梁碳纖維加固計(jì)算書

碳纖維梁加固計(jì)算書項(xiàng)目名稱構(gòu)件編號(hào)日期設(shè)計(jì)校對(duì)審核一、基本資料1.設(shè)計(jì)依據(jù)：《碳纖維片材加固混凝土結(jié)構(gòu)技術(shù)規(guī)程》(CECS146:2003)(以下簡(jiǎn)稱規(guī)程)《混凝土結(jié)構(gòu)設(shè)計(jì)規(guī)范》(GB50010—2002)(以下簡(jiǎn)稱規(guī)范)問題類型：根據(jù)碳纖維片材求承載力截面參數(shù)：截面寬度：b=300.00mm截面高度：h=500.00mm受拉鋼筋面積As=1017.88mm2受拉鋼筋合力點(diǎn)至截面近邊緣的距離a=25.00mm受拉筋:HPB235(Q235),受拉筋抗拉強(qiáng)度設(shè)計(jì)值fy=210.00N/mm2受壓鋼筋面積A；=0.00mm2受壓鋼筋合力點(diǎn)至截面近邊緣的距離a，=20.00mm受壓筋:HPB235(Q235),受壓筋抗拉強(qiáng)度設(shè)計(jì)值f\=210.00N/mm2混凝土：C15軸心抗壓強(qiáng)度設(shè)計(jì)值fc=7.2N/mm2軸心抗拉強(qiáng)度設(shè)計(jì)值f=0.91N/mm2軸心抗拉強(qiáng)度標(biāo)準(zhǔn)值fk=1.27N/mm2梁底受拉碳纖維片材參數(shù)：彈性模量Ecf=1.40x105MPa抗拉強(qiáng)度標(biāo)準(zhǔn)值fcfk=2000.00MPa粘貼層數(shù)ncf=1C單層厚度tcf=0.111mm梁底碳纖維片材的寬度=300.00mm梁底碳纖維片材的截面面積Acf=33.30mm2考慮二次受力，加固前計(jì)算截面上實(shí)際作用的初始彎矩必=20.00kN-m5.梁側(cè)受剪碳纖維片材參數(shù)：粘貼層數(shù)ncfv=1單層厚度tcfv=0.111mm彈性模量Ecfv=1.40x105MPa條帶寬度wcf=100.00mm條帶凈間距scf=100.00mm側(cè)面粘貼高度hcf=100.00mm

加固方式：封閉粘貼，碳纖維片材受剪加固形式系數(shù)取1.00荷載形式：集中荷載(包括集中荷載對(duì)支座截面或節(jié)點(diǎn)邊緣所產(chǎn)生的剪力值占總剪力值的75%以上的情況)，集中荷載至支座距離為600.00mm箍筋參數(shù)：箍筋直徑6mm箍筋肢數(shù)1箍筋間距150.00mm箍筋:HPB235(Q235),箍筋抗拉強(qiáng)度設(shè)計(jì)值fyv=210.00N/mm2彎起筋參數(shù)：彎起筋直徑6mm彎起筋根數(shù)0彎起角度45二、計(jì)算結(jié)果加固前構(gòu)件在初始彎矩作用下，截面受拉邊緣混凝土的初始應(yīng)變8|:考慮二次受力,8|按規(guī)程4.3.4中各式計(jì)算：1h0=h-a=500.00-25.00=475.00mmM.20.00x106Csi=As.*h0=1017.88x0.87x475.00=47.55N/mm2受拉鋼筋拉應(yīng)變不均勻系數(shù)：f1.27w=1.1-0.65e=1.1-0.65x_八=-0.179<0.2*b.p47.55x0.0136site根據(jù)《GB50010-2002》8.1.2的規(guī)定，當(dāng)<0.2時(shí)，取w=0.2。受壓邊緣混凝土壓應(yīng)變綜合系數(shù)：TOC\o"1-5"\h\z_(1+3.5丫'f)%p_(1+3.5x0.00)x9.55x0.00714_'=0.2(1+3.5yf)+6aEp=0.2(1+3.5x0.00)+6x9.55x0.00714=0.112加固前初始彎矩M.作用下受拉鋼筋的拉應(yīng)變：_wM._0.20020.00x106_8si=*,EAh^=0.87x210000.00x1017.88x475.00=0.00005ss0加固前初始彎矩必作用下受壓邊緣的壓應(yīng)變：_M._20.00x106_8ci=JE：bh2=0.112x22000.00x300.00x475.002=0.00012加固前初始彎矩M.作用下，截面受拉邊緣混凝土的初始應(yīng)變：h、500.008i=—(8ci+8si)-8ci=47500x(0.00012+0.00005)-0.00012=0.00005(4.3.2-2)碳纖維加固后混凝土受壓區(qū)高度X和受拉面上碳纖維片材的拉應(yīng)變8cf求解:根據(jù)規(guī)程(432-2.)式以及(4.3.2-3)式聯(lián)立求解：(4.3.2-2)fbx=fA-fA+Ecf8cfAcf(4.3.2-3)X=°.88cuh(4.3.2-3)8cu+8cf+8i代入數(shù)值，得7.20x300.00xx=210.00x1017.88-210.00x0.00+1.40x105x8cfx33.30

x-—°.8X0.00330—x50000x一0.00330+￡cf+0.00005X500.00解上述二元一次方程組，得x-116.23mm,￡cf-0.00800根據(jù)碳纖維加固后混凝土受壓區(qū)高度x的大小采用不同的公式計(jì)算正截面受彎承載力:碳纖維片材厚度折減系數(shù)：=0.963nffEfftff_1X1.40X105X0.111420000km=1-420000=1-碳纖維片材的極限拉應(yīng)變(參見規(guī)程=0.963420000么2000.00w￡cfu=Ecf=L40X105=0.014290.01)=min(0.963x0.01429,2X0.01)=min(0.963x0.01429,2X0.01429,0.01)=0.009522[￡cf]=min(km￡cfu,3Scfu,碳纖維片材達(dá)到其允許拉應(yīng)變與混凝土壓壞同時(shí)發(fā)生時(shí)的界限相對(duì)受壓區(qū)高度(參見規(guī)程4.3.2):_0.8￡cu_0.8x0.00330氧-￡cu+[￡cf]+Si-0.00330+0.00952+0.00005-0.21縱向受拉鋼筋屈服與受壓區(qū)混凝土破壞同時(shí)發(fā)生時(shí)的相對(duì)界限受壓區(qū)高度(根據(jù)規(guī)0.80210.00范7.1.40.80210.00=0.61一f_1+E^1+210000.00X0.00330、h0=0.61x475.00=291.63mm,f=0.21x500.00=102.50mm,2a'=2x20.00=40.00mm,x=116.23mm可見,x>f且x<事0,根據(jù)規(guī)程4.3.2-1式，加固后，其正截面受彎承載力為=0.61xM=fbx(h0-2)+廣yA's(h0-a')+Ecf￡cfAcf(h-h°)=7.20x300.00x116.23x(475.00-^^^)+210.00x0.00x(475.00-20.00)+1.40X105X0.00800x33.30x(500.00-475.00)=105.60kN-m4.側(cè)面采用碳纖維加固后，斜截面受剪承載力計(jì)算：根據(jù)4.4.1-3,達(dá)到受剪承載能力極限狀態(tài)時(shí)碳纖維片材的應(yīng)變：22￡cfv=決0.2+0.12Xb)￡cfu=3x(02+0.12x1.50)x0.01429=0.00362根據(jù)4.4.1-2,碳纖維片材承擔(dān)的剪力：Kf=中2nc*如Ehbcft(sf+wf)cfvcfvcf2x1x100.00x0.111=1.00X/10000■10000X0.00362X1.40X105X100.00=5624.00N=5.6