精选优质文档-----倾情为你奉上1. 平衡梁校核说明:1)2)按吊装载荷10t校核3)跨距为2m4)梁下索具为垂直承力5)梁上索具使用偏角不小于60°(该计算书按60°校核)6)设计安全系数为1.62. 平衡梁示意图3. 与校核G=36.75561kg按吊装载荷10t校核平衡梁在动态平衡状态下,受力如上图示简化,见下图:由作图法知F1 = F4 = 25.882kN平衡梁处于动态平衡中,竖直方向力相等所以:F1×sin15°+ F4×sin15°+ G = F2×sin74°+ F3×sin74°又: F2 = F3所以:F2 = F3 = 7.156kN所以平衡梁受力如图对平衡梁进行受力分析平衡梁轴向力方程:F1横 + F2横 = F3横 + F4横F1横 = F4横 = F1×cos15°= 25.000kNF2横 = F3横 = F2×cos74°= 1.972kN平衡梁纵向力方程:F1竖 = F4竖 = F1×sin15°= 6.699kNF2竖 = F3竖 = F2×sin74°= 6.879kN1)做剪力图、弯矩图(1)剪力图AB、BC、CD、DE各段无载荷作用,FQ为常数,FQ图为斜直线。
从A端开始,求出控则截面剪力如下:FQA = -F1竖 = -6.699kNFQB = F2竖 + FQA = 6.879 - 6.699 = 0.18 kNFQC = - G +FQB = - 0.360 + 0.18= - 0.18 kNFQD = F3竖+FQC = 6.879 -0.18= 6.699 kN(2)弯矩图选A、B、C、D、E为控制截面,求出其弯矩值如下:MA = 0MB = F1竖×0.5 = 6.699×0.5 =3.350kN·mMC = F1竖×1 – F2竖×0.5 = 6.699×1 - 6.879×0.5 = 3.260kN·mMD = F1竖×1.5–F2竖×1+G×0.5=6.699×1.5-6.879×1+0.360×0.5=3.350kN·mME = 02)刚度校核由《起重机设计手册》P521式4-1-30刚度条件为:λ≤[λ]λ=μL / r 式中:L=2000mm r = (I / A)1/2 I = π(D4 – d4 ) / 64对于Φ114×6钢管,I =π(1144 – 1024 ) / 64 = 2.977×106 mm4A =π(572 – 512 ) = 2035.752 mm2故 r = (I / A)1/2 =38.243mm查《起重机设计手册》P545表4-1-40取 μ = 1查《起重机设计手册》P522表4-1-16取[λ]= 150所以 λ=1×2000/38.243 = 52.297 ≤[λ] 所以支撑梁刚度满足要求。
3)强度校核由《起重机设计手册》P521式4-1-30刚度条件为:σ= F / A ≤[σ]式中:F = G/2 = 4.9×104×tan30o = 2.829×104N A = 2035.752 mm2故 σ= 13.897 MPa钢管材料为20钢,σ= 13.897 MPa ≤[σ]= 245 Mpa 所以强度满足要求4)稳定性校核由《起重机设计手册》P523式4-1-36稳定性条件为:σ= F / (ψA) ≤[σ]式中:F = G/2 = 4.9×104×tan30o = 2.829×104N A = 2035.752 mm2由《起重机设计手册》P523表4-1-17取ψ = 0.847所以 σ= 16.407 MPa ≤[σ]所以稳定性满足要求4. 吊耳校核吊耳材质为Q235,σs=235 Mpa安全系数为1.6[σ] =σs/1.6 = 146.875 Mpa[τ] = 80.781 Mpa (取0.55[σ])1)吊耳截面拉伸应力计算吊耳拉伸载荷F2 = 7.156kN吊耳截面拉应力σ=Fv /A式中:Fv = F2 = 7.156kN A = (50-30) ×5 = 100 mm2故σ=F2 /A=7.156×103/[(50-30)×5]=71.560Mpa ≤[σ] = 125 Mpa强度满足。
2)吊耳孔挤压强度计算σr =式中:T = F2 = 7.156kNd 为吊耳孔直径,d = 30mmt1 为吊耳板厚度,t1 = 5mmt2 为加强板厚度,t1 = 0mm故σr =110 Mpa ≤[σ] = 125 Mpa强度满足3)吊耳截面剪切应力计算τ=式中:Fv = F2 = 7.156kN A = (50-30) ×5 = 100 mm2τ= 71.560Mpa ≤ [τ] = 80.781 Mpa强度满足 通过以上分析计算证实该平衡梁能够满足要求专心---专注---专业。