Buckling and ultimate strength criteria of stiffened shells under combined loading for reliability analysis

2003 ◽  
Vol 41 (1) ◽  
pp. 69-88 ◽  
Author(s):  
P.K. Das ◽  
A. Thavalingam ◽  
Y. Bai
Keyword(s):  
Reliability Analysis ◽  
Ultimate Strength ◽  
Combined Loading ◽  
Strength Criteria ◽  
Stiffened Shells

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.

Reliability Analysis of Ultimate Strength of a Capesize Bulk Carrier in Hogging and Alternate Hold Loading Condition

2010 ◽  
Author(s):  
Zhi Shu ◽  
Torgeir Moan
Keyword(s):  
Reliability Analysis ◽  
Ultimate Strength ◽  
Loading Condition ◽  
Structural Reliability ◽  
Bulk Carrier ◽  
Local Loads ◽  
Reliability Method ◽  
Bulk Carriers ◽  
Bending Capacity ◽  
Global And Local

This paper deals with the structural reliability analysis (SRA) of ultimate strength of a Capesize bulk carrier in hogging and alternate hold loading condition (AHL). The ultimate strength in hogging and AHL condition is very important for the safety of bulk carriers since the local loads due to internal cargo loads and external sea pressure can reduce the ultimate bending capacity. In the present paper, the characteristic ultimate bending capacity of the subject bulk carrier is investigated by nonlinear finite element (FE) analysis and the characteristic value of the global and local loads are determined in accordance with the Common Structural Rules for bulk carriers (CSR-BC). The uncertainties associated with the loading capacity and load effects are appropriately modelled. The First Order Reliability Method (FORM) is adopted to calculate the annual probability of failure of this bulk carrier in hogging and AHL condition. The effect of heavy weather avoidance on the global and local loads is also evaluated in the SRA. The results show that the local loads have a significant impact on the failure probability of such vessels in the hogging and AHL condition.

Reliability Analysis of Submarine Pressure Hulls With Failure Governed by Inelastic Buckling

2006 ◽  
Author(s):  
P. Radha ◽  
K. Rajagopalan
Keyword(s):  
Finite Element ◽  
Reliability Analysis ◽  
Sampling Technique ◽  
Collapse Mechanism ◽  
Good Prediction ◽  
Element Analysis ◽  
Inelastic Buckling ◽  
Stiffened Shells ◽  
Finite Element Software ◽  
Hull Structure

Due to the complexity involved in the inelastic buckling collapse mechanism of stiffened shell structures, the reliability analysis of submarine pressure hull, in which failure is dictated by inelastic effects, assumes great significance among structural engineers. In spite of many years of efforts by different authors to develop good prediction techniques for plastic and elastic-plastic buckling of stiffened shells and also to use the reliability concepts in the submarine pressure hull structures, comprehensive and reliable methods are still scarce. Hence in this paper a rigorous Finite Element analysis of a typical internally ring stiffened submarine pressure hull with failure governed by inelastic overall buckling has been done using the general purpose finite element software NISA. The samples required for each random variable were generated using Random Polar Sampling Technique (RPST) in which the combinations of variates are obtained using a random polar sampling of Latin hypercube sampled values. For the obtained collapse pressures, the reliability of the pressure hull structure has been determined and the effect of mean service loads on reliability has been analysed by taking different Central Safety Factors. The results were validated using Johnson-Ostenfeld Inelastic Correction method and the conclusions are advanced.

Reeling Effect on the Ultimate Strength of Sandwich Pipes

2005 ◽  
Author(s):  
Xavier Castello ◽  
Segen F. Estefen
Keyword(s):  
Ultimate Strength ◽  
Numerical Models ◽  
Kinematic Hardening ◽  
External Pressure ◽  
Combined Loading ◽  
Collapse Pressure ◽  
Finite Element Software ◽  
Structural Resistance ◽  
Longitudinal Bending ◽  
Full Scale Tests

Sandwich pipes composed of two steel layers separated by a polypropylene annulus can be used for the transport of oil&gas in deepwaters, combining high structural resistance with thermal insulation in order to prevent blockage by paraffin and hydrates. In this work, sandwich pipes with typical inner diameters of those employed in the offshore production are analyzed numerically to evaluate the ultimate strength under external pressure and longitudinal bending as well as the effect of the reeling installation method on the collapse pressure. Numerical models were developed using the commercial finite element software ABAQUS. The validation was based on experimental results. The analyses for combined loading were performed using symmetry conditions and the pipe was reduced to a ring with unitary length. The analysis of bending under a rigid surface was simulated numerically according to the experiments performed using a bending apparatus especially built for full scale tests. Symmetry conditions were employed in order to reduce the analysis to a quarter of a pipe. Mesh sensitivity studies were performed to obtain an adequate mesh refinement in both analyses. The collapse pressure was simulated numerically either for the pre or post reeling process. Bauschinger effect was included by using kinematic hardening plasticity models. The influences of plasticity and out-of-roundness on the collapse pressure have been confirmed.

Reliability Analysis of Structure with Local Sunken Plate

2010 ◽  
Vol 118-120 ◽  
pp. 424-428
Author(s):  
Wei Guang An ◽  
Ming Liu ◽  
Wei Tao Zhao
Keyword(s):  
Sensitivity Analysis ◽  
Reliability Analysis ◽  
Ultimate Strength ◽  
Plate Element ◽  
Numerical Example ◽  
Reliability Calculation

The influence of the local sunken plate on ultimate strength is analyzed, and reliability calculation and sensitivity analysis expressions of the plate element are also given in this paper. Finally, taking a numerical example, the influence of each sunken factor on plate ultimate strength reliability is analyzed. The result indicates that the influence of sunken diameter and sunken depth on reliability is larger. The method that is given in this paper, it is a reference for reasonable maintenance of structure.

Concrete-Filled Hollow Structural Sections. II: Flexural Members, Beam-Columns, Tension, and Shear

2021 ◽  
Author(s):  
Kyle Tousignant ◽  
Jeffrey Packer
Keyword(s):  
Reliability Analysis ◽  
Axial Compression ◽  
Cross Section ◽  
North American ◽  
Combined Loading ◽  
Flexural Members ◽  
Beam Columns ◽  
First Order ◽  
Hollow Structural Section ◽  
Hollow Structural Sections

This article reviews contemporary North American and international approaches to the design of concrete-filled hollow structural section (HSS) members for flexure, axial compression plus uniaxial bending, tension, and shear. Results from tests on concrete-filled HSS members under flexure and combined loading are compared to predicted strengths using current (CSA S16:19 and AISC 360-16) and recommended CSA S16 design equations (with limits of validity). A first-order reliability analysis of design provisions for flexure is performed in accordance with CSA S408-11, and recommendations are made for potential revision of CSA S16. Design examples are provided, and results are compared to the counterpart American code (AISC 360-16). This paper is Part II of a two-part series. Part I covers materials, cross-section classification, and concentrically loaded columns.

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