Methods for ultimate limit state assessment of ships and ship-shaped offshore structures: Part III hull girders

This paper summarizes results from a Canadian Standards Association (CSA) sponsored study of the uncertainties associated with extreme (1000 to 10,000-yr return periods) environmental loadings acting on offshore structures (Bea, 1991). The evaluations of the loadings addressed loading effects that resulted from dynamic and nonlinear interactions of the structures. Loading uncertainties were organized and characterized in two categories: 1) inherent randomness (aleatory uncertainty), and 2) analytical variability (epistemic uncertainty). The study addressed the global ultimate limit state performance of three structures designed according to the provisions of the draft CSA guidelines (1989a, 1989b) for offshore structures: 1) a concrete Gravity Base Structure (GBS) located off the East coast of Canada (Hibernia), 2) a steel pile template located on the Scotian Shelf off Sable Island, and 3) a caisson retained island located in the Mackenzie Delta area of the Beaufort Sea (Amuligak). The results of this study indicate that, based on presently available information and data, it is often not possible to develop unambiguous characterizations of uncertainties. The different technical communities that background environmental conditions and forces (storms, earthquakes, ice) recognize and integrate these uncertainties into loading characterizations in different ways. In many cases, major sources of uncertainty are not included in probabilistic characterizations. Because of the needs for design code information sensitivity and consistency in demonstrating compliance with target reliability goals, there is a need for well-organized and definitive evaluations of uncertainties in extreme environmental loadings and load effects (Bitner-Gregersen et al., 1993).

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Ultimate Limit State Assessment of Timber Bolt Connection Subjected to Double Unequal Shears

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/245/2/022083 ◽

2017 ◽

Vol 245 ◽

pp. 022083

Author(s):

Josef Musilek ◽

Jan Plachy

Keyword(s):

Limit State ◽

State Assessment ◽

Ultimate Limit State ◽

Bolt Connection ◽

Ultimate Limit

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Some recent developments on ultimate limit state design technology for ships and offshore structures

Ships and Offshore Structures ◽

10.1533/saos.2006.0110 ◽

2006 ◽

Vol 1 (2) ◽

pp. 99-116 ◽

Cited By ~ 20

Author(s):

J. K. Paik ◽

A. K. Thayamballi

Keyword(s):

Limit State ◽

Offshore Structures ◽

Ultimate Limit State ◽

Design Technology ◽

Limit State Design ◽

Recent Developments ◽

Ultimate Limit State Design ◽

Ultimate Limit

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Estimation of Ultimate Limit Statefor Stiffened-Plates Structures: Applying for a Very Large Ore Carrier Structures Designed by IACS Common Structural Rules

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.249-250.1012 ◽

2012 ◽

Vol 249-250 ◽

pp. 1012-1018

Author(s):

Hung Chien Do ◽

Wei Jiang ◽

Jian Xin Jin

Keyword(s):

International Association ◽

Limit State ◽

Offshore Structures ◽

Biaxial Compression ◽

Stiffened Plates ◽

Ultimate Limit State ◽

Ship Structures ◽

Structural Rules ◽

Common Structural Rules ◽

Ultimate Limit

In advanced marine industry, the reduction in weight of hull structures for a very large object ship plays an important role as the economic efficiency is the most significant aspect. In this paper, we investigate the ultimate strength of structural ship stiffened-plates designed by International Association of Classification Societies (IACS) Common Structural Rules (CSR) methods of collapse state, by applying for ANSYS nonlinear finite element analysis (FEA). Specifically, the ultimate limit assessment methods for the outer bottom of ship structures, which have drawn a significant attention from industrial marine and offshore structures, are proposed to reduce the weight of ship structures. To solve this, we study the structures of a hypothetical Very Large Ore Carrier (VLOC) designed by pre-CSR and CSR methods. In particular, the stiffened-plates under the biaxial compression and lateral pressure loads with simply supported or/and clamped boundary condition(s), the results ultimate limit state assessment performance of Nonlinear FEA methods are shown and compared to various states.

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