内科大材料力学习题解答04弯曲内力

BaBaM=qa2P=qaCaA1DB2211ACQ1P=qaqP=qaqBaCP=200N3D11ACB222 CDB八2M=qa2P=qaA11Q1=P+qa=2qaCaCaBM=qa2P=qaM2RDARAP=200N3D11CB2RA=100NM1=_RA×0.2=_Q2=_RA=_100NM2=_RA×0.4=_40Nm=P=200NM2=_P×0.2=_40NmDB2RA200200200RB11ACΣMA=0ΣMB=0RB=2667NM2DBRBQ2=_RB+q×0.2=_0.667NM2=RB×0.2_(q×0.2)×0.1=333.4N.mM=M=qa2P=qaACDBRCRD221ΣMD=0RC×a+q×a×1.5a_M_P×a=0Q1=_qaM1=_qa×qa2AM2求内力RCM2=_RC×a_(q×a)(2)作剪力图和弯矩图；(3)判定lQlmax和lMlmax。22PM0=PaBC22PDPBaqqCBqqBqqCBqqqBCMM0A2M0BCPP6PCaB(f)qq=30kN/mP=20kNq=30kN/mCDEBAAAaCBqaaaAA/CaaA/ACaAAADaaAA/CaaA/ACaAAADaa22PCxMAARAM0=PaBΣY=0RA_2P=0RA=2PΣMA=0MA_2Pa+M0=0MA=PaQxMPa PaQmax=2PMmax=PaAACxBRBMBqΣY=0RB_qa=0RB=qaΣMB=0_MB+qa×1.5a=0xxQMMPP2PRBRB22RADABCaΣ030MRaPaPaBAΣ030MRaPaPaBAΣΣAB xxMxMxx22mCaABCaABRARBm5ΣMB=0_RA×2a+m+2m=0ΣY=0RA_RB=0xM xqqCARABRBΣMB=0_RA×aQxM2222x(f)RRCRBDaPCaBaAΣMB=0P×3a_RC×2a+6P×a=0ΣY=0RC+RB_P_6P=0PxQMMxPaC/C/RCAqqaRBaRBBΣMB=0_RC×axM2222xqq=30kN/mP=20kNq=30kN/mCDEBRCREARC=40kNΣY=0RE=40kNQxMxxQmax=30kNMmax=15kNmCCAqBMBRBqΣMB=0qa×a_qaa_MB=0BM=qa2BΣY=0RB_qa+qa=0RB=0QxQxMxMx2Qmax=qaMmax=qa2QxM2xQmax=qaMmax=qa2ddPPlARABRBxQxMMmaxMxxQxMMmaxMxxNNDBCAACACqBDDDRAHRAVRDABCMB=5kNΣX=01×4_RAH_1=0RAH=3kNΣY=0RAV_8+RD=0RAV=3kNNN’CM’CBCM’BN’BMCNCDDRDRAHARAVAAB杆ΣX=01×4_RAH_QB=0ΣY=0RAV_NB=0NB=3kNMB=4kN.mBC杆N'B=QB=1kNQ'B=NB=3kNM'B=MB=4kNmΣX=0N'B_NC=0NC=1kNQC=kNΣMC=0_M'B_Q'B×3+8×2_MC=0MC=3kN.mkMBMBNBBqqAMARADNCMCAMARAΣY=0RA_NC=0ΣMA=0MC_MA=0qqM’CDN’C2CC4CC4N=N'=qaMCC4CC4CCπ/4OP