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PROBLEM 8.52
The elevation of the end of the steel beam supported by a concrete
floor is adjusted by means of the steel wedges E and F. The base
plate CD has been welded to the lower flange of the beam, and the
end reaction of the beam is known to be 18 kips. The coefficient of
static friction is 0.30 between two steel surfaces and 0.60 between
steel and concrete. If the horizontal motion of the beam is
prevented by the force Q, determine (a) the force P required to
raise the beam, (b) the corresponding force Q.
Copyright © McGraw-Hill Education. Permission required for reproduction or display.
PROBLEM 8.52 (Continued)
Since wedge F is a two-force body,
2
R
and
3
R
are colinear
Thus
28.7
But
1
concrete
tan 0.6 31.0
OK
PROBLEM 8.53
Solve Prob. 8.52 assuming that the end of the beam is to be
lowered.
PROBLEM 8.52
The elevation of the end of the steel beam supported by a concrete
floor is adjusted by means of the steel wedges E and F. The base
plate CD has been welded to the lower flange of the beam, and the
end reaction of the beam is known to be 18 kips. The coefficient of
static friction is 0.30 between two steel surfaces and 0.60 between
steel and concrete. If the horizontal motion of the beam is
prevented by the force Q, determine (a) the force P required to
raise the beam, (b) the corresponding force Q.
PROBLEM 8.53 (Continued)
PROBLEM 8.54
Block A supports a pipe column and rests as shown on wedge B.
Knowing that the coefficient of static friction at all surfaces of contact is
0.25 and that
45 ,
determine the smallest force P required to raise
block A.
PROBLEM 8.55
Block A supports a pipe column and rests as shown on wedge B.
Knowing that the coefficient of static friction at all surfaces of contact is
0.25 and that
45 ,
determine the smallest force
P
for which
equilibrium is maintained.
PROBLEM 8.56
Block A supports a pipe column and rests as shown on wedge B. The
coefficient of static friction at all surfaces of contact is 0.25. If
0,
P
determine (a) the angle
for which sliding is impending, (b) the
corresponding force exerted on the block by the vertical wall.
PROBLEM 8.57
A wedge A of negligible weight is to be driven between two 100-lb
blocks B and C resting on a horizontal surface. Knowing that the
coefficient of static friction between all surfaces of contact is 0.35,
determine the smallest force
P
required to start moving the wedge
(a) if the blocks are equally free to move, (b) if block C is securely
bolted to the horizontal surface.
PROBLEM 8.58
A 15 wedge is forced into a saw cut to prevent binding
of the circular saw. The coefficient of static friction
between the wedge and the wood is 0.25. Knowing that a
horizontal force
P
with a magnitude of 30 lb was required
to insert the wedge, determine the magnitude of the forces
exerted on the board by the wedge after insertion.
PROBLEM 8.59
A 12 wedge is used to spread a split ring. The coefficient of static
friction between the wedge and the ring is 0.30. Knowing that a
force
P
with a magnitude of 120 N was required to insert the wedge,
determine the magnitude of the forces exerted on the ring by the
wedge after insertion.
