绗洓绔?/p>
涔犻
4-1
宸茬煡
F
1
=60N
锛?/p>
F
2
=80N
锛?/p>
F
3
=150N
锛?/p>
m=100N.m
锛岃浆鍚戜负閫嗘椂閽堬紝胃
=30
掳鍥句腑璺?/p>
绂诲崟浣嶄负
m
銆傝瘯姹傚浘涓姏绯诲悜
O
鐐圭畝鍖栫粨鏋滃強鏈�缁堢粨鏋溿�?/p>
4-2
宸茬煡鐗╀綋鎵�鍙楀姏绯诲鍥炬墍绀猴紝
F=10Kn
锛?/p>
m=20kN.m
锛岃浆鍚戝鍥俱�?/p>
锛?/p>
a
锛夎嫢閫夋嫨
x
杞翠笂
B
鐐逛负绠�鍖栦腑蹇冿紝鍏朵富鐭?/p>
L
B
=10kN.m
锛岃浆鍚戜负椤烘椂閽堬紝璇曟眰
B
鐐圭殑浣嶇疆鍙婁富鐭?/p>
R
鈥欍�?/p>
锛?/p>
b
锛?/p>
鑻ラ�夋嫨
CD
绾夸笂
E
鐐逛负绠�鍖栦腑蹇冿紝
鍏朵富鐭?/p>
L
E
=30kN.m
锛?/p>
杞悜涓洪『鏃堕拡锛?/p>
伪
=45
掳锛?/p>
璇曟眰浣嶄簬
CD
鐩寸嚎涓婄殑
E
鐐圭殑浣嶇疆鍙婁富鐭?/p>
R
鈥欍�?/p>
4-3
璇曟眰涓嬪垪鍚勬鎴栧垰鏋剁殑鏀骇鍙嶅姏銆?/p>
瑙ｏ細
锛?/p>
a
锛?/p>
鍙楀姏濡傚浘
鐢扁垜
M
A
=0 F
RB
鈥?/p>
3a-Psin30
掳鈥?/p>
2a-Q
鈥?/p>
a=0
鈭?/p>
FRB=
锛?/p>
P+Q
锛?/p>
/3
鐢?/p>
鈭?/p>
x=0 F
Ax
-Pcos30
掳
=0
鈭?/p>
F
Ax
=
3
2
P