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 Stiffened Plates Subjected to Longitudinal Compression and Lateral Pressure

2014 ◽  
Author(s):  
Karan Doshi ◽  
Suhas Vhanmane
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Lateral Pressure ◽  
Stiffened Plates ◽  
Stiffened Panel ◽  
Element Analysis ◽  
Stiffened Panels ◽  
Linear Finite Element ◽  
Non Linear ◽  
Compressive Loads

This paper presents a non-linear finite element analysis (FEA) and subsequent formula development for ultimate strength of stiffened panels of ship structures. A review of studies on ultimate strength of ship plating subjected to lateral pressure was carried out. The present work takes into account, the influence due to the lateral pressure on the ultimate strength of stiffened plates with initial imperfections subject to longitudinal compressive loads. ANSYS non-linear FE software was used for non linear finite element analyses of stiffened panels (864 cases) considering VLCC hull. Based on regression analysis, a set of semi-analytical formulae were proposed and described. It is observed that depending upon the failure mode, scantlings of the stiffened panel and magnitude of lateral pressure, ultimate strength of the stiffened panels in compression is affected.

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

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.

Ultimate Strength of Stiffened Panels With Cracking Damage Under Axial Compression or Tension

2006 ◽  
Vol 50 (03) ◽  
pp. 231-238
Author(s):  
Jeom Kee Paik ◽  
Y. V. Satish Kumar
Keyword(s):  
Ultimate Strength ◽  
Limit State ◽  
Reliability Assessment ◽  
Nonlinear Finite Element ◽  
Stiffened Panel ◽  
Ultimate Limit State ◽  
Finite Element Analyses ◽  
Stiffened Panels ◽  
Aging Steel ◽  
Ultimate Limit

The aim of the present paper is to investigate the ultimate strength characteristics of a longitudinally stiffened panel with cracking damage and under axial compressive or tensile loads. A series of nonlinear finite element analyses are undertaken with varying the size and location of cracking damage. A relevant theoretical model for predicting the ultimate strength of the stiffened panel with cracking damage is studied. The insights and results developed from the present study will be very useful for the ultimate limit state-based risk or reliability assessment of aging steel plated structures with cracking damage.

Collapse Strength of Stiffened Panels With Local Dent Damage

2008 ◽  
Author(s):  
Malgorzata Witkowska ◽  
C. Guedes Soares
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Linear Analysis ◽  
Local Damage ◽  
Stiffened Panels ◽  
Geometrical Properties ◽  
Geometrical Characteristics ◽  
Collapse Strength ◽  
Non Linear ◽  
Local Dent

In this study the behaviour and ultimate strength of damaged stiffened panels is investigated. The damage is in a form of local imperfection and represents a dent that could be caused by a fall or strike of an object. The model used is a panel made of five plates joined transversally with four longitudinal flat-bar stiffeners. Finite element non-linear analysis of panels having different geometrical properties is carried out. The influence of several parameters has been studied in order to establish their interaction with the presence of the local dent. It has been found that stiffened panels present quite good performance while subjected to the local damage, however, depending on geometrical characteristics, a problem of stiffener deformations may occur, significantly lowering the ultimate strength.

scholarly journals Estimation of Buckling Response of the Deck Panel in Axial Compression

2018 ◽  
Vol 25 (4) ◽  
pp. 98-105 ◽  
Author(s):  
Ozgur Ozguc
Keyword(s):  
Finite Element ◽  
Axial Compression ◽  
Limit State ◽  
Stiffened Panel ◽  
Ultimate Limit State ◽  
Finite Element Code ◽  
Element Analysis ◽  
Strength Assessment ◽  
Stiffened Panels ◽  
Non Linear

Abstract In this work, buckling strength assessment of a deck of a double hull oil tanker is carried out using the non-linear finite element code ADVANCE ABAQUS. The comparisons are performed with the Det Norske Veritas (DNV-GL) PULS (Panel Ultimate Limit State) buckling code for the stiffened panels, DNV-GL Classification Notes (CN) No.30.1 and the DNV-GL Ship Rules. The case studied corresponds to axial compression. Two levels of imperfection tolerances are analyzed, in accordance with the specifications in the DNV-GL Instruction to Surveyors (IS) and the DNV-GL Classification Notes No. 30.1. Both “as built” and DNV-GL Rule “net” dimensions are analyzed. The strength values from ADVANCE ABAQUS and PULS are very close. DNV-GL CN 30.1 is in conservative side, but the strength differences between the “as built” and “net” dimension cases are consistent with the finite element analysis results. This paper gives a brief description of the background for the stiffened panel models used in PULS, and comparison against non-linear FE analysis, and DNV-GL Classification Society Rules. The finite element code ADVANCE ABAQUS is employed in a non-linear buckling analysis of a stiffened deck panel on a double skin tanker that is subjected to a Condition Assessment Program (CAP) hull survey. The aim of the analyses has been to validate and compare the buckling capacity estimates obtained from PULS, DNV-GL Classification Notes No.30.1 (CN 30.1) and the DNV-GL Ship Rules.

Optimization of lightweight sub-stiffened panels with buckling analysis and imperfection sensitivity analysis

2019 ◽  
Vol 233 (15) ◽  
pp. 5507-5521 ◽  
Author(s):  
Hao Chen ◽  
Yuanming Xu ◽  
Junhao Hu ◽  
Xi Wang
Keyword(s):  
Sensitivity Analysis ◽  
Ultimate Strength ◽  
Multidisciplinary Optimization ◽  
Uniaxial Loading ◽  
Stiffened Panel ◽  
Imperfection Sensitivity ◽  
Engineering Structures ◽  
Buckling Loads ◽  
Stiffened Panels ◽  
Post Buckling

On the purpose of improving the structural efficiency of stiffened panels, which is widely used in engineering, three promising layouts of sub-stiffened thin-walled structures were optimized in view of structure's initial buckling and further analyzed through post-buckling and imperfection-sensitivity analysis. The optimization tasks were carried out using an integrated framework, which is based on the multidisciplinary optimization platform Model Center and finite element method software ABAQUS. The particle swarm optimization algorithm was applied to optimize layout parameters. Three optimal sub-stiffened panels were then evaluated based on their performance on critical buckling loads and post-buckling ultimate strength under uniaxial loading. Imperfection-sensitivity analysis was also conducted to investigate the stability behavior of the proposed panels with defect. The results indicate that the introduction of sub-stiffeners into the traditional stiffened panel can achieve significant improvements on the panel's buckling loads and ultimate strength under uniaxial loading, which are favorable to expand design space for engineering structures under requirements of lightweight with high bending stiffness and bucking resistance.

A Simple Design Formula to Estimate the Ultimate Strength of Stiffened Panels Under Bi-Axial Compression Mainly in Transverse Direction

2018 ◽  
Author(s):  
Yusuke Komoriyama ◽  
Daisuke Yanagihara
Keyword(s):  
Ultimate Strength ◽  
Axial Compression ◽  
Transverse Direction ◽  
Yield Condition ◽  
Stiffened Panel ◽  
Simple Design ◽  
Buckling Mode ◽  
Stiffened Panels ◽  
Design Formula ◽  
Collapse Behavior

Most of stiffened panels subjected to bi-axial compression mainly in transverse direction collapse with the buckling deformation of one times one half-wave in a local panel between longitudinal stiffeners and transverse frames. The authors defined this collapse mode as “local panel buckling mode”. In this study, the collapse behavior of the stiffened panel with local panel buckling mode is investigated in detail. Then, a simple design formula to estimate ultimate strength of a stiffened panel with local panel buckling mode is derived based on the collapse behavior. This formula is composed of a formula to predict the ultimate strength of a rectangular unstiffened panel subjected to uniaxial transverse compression, and the effects of stiffeners, bi-axial compression and von Mises yield condition are added to the formula. The ultimate strength calculated by the proposed formula is in good agreement with FEA results. Finally, the proposed formula is compared with an existing method and formulae used in the CSR-OT, CSR-BC and H-CSR. As a result, it is confirmed that the proposed formula has sufficient accuracy and high availability.

Influence of Model Geometry and Boundary Conditions on the Ultimate Strength of Stiffened Panels Under Uniaxial Compressive Loading

2012 ◽  
Author(s):  
Mingcai Xu ◽  
Masahiko Fujikubo ◽  
C. Guedes Soares
Keyword(s):  
Boundary Conditions ◽  
Ultimate Strength ◽  
Geometric Model ◽  
Compressive Loading ◽  
Fe Analysis ◽  
Stiffened Panel ◽  
Stiffened Panels ◽  
Collapse Mode ◽  
Strain Relationship ◽  
Model Geometry

The aim of this paper is to find out an appropriate configuration of boundary conditions and geometric model to calculate the ultimate strength of a continuous stiffened panel under uniaxial compressive loading in FE analysis. The 1+1 bays model with periodical symmetric boundary conditions is proposed to be used in FE analysis, whose results are compared with 1/2+1+1/2 bays model with periodical symmetric and symmetric boundary conditions, and 1/2+1+1+1/2 bays model with symmetric boundary conditions. The effects of the continuity of the stiffened panel with different geometric models and boundary conditions on its collapse mode are investigated. A beam tension test has been used to define the true stress-strain relationship.

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