8.5MP 13.9MP (A) X ()「□∞ 好11-6 ∑M F 15k N 830°=26kN ∑F1=0, FBx=26k N ∑F=0 5kN (2)内力分析 分别绘出轴力图和弯矩图,得危险截面D处的轴力和弯矩分别为图 11-6 M A = 0 , 0 2 − = l FByl F 15 2 = = F FBy ｋＮ 26 30 15 = = =  tg tg F F By By  ｋＮ Fx = 0， FBx = FBx = 26 ｋＮ Fy = 0， FAy = P − FBy = 15 ｋＮ （2）内力分析 分别绘出轴力图和弯矩图，得危险截面Ｄ处的轴力和弯矩分别为