A wooden log is to be used as a foot bridge to span a 2 m gap. The
log is to support a concentrated load of 40 kN.
Allowable shear stress = 1.2 MPa
Allowable bending stress = 6.3 MPa
a. Compute the diameter of the log needed for a maximum shear
. ans. 238 mm
b. Determine the diameter of the lod needed so that the
allowable bending stress is not exceeded. ans. 318 mm
c. A 150 mm wide rectangular log is to be used instead of the
circular log. What is the minimum depth of the log so as not to
exceed the allowable bending stress? . ans. 300 mm
