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1

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

Imperfekcje pierwotne w budynkach wielkopłytowych

Knyziak P., Bieranowski P.

Inżynieria i Budownictwo

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2018

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R. 74, nr 6

297--300

PL

Przedstawiono wybrane przykłady imperfekcji geometrycznych, materiałowych i projektowych dotyczących wykonania i montażu prefabrykatów wielkowymiarowych. Podano normowe dopuszczalne wartości odchyłek wymiarów i montażu prefabrykatów.

EN

The article presents selected examples of geometrical, material and design imperfections of manufacturing and assembly of large size precast concrete elements. Limit values of dimensional deviations and assembly of precast elements specified in technical standards are given.

3

Postbuckling of an Imperfect Plate Subjected to the Shear Load

Psotny M.

Mechanics and Mechanical Engineering

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2016

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Vol. 20, nr 2

177--184

EN

The stability analysis of an imperfect plate subjected to the shear load is presented, a specialized code based on FEM has been created. The nonlinear finite element method equations are derived from the variational principle of minimum of total potential energy. To obtain the nonlinear equilibrium paths, the Newton–Raphson iteration algorithm is used. Corresponding levels of the total potential energy are defined. The peculiarities of the effects of the initial imperfections are investigated. Special attention is paid to the influence of imperfections on the post–critical buckling mode. Obtained results are compared with those gained using ANSYS system.

4

Buckling of imperfect thick cylindrical shells and curved panels with different boundary conditions under external pressure

Alashti R. A., Ahmadi S. A.

Journal of Theoretical and Applied Mechanics

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2014

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Vol. 52 nr 1

25--36

EN

In this paper, the effects of initial imperfections on the buckling behavior of thick cylindrical shells and curved panels are investigated. It is assumed that the shell has an axisymmetric and periodic initial imperfection in the axial direction. The shell is assumed to have different boundary conditions and subjected to pure external pressure loading. Governing differential equations are developed on the basis of the second Piola-Kirchhoff stress tensor and are re- duced to a homogenous linear system of equations using the differential quadrature method. The effects of different boundary conditions, geometric ratios, curvature and imperfection parameter on the buckling behavior of isotropic thick cylindrical shells and curved panels are carefully discussed. The results obtained by the present method are verified with finite element solutions and those reported in the literature.

5

Imperfections in calculations of guyed lattice masts

Matuszkiewicz M.

Archives of Civil Engineering

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2014

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Vol. 60, nr 4

409--420

EN

Influence of geometric imperfections of mast shaft in form of initial mast span curvatures both on internal forces status in the structure elements as well as on those elements effort, which is particularly important at the design stage, was analysed based on an example of certain specific mast. The calculations were performed taking into account L/1000 imperfections equal to the permissible assembly deviations as per [1], and L/500 equal to initial imperfections as for uniform built-up columns according to [2]. Remarks and final conclusions have practical meaning and can be useful in design practice.