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

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Ming Cai Xu ◽  
Masahiko Fujikubo ◽  
C. Guedes Soares
Keyword(s):  
Boundary Conditions ◽  
Ultimate Strength ◽  
Geometric Model ◽  
Compressive Loading ◽  
Fe Analysis ◽  
Stiffened Panel ◽  
Stiffened Panels ◽  
Symmetric Boundary Condition ◽  
Strain Relationship ◽  
Model Geometry

The aim of this paper is to determine an appropriate configuration of the boundary conditions and geometric model to calculate the ultimate strength of a continuous stiffened panel under compressive loading in the finite element (FE) analysis. The 1 + 1 spans model with periodical symmetric boundary conditions is proposed to be used in the FE analysis, whose results are compared with the 1/2 + 1 + 1/2 span model with periodical symmetric and symmetric boundary condition, and the 1/2 + 1 + 1 + 1/2 span 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 in the FE analysis. The two-span model, either 1 + 1 or 1/2 + 1 + 1/2, with periodical symmetric conditions give a reasonable FE modeling, which can consider both odd and even number half waves and, thus, have the smallest model uncertainty.

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.

Numerical Study of the Effect of Geometry and Boundary Conditions on the Collapse Behaviour of Stocky Stiffened Panels

2012 ◽  
Vol 154 (A2) ◽  
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Ultimate Strength ◽  
Material Properties ◽  
Finite Element Modelling ◽  
Numerical Study ◽  
Fe Analysis ◽  
Stiffened Panels ◽  
Element Modelling ◽  
Geometric Configurations

This study aims at studying different configurations of the stiffened panels in order to identify robust configurations that would not be much sensitive to the imprecision in boundary conditions that can exist in experimental set ups. A numerical study is conducted to analyze the influence of the stiffener’s geometry and boundary conditions on the ultimate strength of stiffened panels under uniaxial compression. The stiffened panels with different combinations of mechanical material properties and geometric configurations are considered. The four types of stiffened panels analysed are made of mild or high tensile steel and have bar, ‘L’ and ‘U’ stiffeners. To understand the effect of finite element modelling on the ultimate strength of the stiffened panels, four types of FE models are investigated in FE analysis including 3 bays, 1/2+1+1/2 bays, 1+1 bays and 1 bay with different boundary conditions.

NUMERICAL STUDY OF THE EFFECT OF GEOMETRY AND BOUNDARY CONDITIONS ON THE COLLAPSE BEHAVIOUR OF STOCKY STIFFENED PANELS

2021 ◽  
Vol 154 (A2) ◽  
Author(s):  
M C Xu ◽  
C Guedes Soares
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Ultimate Strength ◽  
Material Properties ◽  
Finite Element Modelling ◽  
Numerical Study ◽  
Fe Analysis ◽  
Stiffened Panels ◽  
Element Modelling ◽  
Geometric Configurations

This study aims at studying different configurations of the stiffened panels in order to identify robust configurations that would not be much sensitive to the imprecision in boundary conditions that can exist in experimental set ups. A numerical study is conducted to analyze the influence of the stiffener’s geometry and boundary conditions on the ultimate strength of stiffened panels under uniaxial compression. The stiffened panels with different combinations of mechanical material properties and geometric configurations are considered. The four types of stiffened panels analysed are made of mild or high tensile steel and have bar, ‘L’ and ‘U’ stiffeners. To understand the effect of finite element modelling on the ultimate strength of the stiffened panels, four types of FE models are investigated in FE analysis including 3 bays, 1/2+1+1/2 bays, 1+1 bays and 1 bay with different boundary conditions.

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.

scholarly journals Comparative manufacture and testing of induction- welded and adhesively bonded carbon fibre PEEK stiffened panels

2018 ◽  
Vol 32 (12) ◽  
pp. 1622-1649 ◽  
Author(s):  
M Flanagan ◽  
A Doyle ◽  
K Doyle ◽  
M Ward ◽  
M Bizeul ◽  
...  
Keyword(s):  
Carbon Fibre ◽  
Compressive Loading ◽  
Welding Process ◽  
Stiffened Panel ◽  
Adhesively Bonded ◽  
Load Bearing Capacity ◽  
Stiffened Panels ◽  
Automotive Components ◽  
Assembly Technique ◽  
Continuous Induction

This work presents details of manufacturing and testing of a carbon fibre polyetheretherketone induction-welded hat-stiffened panel. Mechanical testing is carried out to evaluate the performance of the welded assembly and results are compared with similar testing of an adhesively bonded panel. The results show that the welded panel and the bonded panel had similar load-bearing capacity (<2% difference) and stiffness (<1% difference). Optical microscopy is used to verify the weld quality and identify manufacturing artefacts associated with induction welding. Inspection of the panel after welding shows that the induction welding process caused minor warpage, voids and delamination in the panel. The work addresses the lack of data relating to demonstrator scale welded assemblies in the literature, demonstrates that continuous induction welding is a suitable assembly technique for aerospace and automotive components under uniaxial in-plane compressive loading and identifies process-induced artefacts that may occur during induction welding.

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.

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.

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.

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