課程名稱︰靜力學 Statics
課程性質︰機械系大一必帶
課程教師︰施文彬
開課學院： 工學院 開給 工學院
開課系所︰ 機械系 開給 機械系
考試日期（年月日）︰2013.1.8
考試時限（分鐘）：2小時10分鐘(10:20~12:30)
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
Please provide details of your calculation. Good luck!!
1. (20%) A machine is shown as the picture. Rod BC is
connected to the block C through a pin and passes through
a collar welded to end B of lever AB. The block C is put
on a platform that is supported by a screw. The screw is
double-threaded and right-handed viewed from below. It
has a pitch of 1.5 mm and a mean diameter of 8 mm. A
couple of 30 N-m is applied to the lever as shown. The
hinge and the pin are frictionless. Let the coefficient of
static friction of all contacts is 0.25. The block C is about
to move downward.
(a) Draw the free body diagram of the lever AB.
(b) Draw the free body diagram of the rod BC and Block C.
(c) Determine Couple M that is required to hold the
system in equilibrium.
第1題圖形：http://tinyurl.com/ahzxb8j
2. (20%)
(a) Consider a flat belt passing over a fixed cylindrical drum. Please derive
the relation between T and T
1 2
which can be applied to the problem involving a flat belt passing over the
fixed cylindrical drum.
╭ μβ ╮
│ T / T = e │
╰ 2 1 ╯
(b) The simple band brake is constructed so that the ends of the friction
belt are connected to the pin at A and the lower lever arm at B. If the
drum is subjected to a torque of M = 120 N-m, determine the
smallest force P applied to the lever that is required to hold the drum
stationary.The coefficient of static friction between the belt and the
drum is 0.5. The pin at O is frictionless.
第2題圖形：
http://tinyurl.com/bxgykap
http://tinyurl.com/b3hrxh8
3. (20%)
(a) The cable AB carries a load uniformly distributed along the horizontal.
Draw the F.B.D. of the CD section of the cable.
2
╭ w x ╮
│ Parabola: y = ─── │
╰ 2 T ╯
0
(c) A chain is fixed at its end and hoisted at its midpoint B using a crane.
If the chain has weight of 0.3 kN/m along the horizontal, determine the
minimum height h of the hook in order to Iift the chain
completely off the ground. What is the horizontal force at pin A when
the chain is in this position?
第3題圖形：
http://tinyurl.com/aae5t87
http://tinyurl.com/a2jnofm
4. (20%) Neglect the weight of the mechanism and all frictions.
(a) Apply the principle of virtual work to determine the ratio P/Q
of the forccs that are required to maintain equilibrium of the mechanism
for any arbitrary angle θ.
(b) Determine the forces in member ABC in terms of Q， a and θ?
第4題 與 第5題 圖形：
http://tinyurl.com/cwxxl5d
5. (20%) The simply supported truss is 15 m high and 16 m long.
A 60 kN force is applied at E as shown.
(a) Is there any zero-force member in the truss shown? If yes,
please determine the zero-force members by analyzing a
the F.B.D. If no, please explain the reasons?
(b) Determine the forces in members AC, AD, and DE.
(c) Determine the forces in members GI, FH, GH.
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◆ From: 114.36.13.20
※ 編輯: b01502092 來自: 114.36.13.20 (01/15 16:05)