8 m between supports. The floor supports an imposed load
of 3.5 kPa.
http://img14.imageshack.us/img14/7767/timbertable.png [Broken]
Assuming strength requirements are OK (they may or may not be), what would be the
maximum deflection (in mm) of the joist?
Assume allowable deflection for the joist is L/350. Is the calculated deflection
acceptable?
NOTE: for this calculation use w = 1.0 * Dead + 1.0 * Live
(use gauged, kiln dried section size for timber section)
Homework Equations
Max Deflection = 5wL4 / (384EI)For the above formulae:
L is the length of the beam,
E is Young’s Modulus (Units Pa, MPa, GPa)
I is the Second Moment of Area of the cross-sectional shape of the beam (units m4 or mm4)
The Attempt at a Solution
I think this is the correct formula but need to be certain. Also how do I find "I" if this is the correct forumla.
I also get thrown off by. "use w = 1.0 * Dead + 1.0 * Live" as I have already calculated the UDL in an earlier part of the question using w= 1.2*dead + 1.5*live.
If you guy could point me in the right pirection of which formula to use I would appreciate it.
Regards,
Nick
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