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Estimation of buckling response of the deck panel in axial compression

Ozguc O.

Polish Maritime Research

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2018

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nr 4

98--105

EN

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.

2

Collapse mechanism analysis of a steel moment frame based on structural vulnerability theory

Jihong Y., Liqiang J.

Archives of Civil and Mechanical Engineering

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2018

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Vol. 18, no. 3

833--843

EN

This paper presents an improved method to analyze the collapse mechanism of steel moment frames based on structural vulnerability theory (SVT), in which the failure processes of the essential components are defined according to the damage characteristics of their ductile and brittle members. The improved method can accurately identify possible collapse modes of steel moment frames, because the transformation processes of such connections as beam-column joints and support joints from rigid connections to pinned ones were considered. Structural vulnerability analysis is performed on a 4-story steel frame structure by using the improved method, the results show that the collapse caused by joint failure in the first story had the maximum vulnerability index, so that the weakness of the steel frame may be located in the first story; while the collapse behaving as a “beam plastic hinge” failure, as an expected failure mode, had the minimum value. Moreover, the improved method was validated by a shaking table test due to the consistence between the experimental results and the collapse modes calculated to have the maximum vulnerability index, which demonstrates that such improved method could be effectively to predict the collapse modes of steel frame structures.

3

Identyfikacja krytycznego kinematycznego mechanizmu zniszczenia plastycznego ogarniętej pożarem stalowej ramy portalowej

Maślak M., Tkaczyk A.

Inżynieria i Budownictwo

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2015

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R. 71, nr 2

103--107

PL

Zaprezentowano algorytm wyznaczania temperatury eksponowanej ogniowo stalowej nośnej ramy portalowej, skojarzonej z aktywowaniem się w niej krytycznego mechanizmu zniszczenia plastycznego. Zaproponowano zastosowanie uogólnionego podejścia kinematycznego z wykorzystaniem identyfikacji chwilowego środka obrotu. Miarodajna temperatura jest najniższą spośród uzyskanych ze szczegółowej analizy poszczególnych kinematycznie dopuszczalnych mechanizmów zniszczenia.

EN

Calculation algorithm helpful in the specific temperature assessment for steel load-bearing portal frame exposed to fire, being associated with the activation in such a structure of critical plastic failure mechanism, is presented and discussed in detail. It is proposed to apply to do this a generalized kinematic approach using the identification of the instantaneous centre of rotation. The lowest of the values obtained from a detailed study of all kinematically admissible collapse mechanisms can be recognized to be the conclusive temperature value related to the whole considered frame.