悬臂式标志牌结构设计计算书1设计资料1.1板面数据板面高度:H = 2.00(m)板面宽度:W = 8.00(m)板面单位重量:W1 = 13.26(kg/m^2)边长:0.18(m)横梁长度:L = 7.8(m)横梁壁厚:T = 0.008(m)横梁间距:D1 = 1.0(m)横梁单位重量:W1 = 45.22(kg/m)1.3立柱数据边长: 0.35(m)立柱高度:L = 7.40(m)立柱壁厚:T = 0.014(m)立柱单位重量:W1 = 153.86(kg/m)2荷载计算2.1永久荷载各计算式中系数 1.1 系考虑有关连接件及加劲肋等的重量而添加。
2.1.1板面重量计算标志版单位重量为13.26(kg/m 2)标志版重量:G1 = 13.26× 16× 9.8× 1.1(N) = 2.2871(KN)2.1.2横梁重量计算G2 = 2× 45.22× 7.8× 9.8× 1.1(N) = 7.6046(KN)2.1.3立柱重量计算G3 = 153.86× 7.8× 9.8× 1.1(N) = 12.9372(KN)G = G1 + G2 + G3 = 22.8289(KN)3风荷载计算3.1标志版风力F1 = βz × μs × μz ×ω 0× (W × H)= 12.944(KN)3.2立柱风力F2 = βz × μs × μz ×ω 0× (W × H)= 2.096(KN)4横梁设计计算说明:由于单根横梁材料、规格相同,根据基本假设,可认为每根横梁所受的荷载为总荷载的一半。
对单根横梁所受荷载计算如下:4.1荷载计算竖直荷载G4 = γ 0 × γ G × G1 / 2 = 1.372(KN)均布荷载ω1 = γ 0 × γ G × G2 / (2 × H) = 0.585(KN/m)水平荷载F wb = F1 / 2 =6.472(KN)4.2强度验算计算横梁跟部由重力引起的剪力Q y1 = G4 + ω1 × H = 5.935(KN)计算由重力引起的弯矩M y1 = G4 × (l2 + l3) + ω1 × l12 / 2 = 45.393(KN*m)计算横梁跟部由风力引起的剪力Q x1 = F1 = 6.472(KN)计算由风力引起的弯矩M x1 = F1 × (l2 + l3) = 30.0948(KN*m)4.3横梁截面信息横梁截面积 A = 5.504 × 10-3 (m2)横梁截面惯性矩I = 2.72 × 10-5 (m4)横梁截面模量W = 3.02 × 10-4(m3)4.4计算横梁跟部所受的合成剪力和弯矩合成剪力:Q = (Q x12+ Q y12)0.5 =8.781 (KN)合成弯矩:M = (M x12 + M y12) 0.5 = 54.463 (KN*m)4.5最大正应力验算横梁根部的最大正应力为:σ = M / W = 170.939 (MPa) < [ σ] = 215.000(MPa),满足设计要求横梁根部的最大剪应力为:τ = 2 × Q / A = 3.846 (MPa) < [ τ ] =125.000(MPa), 满足设计要求4.6变形验算计算垂直绕度f y= G4 / (γ 0 × γ G) × (l2 + l3)2× (3 × l1 - l2 - l3) /(6 × E × I) + ω1 / (γ 0× γ G) × l14 / (8 × E × I)= 0.0518(m)计算水平绕度f x = F wb / (γ 0 × γ Q) × (l3 + l2)2× (3 × l1 - l2 - l3) /(6 × E × I) + ω2 / (γ 0× γ Q) × l23 / (6 × E × I)= 0.0707(m)计算合成绕度f = (f x2 + f y2)0.5 = 0.0877(m)f/l1 = 0.0117 > 1/100, 不满足设计要求。
5立柱设计计算对立柱所受荷载计算如下:5.1荷载计算垂直荷载:N= γ 0 × γ G × G = 18.729(KN)水平荷载:H= F1+F2+F3 = 17.148(KN)水平弯矩:M X=(F1+F2)× (L-H/2)+F3 ×L/2 = 123.722(KN*m)立柱根部由永久荷载引起的弯矩为:M Y=2 × M y1 = 42.054(KN*m)合成弯矩:M=(M X2+M Y2)0.5 = 130.674(KN*m)风载引起的合成扭矩:M t=2×M x1 = 68.964(KN*m)5.2强度验算立柱截面信息立柱截面积: A = 9.269 × 10-3 (m2)立柱截面惯性矩:I = 9.594 × 10-5 (m4)立柱截面模量:W = 6.617 × 10-4 (m3)立柱截面回转半径模量:R = (I/A) 0.5 = 0.102(m)立柱截面惯性矩模量:Ip = 2 × I = 1.92 × 10-4(m4)最大正应力验算轴向荷载引起的正应力:σ c=N/A = 2.021(MPa)弯矩引起的正应力:σw= M/W = 197.496(MPa)组合应力:σMax = σc+σw = 199.516(MPa)立柱根部的最大正应力为:σ = M / W = 197.496 (MPa) < [ σ] = 215.000(MPa), 满足设计要求最大剪应力验算水平荷载引起的剪应力:τ Hmax=2× H/A = 3.70(MPa)扭矩引起的剪应力:τ tMax= M t×φ /(2× I p) = 56.428(MPa)组合应力:τ Max = τ Hmax+ τ tmax = 60.128(MPa) < [τ ] =125.000(MPa), 满足设计要,危险点处应力验算最大正应力位置点处,由扭矩产生的剪应力亦为最大,即σ = σ Max = 199.516 (MPa) ,τ = τ tMax = 56.428(MPa)根据第四强度理论的组合应力为:σ4 = = (σ2+3×τ 2)0.5=207.432 (MPa) < [ σ] =215.000(MPa), 满足设计要求变形验算由风荷载标准值引起的立柱顶部的水平位移:23f p =(F1+F2)×(L-H/2)2×(3×L-H)/(γ 0 × γ Q× 6× E×I)+F3× L3/(γ 0 × γ Q×8×E×I)= 0.1012(m)立柱端部的相对水平位移为:f p/L = 0.0127 >1/100, 不满足设计要求立柱顶部扭转角:θ =M t×h/(γ 0 × γ Q× GI p) = 2.79×10-2(rad)标志结构最大总水平水平位移:f =f x+f p+θ×l1 = 0.382(m)标志结构最大相对水平位移为:f p/L = 0.0477 >1/60, 不满足设计要求6立柱与横梁的连接计算6.1螺栓强度验算连接螺栓拟采用高强螺栓6 M 20 , 查表得:单个螺栓受拉承载力设计值N tb = 124 KN , 受剪(单剪)承载力设计值N vb = 55.8KN :合成剪力Q = 9.438 KN , 合成弯距=40.388KN*m :螺栓孔数目 6 :每个螺栓所受的剪力N v = 1.573 KN ,螺栓1 : y1=0.190(m)螺栓2 : y2=0.190(m)螺栓3 : y3=0.00(m)螺栓4 : y4=0.00(m) 螺栓5 : y5=-0.190(m)由各y 值可见,y1 距旋转轴的距离最远,其拉力N max=M b×y1/(∑yi2)=53.289KN< N tb= 124(MPa), 满足设计要求0.9n fμ( nP-1.25∑ N ti) =0.9×1×0.4( 6× 155-1.25×53.289×2+1.25×53.289× 2) =338.4KN>Q=9.438KN, 满足设计要求7柱脚强度验算7.1受力情况铅垂力G= γ 0×γ G×G=1.00×0.90×15.608 = 14.047(kN)水平力F=17.148(kN)合成弯距M=130.674(kN)扭距M=68.964(kN)7.2底板法兰盘受压区的长度X n偏心距e=M/G=130.674/14.047=9.303(m)法兰盘几何尺寸:L=0.800(m) ; B=0.800(m) ; Lt=0.120(m)基础采用C25 砼,n=E s/E c=210000.00×106/28000.00× 106 = 7.5地脚螺栓拟采用8 M 30 高强螺栓受拉地脚螺栓的总面积:A e = 3 × 5.606× e-4= 16.818×10-4(m2)受压区的长度Xn 根据下式试算求解:X n3 + 3×(e-L/2)×X n2–6×n×A e×(e+L/2-L t)×(L-L t-X n) = 0 式中: e = 3.13(m)L = 0.80(m)B = 0.80(m)n = 7.5A e = 16.82 × 10-4(m2)L t = 0.12(m)求解该方程,得X n = 0.1227(m)7.3底板法兰盘下的混凝土最大受压应力σc = 2 × G × (e + L/2 - L t) / (B × X n × (L - L t -X n/3))= 5.351(MPa) < β× f cc = 10.02(MPa), 满足设计要求。