Location dependence of breathing mechanism for a slant crack in a shaft

2020 ◽  
Vol 43 (11) ◽  
pp. 2515-2526
Author(s):  
Hossain Mohammad Mobarak ◽  
Helen Wu ◽  
Chunhui Yang
Keyword(s):  
Slant Crack ◽  
Breathing Mechanism

Dynamics of a Jeffcott rotor with slant crack

2007 ◽  
Vol 303 (1-2) ◽  
pp. 1-28 ◽  
Author(s):  
Ashish K. Darpe
Keyword(s):  
Jeffcott Rotor ◽  
Slant Crack

Experimental Study on Lateral and Torsional Vibration of Cracked Rotor With Torsional Excitation

2013 ◽  
Author(s):  
Chao Liu ◽  
Dongxiang Jiang
Keyword(s):  
Experimental Study ◽  
Normal Condition ◽  
Torsional Vibration ◽  
Transverse Crack ◽  
Rotating Machinery ◽  
Lateral Vibration ◽  
Cracked Rotor ◽  
Diagnostic Features ◽  
Slant Crack ◽  
Torsional Excitation

Crack failures in rotating machinery can result in catastrophic accidents, and they are are difficult to detect online. Condition monitoring is widely applied in field to detect changes of vibration, and form diagnostic features. However, effective features in vibration of the cracked rotor need more tests, especially validating the features with experiments. This work carried out an experimental study on cracked rotors in laboratory. The experiments are as following: (I) vibration of the rotor in normal condition is firstly tested, where lateral vibration and torsional vibration are measured; (II) torsional excitation is exerted on driven end of rotor system, and vibration characteristics of the rotor are tested; (III) cracked rotors are tested with transverse and slant cracks, respectively. With the measured signals, comparisons of vibrations in normal rotor and cracked rotors are carried out. The results show that, the transverse crack introduces more significant changes in 1X frequency and coupled frequency, while the slant crack employs larger changes in 2X frequency. And variation of phases of 1X frequency is presented. Also, the crack plays an impact on the torsional responses.

scholarly journals Stress Intensity Factors Evaluated from Discontinuous Displacements along a Slant Crack with a Center-Hole Notch.

1995 ◽  
Vol 61 (586) ◽  
pp. 1225-1231
Author(s):  
Tashiyuki Torii ◽  
Toshitsugu Onoe ◽  
Kazuo Honda
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Intensity Factors ◽  
Slant Crack

scholarly journals Influence of Torsional Excitation on Dynamic Responses of Rotors with a Breathing Slant Crack

2017 ◽  
Vol 842 ◽  
pp. 012015
Author(s):  
Zhiwen Lu ◽  
Chunrong Hua ◽  
Dawei Dong ◽  
Bing Yan ◽  
Kang Fan
Keyword(s):  
Dynamic Responses ◽  
Slant Crack ◽  
Torsional Excitation

scholarly journals Unraveling the Guest-Induced Switchability in the Metal-Organic Framework DUT-13(Zn)

2021 ◽  
Author(s):  
Bodo Felsner ◽  
Volodymyr Bon ◽  
Jack D. Evans ◽  
Friedrich Schwotzer ◽  
Ronny Grünker ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
Conformational Isomerism ◽  
Hysteresis Width ◽  
Size Dependent ◽  
Semiempirical Approach ◽  
Contraction Mechanism ◽  
Metal Organic ◽  
Wide Hysteresis ◽  
Breathing Mechanism

A guest-induced flexibility in the framework DUT-13 was investigated in situ to analyze the breathing mechanism upon physisorption of nitrogen (77 K) and n-butane (273 K). The crystal structure of cp phase, solved from PXRD data using the computation-assisted semiempirical approach, shows two times smaller pore volume, compared to the op phase, which is consistent with the corresponding isotherms. The contraction mechanism is mainly based on the conformational isomerism of the benztb4- linker, which transforms from a staggered conformation in op phase to a more eclipsed in cp phase, leading to the contraction of the larger pore. A nearly complete op → cp → op transition was observed in the case of n-butane adsorption at 273 K, while in case of weakly interacting nitrogen molecules a portion of the sample remains in the op phase in the entire pressure range. Apparently, in case of DUT-13 the contraction is crystallite size-dependent, similarly as in a number of other switchable MOFs, which should be investigated more in detail in the future. Methane adsorption at varying temperatures showed a wide hysteresis at the temperatures between 111 K and 140 K. The hysteresis width decreases until it disappears completely at 170 K leading to a reversible isotherm, typical for rigid frameworks. The fact that breathing is observed in a broader temperature range in comparison to DUT‑49 demonstrates that thermodynamics and kinetics favour the DUT-13 contraction. Linker and hinges in DUT-13 are not stiff enough to support the metastable states required for NGA.

Stability and dynamics of rotor system with 45° slant crack on shaft

2011 ◽  
Vol 6 (2) ◽  
pp. 203-213 ◽  
Author(s):  
Yanli Lin ◽  
Xiaohui Si ◽  
Fulei Chu
Keyword(s):  
Rotor System ◽  
Slant Crack

Teaching the Whole Musician

2021 ◽  
Author(s):  
Paola Savvidou
Keyword(s):  
Mental Health ◽  
Healthcare Professionals ◽  
Movement Analysis ◽  
Limiting Factors ◽  
Main Argument ◽  
Artistic Practice ◽  
Applied Music ◽  
Contemplative Practices ◽  
Performing Artist ◽  
Breathing Mechanism

This book offers applied music instructors a practical guide for supporting their students’ wellness by integrating holistic techniques into their pedagogy. The main argument in this book is that the mentorship dynamic within the applied studio situates pedagogues in a unique position to guide and mentor their students toward a healthy and satisfying artistic life. Wellness, as a relatively new dimension within health education for musicians, can be intimidating for applied instructors. Many teachers lack the training and confidence to enter conversations in this arena. Grounded in recent research, coupled with extensive in-person interviews with students, faculty, and healthcare professionals, this book demystifies the causes, challenges, and limiting factors around maintaining a healthy artistic practice, while revealing practical solutions for achieving and maintaining wellness as a performing artist. Each chapter includes a toolkit of practical exercises and activities that can be easily integrated within the applied lesson. Topics covered include injury prevention, alignment and the breathing mechanism, mental health, contemplative practices, Laban Movement Analysis, nutrition, and sleep.

An Experimental Study of Breathing Mechanism for the Transversely Cracked Shafts

2011 ◽  
Vol 338 ◽  
pp. 547-552
Author(s):  
He Len Wu ◽  
Zhong Yi Cai ◽  
Ke Qin Xiao
Keyword(s):  
Fatigue Crack ◽  
Diagnostic Techniques ◽  
Transverse Cracks ◽  
On Line ◽  
Stiffness Variation ◽  
Heavy Loads ◽  
Opening And Closing ◽  
Cracked Shafts ◽  
Breathing Mechanism ◽  
Line Crack

Shaft fatigue crack is one of the most common defects in rotating equipment, due to its extensive operation with continuous heavy loads. Finding an efficient way to evaluate the true stiffness variation due to the crack rotation is the key step to develop both on-line and off-line crack diagnostic techniques. This study analyzed time-variant bending stiffness of elastic shafts with experimentally-induced fatigue, welding and wire cut transverse cracks. It was found that crack gap has a significant effect on the opening and closing behaviour of the transverse crack. As in the case of a cut crack, large crack gap could completely prevent the crack from closing during rotation. A fatigue crack without a clear gap shows a typical opening and closing behavior. Further, it remains fully closed within a small angular range and most of time it is partially closed. It was also observed that both switch and harmonic models cannot describe periodic stiffness variation well enough to represent the actual breathing function of the fatigue crack.

An insight into the breathing mechanism of a crack in a rotating shaft

2008 ◽  
Vol 318 (1-2) ◽  
pp. 279-295 ◽  
Author(s):  
S.K. Georgantzinos ◽  
N.K. Anifantis
Keyword(s):  
Rotating Shaft ◽  
Breathing Mechanism ◽  
Insight Into

Experimental Investigation of Slant Crack Propagation in X100 Pipeline Steel

2008 ◽  
pp. 151-152
Author(s):  
S. H. Hashemi ◽  
I. C. Howard ◽  
J. R. Yates ◽  
R. M. Andrews
Keyword(s):  
Experimental Investigation ◽  
Crack Propagation ◽  
Pipeline Steel ◽  
Slant Crack ◽  
X100 Pipeline Steel
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