结构力学9影响线ch93习题讲解

取整体为研究对象，35/12+BEC3m2m2m3mP=1ADx作NCD影响线6-2习题课BEC3m2m2m3mP=1ADx作ME影响线当P=1位于E左侧时，当P=1位于E右侧时，20,224££=×=xxxMEMEMEBEC3m2m2m3mP=1ADx20,2££=xxME1+-BEC3m2m2m3mP=1ADxMC影响线-3P=1在C以右，MCMC=0P=1在C以左，xP=1MCBEC3m2m2m3mP=1ADxVC右影响线13/4++P=1位于C以左，VC右P=1位于C以右时，P=1xVC右BEC3mP=1ADBECP=1ADx机动法BEC3mP=1ADBECP=1ADBEC3mP=1ADBECP=1ADBEC3mP=1ADBECP=1AD++6-11MD，VC，MC3ddd2d2dDP=1CxDP=1CxMD3ddd2d2dDP=1Cx-3dDP=1Cx0

P=1CxP=1CxDP=1Cx-12/3DP=1Cx-5d2d/3VEEFDCVF6-18MCVC右ADnVA2m1m1m3m6/51/5+6-191/5ADnxP=16-19Vn右Mn右VAADnxP=1MDADnxP=1P=1Vn右Mn右VAADnxP=1P=1MDADnP=1xVn右Mn右VAADnP=1xMD6-19ADn2m1m1m3mVA6/51/5+MD1/56/5VD左7/157/15Vn右7/157/15+++---6-31x12DCN1，N2，MDN1xyx12DC+--x12DCMDCN2N1MDCN2N1P=1d/23d/2-6-40车队左行51010601201204.33由于对称，右行与左行相同0.50.560601201200.30.230.50.560601201200.30.43左行0.50.560601201200.230.43Vmin=-60×0.23-120×(0.5+0.43)=-125.4kN左行0.50.560601201200.230.43VCmax=60×0.23+120×(0.5+0.43)=125.4kNMCmax=1296kNmMCmin=185kNmVcmax=125.4kNVcmin=-125.4kN右行车队右行3.756012012010m15m不取极值70130601201204m10m4m1.4m15m13015m701303.756012012010m0.753.40.9701303.756012012010m70130不取极值0.256012012010m15m0.750.550.48车队右行60kN轴重在D左侧0.256012012010m15m0.750.680.180.0570第一个120kN轴重在D左侧0.25

6012012010m0.750.180.2570V=120×(0.18+0.25)-70×0.25=34.1kN车队右行第2个120kN轴重在D右侧MDmax=966VDmax=34.1VDmin=-181.23.75车队左行6012012010m15m3.42.43.756012012010m15m3.42.4不取极值0.25车队左行6012012010m15m0.750.550.18Vmax=120×(0.25+0.18)-60×0.55=51.6kN0.25车队左行6012012010m15m0.750.48Vmin=-120×(0.75+0.68)-60×0.48=