Influence of stochastic geometric imperfection on the ultimate strength of stiffened panel in compression

2021 ◽  
pp. 95-103
Author(s):  
D.G. Georgiadis ◽  
M.S. Samuelides ◽  
S. Li ◽  
D.K. Kim ◽  
S. Benson
Keyword(s):  
Ultimate Strength ◽  
Stiffened Panel ◽  
Geometric Imperfection

Assessment of Residual Ultimate Strength of VLCC According to Damage Extents and Average Compressive Strength of Stiffened Panel

2014 ◽  
Author(s):  
Ji-Myung Nam ◽  
Joonmo Choung ◽  
Se-Yung Park ◽  
Sung-Won Yoon
Keyword(s):  
Compressive Strength ◽  
Ultimate Strength ◽  
Probabilistic Approach ◽  
Stiffened Panel ◽  
Moment Capacity ◽  
Hull Girder ◽  
Damage Area ◽  
Damage Indices ◽  
Smith Method ◽  
Average Compressive Strength

This paper presents the prediction of residual ultimate strength of a very large crude oil carrier considering damage extents due to collision and grounding accidents. In order to determine extents of damage, two types of probabilistic approaches are employed: deterministic approach based on regulations based on ABS [1], DNV [2], and MARPOL [3] and probabilistic approach based on IMO probability density functions (PDFs) (IMO guidelines [4]). Hull girder ultimate strength is calculated using Smith method which is dependent on how much average compressive strength of stiffened panel is accurate. For this reason, this paper uses two different methods to predict average compressive strength of stiffened panel composing hull girder section: CSR formulas and nonlinear FEA. Calculated average compressive strength curves using CSR formulas (IACS [5, 6]) and nonlinear FEA are imported by an in-house software UMADS. Residual ultimate moment capacities are presented for various heeling angles from 0° (sagging) to 180° (hogging) by 15° increments considering possible flooding scenarios. Three regulations and IMO guidelines yield minimum of reduction ratios of hull girder moment capacity (minimum of damage indices) approximately at heeling angles 90° (angle of horizontal moment) and 180° (angle of hogging moment), respectively, because damage area is located farthest from neutral axis.

Buckling/Ultimate Strength Evaluation for Continuous Stiffened Panel Under Combined Shear and Thrust

2016 ◽  
Author(s):  
Hiroaki Ogawa ◽  
Tomoki Takami ◽  
Akira Tatsumi ◽  
Yoshiteru Tanaka ◽  
Shinichi Hirakawa ◽  
...  
Keyword(s):  
Ultimate Strength ◽  
Fem Analysis ◽  
Strength Analysis ◽  
Stiffened Panel ◽  
Fe Modeling ◽  
Test Results ◽  
Strength Evaluation ◽  
Shear Buckling ◽  
Collapse Behavior ◽  
Good Agreement

In this study, FE modeling method for the buckling/ultimate strength analysis of a continuous stiffened panel under combined shear and thrust is proposed. In order to validate the proposed method, shear buckling collapse tests of a stiffened panel and FEM analysis are carried out. As the result of these, it is confirmed that the buckling collapse behavior and the ultimate strength estimated by the proposed method are in good agreement with the test results.

A Benchmark Study of ISO 18072-2 on the Stiffened Panel Ultimate Strength

2011 ◽  
Author(s):  
Paul A. Frieze ◽  
Martino Abbattista ◽  
Mirella Vallascas ◽  
Jeom K. Paik
Keyword(s):  
Ultimate Strength ◽  
Structural Reliability ◽  
Close Correlation ◽  
Stiffened Panel ◽  
Stiffened Panels ◽  
The Public ◽  
Benchmark Study ◽  
Wide Range ◽  
Non Linear ◽  
Complete Set

The paper presents a major benchmarking exercise to demonstrate the accuracy of the formulations for the ultimate strength of stiffened panels that had been proposed for inclusion in ISO TS 18072-2. The complete set of formulations addressed the ultimate strength of plates, hull girders and support members, in particular, transverse frames and webs. The stiffened panel strength formulations have been in the public domain for some time and represent the most comprehensive set yet published. Their potential application is to a wide range of structural forms, e.g. floating dock gates, caissons, bridge decks, FPSOs, etc, and as such have much to recommend for other than just ship structures. The benchmark study presents comparisons between two implementations of the formulations and the results of non-linear FEA. The structures analysed represent a range of different stiffened panels with varying overall dimensions, plate dimensions and stiffener shapes, in particular, flats, angles and Tees. Close correlation is generally realized but where differences arise, these are readily related to the approximations used in developing the strength formulations. The comparisons between the strength formulations and non-linear FEA results provides the basis for quantifying statistical uncertainties in the formulations which can be used in subsequent structural reliability analysis and partial resistance factor derivation.

Ultimate Strength of Hull Structural Stiffened Plate with Grooving Corrosion Damage under Uniaxial Compression

2020 ◽  
pp. 1-11
Author(s):  
Yufan Zhu ◽  
Yan Zhang ◽  
Fei Du
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Corrosion Damage ◽  
Groove Depth ◽  
Assessment Method ◽  
Welding Residual Stress ◽  
Stiffened Plates ◽  
Width Ratio ◽  
Geometrical Parameters ◽  
Geometric Imperfection

Grooving corrosion results in a decrease in the ability of the structure to resist external loads. In the present study, a new assessment method was developed to investigate the ultimate loading capacity of stiffened plates with grooving corrosion damage. First, the basic parameters of stiffened plates (including model range, boundary condition, welding residual stress, initial geometric imperfection, and size of finite element) were assumed. Second, the influences of corrosion parameters and geometrical parameters of stiffened plates (such as finite element type, groove width, groove depth, groove depth-to-width ratio, plate flexibility, stiffener flexibility, and number of stiffeners) were analyzed. Third, based on the data analysis from a large number of nonlinear finite element analyses, the ultimate strength reduction formula of stiffened plates was derived. Last, the correctness of the formula was verified by ultimate strength experiment.

Benchmark study on use of ALPS/ULSAP method to determine plate and stiffened panel ultimate strength

2011 ◽  
pp. 169-186 ◽  
Author(s):  
J Paik ◽  
S Kim ◽  
D Kim ◽  
D Kim ◽  
P Frieze ◽  
...  
Keyword(s):  
Ultimate Strength ◽  
Stiffened Panel ◽  
Benchmark Study

A parametric study on the dynamic ultimate strength of a stiffened panel subjected to wave- and whipping-induced stresses

2020 ◽  
pp. 1-15 ◽  
Author(s):  
George Jagite ◽  
Fabien Bigot ◽  
Quentin Derbanne ◽  
Šime Malenica ◽  
Hervé Le Sourne ◽  
...  
Keyword(s):  
Ultimate Strength ◽  
Parametric Study ◽  
Stiffened Panel ◽  
Induced Stresses

Probabilistic Assessment of Stiffened Panel Strength: An Interactive Tool Using PROBAN and PULS

2010 ◽  
Author(s):  
Hadi Amlashi ◽  
Torfinn Ho̸rte ◽  
Eivind Steen ◽  
Jon Kippenes
Keyword(s):  
Ultimate Strength ◽  
Probability Distributions ◽  
Ship Design ◽  
Probabilistic Methods ◽  
Computational Time ◽  
Stiffened Panel ◽  
Probabilistic Assessment ◽  
Limit States ◽  
Stiffened Panels ◽  
Safety Margins

To achieve an economic and reliable ship design, the ship structure has to be designed with adequate safety margins. This can be accomplished by a reliability-based limit states design approach, in which probabilistic methods are used to guide the development of the design criteria. A tool is developed to probabilistically assess the capacity distribution of the stiffened panels. A Monte Carlo simulation scheme, which samples a number of probability distributions, has been applied using PROBAN (DNV) which interactively utilizes PULS (DNV) as an efficient ultimate strength prediction tool for plated panels. It is demonstrated that this tool can successfully link the two internationally recognized programs, i.e. PROBAN and PULS for probabilistic assessment of stiffened panel’s ultimate strength. The results demonstrate that the suitability of the assumed distribution for the strength can be assessed with relatively little computational time, where the yield stress and imperfection sizes are treated as random variables. Such results are very informative and useful for further development of existing safety format ensuring a safe, economic and reliable ship design.

An Approximate Calculation Approach for Ultimate Strength of Ship Hull Girder

2013 ◽  
Author(s):  
Chenfeng Li ◽  
Huilong Ren ◽  
Zhongqiu Zhao ◽  
Xiaodong Zhao ◽  
Ji Zeng ◽  
...  
Keyword(s):  
Ultimate Strength ◽  
Calculation Method ◽  
Approximate Calculation ◽  
Progressive Collapse ◽  
Beam Theory ◽  
Stiffened Panel ◽  
Collapse Mechanism ◽  
Hull Girder ◽  
Post Buckling ◽  
Progressive Collapse Analysis

The assessment of the ultimate strength of a ship structure is very important not only for the initial design but also for the operation, maintenance, and repair of the structure. There exist two typical methods to assess the ultimate strength of stiffened panel and hull girder. One is the approximate calculation method and the other is the progressive collapse analysis. The approximate calculation method is based on ship beam-theory mainly, and the ultimate moment was calculated by assuming stress distribution of the whole section of the ship girders, which can not effectively consider the structural post-buckling behaviour. Based on progressive collapse mechanism and hull’s beam theory, A approximate calculation approach was proposed. By calculating the ultimate strength of stiffened panels in the distal end hull section, the deflections were obtained when the different stiffened panel reaching in the limit state, and then the stress state and bending moment of section were determined with different deflections, the hull’s ultimate moment value is determined by searching and comparing finally. The numerical examples show that the presented method was reasonable and effective compared with traditional direct calculation method and progressive collapse analysis. The method given hereof followed the progressive collapse mechanism through inversion searching in some degree, and the structural post-buckling behaviour was effectively considering.

Ultimate strength of a cracked stiffened panel repaired by CFRP and stop holes

2021 ◽  
Vol 226 ◽  
pp. 108850
Author(s):  
Xing Hua Shi ◽  
Zhongqian Hu ◽  
Jing Zhang ◽  
C. Guedes Soares
Keyword(s):  
Ultimate Strength ◽  
Stiffened Panel
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