鋼結構優(yōu)質(zhì)課程設計21米梯形屋架

1、21m跨徑簡支梯形鋼屋架設計（有檁）一、設計資料廠房跨度為21m,長度為108m，柱距為12m，簡支于鋼筋混凝土柱上，屋面材料為長尺 壓型鋼板，屋面坡度為i=1/10，采用軋制H型鋼檁條，水平間距自定，雪荷載為s=0.25 KN/m2，不考慮風壓。鋼材采用Q235B，焊條采用E43型，混凝土標號為C20。1、屋面荷載原則值：屋架及支撐自重0.117+0.11L=0.117+0.011*21=0.348 KN：M2壓型鋼板0.15* 10/10 =0.151 KNM2檁條（約 0.5KN/M，間距 1.5m）0.333 KN M2恒荷載總和0.832 KNM2雪荷載0.25 KNM2 （不不小于

2、0.5，取屋面活載0.5KN：M 2）積灰荷載0.6 KNM 2活載總和1.1 KNM 22、屋架計算跨徑：10 = L - 2 x 0.15 = 21 - 2 x 0.15 = 20.7m。3、屋架形式及圖示如圖1：二、荷載與內(nèi)力計算2.1、荷載計算根據(jù)荷載規(guī)范，屋面活荷載與雪荷載不會同步浮現(xiàn)，取兩者較大值計算。屋面荷載匯總：表1屋面荷載匯總荷載類型荷載名稱荷載原則值永久荷載D總計0.832 kN/m2可變荷載雪荷載L1.1 kN/m22.2、荷載組合節(jié)點荷載設計值按可變荷載效應控制日勺組合F = (1.2X 0.832 +1.4 X 0.5 +1.4 x 0.9 x 0.6) x 1.5

3、x 12 = 44.1792 KNM 2其中永久荷載日勺分項系數(shù)Yg4.2，屋面活載或雪荷載載荷分項系數(shù)yg1 4.4 ,組合只設計值平.7 ，積灰荷載 y = 1.4 中=0.9按永久荷載效應控制勺組合F = (1.35x0.832 +1.4x0.5x0.7 +1.4x0.9x0.6) x1.5 x12 = 42.6456 KNM2其中永久荷載勺勺分項系數(shù)Yg 4.35，活荷載勺分項系數(shù)ye14.4，故節(jié)點荷載取44.1792 KNM2,支座反力 R=7F = 309.2544 KNM2。2.3、內(nèi)力計算屋架在上述荷載組合伙用日勺計算簡圖4所示，用軟件求得在F=44.1792 KN：M2作用

4、下屋架各桿日勺內(nèi)力入圖4所示。內(nèi)力計算桿端內(nèi)力值（乘子二1）桿端1桿端2單元碼軸力剪力彎矩軸力剪力彎矩-1182.4341080.000000000.00000000182.4341080.000000000.000000002433.1383420.000000000.00000000433.1383420.000000000.000000003531.3663410.000000000.00000000531.3663410.000000000.000000004522.4829350.000000000.00000000522.4829350.000000000.000000005522

5、.4829350.000000000.00000000522.4829350.000000000.000000006531.3663410.000000000.00000000531.3663410.000000000.000000007433.1383420.000000000.00000000433.1383420.000000000.000000008182.4341080.000000000.00000000182.4341080.000000000.000000009-22.08960000.000000000.00000000-22.08960000.000000000.00000

6、000100.000000000.000000000.000000000.000000000.000000000.000000001112131415161718192021222324252627-332.2647380.000000000.00000000-332.2647380.000000000.00000000-332.2647380.000000000.00000000-332.2647380.000000000.00000000-500.4647910.000000000.00000000-500.4647910.000000000.00000000-500.4647910.00

7、0000000.00000000-500.4647910.000000000.00000000-540.9023010.000000000.00000000-540.9023010.000000000.00000000-540.9023010.000000000.00000000-540.9023010.000000000.00000000-540.9023010.000000000.00000000-540.9023010.000000000.00000000-540.9023010.000000000.00000000-540.9023010.000000000.00000000-500.

8、4647910.000000000.00000000-500.4647910.000000000.00000000-500.4647910.000000000.00000000-500.4647910.000000000.00000000-332.2647380.000000000.00000000-332.2647380.000000000.00000000-332.2647380.000000000.00000000-332.2647380.000000000.000000000.000000000.000000000.000000000.000000000.000000000.00000

9、000-22.08960000.000000000.00000000-22.08960000.000000000.00000000-340.2143820.000000000.00000000-340.2143820.000000000.00000000256.9550550.000000000.00000000256.9550550.000000000.00000000123.2628050.000000000.00000000123.2628050.000000000.00000000-44.1790.000000000.00000000-44.1790.000000000.0000000

10、0-69.23138810.000000000.00000000-69.23138810.000000000.0000000014.20816600.000000000.0000000014.20816600.000000000.00000000-44.1790.000000000.00000000-44.1790.000000000.000000003435.41922100.000000000.0000000035.41922100.000000000.00000000350.000000000.000000000.000000000.000000000.000000000.0000000

11、03635.41922100.000000000.0000000035.41922100.000000000.00000000-44.1790.000000000.00000000-44.1790.000000000.0000000014.20816600.000000000.0000000014.20816600.000000000.00000000-69.23138810.000000000.00000000-69.23138810.000000000.00000000-44.1790.000000000.00000000-44.1790.000000000.00000000123.262

12、8050.000000000.00000000123.2628050.000000000.00000000-194.8902860.000000000.00000000-194.8902860.000000000.00000000-44.1790.000000000.00000000-44.1790.000000000.00000000三、桿件截面選擇腹桿最大內(nèi)力340.21KN （壓），由屋架節(jié)點板日勺厚度參照表7.4可知，支座節(jié)點板日勺厚度取12mm，中間節(jié)點板厚度10mm。3.1上弦整個上弦不變化截面，按最大內(nèi)力計算N =-540.90KN , l = 150.8cm, l = 300c

13、m.=3.35cmi = 4.96 cm選用 2L110X 12=3.35cmi = 4.96 cmxX = X = lx =如=45 x i3.35=-ox =中廣0.807 中廣0.807 (b類)=108.20mpa215mpa人=-y =3。 60 人=150y i 4.96V雙角鋼T型截面繞對稱軸（y）軸應按彎扭屈曲計算長細比人yz11 = 9.17 性=爵8X 300 =15.8 t 1.2b 110.475b 4)故Xmax =Xy = 63，按b類附表查中=0.791N540.9 x103b =甲 A 0.791 x 63.2 X102填板每個節(jié)間放一塊（滿足l范疇內(nèi)不少于兩塊

14、）l = 75.4 40i = 40 x3.35 = 134cm3.2下弦整個下弦桿采用同一截面，按最大內(nèi)力計算N =531.37KN l = 300cm婦=1050cm連接支撐日勺螺栓孔中心至節(jié)點邊沿日勺距離約為100mm，可不考慮螺栓孔削弱。選用 2L125x80X10 （斷肢相并）A=39.4cm2 i = 2.26cm = 6.11cm人=Lox = 3 =132.7 人=350 x i 2.26人=oy = 171.8 x =350y i 6.11y=134.87mpa215mpaN _ 531.37 x 103 元 _ 39.4 x102=134.87mpa215mpa填板每個節(jié)間放一塊 l = 150 80i = 80 x 3.98 = 318.4cm3.3斜腹桿(45)桿 N=-340. 21KN I = 251.8cm I =0.8/ = 201.44cm oyoxoy選用 2L110 x70 x8 (長肢相并)A=27.8cm2 i =3.51cm i = 2.92cm xy. I201.44 e a 1X = ft = 57.4 Ay故由人 按b類截面查表4.2日勺P =0.64