(f)lg max=30kn M max=15kn?7m (g)LOmax=ga M max=ga2/2 10kN 15kN-m 5kNm 1SkN- m (h) g max= ga 1max=ga OA=RA=qaL, OB=qa/2, 0c=0A-ga=-ga2: MA=O, MC=MA+0. 5(ga2-ga2)=0 M=M4+0.5X(q2+0)Xa2=qa2/8; M 5.设梁的剪力图如图所示,试作弯矩图及载荷图。已知梁上设有作用集中力偶 q=lkN/m 4kN 3kN 3kN kN5 x M - 15kN m. 15kN m. 5kN m. 3kN 1kN 3kN 1kN A B C D 2m 2m 4m Q x (f) Q kn max 30 = M kn m max 15 = ? （g）Q max = qa  M  max = qa2 /2 (g) Q qa max = 1 2 max 2 M qa = (h) max 2 qa Q = 1 2 max 8 M qa = QA=RA=qa/2, QB =qa/2, QC=QA – q.a = - qa/2; MA=0, MC =MA +0.5(qa/2-qa/2)=0 MF=MA+0.5×(qa/2 + 0)×a/2 = qa2 /8; 5. 设梁的剪力图如图所示，试作弯矩图及载荷图。已知梁上设有作用集中力偶。 (a) Q x - - + + 30kN 10kN 30kN 10kN - qa x Q - qa /22 2 qa /2 2 qa /2 + - x M qa/2 qa/2 qa/2 - + + Q x qa /82 2 qa /8 + - M x 3kN 3kN 2kN 4kN q=1kN/m