Mechanism

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Mechanism

• ENGR 221
• March 5, 2003

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Lecture Goals

• Problems

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Class Frame Problem
Determine the maximum value of the force caused
in link connection (a) points B and E and (b)
points C and F.
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Class Frame Problem
Knowing that the central portion of the link BD
has a uniform cross-section area of 800 mm2.
Determine the magnitude of the load P for the
normal force in the portion of BD is 40 kN.
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Class Frame Problem
Knowing that the central portion of the link BD
has a uniform cross-section area of 800 mm2.
Determine the magnitude of the load P for the
normal force in the portion of BD is 40 kN.
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Class Machine Problem
A cylinder weighs 400 lb and is lifted by a pair
of tongs as shown determine the force exerted at
D and C on the tong BCD.
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Class Machine Problem
A force P of magnitude 400-lb is applied to the
piston of the engine system. For each of the two
positions, determine the moment couple M required
to hold the system in equilibrium. What would
the forces be if M 210 lb-ft is applied
determine the force.
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Class Mechanism Problem
An aircraft tow bar is positioned by means of a
single hydraulic cylinder connected by a 25 mm
diameter steel rod to two identical arm-and-wheel
units DEF. The weight of the entire tow bar is 2
kN and the center of gravity is located at G.
Determine the normal force in the rod.
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Class Mechanism Problem
A pipe of diameter 50 mm is gripped by the
Stilton wrench. Portions AB and DE of the wrench
are rigidly attached to each other and portion CF
is connected by a pin at D. Assume that no
slopping occurs between the pipe and the wrench
determine the components of the forces on the
pipe at A and C.
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Class Mechanism Problem
Determine the magnitude of the gripping forces
produced when two 60-lb forces are applied.
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Homework (Due 3/19/03)
Problems
7-84, 7-87, 7-95, 7-103
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Extra Class Problem
Knowing that the average normal stress in the
link is not to exceed 6.25 kips, determine the
largest load which may be applied at point E if
this load is directed (a) vertically down ward
and (b) vertically upward
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Extra Class Problem
Link AC has a uniform rectangular cross section,
determine the normal force in central portion of
that link is a 0o and 60o .