7.弯曲变形PPT课件

2021/6/71弯曲变形弯曲变形2021/6/722021/6/732021/6/74OB2021/6/75OBA）（xfy 2021/6/76OB2021/6/77tgdxdytg)()(xfdxdyxdxdyOB2021/6/78EIxMx)()(123222dd1dd)(1xyxyxEIMxy22dd2021/6/79ZEIxMxfxdyd)()(22 00dd22Mxw,00dd22Mxw,EIMxw22ddEIMxw22dd2021/6/710：梁的弯曲方程xM 1CdxxMxfEIxEIZZ 21CxCdxdxxMxyEIZZEIxMxfxdyd)()(22 2021/6/711程代入挠曲线近似微分方)()(xlPxM)()()(xlPxMxyEIZ 122)(CPxPlxxEIZ213262)(CxCPxPlxxyEIZ2021/6/71200000012CxCyx，；，)2(1)(2PxPlxEIxZ122)(CPxPlxxEIZ213262)(CxCPxPlxxyEIZ)62(1)(32PxPlxEIxyZmaxmax、，ylxZZEIPlyEIPl323max2max、2021/6/713qABLxmaxA似微分方程：代入挠曲线近maxBmaxy22121)(qxqlxxMqlxqxxMxyEIZ2121)()(2 1234161)(CqlxqxxEIZ2134121241)(CxCqlxqxxyEIZ2021/6/714qABLxmaxAmaxBmaxy1234161)(CqlxqxxEIZ2134121241)(CxCqlxqxxyEIZ000ylxyx，；，)46(241)(323qxqlxqlEIxZ)2(24)(323xlxlEIqxxyZmax0，lxxZEIql243maxmax2ylx，ZEIqly38454max240312qlCC2021/6/715maxymaxAmaxB）段：（20lxAC）段：（lxlCB2PxxM21)()2(21)(lxPPxxMPxxyEIZ21)(PxlxPxyEIZ21)2()(2021/6/716PxxyEIZ21)(PxlxPxyEIZ21)2()(12141CPxEIZ1131121DxCPxyEIZ222241)2(2CPxlxPEIZ22332121)2(6DxCPxlxPyEIZ右左右左，CCCCyylx22121DDCC00Ayx，0Bylx，021DD16221PlCC2021/6/717)416(1221PxPlEIZ1641)2(212222PlPxlxPEIZ)1216(1321PxxPlEIyZ16121)2(612332xPlPxlxPEIyZmax0，lxxZEIPl162maxmax2ylx，ZEIPly483max2021/6/718EIPly33maxEIPl22maxEIMly22maxEIMlmaxEIql63maxEIqly84maxEIMlEIMl63、ZEIPl162maxZEIPly483maxZEIql243maxZEIqly38454max2021/6/7192021/6/72021BBByyy21BBB2021/6/72113113EIPly 12112EIPl2021/6/72223223EIPly22222EIPl21221222EIlPlly 2213)(EIlPl222132)(EIlPly2121133)(EIllPlly 2021/6/723）（）（33221yyyyyy 3212021/6/724P1y2yqLqABPCmaxyqcPcCyyyEIqlEIPly384548432021/6/725EIPay331aEIlPaayB3)(2)(32laEIPayEIlPaEIPayyy3323212021/6/726maxmaxy2021/6/727EIlPB16222EIalPayBC162222EIalPB311)(3211laEIaPyC2021/6/728EIalPEIalaPyyyCCC163222121）（EIlPEIlaPBB163221216102.6Cy5103.454100.410lyC310B46441088.164mdDI）（2021/6/729EIlyn系数荷载2021/6/7302021/6/731q2021/6/732EIPly33maxEIPl22maxEIMly22maxEIMlmaxEIql63maxEIqly84maxEIMlEIMl63、ZEIPl162maxZEIPly483maxZEIql243maxZEIqly38454max2021/6/733qllABC（静定基）2021/6/734qCR（相当系统）（静定基）qCR0）（）（CRcqcyy2021/6/735qCRqCR（相当系统）（静定基）0）（）（CRcqcyyEIlREIlRyCCRCC648233）（）（EIqlEIlqyqC245384)2(544）（0624534EIlREIqlCqlRC45qlRRBA832021/6/736BCBLyEIlREIqlyyyBRqBB3834EAlRLBBC)2(2021/6/737BCBLyEAlREIlREIqlBB)2(3834)32(4323IAlAqlRB2021/6/738EIqlEIlqy1288)2(4412021/6/739EIqlEIlqy1288)2(441EIlqlEIlqlyyyMP2)2(83)2(222322)2(82)2(2(2)(223lEIlqlEIlqllyMPEIqly3844142021/6/7402021/6/741叠加法应用于弹性支承与简单刚架 用叠加法求AB梁上E处的挠度 wEwE 1wE 2BwB=?wE=wE 1+wE 2=wE 1+wB/22021/6/742wB=wB1+wB2+wB32021/6/743叠加法斜弯曲梁的位移=yzFFPPtanyzwwtan2021/6/7440By03)2(2)2)(3)2(323EIaREIaPaEIaPBPRB472021/6/745EIPaEIaRaEIaREIaPyBBc653)2(2)2(3)3(3323PaMmax62maxmax1016061bhPaWMZKNP4.62021/6/74651292maxqaM右左BByyEIaREIqayBB3834左EIaRyBB33右163qaRB1631613qaRqaRCA，2021/6/747BCBCLyyEIREIRPyBBC32484)(332021/6/74833450101851066.118mmWmINZZ：EIREIRPyBBC32484)(33KNRB10mmEIRPyBC03.8484)(3mKNMGDAB.20max梁：、MPaWMZ108maxmaxMPaAN8.31max杆：2021/6/749)()(DCCABCyy)2(3)2(2)2(23)2)(323EIlREILPlEIlRPCCPRC352021/6/750EIlPEIMl2)2(2lMP8EIMlEIMlEIlPlEIlPyc323)2(22)2(22322021/6/7511313EIPay 22)(EIabPay222)(EIbPax)3(21221IbIaEPayyy2021/6/752 2021/6/753 2021/6/754 2021/6/755 2021/6/7562021/6/757 2021/6/758naxnax)(0)(ax)(ax 2021/6/759xaxndd1)(naxn0)(ax)(ax xaxnd0)(ax)(ax Caxnn1)(112021/6/760集中力偶作用的情形0)(iiiaxMMM弯矩方程的奇异函数表示j1PP)(jjjbxFFM集中力作用的情形221)(kkkcxqMq均布力作用的情形2021/6/761 弯矩方程的奇异函数表示1q2qP1FP2FP3F一般情形0)(iiaxMxM1jPjbxF221kkcxq2021/6/762例题1（1）弯矩方程（只需考虑左端约束力3FP/4 和载荷FP)0(41lxlxFP1043xFP)(xM（2）挠度微分方程22dxwdEI)(xMxFP4314lxFP用奇异函数确定加力点的挠度和支承处的转角用奇异函数确定加力点的挠度和支承处的转角已知：已知：FP、EI、l（3）微分方程的积分（4）利用约束条件确定积分常数ClxFxFEIdxdwEIPP224283DCxlxFxFEIwPP334681212870)(00)0(lFClwDwP2021/6/763（5）挠度与转角方程xlFlxFxFEIxwlFlxFxFEIxPPPPPP233222128746811)(128742831)(EIlFlwwEIlFlEIlFPBPCPA3222563)4(1285)(1287)0(部分资料从网络收集整理而来，供大家参考，感谢您的关注！