Comparison of residual strength-grounding damage index diagrams for tankers produced by the ALPS/HULL ISFEM and design formula method

2020

J. Marine. Sci. Appl.

The objective of this work is to provide an overview of the ultimate strength assessment of ageing and damaged ship structures in the last decades. Particular attention is paid to the ultimate strength of plates, stiffened panels, box girders, and entire ship hull structures subjected to corrosion degradation, fatigue cracking, and mechanical damage caused by accidental loading or impact. A discussion on the effect of the cyclic load on the plate rigidity, re-yielding, and ultimate load capacity on the ship hull girder is also part of the present study. Finally, some conclusions and discussions about potential future work are provided, identifying that more studies about the impact of corrosion degradation on the structural behaviour of the stiffened panels and the overall hull girders are needed. Studies related to the dynamic collapse behaviour of corroded and damaged ship structures under time-variant load also requires additional attention.

Section: Damaged Ship Structuresmentioning

confidence: 99%

Review of Ultimate Strength Assessment of Ageing and Damaged Ship Structures

Tekgoz

Garbatov

2020

J. Marine. Sci. Appl.

“…This approach, looking soundly from an engineering point of view, is adopted also in the present study. The approach is further explored in Kim et al (2013), using the concept of the grounding damage index (GDI). The assumed general damage scenario for grounding caused by conically shaped rock is shown in Figure 1.…”

Section: Groundingmentioning

confidence: 99%

“…More details of the definition of the geometry of the rocking angle may be found in Paik et al (2012), Kim et al (2013) and Bužančić Primorac and Parunov (2015). An efficient method for predicting extent of the bottom damage is presented by Heinvee and Tabri (2015) and subsequently employed for structural reliability assessment of grounded ship by Ćorak et al (2017).…”

Section: Groundingmentioning

confidence: 99%

Structural Reliability Analysis of Ship Hulls Accounting for Collision or Grounding Damage

Primorac

Parunov

2020

J. Marine. Sci. Appl.

Classical structural reliability analysis of intact ship hulls is extended to the case of ships with collision or grounding damages. Still water load distribution and residual bending moment capacity are included as random variables in the limit state equation. The probability density functions of these random variables are defined based on random damage parameters given by the Marine Environment Protection Committee of the International Maritime Organization, while the proposed reliability formulation is consistent with international recommendations and thus may be valuable in the development of rules for accidental limit states. The methodology is applied on an example of an Aframax oil tanker. The proposed approach captures in a rational way complex interaction of different pertinent variables influencing safety of damaged ship structure.

“…In the present study the assessment of the sagging ultimate longitudinal strength of Aframax oil tanker (Table 1), damaged in a hypothetical grounding accident is calculated using an innovative Paik et al method [17], assuming that grounding is caused by conically shaped rock. Reduction of the ultimate strength is calculated by regression equations developed by Kim et al [18] using concept of grounding damage index (GDI). The GDI takes into account the extent and the location of grounding damage for both, inner and outer bottom structures.…”

Section: Hull-girder Residual Ultimate Longitudinal Strengthmentioning

confidence: 99%

Structural Reliability Assessment of an Oil Tanker Accidentally Grounded in the Adriatic Sea

Ćorak

Parunov

Volume 3A: Structures, Safety and Reliability

2017

The aim of the paper is to present a methodology for the assessment of the structural reliability of an oil tanker damaged in a hypothetical grounding accident in the Adriatic Sea. The grounding accident affects the ultimate hull girder capacity in the damaged region, the still water bending moment (SWBM) distribution along the vessel as well as the vertical wave bending moments (VWBM). The extent of the damage on the ship's hull after a grounding accident depends on several parameters such as ship`s speed, rock size, penetration depth, longitudinal and transversal location of stranding along the hull. These parameters are in the present study assumed as random variables, described by probability density functions. Based on defined statistical properties, random realizations of grounding parameters are simulated by Monte Carlo (MC) simulation. For each such random grounding scenario, the damage size is calculated by the surrogate model based on numerical grounding simulations. Residual ultimate strength and SWBM distribution are determined based on the size and location of the damage. VWBM is calculated for average sea state in the area with increased risk of grounding accident in the Adriatic Sea. Structural reliability analysis is employed to determine the safety index with respect to the ultimate hull girder failure for salvage period of 12 hours. As each grounding scenario results in different hull-girder reliability, histogram of safety indices is obtained representing new measures for the performance assessment of the damaged ship.