The thesis considers 3 kinds of imperfection forms: the welded-joint imperfection, the consistent mode imperfection and the randomimperfection.
全文对筒仓引入了3种缺陷，即周圈焊缝凹陷缺陷、一致模态缺陷和随机缺陷。
2
The initial imperfection and the strength parameters are considered as random variables. Ply-level failure probability is evaluated by the first order reliability method.