Experimental, theoretical and numerical fatigue damage estimation using a temperature modified Dirlik method

2015 ◽  
Vol 96 ◽  
pp. 56-65 ◽  
Author(s):  
Aleš Zalaznik ◽  
Marko Nagode
Keyword(s):  
Fatigue Damage ◽  
Damage Estimation

Spectral analysis of sine-sweep vibration: A fatigue damage estimation method

2021 ◽  
Vol 157 ◽  
pp. 107698
Author(s):  
M. Palmieri ◽  
F. Cianetti ◽  
G. Zucca ◽  
G. Morettini ◽  
C. Braccesi
Keyword(s):  
Spectral Analysis ◽  
Fatigue Damage ◽  
Estimation Method ◽  
Damage Estimation ◽  
Sine Sweep

Structural health monitoring and fatigue damage estimation using vibration measurements and finite element model updating

2018 ◽  
Vol 18 (4) ◽  
pp. 1189-1206 ◽  
Author(s):  
Dimitrios Giagopoulos ◽  
Alexandros Arailopoulos ◽  
Vasilis Dertimanis ◽  
Costas Papadimitriou ◽  
Eleni Chatzi ◽  
...  
Keyword(s):  
Finite Element ◽  
Structural Health Monitoring ◽  
Finite Element Model ◽  
Fatigue Damage ◽  
Health Monitoring ◽  
Model Updating ◽  
Element Model ◽  
Finite Element Model Updating ◽  
Damage Estimation ◽  
Vibration Measurements

Empirical Procedures for Long-Term Prediction of Fatigue Damage for an Instrumented Marine Riser

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
C. Shi ◽  
L. Manuel ◽  
M. A. Tognarelli
Keyword(s):  
Fatigue Damage ◽  
Field Measurements ◽  
Damage Estimation ◽  
Current Profile ◽  
Short Term ◽  
Response Characteristics ◽  
Damage Rate ◽  
Using Data ◽  
Analytical Approaches

Slender marine risers used in deepwater applications can experience vortex-induced vibration (VIV). It is becoming increasingly common for field monitoring campaigns to be undertaken wherein data loggers such as strain sensors and/or accelerometers are installed on such risers to aid in VIV-related fatigue damage estimation. Such damage estimation relies on the application of empirical procedures that make use of the collected data. This type of damage estimation can be undertaken for different current profiles encountered. The empirical techniques employed make direct use of the measurements and key components in the analyszes (such as participating riser modes selected for use in damage estimation) are intrinsically dependent on the actual current profiles. Fatigue damage predicted in this manner is in contrast to analytical approaches that rely on simplifying assumptions on both the flow conditions and the response characteristics. Empirical fatigue damage estimates conditional on current profile type can account explicitly even for complex response characteristics, participating riser modes, etc. With significant amounts of data, it is possible to establish “short-term” fatigue damage rate distributions conditional on current type. If the relative frequency of different current types is known from metocean studies, the short-term fatigue distributions can be combined with the current distributions to yield integrated “long-term” fatigue damage rate distributions. Such a study is carried out using data from the Norwegian Deepwater Programme (NDP) model riser subject to several sheared and uniform current profiles and with assumed probabilities for different current conditions. From this study, we seek to demonstrate the effectiveness of empirical techniques utilized in combination with field measurements to predict the long-term fatigue damage and the fatigue failure probability.

Critical Evaluation of Frequency-Domain Approach for Fatigue Damage Estimation

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Gašper Vidic ◽  
Marko Nagode
Keyword(s):  
Frequency Domain ◽  
Fatigue Damage ◽  
Input Data ◽  
Critical Evaluation ◽  
High Amplitude ◽  
Damage Estimation ◽  
Accumulated Damage ◽  
Power Spectral ◽  
History Of ◽  
Frequency Domain Approach

Frequency-domain approach for fatigue damage estimation and lifetime prediction of mechanical components is often used for its computational efficiency and the capability to give a synthetic representation of a random process. The problem with the approach is that the input data, the stress power spectral density (PSD), may not include the information about potential small amount of high amplitude cycles which can substantially increase the accumulated fatigue damage. The paper investigates the scatter of the accumulated damage in generated random stress histories and compares them to the results obtained by a frequency-domain approach—the Dirlik method. The results show a possibility of a severe underestimation of accumulated damage when using frequency-domain approach. In case a typical stress, history of a certain mechanical component includes sporadic high amplitude cycles their effect shoud be taken into consideration when using frequency-domain approach.

An Empirical Procedure for Fatigue Damage Estimation in Instrumented Risers

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
C. Shi ◽  
L. Manuel
Keyword(s):  
Fatigue Damage ◽  
Waveform Analysis ◽  
Damage Estimation ◽  
Response Characteristics ◽  
Empirical Procedure ◽  
Natural Modes ◽  
Spatial Modes ◽  
Few Data ◽  
Proper Orthogonal ◽  
Sensor Locations

In order to assess the effects of vortex-induced vibration (VIV) and to ensure riser integrity, field monitoring campaigns are often conducted wherein the riser response is recorded by a few data sensors distributed along the length of the riser. In this study, two empirical techniques–proper orthogonal decomposition (POD) and weighted waveform analysis (WWA)–are sequentially applied to the data; together, they offer a novel empirical procedure for fatigue damage estimation in an instrumented riser. The procedures are briefly described as follows: first, POD is used to extract the most energetic spatial modes of the riser response from the measurements, which are defined only at the available sensor locations. Accordingly, a second step uses WWA to express each dominant POD mode as a series of riser natural modes that are continuous spatial functions defined over the entire riser length. Based on the above empirically identified modal information, the riser response over the entire length is reconstructed in reverse–i.e., compose identified natural modes into the POD modes and, then, assemble all these dominant POD modal response components into the derived riser response. The POD procedure empirically extracts the energetic dynamic response characteristics without any assumptions and effectively cleans the data of noisy or less important features; this fundamental application of WWA is used to identify dominant riser natural modes–all this is possible using the limited number of available measurements from sensor locations. Application of the procedure is demonstrated using experimental data from the Norwegian Deepwater Programme (NDP) model riser.

Analytical Method of Fatigue Damage Estimation for Compressor Stator Blades of Gas Turbines Experiencing Rotating Stall

2002 ◽  
Author(s):  
Yasushi Hayasaka ◽  
Shigeo Sakurai ◽  
Takeshi Kudo ◽  
Kunihiro Ichikawa
Keyword(s):  
Stress Analysis ◽  
Fatigue Damage ◽  
Analytical Method ◽  
Gas Turbines ◽  
Estimation Method ◽  
Rotating Stall ◽  
Environmental Data ◽  
Response Analysis ◽  
Damage Estimation ◽  
Stress Peak

To improve the reliability of compressor stator blades of gas turbines, an analytical method for estimating their fatigue damage has been developed. This method is based on blade-vibratory-stress analysis, stress-peak counting, and use of actual environmental data. The blade-vibratory-stress analysis takes the superposition of multi-peaks of the stress spectrum into account. The numerically simulated stress showed better agreement with measured stress than that from a conventional stress analysis, which is based on frequency-response analysis considering a single peak of the lowest single eigen-vibration-mode. A time-domain stress history was synthesized from the blade-vibratory-stress analysis results. Furthermore, the fatigue damage of the blade under rotating stall was estimated by the linear-damage-rule from the stress-peak counting of the stress and from material data. The estimated fatigue-damage agrees well with the measured results. This agreement means that our new fatigue-damage-estimation method is more accurate than the conventional one.

Empirical Procedures for Long-Term Prediction of Fatigue Damage for an Instrumented Marine Riser

2011 ◽  
Author(s):  
C. Shi ◽  
L. Manuel ◽  
M. A. Tognarelli
Keyword(s):  
Fatigue Damage ◽  
Field Measurements ◽  
Damage Estimation ◽  
Current Profile ◽  
Short Term ◽  
Response Characteristics ◽  
Damage Rate ◽  
Using Data ◽  
Analytical Approaches

Slender marine risers used in deepwater applications can experience vortex-induced vibration (VIV). It is becoming increasingly common for field monitoring campaigns to be undertaken wherein data loggers such as strain sensors and/or accelerometers are installed on such risers to aid in VIV-related fatigue damage estimation. Such damage estimation relies on the application of empirical procedures that make use of the collected data. This type of damage estimation can be undertaken for different current profiles encountered. The empirical techniques employed make direct use of the measurements and key components in the analyses (such as participating riser modes selected for use in damage estimation) are intrinsically dependent on the actual current profiles. Fatigue damage predicted in this manner is in contrast to analytical approaches that rely on simplifying assumptions on both the flow conditions and the response characteristics. Empirical fatigue damage estimates conditional on current profile type can account explicitly even for complex response characteristics, participating riser modes, etc. With significant amounts of data, it is possible to establish “short-term” fatigue damage rate distributions conditional on current type. If the relative frequency of different current types is known from metocean studies, the short-term fatigue distributions can be combined with the current distributions to yield integrated “long-term” fatigue damage rate distributions. Such a study is carried out using data from the Norwegian Deepwater Programme (NDP) model riser subject to several sheared and uniform current profiles and with assumed probabilities for different current conditions. From this study, we seek to demonstrate the effectiveness of empirical techniques utilized in combination with field measurements to predict long-term fatigue damage and life.

Sign in / Sign up

Export Citation Format

Share Document