考虑动载荷作用
(1)按抗剪确定的螺栓的承载力 nυπd2[τ][Nυ]=
4
式中nυ——剪切面数目,单剪nυ=1; d——螺杆直径;d=32mm
[τ]——螺杆的许用剪应力。粗制螺栓[τ]=0.6[σ];[σ]为螺栓材料的许用正应力。 nυπd2[τ]π×322×0.6×600[Nυ]= = =216.07kN
44×1.34(2)按承压确定螺栓承载力[NC] [NC]= d·∑t·[σc]
式中 ∑t——同一受力方向的承压构件的较小总厚度;∑t=24mm
[σc]孔壁的许用承压应力。粗制螺栓[σc]=1.4[σ],[σ]为基材的许用正应力。 [NC]= d·∑t·[σc]=32×24×1.4×335/1.34=268.80kN [Nυ]<[NC],取[Nυ] =216.07kN作为单栓的抗剪承载力。
当上小车及下小车位于桥架极限位置,上小车满载,下小车空载,大车制动(考虑动载作用),考虑桥架自重。
螺栓强度计算式 N1=
N21x+ (N1y + N1F )2 ≤[Nυ]
轴心力F=1.1×〔(1580-150-270)/4+(1200+150+270)/2〕=1210kN 1210
每个螺栓受剪力N1F= = =75.63N
n16
F
1.1×Fx·e1.1×150×850
偏心力产生的扭矩T = = =70125kN·mm
22∑xi2=16×5002=4000000mm2
∑yi2=4×(752+2252+3752+5252)= 1890000mm2 受力最大螺栓的水平分力和垂直分力:
N1T·y1T·y170125×525
N1Tx= = = =6.25kN
r1∑xi2+∑yi2 4000000+1890000N1Ty=
N1T·x1r1
=
T·x1∑xi2+∑yi2
=
=5.95kN
4000000+1890000
70125×500
(158+120)×0.104
由大车制动产生的水平惯性力NZX= =7.23kN
4N1= =
(N1TX+ NZX )2+ (N1Ty + N1F )2
(6.25+7.23)2+ (5.95+75.63)2 =82.73kN<[Nυ] =216.07kN
当上小车及下小车位于桥架极限位置,下小车满载,上小车起吊45t载荷,大车制动(考虑动载作用),考虑桥架自重。
螺栓强度计算式N1= N21x+ (N1y + N1F )2 ≤[Nυ]
轴心力F=1.1×〔 (1580-150-270)/4+(750+450+150+270)/2〕=1210kN 1210
每个螺栓受剪力N1F= = =75.63N
n16
1.1×Fx·e1.1×(750+150)×850
偏心力产生的扭矩T= = =420750kN·mm
22∑xi2=16×5002=4000000mm2
F
∑yi2=4×(752+2252+3752+5252)= 1890000mm2 受力最大螺栓的水平分力和垂直分力:
N1T·y1T·y1420750×525
N1Tx= = = =37.50kN 22r1∑xi+∑yi 4000000+1890000N1Ty=
N1T·x1r1
=
T·x1∑xi2+∑yi2
=
=35.72kN
4000000+1890000
420750×500
(158+75+45)×0.104
由大车制动产生的水平惯性力NZX= =7.23kN
4N1= =
(N1TX+ NZX )2+ (N1Ty + N1F )2
(37.50+7.23) 2+ (35.72+ 75.63)2 =120.00kN<[Nυ] =216.07kN
只考虑静载荷作用
(1)按抗剪确定的螺栓的承载力
nυπd2[τ][Nυ]=
4
式中nυ——剪切面数目,单剪nυ=1; d——螺杆直径;d=32mm
[τ]——螺杆的许用剪应力。粗制螺栓[τ]=0.6[σ];[σ]为螺栓材料的许用正应力。 nυπd2[τ]π×322×0.6×600[Nυ]= = =159.63kN
44×1.48(2)按承压确定螺栓承载力[NC]
[NC]= d·∑t·[σc]
式中 ∑t——同一受力方向的承压构件的较小总厚度;∑t=24mm
[σc]孔壁的许用承压应力。粗制螺栓[σc]=1.4[σ],[σ]为基材的许用正应力。 [NC]= d·∑t·[σc]=32×24×1.4×335/1.48=243.37kN [Nυ]<[NC],取[Nυ] =159.63kN作为单栓的抗剪承载力。
当上小车及下小车位于桥架极限位置,上小车满载,下小车空载,大车静止,考虑桥架自重。
螺栓强度计算式 N1=
N21x+ (N1y + N1F )2 ≤[Nυ]
轴心力F= (1580-150-270)/4+(1200+150+270)/2=1100kN 1100
每个螺栓受剪力N1F= = =68.75N
n16
Fx·e150×850
偏心力产生的扭矩T = = =63750kN·mm
22∑xi2=16×5002=4000000mm2
∑yi2=4×(752+2252+3752+5252)=1890000mm2 受力最大螺栓的水平分力和垂直分力:
N1T·y1T·y163750×525
N1Tx= = = =5.68kN 22r1∑xi+∑yi 4000000+1890000N1Ty=
N1T·x1r1
=
T·x1∑xi2+∑yi2
=
=5.41kN
4000000+1890000
63750×500
F
(158+120)×0.104
由大车制动产生的水平惯性力NZX= =7.23kN
4N1= =
(N1TX+ NZX )2+ (N1Ty + N1F )2
(5.68+7.23)2+ (5.41+ 68.75)2 =75.28kN<[Nυ] =159.63kN
当上小车及下小车位于桥架极限位置,下小车满载,上小车起吊45t载荷,大车静止,考虑桥架自重。
螺栓强度计算式N1= N21x+ (N1y + N1F )2 ≤[Nυ]
轴心力F= (1580-150-270)/4+(750+450+150+270)/2=1100kN 1100
每个螺栓受剪力N1F= = =68.75kN
n16
Fx·e(750+150)×850
偏心力产生的扭矩T= = =382500kN·mm
22∑xi2=16×5002=4000000mm2
∑yi2=4×(752+2252+3752+5252)=1890000mm2 受力最大螺栓的水平分力和垂直分力:
N1T·y1T·y1382500×525
N1Tx= = = =34.09kN
r1∑xi2+∑yi2 4000000+1890000N1Ty=
N1T·x1r1
=
T·x1∑xi2+∑yi2
=
=32.47kN
4000000+1890000
382500×500
F
(158+75+45)×0.104
由大车制动产生的水平惯性力NZX= =7.23kN
4N1= =
(N1TX+ NZX )2+ (N1Ty + N1F )2
(34.09+7.23) 2+ (32.47+ 68.75)2 =109.33kN<[Nυ] =159.63kN
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