Applicability of Hollow Cylindrical Specimens to Environmental Assisted Fatigue Tests

2017 ◽  
Author(s):  
Seiji Asada ◽  
Kazuya Tsutsumi ◽  
Yuichi Fukuta ◽  
Hiroshi Kanasaki
Keyword(s):  
Fatigue Test ◽  
Cylindrical Specimen ◽  
Fatigue Tests ◽  
Test Facility ◽  
Testing Method ◽  
Research Institutes ◽  
Solid Specimen ◽  
Hollow Cylindrical Specimen

When an environmental assisted fatigue (EAF) test is performed, the surface of a specimen has to contact with simulated LWR water. Autoclave equipment with a solid specimen is a commonly used method for EAF testing. It, however, takes time to setup a specimen into the autoclave and also it is necessary to strive to directly measure the displacement of the specimen. Another EAF testing method, which has been utilized by several research institutes, is to use a hollow cylindrical specimen. The hollow cylindrical specimen does not need the autoclave equipment and can be easily assembled to the fatigue test facility. This paper introduces the EAF test using the hollow cylindrical specimen, comparison between fatigue lives by hollow cylindrical specimens and solid specimens and gives some technical notes to use the hollow cylindrical specimen.

Concepts and Techniques for Helicopter Airframe Fatigue Tests

1966 ◽  
Vol 11 (3) ◽  
pp. 45-57 ◽  
Author(s):  
Walter A. Lane
Keyword(s):  
Experimental Design ◽  
Fatigue Test ◽  
Structural Integrity ◽  
Fatigue Cracking ◽  
Fatigue Tests ◽  
Test Facility ◽  
Test Results ◽  
Fail Safe ◽  
Inspection Techniques ◽  
Automatic Simulation

Between February 1961 and June 1963, Sikorsky Aircraft, under the sponsorship of the U. S. Navy Bureau of Naval Weapons, performed the first laboratory fatigue test of a full scale helicopter airframe. This paper presents the concepts and techniques developed by Sikorsky for such tests. Airframe fatigue test concepts are directed toward defining modes of fatigue cracking, measuring rates of crack propagation, and demonstrating the adequacy of recommended inspection techniques and intervals to provide “fail safe” structural integrity. The experimental design includes consideration of the test article configuration, acceleration of test loads, loading spectra, and evaluation of test fractures. The design of the SH‐3A airframe fatigue test facility to provide automatic simulation of flight and landing loads, and the development problems encountered in achieving this capability are described. The facility and techniques to be used for CH‐53A airframe fatigue tests reflect improvements resulting from SH‐3A test experience. Correlation of airframe fatigue test results and service experience demonstrates the validity of the test concepts and techniques as well as the “fail safe” characteristics of the SH‐3A airframe.

scholarly journals Analysis of the Correlation between the Static and Fatigue Test Results of the Interlayer Bondings of Asphalt Layers

2016 ◽  
Vol 62 (1) ◽  
pp. 83-98 ◽  
Author(s):  
A. Szydło ◽  
K. Malicki
Keyword(s):  
Fatigue Life ◽  
Fatigue Test ◽  
Asphalt Mixture ◽  
Fatigue Tests ◽  
Test Results ◽  
Static Tests ◽  
Bonding State ◽  
Road Pavement ◽  
The Future ◽  
Pavement Structure

Abstract The bonding state of the asphalt layers in a road pavement structure significantly affects its fatigue life. These bondings, therefore, require detailed tests and optimization. In this paper, the analyses of the correlation between the results of laboratory static tests and the results of fatigue tests of asphalt mixture interlayer bondings were performed. The existence of the relationships between selected parameters was confirmed. In the future, the results of these analyses may allow for assessment of interlayer bondings’ fatigue life based on the results of quick and relatively easy static tests.

Fatigue Capacity of Stiffener to Web Frame Connections

2009 ◽  
Author(s):  
Torbjo̸rn Lindemark ◽  
Inge Lotsberg ◽  
Joong-Kyoo Kang ◽  
Kwang-Seok Kim ◽  
Narve Oma
Keyword(s):  
Fatigue Test ◽  
Test Data ◽  
Large Scale ◽  
Fatigue Tests ◽  
Life Assessment ◽  
Shear Stresses ◽  
Test Model ◽  
The Difference ◽  
Marine Engineering ◽  
Plate Connections

Daewoo Shipbuilding & Marine Engineering Co., Ltd. (DSME), StatoilHydro and DNV established a common project to investigate the reason for the difference between calculated fatigue lives and the in-service experience and to assess the fatigue capacity of stiffener web connections subjected mainly to web frame shear stresses. The main objective of the work was to establish fatigue test data and perform numerical analysis of collar plate connections in order to provide improved confidence in analysis methodology for fatigue life assessment. Large scale fatigue tests of different types of connections were carried out to obtain fatigue test data of collar plate connections. Finite element analyses were carried out for comparison with fatigue test data and with measured stresses on the test model. Based on this work recommendations on fatigue design analysis of connections between stiffeners and web frames have been derived. The background for this is presented in this paper.

scholarly journals The methodology for measuring the vibration amplitude of the blade of the aircraft engine compressor in the fatigue test

Mechanik ◽  
2018 ◽  
Vol 91 (3) ◽  
pp. 230-232
Author(s):  
Leszek Bielenda ◽  
Wojciech Obrocki ◽  
Maciej Masłyk ◽  
Jan Sieniawski
Keyword(s):  
Fatigue Test ◽  
Eddy Current ◽  
Vibration Amplitude ◽  
Aircraft Engine ◽  
Fatigue Tests ◽  
Compressor Blade ◽  
Additional Test ◽  
Blade Vibration ◽  
Comparison Research ◽  
Engine Compressor

Results of comparison research of various sensors types used in the fatigue tests for aircraft engine compressor blade vibration amplitude measurement were analysed. Sensors under tests: inductive, capacitive, eddy-current, laser and vibration. Presented were sensors characteristics and their faults. Additional test stand instrumentation was designed and performed, including mounting bracket.

scholarly journals An Ultra-High Frequency Vibration-Based Fatigue Test and Its Comparative Study of a Titanium Alloy in the VHCF Regime

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1415
Author(s):  
Wei Xu ◽  
Yanguang Zhao ◽  
Xin Chen ◽  
Bin Zhong ◽  
Huichen Yu ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Fatigue Test ◽  
High Frequency ◽  
High Efficiency ◽  
Fatigue Tests ◽  
Loading Frequency ◽  
Fatigue Specimen ◽  
Ultra High Frequency ◽  
High Frequency Vibration ◽  
Testing Data

This paper proposes an ultra-high frequency (UHF) fatigue test of a titanium alloy TA11 based on electrodynamic shaker in order to develop a feasible testing method in the VHCF regime. Firstly, a type of UHF fatigue specimen is designed to make its actual testing frequency reach as high as 1756 Hz. Then the influences of the loading frequency and loading types on the testing results are considered separately, and a series of comparative fatigue tests are hence conducted. The results show the testing data from the present UHF fatigue specimen agree well with those from the conventional vibration fatigue specimen with the loading frequency of 240 Hz. Furthermore, the present UHF testing data show good consistency with those from the axial-loading fatigue and rotating bending fatigue tests. But the obtained fatigue life from ultrasonic fatigue test with the loading frequency of 20 kHz is significantly higher than all other fatigue test results. Thus the proposed ultra-high frequency vibration-based fatigue test shows a balance of high efficiency and similarity with the conventional testing results.

Three Ways of Sampling and Fatigue Test Results of Steel P92

2014 ◽  
Vol 891-892 ◽  
pp. 273-277
Author(s):  
Josef Volák ◽  
Zbynek Bunda
Keyword(s):  
Mechanical Properties ◽  
Power Plant ◽  
Fatigue Test ◽  
Fatigue Tests ◽  
Energy Industry ◽  
Fatigue Properties ◽  
Test Results ◽  
Steam Turbines ◽  
Standard Samples ◽  
Energy Component

This paper describes the fatigue properties of the steel P92. This material is widely used in the energy industry, especially for pipes and pipe bends of supercritical steam turbines. Steel P92 is alloyed with 2 % of tungsten compared to steel P91. This increases a creep strenght of the material. It is possible to reduce wall thickness of the P92 pipe up to about 20%. Fatigue tests were carried out on standard samples and compared with SFT samples (Small Fatigue Test). Using the device SSam 2 made by company Rolce Royce, it is possible to gently remove a samples from energy component without power plant shutdowns. Consider these correlations, i tis possible to determine mechanical properties of the material from small amount of removed experimental material.

Fatigue Evaluation Under Continuous Strain Rate Changing Condition of Carbon Steel in BWR Environment

2014 ◽  
Author(s):  
Akihiko Hirano ◽  
Satoko Mizuta
Keyword(s):  
Surface Roughness ◽  
Fatigue Life ◽  
Strain Rate ◽  
Fatigue Test ◽  
Fatigue Tests ◽  
Wave Form ◽  
Strain Wave ◽  
Water Reactor ◽  
Component Size ◽  
Fatigue Evaluation

Fatigue evaluation methods have been proposed based on environmental fatigue test results regarding parameters selected for simulating Boiling Water Reactor (BWR) and Pressurized Water Reactor (PWR) conditions. The effects of strain wave form have been discussed by comparing experimental fatigue life with predicted fatigue life evaluated by modified rate approach (MRA) method. The applicability of the MRA method has been verified extensively by the environmental fatigue tests with strain rate changing conditions consisting of combined constant strain rates. However, different results have been obtained for a sine strain wave in simulated BWR and PWR conditions. More study for evaluating the applicability of MRA method was required by evaluating with continuous strain rate conditions such as a sine wave. For the purpose of verification, two approaches were applied. One is performing the environmental fatigue tests with the sine strain wave in simulated BWR condition. The other is to evaluate the low cycle thermal fatigue test performed in simulated BWR condition because the wave form of this test contains continuous strain rate changing condition. MRA method was indicated to be applicable to predict fatigue lives under these kinds of continuous strain rate changing conditions. All of the studies including this study verifying the applicability of the MRA method were performed with small specimens having the well polished surfaces in the gage length. These results indicate that the evaluation by the MRA method includes the synergistic effect between the water environment and the transient. However, the synergistic effects with the surface roughness and the component size are not known. Design margin derived by the multiplication of the sub-factors of environment, surface roughness and component size may be conservative. The evaluation of the conservatism is considered to be beneficial.

Comparison Between ASME Code-Case N-761, NUREG/CR-6909 and Stainless Steel Component Fatigue Test Results

2014 ◽  
Author(s):  
H. T. Harrison ◽  
Robert Gurdal
Keyword(s):  
Stainless Steel ◽  
Fatigue Test ◽  
Fatigue Tests ◽  
Test Series ◽  
Test Results ◽  
Actual Number ◽  
Steel Component ◽  
Class 1 ◽  
Asme Code ◽  
Number Of Cycles

For Class 1 components, the consideration of the environmental effects on fatigue has been suggested to be evaluated through two different methodologies: either NUREG/CR-6909 from March 2007 or ASME-Code Case N-761 from August 2010. The purpose of this technical paper is to compare these two methods. In addition, the equations from Revision 1 of the NUREG/CR-6909 will be evaluated. For these comparisons, two stainless steel component fatigue test series with documented results are considered. These two fatigue test series are completely different from each other (applied cyclic displacements vs. insurge/outsurge types of transients). Therefore, they are producing an appropriate foundation for these comparisons. In general, the severities of the two methods are compared, where the severity is defined as the actual number of cycles from the fatigue tests, including an evaluation of the scatter, divided by the number of design cycles from the two methods. Also, how stable the methods are is being evaluated through the calculation of the coefficient of variation for each method.

An investigation of particle degradation by impact within a centrifugal accelerator type degradation tester

2003 ◽  
Vol 217 (3) ◽  
pp. 257-266 ◽  
Author(s):  
H Abou-Chakra ◽  
U Tüzün ◽  
I Bridle ◽  
M Leaper ◽  
M S A Bradley ◽  
...  
Keyword(s):  
Particle Velocity ◽  
Test Facility ◽  
Test Material ◽  
Vacuum System ◽  
Poor Control ◽  
Testing Method ◽  
Scale Unit ◽  
Major Disadvantage ◽  
The World ◽  
Mechanical Devices

There are several testing devices that are used throughout the world for quantifying particle degradation by impact against a solid surface. Some devices use pressurized air to accelerate particles so that they impinge upon a target, some use a vacuum system or mechanical devices to accelerate the particles. Others attempt to drop particles from a height to achieve the required velocity. All previous testers have some disadvantage associated with them, the most common being poor control over particle velocity. Because it is well known that impact velocity is the single most important controlling factor in particle degradation, this is a major disadvantage. The second major disadvantage of most previous work is that it involves only single or small numbers of particles, making it very difficult to scale to bulk. The purpose of this work was to design and construct an improved testing method in a pilot bench-scale unit for assessing degradation by impact. This test facility can control both the velocity of the particles and the angle of impact. Benefits associated with this facility are that the particle velocity is very closely controlled, the tester is portable, and only a small quantity of test material is required for each test.

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