Material Fatigue Testing of a New Intraureteral Wire Stent (Zebrastent™)

2008 ◽  
Vol 22 (6) ◽  
pp. 1389-1394 ◽  
Author(s):  
Dimitrios Staios ◽  
Mayur Patel ◽  
Athanasios Papatsoris ◽  
Stefanos Almpanis ◽  
Malcom Birch ◽  
...  
Keyword(s):  
Fatigue Testing ◽  
Material Fatigue

scholarly journals Microstructural Aspects of Fatigue Parameters of Lead-Free Sn-Zn Solders with Various Zn Content

2017 ◽  
Vol 17 (1) ◽  
pp. 131-136 ◽  
Author(s):  
K. Pietrzak ◽  
A. Klasik ◽  
M. Maj ◽  
A. Wojciechowski ◽  
N. Sobczak
Keyword(s):  
Fatigue Testing ◽  
Matrix Material ◽  
Morphological Characteristics ◽  
Fatigue Tests ◽  
Lead Free ◽  
Eutectic System ◽  
Material Fatigue ◽  
Zn Content ◽  
The Matrix ◽  
Static Tensile

Abstract The study includes the results of research conducted on selected lead-free binary solder alloys designed for operation at high temperatures. The results of qualitative and quantitative metallographic examinations of SnZn alloys with various Zn content are presented. The quantitative microstructure analysis was carried out using a combinatorial method based on phase quanta theory, per which any microstructure can be treated as an array of elements disposed in the matrix material. Fatigue tests were also performed using the capabilities of a modified version of the LCF method hereinafter referred to in short as MLCF, which is particularly useful in the estimation of mechanical parameters when there are difficulties in obtaining many samples normally required for the LCF test. The fatigue life of alloys was analyzed in the context of their microstructure. It has been shown that the mechanical properties are improved with the Zn content increasing in the alloy. However, the best properties were obtained in the alloy with a chemical composition close to the eutectic system, when the Zn-rich precipitates showed the most preferred morphological characteristics. At higher content of Zn, a strong structural notch was formed in the alloy because of the formation in the microstructure of a large amount of the needle-like Zn-rich precipitates deteriorating the mechanical characteristics. Thus, the results obtained during previous own studies, which in the field of mechanical testing were based on static tensile test only, have been confirmed. It is interesting to note that during fatigue testing, both significant strengthening and weakening of the examined material can be expected. The results of fatigue tests performed on SnZn alloys have proved that in this case the material was softened.

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.

A Device for Mechanically Folding Yarns and Woven Fabrics of Ballistic Fibers

2008 ◽  
Vol 75 (1) ◽  
Author(s):  
J. H. Kim ◽  
N. Brandenburg ◽  
W. McDonough ◽  
W. Blair ◽  
G. A. Holmes
Keyword(s):  
Tensile Strength ◽  
Fatigue Testing ◽  
Slight Modification ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Fiber Properties ◽  
Testing Protocol ◽  
Material Fatigue ◽  
The Impact ◽  
Open Position

A device was designed and built that attaches to servohydraulic machines that typically perform material fatigue testing. The device was designed to systematically fold woven fabric and yarns of ballistic fibers to assess the impact of mechanical folding, such as may occur during use, on ballistic fiber properties. Initial tests indicate that the device repeatedly folds a piece of woven fabric at the same location. However, when the device is in the open position, a consistent 1cm movement of the fabric was observed. A slight modification of the device is required to eliminate this movement. After cycling a piece of woven poly(benzoxazole) (PBO) fabric for 5500 cycles, an 18% reduction in the ultimate tensile strength and strain to failure of the PBO fibers was observed. Research is continuing to determine a relevant and optimized testing protocol.

Fatigue of Unidirectional Cord-Rubber Composites

1999 ◽  
Vol 27 (1) ◽  
pp. 48-57 ◽  
Author(s):  
Y. Liu ◽  
Z. Wan ◽  
Z. Tian ◽  
X. Du ◽  
J. Jiang ◽  
...  
Keyword(s):  
Damage Accumulation ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Constant Load ◽  
Testing System ◽  
Rubber Composites ◽  
Cycle Frequency ◽  
Periodic Loading ◽  
Fatigue Damage Accumulation ◽  
Rubber Composite

Abstract A fatigue testing system is established with which the real-time recording of stress, strain, temperature, and hysteresis loss of rubbers or cord-rubber composite specimens subjected to periodic loading or extension can be successfully carried out. Several problems are connected with the experimental study of the fatigue of rubber composites. In constant extension cycling, the specimen becomes relaxed because of the viscoelasticity of rubber composites, and the imposed tension-tension deformation becomes complex. In this method, the specimen is unlikely to fail unless the imposed extensions are very large. Constant load cycling can avoid the shortcomings of constant extension cycling. The specially designed clamps ensure that the specimen does not slip when the load retains a constant value. The Deformation and fatigue damage accumulation processes of rubber composites under periodic loading are also examined. Obviously, the effect of cycle frequency on the fatigue life of rubber composites can not be ignored because of the viscoelasticity of constituent materials. The increase of specimen surface temperature is relatively small in the case of 1 Hz, but the temperature can easily reach 100°C at the 8 Hz frequency. A method for evaluating the fatigue behavior of tires is proposed.

On a New Rotating Bending Fatigue Testing Machine

1966 ◽  
Vol 15 (148) ◽  
pp. 49-54
Author(s):  
Minoru KAWAMOTO ◽  
Katsumi SUMIHIRO ◽  
Koji KIDA
Keyword(s):  
Fatigue Testing ◽  
Testing Machine ◽  
Bending Fatigue ◽  
Rotating Bending Fatigue ◽  
Rotating Bending
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