MECH2308 Tutorial #10 Dec 2012

Question One A timber beam is loaded and supported as shown in Figure. At section A-A of the beam, determine the

shearing stresses on horizontal planes that pass through points a, b, and c of the cross section.

Question Two A timber beam 4 m long is simply supported at its ends and carries a uniformly distributed load w of 8

kN/m over its entire length. If the beam has the cross section shown in Figure below, determine

(a) The maximum horizontal shearing stress in the glued joints between the web and flanges of the

beam.

(b) The maximum horizontal shearing stress in the beam.

Question Three A 5-m long simply supported timber beam carries two concentrated loads, as shown in fig.

Determine:

a) The reactions on both supports

(RA and RD),

b) The moment of inertia about the

z-axis,

c) The magnitude of the shear stress

in the beam at point H in section

a-a (),

d) The maximum horizontal shear

stress that occurs in the beam

( .),

e) The bending stress that occurs in the beam at the neutral axis ().

MECH2308 Tutorial #10 Dec 2012

Question Four The beam shown in Figure a below is composed of three pieces of timber that are glued together as shown

in Figure b below. Determine

(a) The maximum horizontal shearing stress in the glued joints.

(b) The maximum horizontal shearing stress in the wood.

(c) The maximum tensile and compressive flexural stresses in the beam.

Question Five A timber beam is simply supported and carries a uniformly distributed load of 4 kN/m over the full length

of the beam. If the beam has the cross section shown in Figure and a span of 6 m, determine

(a) The horizontal shearing stress in the glued joint 50 mm below the top of the beam and 1 m

from the left support

(b) The horizontal shearing stress in the glued joint 50 mm above the bottom of the beam and ½

m from the left support.

(c) The maximum horizontal shearing stress in the beam.

(d) The maximum tensile flexural stress in the beam.