压型钢板屋面板计算

屋面板的验算

屋面材料采用压型钢板,檩条间距为0.9M, 设计活荷载0.75KN/M2, 恒载0.2KN/M2， 基本风压2.59 KN/M2，

选用830型PU发泡板,板厚0.426mm, 截面形状及尺寸见: W x=4.02Cm3=4020mm3

I x=7.98Cm4=79800mm4 分析:

(1)内力计算: 压型钢板采用单波线荷载 q x1=0.75KN/m2 x1mx1.5=1.125KN/m q x2=2.59KN/m2 x1mx1.5=3.885KN/m q x=0.2KN/m2x1m x1.35=0.27KN/m

q=1.125KN/m+3.885KN/m+0.27KN/m=5.28KN/m 按简支梁计算压型钢板跨中最大弯距 M max=1/8qL2

=1/8 x 5.28KN/M x( 0.9m)2=0.594KN.M (2)截面几何特性

由830型PU发泡板,板厚0.426mm得知: W x=4.02Cm3=4020mm3 δ=M max/W x

=0.594kN.M/4020mm3

=0.594x103x1x103mm/4020 mm3 =147.76N/mm2<[w]=215N/mm2 满足要求 (3)强度验算 (a)正应力验算 δ= M max/W x

=0.594KN.M/79800mm3=74.436N/mm2<[w]=215N/mm2

满足要求

(b)剪应力验算 V max=1/2qL

=1/2 x 5.28KN/m x 0.9m=2.376KN (c)腹板最大剪应力: δ=V/∑ht

= 2.376KN x 103/( 2 x25mm x 0.5mm) =2.376 x 103 / (2 x 25 x 0.5)

=95.04N/mm2 < [ f ]=120N/mm2 满足要求 (4)钢度验算

按单跨简支板计算跨中最大挠度 W max=5q x L4 / 384EI x

=5 x 0.27KN/N /1.4 x 0.9M x 1012 / (384 x 2.06 x 105 x79800 mm4)

=0.13mm < [w] = L/300 = 3.4mm 满足要求 通过以上计算,可知满足设计要求.