Asphalt material fatigue test under cyclic loading: the lengthening of samples as a way to characterize the material damage experiments and modelling

2005 ◽  
Vol 38 (1) ◽  
pp. 115-119 ◽  
Author(s):  
Y. Lefeuvre ◽  
C. de La Roche ◽  
J. -M. Piau
Keyword(s):  
Cyclic Loading ◽  
Fatigue Test ◽  
Material Damage ◽  
Material Fatigue

Fatigue Performance of Concrete with Pre-Cracks in Tension-Compression Cycles

2014 ◽  
Vol 584-586 ◽  
pp. 1054-1061
Author(s):  
Jian Shen ◽  
Xiao Yun Liu ◽  
Lang Wu
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
Cyclic Loading ◽  
Fatigue Test ◽  
Stress Ratio ◽  
Fatigue Property ◽  
Fatigue Performance ◽  
Cycle Fatigue ◽  
Fatigue Load ◽  
Compression Cycle

A tension-compression cycle fatigue test was performed in order to study the fatigue property of C50 concrete with pre-cracks in cyclic loading. The stress ratio was-1 and the amplitude was 0.2 MPa ~1.30 MPa. The results show that the modified coefficient of fatigue strength is 0.198~0.265 and the infinite life fatigue strength is below 0.45MPa. While the log value of fatigue life is approximately linear with the amplitude of fatigue load stress, the discreteness of fatigue life, the particularity of concrete, has little to do with the amplitude. The S-N, P-N fatigue life curves and the constant fatigue life diagram of pre-crack concrete are obtained.

scholarly journals PERANCANGAN ULANG ALAT UJI FATIGUE ROTARY BENDING

POROS ◽  
2017 ◽  
Vol 13 (2) ◽  
pp. 42
Author(s):  
Clementinus Benny Agung Pambayu ◽  
Agustinus Purna Irawan ◽  
Didi Widya Utama
Keyword(s):  
Yield Strength ◽  
Fatigue Test ◽  
Design Tool ◽  
Dynamic Loads ◽  
Test Equipment ◽  
Digital Readout ◽  
Material Fatigue ◽  
Long Time

Abstract: Fatigue is a form of failure that occurred in the structure due to fluctuating dynamic loads that occur below the yield strength for a long time and repeatedly. Determines the required material fatigue test equipment fatigue. Fatigue test equipment is designed with rotary bending systems. Re-design tool that was originally done to digitize readings manually replaced with a digital readout. Digitization include the addition of pulse digital meter, digital meter counter and the system auto shutdown. The addition of a digital readout to facilitate the conduct of research and testing of materials. 

A Probabilistic Approach for Determining the Component’s Dimension Under Fatigue Loadings

2009 ◽  
Author(s):  
Xiaobin Le ◽  
Jahan Rasty
Keyword(s):  
Fatigue Test ◽  
Test Data ◽  
Probabilistic Approach ◽  
Random Variables ◽  
Random Variable ◽  
Design Equation ◽  
Probabilistic Design ◽  
Material Fatigue ◽  
Stress Levels ◽  
Design Scenario

Due to inherent scatters in fatigue test data, the P-S-N curves are normally used to describe material fatigue behaviors. For probabilistic component’s design under fatigue loadings, the component’s dimension should be treated as a random variable because every dimension is certainly with a dimension tolerance. In this design scenario, it is difficult to determine the component’s dimension under fatigue loadings by using the P-S-N curves because stress levels are unknown and random variables. In this paper, a probabilistic approach is presented to build a generic probabilistic design equation which is governed by random variables related to material fatigue behaviors, component conditions and fatigue loadings. The generic probabilistic design equation can be used to determine component’s dimension with a given reliability. One example is presented for explaining the approach in details.

Statistical Analysis of Fatigue Test Data

2017 ◽  
Author(s):  
Carol Johnston
Keyword(s):  
Statistical Analysis ◽  
Fatigue Strength ◽  
Cyclic Loading ◽  
Fatigue Test ◽  
Test Data ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Test Results ◽  
Girth Welds ◽  
New Procedures

The offshore environment contains many sources of cyclic loading. Standard design S-N curves, such as those in DNVGL-RP-C203, are usually assigned to ensure a particular design life can be achieved for a particular set of anticipated loading conditions. Girth welds are often the ‘weak link’ in terms of fatigue strength and so it is important to show that girth welds made using new procedures for new projects that are intended to be used in fatigue sensitive risers or flowlines do indeed have the required fatigue performance. Alternatively, designers of new subsea connectors, used for example in tendons for tension leg platforms, mooring applications or well-heads which will experience cyclic loading in service, also wish to verify the fatigue performance of their new designs. Often operators require contractors to carry out resonance fatigue tests on representative girth welds in order to show that girth welds made using new procedures qualify to the required design S-N curve. Operators and contractors must then interpret the results, which is not necessarily straightforward if the fatigue lives are lower than expected. Many factors influence a component’s fatigue strength so there is usually scatter in results obtained when a number of fatigue tests are carried out on real, production standard components. This scatter means that it is important first to carry out the right number of tests in order to obtain a reasonable understanding of the component’s fatigue strength, and then to interpret the fatigue test results properly. A working knowledge of statistics is necessary for both specifying the test programme and interpreting the test results and there is often confusion over various aspects of test specification and interpretation. This paper describes relevant statistical concepts in a way that is accessible to non-experts and that can be used, practically, by designers. The paper illustrates the statistical analysis of test data with examples of the ‘target life’ approach (that is now included in BS7608:2014 + A1) and the equivalent approach in DNVGL-RP-C203, which uses the stress modification factor. It gives practical examples to designers of a pragmatic method that can be used when specifying test programmes and interpreting the results obtained from tests carried out during qualification programmes, which for example, aim to determine whether girth welds made using a new procedure qualify to a particular design curve. It will help designers who are tasked with specifying test programmes to choose a reasonable number of test specimens and stress ranges, and to understand the outcome when results have been obtained.

A thermodynamic model for material fatigue under cyclic loading

2012 ◽  
Vol 407 (9) ◽  
pp. 1415-1416 ◽  
Author(s):  
Michela Eleuteri ◽  
Jana Kopfová ◽  
Pavel Krejčí
Keyword(s):  
Cyclic Loading ◽  
Thermodynamic Model ◽  
Material Fatigue

A New Method to Determine the Fatigue Limit and the p-S-N Curve

2012 ◽  
Vol 248 ◽  
pp. 256-261 ◽  
Author(s):  
Jian Ming Zhai ◽  
Xiao Yang Li
Keyword(s):  
Density Distribution ◽  
Probability Density ◽  
Fatigue Limit ◽  
Fatigue Test ◽  
Conditional Probability ◽  
Mechanical Design ◽  
New Method ◽  
Conditional Probability Density ◽  
Probability Density Distribution ◽  
Material Fatigue

The performances of material fatigue can be illustrated by the S-N curve, the p-S-N curve and the fatigue limit, which are very important to engineering and the mechanical design. Recently, the author proposed a new method to determine a conditional probability density distribution surface(CPDDS) of the material, and the surface can reflects most properties of the material’s fatigue. Methods to obtain the theoretical fatigue limit and the p-S-N curve are introduced in this paper on the basis of previous study. The methods are applied on the fatigue test data of C45 steel, and the p-S-N curves that obtained by various methods are compared in this paper.

scholarly journals Innovative Adaptive Control of Material Fatigue Test Machines Using an MCS Controller

2018 ◽  
Vol 1 (1) ◽  
pp. 287-294
Author(s):  
Adam Heyduk ◽  
Krystian Kalinowski ◽  
Roman Kaula ◽  
Joachim Pielot
Keyword(s):  
Fatigue Test ◽  
Feedback Loop ◽  
Fatigue Testing ◽  
Reference Signal ◽  
Nonlinear Behavior ◽  
Fatigue Tests ◽  
Significant Deterioration ◽  
New Approach ◽  
Control Quality ◽  
Material Fatigue

Abstract The paper presents some issues related to the control of fatigue test machines based on W(t) parameter taking into account the simultaneous interaction of stress and strain. This parameter is defined as a product of these values. Such a research method represents a new approach in fatigue testing with an innovative control system. Because of the W(t) function characteristics, the system presents nonlinear behavior and there is a significant deterioration of the control quality and the controlled signal significantly differs from the reference signal waveform. This problem can be solved by introducing a nonlinear block into the feedback loop. Fatigue tests have been carried out for sinusoidal and randomized reference signal waveforms. These tests have proved that the controlled signal follows reference values with an appropriate control quality.

Sign in / Sign up

Export Citation Format

Share Document