scholarly journals Temperature distribution as a method of measuring crack length in fatigue tests of compressor blade

2016 ◽  
pp. 5-16
Author(s):  
Arkadiusz Bednarz ◽  
Michał Kuźniar ◽  
Evgeniy Boltynjuk
Keyword(s):  
Temperature Distribution ◽  
Crack Length ◽  
Fatigue Tests ◽  
Compressor Blade

scholarly journals Methods for automated crack length detection in fracture mechanical fatigue tests of unreinforced polymers

2020 ◽  
Vol 28 ◽  
pp. 1184-1192
Author(s):  
Anja Gosch ◽  
Jutta Geier ◽  
Florian Arbeiter ◽  
Michael Berer ◽  
Gerald Pinter
Keyword(s):  
Crack Length ◽  
Fatigue Tests ◽  
Mechanical Fatigue

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.

Corrosion Fatigue Tests Using Strain Gauges for Measuring Load and Crack Length

CORROSION ◽  
10.5006/2123 ◽  
2016 ◽  
Vol 72 (12) ◽  
pp. 1547-1555 ◽  
Author(s):  
Rodrigo R.A. Garcia ◽  
Felipe Cristaldi C. Caldas ◽  
Oscar Rosa Mattos
Keyword(s):  
Crack Length ◽  
Corrosion Fatigue ◽  
Fatigue Tests ◽  
Strain Gauges

scholarly journals Influence of the Cyclic Hardening Model on the Results of the Numerical Analysis of Fatigue Life on Example of the Compressor Blade

2019 ◽  
Vol 26 (2) ◽  
pp. 7-14
Author(s):  
Arkadiusz Bednarz
Keyword(s):  
Numerical Analysis ◽  
Leading Edge ◽  
Experimental Tests ◽  
Cyclic Hardening ◽  
Load Cycle ◽  
Geometrical Model ◽  
Fatigue Tests ◽  
Compressor Blade ◽  
Hardening Model ◽  
The Impact

Abstract The main goal of the presented work is to determine the impact of the cyclic hardening model on the numerical results of the ε-N fatigue test. As an object of study, compressor blade (from PZL-10W helicopter engine) was used. The examined blade was made of EI-961 alloy. In numerical analysis, a geometrical model of the blade with a preliminary defect was created. Geometrical defect – V-notch was created on the leading edge. This defect was introduced in order to weaken the structure of the element and the possibility of observing the crack initiation process (in experimental tests). Material data to ε-N analysis, based on Manson-Coffin-Basquin equation, were estimated for Mitchell’s model. This model was built based on strength data provided by the steel producer. Based on three different models of cyclic hardening (Manson, Fatemi, and Xianxin), a number of load cycles were calculated. Load cycle during numerical analysis was represented as resonance bending with an amplitude of displacement equal to A = 1.8 mm. Obtained results were compared with experimental data. Additionally, the analytical model of ε-N fatigue (depending on the cyclic hardening) was prepared. All the work carried out has been summarized by a comprehensive comparative analysis of the results. Obtained results and dependencies can be used in the selection of an appropriate model of cyclic hardening in further fatigue tests of many aerospace elements.

Application of Infrared Imaging Technology in Fatigue Failure Prediction of Vehicle Wheel in Wheel Bending Fatigue Test

2016 ◽  
Author(s):  
W. H. Chai ◽  
X. D. Liu ◽  
Y. C. Shan ◽  
J. G. Wang
Keyword(s):  
Temperature Distribution ◽  
Real Time ◽  
Fatigue Test ◽  
Fatigue Failure ◽  
Infrared Imaging ◽  
Bending Moment ◽  
Fatigue Tests ◽  
Bending Fatigue ◽  
Time Prediction ◽  
Bending Fatigue Test

Bending fatigue test of vehicle wheel is the main test to verify the mechanics performance of spoke. The wheel is fastened to the bending fatigue test platform with bolts in the bending fatigue test. A cyclic bending moment is applied to the wheel, and after some number of cycles, fatigue failure will happen. In this paper, the bending fatigue test is carried out on a steel wheel and a wheel made of long glass fiber reinforced thermoplastic (LGFT) wheel, and infrared imager is used to monitor the temperature distribution and variation of wheels under bending loads in the test process. After the test, it is found that there are cracks at the highest-temperature spots. In addition, because some cracks of LGFT wheel are too tiny to be found, it’s convenient to search those cracks according to the high-temperature areas in infrared images. All above indicate that it is practicable to predict fatigue failure area by monitoring temperature distribution and variation in wheel bending fatigue test. A method for real-time prediction of fatigue failure area in wheel bending fatigue test is described in this paper, which is also helpful to real-time prediction of fatigue failure area in fatigue tests of other products.

scholarly journals Stress Intensity Factor Calculations for the Compressor Blade with Half-Elliptical Surface Crack Using Raju-Newman Solution

2011 ◽  
Vol 2011 (3) ◽  
pp. 154-165 ◽  
Author(s):  
Lucjan Witek
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Rectangular Plate ◽  
Crack Growth ◽  
Surface Crack ◽  
Fatigue Tests ◽  
Compressor Blade ◽  
Experimental Investigations ◽  
Beach Marks

Stress Intensity Factor Calculations for the Compressor Blade with Half-Elliptical Surface Crack Using Raju-Newman Solution This paper presents results of the stress intensity factor calculations for the compressor blade including a half-elliptical crack, subjected to vibration. In this analysis, the Raju-Newman empirical solution for stress intensity factor calculations in the rectangular plate with a half-elliptical flaw was used. The bending stress used in the Raju-Newman solution was computed for the real blade using the finite element method. The K-factor values were calculated only at one point of the crack front, where the crack tip contacts the free surface, because the crack length during experimental investigations was measured just in this direction. In order to determine the stress intensity factors for different crack sizes, ten diverse flaws in the blade were defined. Results of the experimental fatigue tests performed for the blade without preliminary defects showed that the cracks developed from the convex blade surface. On the blade fracture, the beach marks typical of the fatigue damage were visible. The dimensions of cracks in the rectangular plate were defined based on the beach marks shape. In the next part of the work, the stress intensity factor values were used as an input data into the Paris-Erdogan equation. As a result of this calculation, the crack growth rate for the compressor blade vibrating at constant amplitude was estimated. The results obtained were finally compared with the results of the experimental crack growth analysis performed for 1st stage compressor blades of the helicopter turbo-engine.

Quantitative Analysis of Transmission Shafts after Torsion Fatigue Test

2007 ◽  
Vol 353-358 ◽  
pp. 2790-2793
Author(s):  
Xin Ling Liu ◽  
Wei Fang Zhang ◽  
Chun Hu Tao
Keyword(s):  
Quantitative Analysis ◽  
Stress Concentration ◽  
Fracture Surface ◽  
Crack Length ◽  
Fatigue Test ◽  
Fatigue Tests ◽  
Fracture Features ◽  
Total Life

Twelve transmission shafts were developed unilateralism torsion fatigue tests. Macroscopic and microscopic fracture features of transmission shafts were observed and analyzed. No defect was found in the origin which was usually located at the bolt bores or nearby the bolt bores because of the stress concentration. Using the fractography quantitative analysis technology the propagation life, the origination life and the relation curve between the crack length and the cycle numbers for all of the twelve shafts were estimated. For only one origin on the fracture surface the total life of the shaft with two expanding directions is usually obvious longer than that with one expanding direction, but the main propagation life is obvious smaller. However for two origins and two expanding directions on the fracture surface the total life of the shaft is usually shorter.

On the Modal Analysis of a Cracking Compressor Blade

2008 ◽  
Vol 23 (1) ◽  
pp. 21-36 ◽  
Author(s):  
Mirosław Witoś
Keyword(s):  
Modal Analysis ◽  
Fatigue Tests ◽  
Compressor Blade ◽  
Jet Engines ◽  
Compressor Blades ◽  
Blade Vibration ◽  
Laser Measurements ◽  
Military Aviation ◽  
Verification Process ◽  
Reliable Differentiation

On the Modal Analysis of a Cracking Compressor Blade The paper deals with issues related to reliable recognition and prediction of health of steel compressor blades. It outlines symptoms that indicate the blade cracking, and identification methods that can be used during operation, maintenance and repairs/overhauls of turbine jet engines of the SO-3 type. An optical method involving laser measurements of blade vibration while on the excitation source is presented in details as it is implemented in the WZL-3 (Military Aviation Works No. 3). The method has been verified in practice and some findings from the verification process are discussed. Next, new testing capabilities offered by the method are presented, including identification of early symptoms of material fatigue (the strengthening and the weakening of the material) and the crack initiation. The topics under discussion have been illustrated with some examples taken while measuring modal properties typical of both defect-free and faulty blades as well as from fatigue tests conducted according to the LCF and HCF profiles. It has been proved that the analysis of resonance responses for specific modes of operation allows of reliable differentiation between material's fatigue and cracking.

scholarly journals Influence of aircraft engine compressor blades leading edge damage on their fatigue strength

Mechanik ◽  
2018 ◽  
Vol 91 (3) ◽  
pp. 205-209
Author(s):  
Wojciech Obrocki ◽  
Amadeusz Setkowicz ◽  
Maciej Masłyk ◽  
Jan Sieniawski
Keyword(s):  
Fatigue Strength ◽  
Leading Edge ◽  
Fatigue Cracking ◽  
Aircraft Engine ◽  
Fatigue Tests ◽  
Compressor Blade ◽  
Compressor Blades ◽  
Fluorescent Method ◽  
Engine Compressor ◽  
Edge Damage

Article presents the research results of aircraft compressor blade damage length and its position influence on fatigue strength under high number cycles conditions. The criteria for blade damage detection classification and test research methodology were developed. Designed and tested the instrumentation for compressor blades fatigue tests. Fluorescent method was used to determine the source of fatigue cracking initiation and its propagation direction during fatigue test.

Fatigue Characteristics of Vulcanized Natural Rubber for Automotive Engine Mounting

2007 ◽  
Vol 353-358 ◽  
pp. 178-181 ◽  
Author(s):  
S. Shibata ◽  
K. Ochi ◽  
Y. Aono ◽  
Hiroshi Noguchi ◽  
Hideki Oshima
Keyword(s):  
Fatigue Crack ◽  
Natural Rubber ◽  
Crack Length ◽  
Early Stage ◽  
Fatigue Cracks ◽  
Fatigue Tests ◽  
Miner’S Rule ◽  
Fatigue Characteristics ◽  
Stress Ratios ◽  
Miner's Rule

In order to investigate fatigue characteristics of vulcanized natural rubber (NR), fatigue tests are carried out under various stress ratios R (R = minimum stress / maximum stress). It was considered that the fatigue cracks were initiated from flaws in very early stage of total life. The fatigue damage process was almost the fatigue crack propagation process and it is independent of R. The crack growth rate was proportional to the crack length to about the first power, when the crack length was defined as the length of the direction perpendicular to the loading direction. Miner’s rule was examined to observe the fatigue crack behavior and checked by using two-step loading fatigue tests experimentally. It seems Miner’s rule has a possibility to predict fatigue lives.

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