Ultimate Strength of Stiffened Panels Assesment Taking Into Account Model Uncertainty

2006 ◽  
Author(s):  
C. Toderan ◽  
T. Richir ◽  
J. D. Caprace ◽  
Ph. Rigo
Keyword(s):  
Data Base ◽  
Ultimate Strength ◽  
Model Uncertainty ◽  
Progressive Collapse ◽  
Random Variable ◽  
Test Results ◽  
Research Activity ◽  
Element Analysis ◽  
Stiffened Panels ◽  
Hull Girder

This paper presents a methodology to take into account model uncertainties related to the load-end shortening curve of stiffened panels. This method is a part of a research activity carried out at University of Liege. His goal is to propose a reliability based model to assess hull girder ultimate strength using a progressive collapse algorithm. The numerical results presented here concern the load-shortening model chosen for this research, which is based on Bureau Veritas rules. Model uncertainty is quantified as a parameter considered as a random variable. Four statistical moments (mean, standard deviation, skewness and kurtosis) of this parameter are calculated and analyzed using a data-base of stiffened panels test results published in recent years. In order to increase the number of “actual” values for the statistical assessment, the data-base is completed with non-linear finite element analysis results. The paper contains also some recommendation for the implementation of the proposed method in ultimate strength reliability based analysis.

Finite Element Analysis on the Hull Girder Ultimate Strength of Asymmetrically Damaged Ships

2016 ◽  
Author(s):  
Muhammad Zubair Muis Alie ◽  
Ganding Sitepu ◽  
Juswan Sade ◽  
Wahyuddin Mustafa ◽  
Andi Mursid Nugraha ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Ultimate Strength ◽  
Cross Sections ◽  
Progressive Collapse ◽  
Ship Hull ◽  
Strength Analysis ◽  
Functional Requirements ◽  
Element Analysis ◽  
Hull Girder

This paper discusses the influence of asymmetrically damaged ships on the ultimate hull girder strength. When such damages take place at the asymmetric location of cross sections, not only translation but also inclination of instantaneous neutral axis takes place during the process of the progressive collapse. To investigate this effect, the Finite Element Analysis (FEA) is employed and the damage is assumed in the middle hold. The collision damage is modeled by removing the plate and stiffener elements at the damage region assuming the complete loss of the capacity at the damage part. For the validation results obtained by Finite Element Analysis of the asymmetrically damaged ship hull girder, the simplified method is adopted. The Finite Element method of ultimate strength analysis of a damaged hull girder can be a practical tool for the ship hull girder after damages, which has become one of the functional requirements in IMO Goal Based Ship Construction Standard.

Buckling and Ultimate Strength Assessment of FPSO Structures

2005 ◽  
Author(s):  
Haihong Sun ◽  
Xiaozhi Wang
Keyword(s):  
Ultimate Strength ◽  
Oil And Gas ◽  
Element Analysis ◽  
Strength Criteria ◽  
Strength Assessment ◽  
Stiffened Panels ◽  
Oil And Gas Fields ◽  
Extensive Test ◽  
Offshore Oil And Gas ◽  
Classification Society

Floating production, storage and offloading systems (FPSOs) have been widely used for the development of offshore oil and gas fields because of their attractive features. They are mostly ship- shaped, either converted from existing tankers or purposely built, and the hull structural scantling design for tankers may be applicable to FPSOs. However, FPSOs have their unique characteristics. FPSOs are sited at specific locations with a dynamic loading that is quite different from those arising from unrestricted service conditions. The structures are to be assessed to satisfy the requirements of all in-service and pre-service loading conditions. The fundamental aspects in the structural assessment of FPSOs are the buckling and ultimate strength behaviors of the plate panels, stiffened panels and hull girders. The focus of this paper is to address the buckling and ultimate strength criteria for FPSO structures. Various aspects of the criteria have been widely investigated, and the results of the design formulae proposed in this paper have been compared to a very extensive test database and numerical results from nonlinear finite element analysis and other available methods. The procedures presented in this paper are based on the outcomes of a series of classification society projects in the development of buckling and ultimate strength criteria and referred to the corresponding classification society publications.

Automated Assessment of Ultimate Hull Girder Strength

2003 ◽  
Vol 125 (3) ◽  
pp. 211-218 ◽  
Author(s):  
M. J. Smith ◽  
N. G. Pegg
Keyword(s):  
Ultimate Strength ◽  
Progressive Collapse ◽  
Three Dimensional ◽  
Strength Analysis ◽  
Cross Sectional ◽  
Strength Assessment ◽  
Hull Girder ◽  
Single User Interface ◽  
Interaction Curves ◽  
The Uk

An automated approach to ultimate hull girder strength assessment using DRDC’s ultimate strength analysis suite (ULTSAS) is described. The analysis suite improves the ability to perform rapid ultimate strength assessments by providing access to UK and Canadian analysis codes and databases under a single user interface. The interface also allows for automatic cross-sectional model generation from three-dimensional ship finite element models with the MGDSA program. The main features of the ULTSAS system are described, including cross-sectional modelling, and the use of load-shortening curve databases. The paper also provides a review of the progressive collapse method for determining ultimate strength, which is now used in both the UK and Canadian analysis codes. Two numerical approaches are described, one based on curvature incrementing and the other on moment incrementing. It is shown that the moment incrementing procedure produces more accurate bi-axial interaction curves in some instances. Results are obtained for two damage configurations of the HALIFAX class frigate.

Ultimate Behavior of Single Shear Bolted Connections with Thin-Walled Aluminum Alloys(6061-T6)

2012 ◽  
Vol 446-449 ◽  
pp. 3441-3445 ◽  
Author(s):  
Tae Soo Kim ◽  
Yong Hyun Jo ◽  
Seung Hun Kim ◽  
Yong Taeg Lee
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Plane Deformation ◽  
Free Edge ◽  
Fe Analysis ◽  
Test Results ◽  
Bolted Connections ◽  
Element Analysis ◽  
Out Of Plane ◽  
Single Shear

The purpose of this study is to investigate the ultimate behaviors of aluminum alloy bolted connections assembled with four bolts. Specimens for single shear bolted connections were tested and finite element analysis based on this test results was conducted. The validity of finite element(FE) analysis for predicting the structural behaviors such as ultimate strength, fracture mode and curling(out-of-plane deformation) occurrence was verified through the comparisons between test results and FE analysis results. It is known that the curling resulted in sudden strength drop. Moreover, FE models with free edge and restrained out-of-plane deformation for curled specimens are analyzed additionally, therefore, the influence of curling on the ultimate strength; strength reduction ratio is estimated.

Finite Element Analysis of Longitudinal Bending Collapse of Container Ship Considering Bottom Local Loads

2016 ◽  
Author(s):  
Akira Tatsumi ◽  
Masahiko Fujikubo
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Container Ship ◽  
Element Analysis ◽  
Local Loads ◽  
Hull Girder ◽  
Longitudinal Bending ◽  
Collapse Behavior ◽  
Large Container ◽  
Collapse Region

The purpose of this research is to clarify the effect of bottom local loads on the hull girder collapse behavior of large container ship (8000TEU class) A 1/2+1+1/2 hold model of container ship is analyzed using implicit finite element method. The results reveal two major causes of reduction of hull girder ultimate strength due to local loads. One is biaxial compressive stresses induced at outer bottom. Thus, smaller hogging moment can induce a collapse of bottom panels. The other is a reduction of effectiveness of inner bottom that is on the tension side of local bending. As a result, the container ship attains hull girder ultimate strength with smaller spread of collapse region compared to that under pure bending.

Block Shear Behaviors of Angle Two-Bolted Connections with Austenitic Stainless Steel – Experiment and Finite Element Analysis

2013 ◽  
Vol 658 ◽  
pp. 350-353
Author(s):  
Tae Soo Kim ◽  
Min Seung Kim ◽  
Sung Woo Shin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Ultimate Strength ◽  
Strength Reduction ◽  
Test Results ◽  
Bolted Connections ◽  
Element Analysis ◽  
Block Shear

Since stainless steel has significant characteristics such as its superior corrosion resistance, durability, aesthetic appeal etc., it has been utilized as structural members in buildings. Recently, ultimate behaviors and curling influence in austenitic stainless steel single shear bolted connections with thin-walled plane plates have been investigated by T.S. Kim. In this paper, finite element analysis (FEA) has been conducted based on the existing test results of angle bolted connections in fabricated with austenitic stainless steel. The validation of the numerical analysis prediction was verified through the comparison of test results for fracture mode, ultimate strength and curling occurrence. Curling (out-of- plane deformation) also observed in the connections with a long end distance. The curling caused the ultimate strength reduction and the ultimate strength reduction ratios (varied from 12% to 25%) caused by curling have been estimated quantitatively through the comparison of FEA results of FE models with free edge and restrained curling.

Numerical Study for the Progressive Collapse of Scale Model for ULCS Hull Girder Under Longitudinal Bending

2018 ◽  
Author(s):  
Chonglei Wang ◽  
Deyu Wang
Keyword(s):  
Numerical Study ◽  
Progressive Collapse ◽  
Similarity Criterion ◽  
Bending Moment ◽  
Scale Model ◽  
Stiffened Panels ◽  
Hull Girder ◽  
Load Carrying ◽  
Longitudinal Bending ◽  
Large Container

For evaluating reliable load carrying capacity of actual hull girder, experiments for similar scale model are necessary. The object of the present paper is to figure out a reliable FE analysis method in the similar scale model experiment regarding hull girder ultimate strength. The compared results between the true hull girder of a typical ultra large container ship (ULCS) and the scale experimental model created by the similarity criterion proposed in this paper assessed by finite element method (FEM) under longitudinal bending moment considering the effects of initial deflections are obtained guaranteeing the similarity in both elastic and inelastic range during the progressive collapse of plates, stiffened panels and hull girder. Finally, a series of elastic-plastic large deflection analyses is conducted to ensure the failure mode of hull girder is consistent with the actual ship.

Finite Element Analysis of the Ultimate Strength of Aluminum-Stiffened Panels With Fixed and Floating Transverse Frames

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Chenfeng Li ◽  
Zhiyao Zhu ◽  
Huilong Ren ◽  
C. Guedes Soares
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Residual Stresses ◽  
Ultimate Strength ◽  
Simulation Method ◽  
Tensile Tests ◽  
Element Analysis ◽  
Stiffened Panels ◽  
Aluminum Panels

The aim of this study was to analyze the ultimate strength of stiffened aluminum panels by the nonlinear finite element method. A new type of stiffened aluminum alloy panel has been designed, which has fixed longitudinal and alternating floating transverse frames. Based on material tensile tests, the material properties of the aluminum alloy were obtained. Then, the simulation method of welding residual stresses and the effect of heat-affected zone (HAZ) are investigated. The finite element analysis (FEA) software abaqus V6.11 is used to estimate the ultimate strength of these stiffened panels under axial compression. The results show that: (1) the mechanical imperfections have significant effect on the ultimate strength of stiffened panels; (2) residual stresses may have positive effect on the ultimate strength; and (3) the new stiffened panels also have good performance on ultimate bearing capacities.

Buckling and Ultimate Strength Assessments of Ship Structures

2013 ◽  
Author(s):  
Shengming Zhang
Keyword(s):  
Ultimate Strength ◽  
Fe Analysis ◽  
Development Work ◽  
Ship Structures ◽  
Element Analysis ◽  
Strength Assessment ◽  
Stiffened Panels ◽  
Development History ◽  
Bulk Carriers ◽  
Oil Tankers

This paper presents buckling and ultimate strength assessment methods for ship structures. Buckling and collapsing analysis approaches for plates, stiffened panels and hull girders are described and their development history and employments in ship design assessments are reviewed and discussed. Examples using non-linear finite (FE) element analysis are given and comparisons between results obtained by formulae and FE analysis are carried out. Lloyd’s Register’s recent research and development work on ultimate strength and its applications to existing oil tankers and bulk carriers are also presented.

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