取整体:拍拆
∑Fx=0 NAx-Fcosθ+NDx=0 --- (1)
∑Fy=0 NAy-Fsinθ+NDy=0 --- (2)
∑MA=0 M'-Fsinθ.L-M+NDx.2L+NDy(2L+L.tagφ)=0 --- (3)
取CD:
∑Fx=0 NDx-NC.sinφ=0 --- (4)
∑Fy=0 NDy+NC.cosφ=0 --- (5)
∑橘贺腔MD=0 -M+NC.sinφ.2L=0 --- (6)
代入已知数据联立解以上6个方程可解6个未知约束力。如结果为负,则该约束力方向与所设相反。圆衫