Fatigue Life Assessment of Crane Reel

2011 ◽  
Vol 383-390 ◽  
pp. 2941-2944
Author(s):  
Wei Ming Du ◽  
Fei Xue

The crane reel is generally manufactured by section welding method when the diameter is over 380mm. With the cumulative fatigue damage principle which is based on stress S-N curve, the fatigue damage of one crane reel is analyzed by finite element method, the reel weld fatigue strength and fatigue life are calculated, and the simulation results are proved to be reliable. This method provides an efficient reference for crane reel design and residual life estimation.

2013 ◽  
Vol 569-570 ◽  
pp. 88-95 ◽  
Author(s):  
Pablo Zuluaga-Ramírez ◽  
Malte Frövel ◽  
René Restrepo ◽  
Rafael Trallero ◽  
Ricardo Atienza ◽  
...  

A strong knowledge of the fatigue state of highly advanced carbon fiber reinforced polymer composite (CFRP) structures is essential to predict the residual life and optimize intervals of structural inspection, repairs, and/or replacements. Current techniques are based mostly in measurement of structural loads throughout the service life by electric strain gauge sensors. These sensors are affected by extreme environmental conditions and by fatigue loads in such a way that the sensors and their systems require exhaustive maintenance throughout system life.This work is focused on providing a new technique to evaluate the fatigue state of CFRP structures by means of evaluating the surface roughness variation due to fatigue damage. The surface roughness is a property that can be measured in the field by optical techniques such as speckle and could be a useful tool for structural health monitoring. The relation between surface roughness and fatigue life has been assessed on CFRP test specimens. A tensile fatigue load with an R=0.1 (T-T) and a maximum load of 60% of the material ultimate strength has been applied. The surface roughness of the specimens has been determined from the surface topography measured by a high precision confocal microscope. Results show that the surface roughness of the specimens increases with the accumulation of fatigue cycles in such a way that the roughness could be taken into account as a fatigue damage metrics for CFRP.


2014 ◽  
Vol 945-949 ◽  
pp. 1086-1089
Author(s):  
Bin Xu ◽  
Tao Zhang ◽  
Feng Qi Wu ◽  
Zhen Rong Yan

Ship unloader crane was widely used in transportation, and uploaded or unloaded cargoes from ships, which could influence efficiency and benefits of transportation greatly. In order to improve the reliability and safety, and decrease its risk in working flow, a method of fatigue life assessment was proposed in this paper. According to related standards and properties of risk, finite element method and experimental stress analysis were integrated to assess the working condition of a ship unloader crane. Finite element models of primary structures subjected to loads were built to achieve dynamic properties, which could supply a basic reference to experiment and guidance to locate the tested positions. Afterwards, wireless dynamic resistance strain-gauges were adopted to execute static and dynamic stress, and the tested results combined with finite element analysis were applied to strength analysis. Based on nominal stress and Miner principle, rainflow method was developed to fatigue life assessment of this ship unloader crane. The final results indicated that residual life of this crane was 4.67 years.


Author(s):  
Zhigang Wei ◽  
Pingsha Dong ◽  
Litang Gao ◽  
Robert Kurth

Risk based treatment of degradation and failure in engineering components is an important topic in recent years with an emphasis on obtaining more detailed information for extreme events. Fatigue damage and life degradation caused by variable amplitude cyclic loading is dominated by such extreme events, and can be properly treated with the extreme value theory, which could help understand the damage nature of the fatigue damage process as well as to provide more efficient and robust approaches for engineering applications. In this paper, advanced extreme value theory is reviewed first. Methods such as peak counting, block maxima, and peaks over thresholds are investigated and compared in this paper with an emphasis on the relationship between the extreme value theory and the existing methods for fatigue life assessment. A few simple examples of uniaxial and multi-axial fatigue life assessment process are provided and the results are discussed. It is found that, if properly used, the extreme value theories can improve the efficiency of fatigue life assessment. Finally, a hybrid time- and frequency-based multi-axial fatigue life assessment procedure is proposed for wide band loadings.


2014 ◽  
Vol 891-892 ◽  
pp. 1717-1722
Author(s):  
Teuku Edisah Putra ◽  
Shahrum Abdullah ◽  
Dieter Schramm ◽  
Mohd Zaki Nuawi ◽  
Tobias Bruckmann

The study presents the development of a wavelet-based segmentation algorithm for fatigue life assessment. Strain data was extracted using the Morlet family. The extraction process identified damaging segments, and it was able to shorten the original signal by 74.3%, with less than 10% difference with statistical parameters. The extraction algorithm was able to retain at least 97.9% of fatigue damage. The damaging segments drawn were clustered using the k-means method to provide three groups of segments, i.e., lower, moderate, and higher groups representing statistical values. The approach was suggested as an alternative method for evaluating and clustering fatigue strain signals.


Author(s):  
Esakki Muthu Shanmugam ◽  
Raghu V. Prakash ◽  
Shakthivel Ammaiappan

The fatigue life of the titanium alloy axial compressor rotor blade was estimated based on stress based life method. The fatigue life of the compressor blade was evaluated through incremental amplitude test method. The incremental amplitude test method involves cumulative fatigue damage at different stress levels by using Miner’s Hypothesis. The probabilistic analysis of fatigue life was carried out by Weibull distribution method. The analytical and test methods results were compared and found satisfactory.


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