1、求AC段剪力和弯矩
Fs1=FAy=15kN
M(x)=FAy·x=15x (0<=x<=2)
Mmin=0,Mmax=30
2、求CD段剪力和弯矩
Fs2=FAy-Fs=5kN
M(x)=FAy·x-Fs(x-2)=5x+20 (2<=x<=4)
Mmin=30,Mmax=40
3、求DB段剪力和弯矩
Fs3=FAy-Fs-q(x-4)=25-5x (4<x<8)
Fsmin=-15,Fsmax=5
M(x)=FAy·x-Fs(x-2)-M-[q(x-4)^2]/2=5x-[q(x-4)^2]/2
当x=4时,M=20kN·m
当x=5时,Mmax=22.5kN·m
当x=8时,Mmin=0