Constant Amplitude of Prestressed Concrete Sleeper (PCS) Subjected to Three Coaches Train

- Concrete sleeper is the main structrural component in railways track. Concrete sleeper is used to transmit the load from the train to the ballast. In this study, the pattern of load applied to the concrete sleeper was determined. The pattern of load is important as it affecting the design and lifetime of conrete sleeper. The raw data for load of train will produced variable amplitude value as the concrete sleeper will be experiencing the different type of loading. The value of raw data when the wheel of train hit the concrete sleeper will be higher than the raw data when the conrete sleeper is experiencing vibration due to incoming train. In this study, the pattern of load will be analysed to understand the behaviour of the load applied to concrete sleeper. Other than that, the variable amplitude value of raw data will convert into a constant amplitude value using a method of calculation. The determination of constant value amplitude will be divided into N-section to finding the maximum and minimum value for the section. In addition, the actual number of cycle from the raw data will determined using Rainflow Counting method. This study can be further used for laboratory work as it’s determine the suitable loading and cycle applied to the concrete sleeper under dynamic loading.

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CONSTANT AMPLITUDE SPECTRUM OF THREE COACHES TRAIN AND CYCLIC COUNTING ON PRESTRESSED CONCRETE SLEEPERS (PCS)

Jurnal Teknologi ◽

10.11113/jt.v76.5873 ◽

2015 ◽

Vol 76 (11) ◽

Cited By ~ 2

Author(s):

Mohd Ikmal Fazlan R. ◽

Sharul Nizam I. ◽

Afidah A.B. ◽

Siti Hawa H.

Keyword(s):

Prestressed Concrete ◽

Constant Amplitude ◽

Counting Method ◽

Loading Test ◽

Freight Train ◽

Variable Amplitude ◽

Amplitude Data ◽

Strain Data ◽

Rainflow Cycle Counting ◽

Current Loading

The raw strain data collected from Keretapi Tanah Melayu Berhad (KTMB) railway are in variable amplitude. This paper discovers how the variable amplitude data can be changed to the constant amplitude data. It is found that the raw strain data is not suitable for fatigue and strength testing on Prestressed Concrete Sleepers (PCS). Apart from that, the most suitable method in determining the numbers of cycles is Rainflow Cycle Counting Method. Through rainflow cycle counting method, the number of cycles is determined. The numbers of cycles are used to simplify the laboratory test such as fatigue and strength test for the PCS. The frequencies of dynamic loading test on the PCS are set based the numbers of cycles. The constant strain data are also converted into constant loading data using the relationship of stress-strain and loading-stress. Constant amplitude loading will again simplify the laboratory testing. The goal is to show that the designs used in PCS are appropriate based on current loading demand. Then, a comparison of constant amplitude data is made between different numbers of coaches and freight train. The maximum data from the comparison shows that the higher loadings are obtained from freight train.

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CONVERTING CONSTANT AMPLITUDE LOADING OF PRESTRESSED CONCRETE SLEEPER (PCS) FROM VARIABLE AMPLITUDE

Jurnal Teknologi ◽

10.11113/jt.v76.5910 ◽

2015 ◽

Vol 76 (11) ◽

Author(s):

Sharul Nizam I. ◽

Afidah A.B. ◽

Siti Hawa H. ◽

Mohd Ikmal Fazlan R.

Keyword(s):

Fatigue Life ◽

Prestressed Concrete ◽

Constant Amplitude ◽

Variable Loading ◽

Study Variable ◽

Variable Amplitude ◽

Railway System ◽

Rainflow Cycle Counting ◽

Number Of Cycles ◽

Stress Block

Prestressed Concrete Sleepers are structures that support railway system and absorb variable loading from the train that pass along the rail. In this study, variable amplitude loading from PCS taken from site measurement was converted into constant amplitude loading. Therefore the number of cycles and frequency are also important to be determined. There are various method for counting the number of cycles and the best adoptive method was Rainflow Cycle Counting. Once the number of cycles is obtained as well as the constant amplitude stress in a series of stress block, the prediction of fatigue life of PCS can be analyzed by further research in the laboratory work. However the limitation of this study is only to obtain the constant amplitude loading of PCS and also counting the number of cycles in various series of stress blocks.

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Alternative Fatigue Lifetime Prediction Formulations for Variable-Amplitude Loading

ASME 2002 Wind Energy Symposium ◽

10.1115/wind2002-22 ◽

2002 ◽

Cited By ~ 1

Author(s):

R. P. L. Nijssen ◽

D. R. V. van Delft ◽

A. M. van Wingerde

Keyword(s):

Turbine Rotor ◽

Rotor Blades ◽

Lifetime Prediction ◽

Constant Amplitude ◽

Variable Amplitude Loading ◽

Variable Amplitude ◽

Amplitude Data ◽

The Difference ◽

Rainflow Counting ◽

Sn Curve

Possible alternative fatigue formulations to predict lifetime under variable-amplitude loading are investigated. Test results of WISPER and WISPERX variable-amplitude tests on a material representative for wind turbine rotor blades are used. All fatigue calculations are performed using Rainflow counting of the WISPER(X) load histories and employing the Miner summation. The formulation of the SN-curve and the constant-life diagram are varied. Commonly, a log-log SN-curve is used in combination with a linear Goodman constant-life relation. However, in previous work, it was found that these formulations overestimate lifetime of specimens subjected to the variable-amplitude WISPER and WISPERX load histories. This previous work suggested that the SN-formulation be changed and also used an alternative constant-life formulation with parallel lines. These formulations and variations on them are investigated. Also, constant-amplitude data for R = 0.1 are included to construct an alternative constant-life diagram. Including R = 0.1 constant-amplitude data in the lifetime predictions for WISPER(X) seems to improve the accuracy of the calculation. The alternative constant-life formulation might remove the non-conservatism from the lifetime prediction and account for the difference in lifetime between WISPER and WISPERX.

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