A new approach to characterizing and modeling the high cycle fatigue properties of cast materials based on self-heating measurements under cyclic loadings

Ezanno, Anthony; Doudard, Cédric; Calloch, Sylvain; Heuzé, Jean-Loup

doi:10.1016/j.ijfatigue.2012.09.005

Cited by 35 publications

(21 citation statements)

References 29 publications

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“…The analysis of the heat build curve in order to predict the fatigue properties can be more or less complex and accurate, depending on the maturity of the constitutive description [15] or on the quality of the microstructural description [16]. In the case investigated here, these are the very first tests performed on ropes and the analysis will remain very simple.…”

Section: First Analysis Of the Heat Build-up Tests And Comparison To mentioning

confidence: 99%

Fatigue of polyamide mooring ropes for floating wind turbines

et al. 2018

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Abstract. This paper describes a study of the fatigue characterization of polyamide mooring ropes for floating wind turbines. Under some conditions polyester ropes, which are favoured for offshore platform station-keeping, are too stiff for wind turbine moorings, and polyamide may be a suitable alternative. While early studies on fatigue of braided nylon ropes showed very short lifetimes some recent results have indicated that it is possible to significantly enhance lifetime by modifying rope construction and improving fibre coatings [1]. The fatigue results presented here for ropes from a different supplier, confirm this result. In order to develop an accelerated evaluation of the fatigue performance, heat build-up tests have been performed, and promising first results are shown. Finally, the influence of coating is examined by microscopy and yarn-on-yarn tests, in order to improve understanding of the fatigue mechanisms leading to failure. IntroductionAs the development of Marine Energy Converter systems (such as wave energy generators, tidal current turbines and floating wind turbines) starts to flourish, there is a need for mooring lines in shallow water (between 50 and 100 m). Since these applications aim at harnessing marine energies, the systems are located on exposed area where dynamic loading are significant. In addition, the inherent moderate to small water depth induce a global stiff behaviour of the mooring system in using standard components as per done for deepwater floating oil platforms [1] (steel chains or polyester rope).The system integrity will be maintained by damping the dynamic loadings, so requiring the use of more stretchable fibre ropes than polyester. also examined a nylon rope which had been tested at sea for 18 months on a wave energy buoy, and showed the importance of loading history and operating conditions on nylon performance.The idea of using long term mooring lines in this material is relatively new, and there is little knowledge on the durability behaviour of such structures. It is therefore crucial to further investigate the behaviour of polyamide mooring ropes, in order to optimise their utilisation.The database is still very limited, only the paper by Ridge et al provides long lay length stranded PA rope fatigue results [3]. Thus the deployment of these fibres for permanent mooring is currently impossible due to the lack of data on their long term mechanical properties.The goals of the present study are therefore to provide a better understanding of the mechanical behaviour and the fatigue damage of these polyamide ropes, in order to help designing floating wind turbine mooring lines. However, fatigue studies are quite long and costly, this is why an evaluation of rapid characterization by heat build-up measurements [5] [6] has been included in the test programme. This kind of test has proven to be efficient on a wide range of materials [7]. These techniques have been developed and successfully applied in recent years to various polymeric materials included polyamide, from ...

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Section: First Analysis Of the Heat Build-up Tests And Comparison To mentioning

confidence: 99%

Fatigue of polyamide mooring ropes for floating wind turbines

et al. 2018

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“…Since the pioneer studies [12,13], this technique has become of considerable interest over the last few years, on metallic materials for empirical approaches [14][15][16][17] or throughout constitutive modeling [18][19][20]. This is explained mainly by the considerable development of thermography devices and analysis [16,21,22].…”

Section: Introductionmentioning

confidence: 99%

Fast screening of the fatigue properties of thermoplastics reinforced with short carbon fibers based on thermal measurements

et al. 2018

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The goal of this paper is to investigate the ability of the heat build-up technique to predict the fatigue lifetime of injected thermoplastic reinforced with short carbon fibers. Several commercial grades and filler ratios are considered here in order to challenge the ability of the technique to capture the influence of these variations. First, the materials are investigated and the mechanical and thermal protocols are described. The way to build the heat-build-up curves is outlined. Then the results obtained from the heat build-up and fatigue experiments are presented. The heat build-up curves are obtained both from measurements performed on the front surface of the sample and from the side surface. Finally, these results are used to discuss two main points. The first is the validity of the hypotheses needed to apply the approach, ranging from the evaluation of the dissipation to the fatigue response. The second is the capability to predict the fatigue curves accurately throughout an energetic criterion, and to identify the influence of the variations of matrix grade and fiber content on the fatigue properties. It appears that the predictions obtained match the results obtained from classic fatigue tests and validates the use of the technique for fast material screening.

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“…Since Reifsnider and Williams applied an IR-camera in this field for the first time [7], there is an increasing number of publications dealing with similar methods [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. Among these different activities having been published, the parameters commonly used to describe the change in temperature of defined measurement areas are [3,4,6], [5] or [12], which are given different physical meanings by different authors while the symbols being similar.…”

Section: Introductionmentioning

confidence: 99%

Characterization of the fatigue behaviour and lifetime evaluation of metallic materials based on thermographic NDT-methods

Wu¹,

Starke²,

Boller³

2018

Proceedings of the 2018 International Conference on Quantitative InfraRed Thermography

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The fatigue behaviour of a metallic material can be characterized by extracting the material response during cyclic loading. Due to the good heat conductivity of metallic materials, thermographic NDT-methods are well suited to visualize and record the dissipated heat energy of specimens during cyclic loading, which is correlated mainly with the plastic deformation caused by the applied mechanical work. The acquired data can serve as a feed-in for short-time procedures or fatigue life calculation methods. In the framework of this paper, load increase and constant amplitude tests were performed and the cyclic deformation behaviour was traced by an infrared camera system.

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A new approach to characterizing and modeling the high cycle fatigue properties of cast materials based on self-heating measurements under cyclic loadings

Cited by 35 publications

References 29 publications

Fatigue of polyamide mooring ropes for floating wind turbines

Fatigue of polyamide mooring ropes for floating wind turbines

Fast screening of the fatigue properties of thermoplastics reinforced with short carbon fibers based on thermal measurements

Characterization of the fatigue behaviour and lifetime evaluation of metallic materials based on thermographic NDT-methods

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