scholarly journals Maximum Load Carrying Capacity Estimation of The Ship and Offshore Structures by Progressive Collapse Approach

2016 ◽  
Vol 23 (3) ◽  
pp. 28-38 ◽  
Author(s):  
Hasan Ölmez ◽  
Ertekin Bayraktarkatal

Abstract The aim of the paper is to represent step by step progressive collapse analysis for maximum load carrying capacity estimation of a hull girder by using variant of Smith Method, named HULT by authors, with different element separation including single plates, stiffeners, hard corners and stiffened panels. The structural elements that form the ships and offshore structures are exposed to large vertical bending moments and especially compression or tension forces in the longitudinal axis in case of hogging and sagging under bad sea conditions. In recent years, it becomes very important and valuable to practically, fast and nearly correct estimation of the maximum vertical bending moment just before breaks in two (collapse) under the worst conditions. The optimum (accuracy, time, practicality) estimation of these values depend on how accurate the stress-strain relation of the structural elements are established. In this first part of study, the ultimate strength behaviour of the stiffened panels in decks, bottoms and sides is estimated by developed semi-analytical method with updated orthotropic panel calculation approach under uniaxial (only longitudinal axis) compression loads. The second part of calculation is focused on the progressive collapse analysis of hull girders under longitudinal uniaxial compression with Smith Method but with different element discretization in contrast to the conventional beam-column elements. Also some benchmark studies of such methods on ultimate limit state assessment of stiffened panels and nine benchmark hull girders of ships are conducted, using some candidate methods such as IACS Common Structural Rules (CSR), FEA with Ansys v13 and HULT prepared by authors. The results from the tests, FEM analysis and different computational approaches are compared to determine performance of the method.

The developments in construction make it compulsory for architects to plan the high rise structures in RCC. Unfortunately due to some reasons like gas explosion, terrorist attack, fire etc. high rise structures undergoes some major component failure. As the major component fails, sometimes part of the structure or whole structure tends to collapse. This behavior of the structure is called as progressive collapse. Progressive collapse may be a chain reaction of failures that circulates either throughout or some of the structure lopsided to the first local failure. The progressive collapse of building structure is commenced when one or more vertical load carrying members are removed. One of the important characteristics of progressive collapse is that the final damage is not related to the initial damage. In this project it is proposed to carry out progressive collapse analysis of regular and irregular structures. Structural model of building has been fashioned din ETABS and loads are applied as per GSA guidelines, for evaluation of progressive collapse nonlinear static method of analysis has been used. The analysis is done using ETABS 18 software and using codes of analysis, IS 1893: 2016, IS 456: 2016. Joint displacements, axial force, bending moment are evaluated. In all cases progressive collapse of internal column is more critical as compared to other cases.


Author(s):  
Marco Gaiotti ◽  
Cesare Mario Rizzo ◽  
Nicole Ferrari ◽  
Adriano Montella

This paper deals with the buckling assessment of stiffened panels, typical of ship and offshore structures. In particular, rather slender structures, involving very thin plates and stiffeners with limited cross section, are considered. In order to limit the computational burden of a fully nonlinear progressive collapse analysis but, at the same time, to retain some benefits of a numerical finite element model assessment, an improved linearized buckling procedure is proposed in this work. The idea is to linearize the computation in a suitable point based on the design load of the structure, so that the results of a linearized buckling analysis are more informative in practice. Results are assessed with nonlinear collapse analyses, comprehensively considering various loading cases. Eventually, a hands-on buckling assessment procedure is suggested, which can be implemented in rules and design process if adequately validated by a suitable number of test cases and, possibly, experimental data.


Structures ◽  
2021 ◽  
Vol 33 ◽  
pp. 2166-2176
Author(s):  
Hao Zhou ◽  
Youbao Jiang ◽  
Sondipon Adhikari ◽  
Qianqian Yin ◽  
Jianguo Cai

1992 ◽  
Vol 114 (1) ◽  
pp. 1-8
Author(s):  
T. C. Thuestad ◽  
F. G. Nielsen

The Oseberg jacket was installed at the Oseberg field in the North Sea during the summer of 1987 and the production started on December 1, 1988. On March 6, 1988, a submarine accidentally impacted with the Oseberg jacket. This paper presents results from the evaluation of the importance of the damage to the overall structural safety. A nonlinear progressive collapse analysis is applied for the safety check. The theoretical computations are verified through evaluation of strain and acceleration time series recorded during the submarine impact. The reduction in the overall structural capacity of the jacket was in the order of 10 percent. However, the local member capacity was significantly reduced and it was necessary to remove the damaged member in order to obtain the initial level of safety.


2016 ◽  
Vol 123 ◽  
pp. 31-40 ◽  
Author(s):  
Behrouz Asgarian ◽  
Soheil Dadras Eslamlou ◽  
Arash E. Zaghi ◽  
Masoud Mehr

Author(s):  
José Manuel Gordo ◽  
C. Guedes Soares

The results of a four points bending test on a box girder are presented. The experiment is part of series of tests with similar configuration but with different thickness and span between frames. The present work refers to the slenderest plate box girder with a plate's thickness of 2 mm but with a short span between frames. The experiment includes initial loading cycles allowing for partial relief of residual stresses. The moment curvature relationship is established for a large range of curvature. The ultimate bending moment (UM) of the box is evaluated and compared with the first yield moment and the plastic moment allowing the evaluation of the efficiency of the structure. The postbuckling behavior and collapse mode are characterized. Comparison of the experiment with a progressive collapse analysis method is made taking into consideration the effect of residual stresses on envelop of the moment curvature curve of the structure.


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