By simplifying the A-shaped derrick as a detendnatestmctUre, the fuzzy reliability of the struclure is caIculated by using a series-to-parallel system model.

• 在求得井架各杆强度普通可靠度的基础上，将整个A形井架简化为一静定结构，采用混联系统模型计算其结构模糊可靠度。