This preview shows page 1. Sign up to view the full content.
Unformatted text preview: 05Ch05.qxd 9/24/08 4:59 AM Page 417 SECTION 5.6 Design of Beams Problem 5.6-8 The wood joists supporting a plank floor (see figure) are
40 mm * 180 mm in cross section (actual dimensions) and have a span
length L 4.0 m. The floor load is 3.6 kPa, which includes the weight
of the joists and the floor.
Calculate the maximum permissible spacing s of the joists if the
allowable bending stress is 15 MPa. (Assume that each joist may be
represented as a simple beam carrying a uniform load.) Solution 5.6-8 Spacing of floor joists L
w floor load s q 4.0 m
spacing of joists 15 MPa SPACING OF JOISTS bh
S sallow ws
2 S 3.6 kPa smax 4 bh2sallow
3wL2 Substitute numerical values:
6 4(40 mm)(180 mm)2(15 MPa)
3(3.6 kPa)(4.0 m)2
0.450 m 450 mm ; ; 417 ...
View Full Document
This note was uploaded on 12/22/2011 for the course MEEG 310 taught by Professor Staff during the Fall '11 term at University of Delaware.
- Fall '11