Crack Depth Estimation in Shaft for an Overhung Rotating Shaft System: An Experimental Investigation

2021 ◽  
Author(s):  
Rohit Tamrakar ◽  
Narain Das Mittal ◽  
Raj Kumar Singh
Keyword(s):  
Experimental Investigation ◽  
Crack Depth ◽  
Depth Estimation ◽  
Rotating Shaft ◽  
Shaft System

Experimental Investigation of Multi-Span Rotor Balancing Using Least Squares Method

1980 ◽  
Vol 102 (3) ◽  
pp. 589-596 ◽  
Author(s):  
F. Fujisawa ◽  
K. Shiohato ◽  
K. Sato ◽  
T. Imai ◽  
E. Shoyama
Keyword(s):  
Experimental Investigation ◽  
Least Squares ◽  
Least Squares Method ◽  
Rotor System ◽  
Rotating Shaft ◽  
Good Balance ◽  
Shaft System ◽  
Influence Coefficients ◽  
Vertical Vibrations ◽  
Rotor Balancing

The least-squares method which uses influence coefficients was applied to simultaneous balancing of a multibearing rotating shaft system, and an experiment was conducted to demonstrate its effectiveness. The rotor system used in the experiment was a 10-bearing, 5-span rotor system. Vibrations were detected simultaneously in horizontal and vertical directions. Using these data, correction weights were calculated with a computer program based on the above least-squares method. Balancing accuracy was considered with regard to two cases, horizontal and vertical vibrations. The balancing experiments were conducted for the cases where unbalance is distributed in one and in all rotors of the multispan rotor system. In both cases, good balance was achieved in one run.

Analysis of the rub-impact forces between a controlled nonlinear rotating shaft system and the electromagnet pole legs

2021 ◽  
Vol 93 ◽  
pp. 792-810
Author(s):  
N.A. Saeed ◽  
Emad Mahrous Awwad ◽  
Mohammed A. EL-meligy ◽  
Emad Abouel Nasr
Keyword(s):  
Rotating Shaft ◽  
Shaft System ◽  
Impact Forces

Dynamic Behaviour and Crack Detection of a Multi Cracked Rotating Shaft using Adaptive Neuro-Fuzzy-Inference System

2016 ◽  
Vol 6 (4) ◽  
pp. 1-10 ◽  
Author(s):  
Rajeev Ranjan
Keyword(s):  
Finite Element ◽  
Fuzzy Inference System ◽  
Crack Detection ◽  
Fuzzy Inference ◽  
Crack Depth ◽  
Multiple Cracks ◽  
Rotating Shaft ◽  
Element Analysis ◽  
Inference System ◽  
Neuro Fuzzy

The presence of crack changes the physical characteristics of a structure which in turn alter its dynamic response characteristics. So it is important to understand dynamics of cracked structures. Crack depth and location are the main parameters influencing the vibration characteristics of the rotating shaft. In the present study, a technique based on the measurement of change of natural frequencies has been employed to detect the multiple cracks in rotating shaft. The model of shaft was generated using Finite Element Method. In Finite Element Analysis, the natural frequency of the shaft was calculated by modal analysis using the software ANSYS. The Numerical data were obtained from FEA, then used to train through Adaptive Neuro-Fuzzy-Inference System. Then simulations were carried out to test the performance and accuracy of the trained networks. The simulation results show that the proposed ANFIS estimate the locations and depth of cracks precisely.

MEASUREMENT OF CRACK DEPTH LOCATED UNDER REINFORCEMENT IN REINFORCED CONCRETE SPECIMENS USING ULTRASONIC METHOD

2008 ◽  
Vol 22 (11) ◽  
pp. 1019-1024 ◽  
Author(s):  
SANG-KYUN WOO ◽  
YOUNG-CHUL SONG ◽  
HONG-CHUL RHIM
Keyword(s):  
Reinforced Concrete ◽  
Wave Diffraction ◽  
Ultrasonic Method ◽  
Crack Depth ◽  
Experimental Studies ◽  
Depth Estimation ◽  
Experimental Results ◽  
P Wave ◽  
Inclined Surface

The objective of this study is to determine crack depth located under reinforcement in concrete specimens using ultrasonic method. Experimental studies were performed on concrete specimens containing vertical and inclined surface-opening cracks with known depths. Experimental results have shown that the crack depth can be effectively measured when the distance between the probes is less than the crack depth. The effect of reinforcement on crack depth estimation is studied through a model by considering P-wave diffraction at the tip of crack and reinforcement. In addition, experimental results show that the ultrasonic method is one of useful methods to evaluate the crack depth in reinforced concrete.

In-Plane Vibration and Crack Detection of a Rotating Shaft-Disk Containing a Transverse Crack

1998 ◽  
Vol 120 (2) ◽  
pp. 551-556 ◽  
Author(s):  
Ming-Chuan Wu ◽  
Shyh-Chin Huang
Keyword(s):  
Crack Detection ◽  
Transverse Crack ◽  
Rotation Speed ◽  
Crack Depth ◽  
Multiple Scale ◽  
Crack Identification ◽  
Response Curves ◽  
Rotating Shaft ◽  
Crack Location ◽  
Depth Rotation

Dynamic response and stability of a rotating shaft-disk containing a transverse crack is investigated. FFT analysis of response amplitudes showed that the 2Ω component (Ω: rotation speed) was excited by crack breathing and could serve as a good index for crack identification. Intensive numerical studies of crack location, crack depth, rotation speed, and sensing position on response amplitudes displayed a feasible technique for the identification of crack depth and crack location. It is achieved by intersecting the two equi-amplitude response curves of two separated sensing probes. Finally, the instability of the system caused by a crack is examined via Floquet theory and the multiple scale method. The stability diagrams, illustrated as functions of crack depth, rotation speed, and damping, are shown and discussed.

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