平面汇交力系 90 结点 N22=40 纷 60 4N=60 40kN 60kN80kN 4×3m=12m 40 V=8OkN Vo=100kN +40-80=0 结点1 ,=-80 结点 y≈40 80)×2=-60 334=40x3 =30 60 80× N,=40×=50 N12+X13=0 8040134 N2+30+60=0 N12=60 901 2 3 4 5 6 7 8 4×3m=12m 4m 40kN 60kN 80kN H=0 V1=80kN V8=100kN 一、平面汇交力系 N12 1 X13 Y13 3 5 4 结点1 80 80 Y13 = − ( ) 60 4 3 80 X13 = −  = − 100 4 5 80 N13 = −  = − N12 + X13 = 0 N12 = 60 2 40 60 N23 N24 结点2 N23 = 40 N24 = 60 3 40 60 80 N35 X34 Y34 结点3 40 40 80 0 34 34 = + − = Y Y 30 4 3 X34 = 40 = 50 4 5 40 N34 =  = 90 30 60 0 35 35 = − + + = N N 60 40 60 -90