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1

Finite element fatigue analysis of unsupported crane

Buczkowski Ryszard, Żyliński Bartłomiej

Polish Maritime Research

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2021

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nr 1

127--135

EN

The presented strength and fatigue calculations refer to an unsupported deck crane and its three distinct parts: housing, jib and column. Static loads applied to the structure were due to the crane’s own weight and a maximum working load, corresponding to a maximum lifting capacity at a maximum outreach of the crane. The numerical analysis was aimed at determining the thickness of the skin plating of the column and the number, shape and distribution of stiffeners in the column, housing and jib, ensuring that the crane yields correct strength and fatigue parameters. During the process of designing marine structures, the standard numerical analysis is, in many cases, limited to calculations in the basic strength range. Even when using numerical methods of analysis, complex strength and fatigue calculations are often not performed. The modern numerical analysis chain for marine structures should concentrate not only on strength analysis, but should take a further step, which encompasses fatigue analysis. The article presents a new outlook on design methods, which should be the entry point to the design of marine structures. Based on the acquired number of cycles of fatigue life, it is possible to estimate, with a sufficient degree of accuracy, the practical service life of a structure. To solve the problem, the authors used the finite element analysis software ABAQUS supported by the fe-safe system.

2

Fatigue strength determination of ship structural joints. Part I. Analytical methods for determining fatigue strength of ship structures

Kozak J., Górski Z.

Polish Maritime Research

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2011

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nr 2

28-36

EN

Spectacular accidents at sea which have happened for a few last years show that hull structures of contemporary sea-going ships are not perfect and must be systematically improved. Fatigue strength is one of the groups of strength problems which affect design of contemporary ship’s structures and greatly contribute in their improvement process. In this paper several approaches to estimation of fatigue life of hull structural elements are presented. In practice the some approaches based on nominal stresses, „hot spot” stresses or notch stresses which constitute the basis for fatigue life determination by using ó-N design curves are applied. In this paper the existing proposals have been critically analyzed and their drawbacks (often hidden) presented.

3

Numerical strength and fatigue analysis in application to hydraulic cylinders

Torbacki W.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 25, nr 2

65-68

EN

Purpose: The main issue of this paper is to present results of strength and fatigue limit analysis applied to piston type hydraulic cylinders. It will also shows advantages of application of the up-to-date digital chain of engineering analysis within which CAD tools are being used as well as strength and fatigue limit analysis. Design/methodology/approach: Computer analysis of the strength analysis by using Finite Element Method (FEM) and fatigue life analysis by using Fatigue Life Prediction Method (FLP) were carried out. Findings: The most strenuous and at the same time opened to a damage risk cylinder zones were localized. Two construction solution possibilities of fixing the tongue stub with a hydraulic cylinder jacket were analysed. Finally Wöhler fatigue graphs for a different values of operating average pressure and stress concentration factor were presented. Research limitations/implications: Further researches should concentrate on modifications and analysis which will help to recognize the best possible zones of fixing a tongue stub with a hydraulic cylinder jacket in order to find the best configuration of construction kinematic pair. Practical implications: Modern engineering construction analyze require not only standard strength analysis but also calculation of fatigue life. Originality/value: The paper can be useful for person who performs strength analysis with a use of finite element method but has never used digital fatigue life analysis method. It might be also useful for a person interested in recognizing of both methods.