加強箱型結構物之系統可靠度分析

System Reliability Analysis of A Box Girder

楊澤民(J. M. Yang) ； 張士祥(S. S. Chang)

《中國造船暨輪機工程學刊》 21卷2期 (2002/05) Pp. 117-125

https://doi.org/10.29982/JTSNAME.200205.0004

摘要

在具有高度不確定性與複雜性的海洋環境中，以極限強度與系統可靠度為基準的分析方法是評估結構安全性較佳的方法。過去以桁架結構為主來進行系統可靠度分析的研究其所分析的破壞模式較為單純，不能掌握許多其他形式的破壞模式，因此在安全性的考量上並不適用於以板架為主的船舶結構上。故本研究是以典型的加強平板箱型結構為主要分析模型來進行系統可靠度分析，其中是以極限強度與結構可靠度理論之高等一階二次矩法為基礎，再配合系統可靠度方法與有限元素分析MSC/NASTRAN來求得結構物的破壞機率，最後求取結構物之系統可靠度。

關鍵字

結構系統可靠度 ； 破壞路徑 ； 破壞機率 ； 可靠度指標

並列摘要

Structural system reliability based on ultimate strength analysis is more favorable in assessing the safety of ship structures due to the high degree of indeterminacy and the complicated marine environment. In the past, most of the structural system reliability studies were performed for framed structures with simple failure modes. However, such studies are not applicable in ship structures since the failure modes are much more complicated in present investigation. The typical stiffened box structures are examined in this study to do the system reliability analysis.
The main objective of this project is to evaluate structures with the system reliability analysis. Based on the ultimate strength analysis and the advanced first order second moment (AFOSM) reliability method, the system reliability index or the probability of failure of a structure can be obtained. In this research, the β- unzipping method, the Ditlevsen’s bounds method and the finite element analysis (MSC/NASTRAN) are used to find the bounds of the probability of failure of structures.

並列關鍵字

Structural System Reliability ； Failure Path ； Probability of Failure ； Safety Index