203 Damage Diagnosis Method for Roll Bearing Using Jerk Sensor : Investigation for Failure on Roller

2014 ◽  
Vol 2014.51 (0) ◽  
pp. _203-1_-_203-2_
Author(s):  
Shingo TAKEUCHI ◽  
Hisashi TANAKA ◽  
Nobuhiko HENMI
Keyword(s):  
Damage Diagnosis ◽  
Roll Bearing ◽  
Diagnosis Method

New Method Using Piezoelectric Jerk Sensor to Detect Roller Bearing Failure

2013 ◽  
Vol 7 (5) ◽  
pp. 550-557 ◽  
Author(s):  
Nobuhiko Henmi ◽  
◽  
Shingo Takeuchi
Keyword(s):  
Rotation Speed ◽  
Roller Bearing ◽  
New Method ◽  
Bearing Failure ◽  
Acceleration Sensor ◽  
Damage Diagnosis ◽  
Vibration Detection ◽  
Diagnosis Method ◽  
Bearing Damage ◽  
Conical Roller

An acceleration sensor is usually used to examine for roller bearing damage. It is difficult, however, to detect abnormal vibration and examine for roller bearing damage when rotation speed is low. The final target of this study is to establish a bearing damage diagnosis system based on the piezoelectric jerk sensor we developed, which can be used for both low- and highspeed rotations. For this purpose, this paper aims to identify the features of an abnormal vibration detection signal at a low rotation speed, propose a new roller bearing damage diagnosis method that uses the features, and clarify the validity of the method. Experiments are conducted to analyze a scratch purposely made on the outer ring of a conical roller bearing that rotates at the low speeds of 10 or 40 rpm. The results verify the advantages of using the jerk sensor for the bearing damage diagnosis and the validity of the method proposed in this paper.

scholarly journals Investigation of Damage Diagnosis of Retaining Wall Structures Based on the Hilbert Damage Feature Vector Spectrum

2019 ◽  
Vol 2019 ◽  
pp. 1-22
Author(s):  
Qian Xu
Keyword(s):  
Energy Spectrum ◽  
Feature Vector ◽  
Retaining Wall ◽  
Damage Index ◽  
Wall Structure ◽  
Impulse Response Functions ◽  
Damage State ◽  
Damage Diagnosis ◽  
Wall Structures ◽  
Diagnosis Method

To diagnose damages within the retaining wall structure, the Hilbert marginal energy spectrum was acquired via the Hilbert–Huang transformation of virtual impulse response functions of responses to the retaining wall under ambient excitations. Based on the Hilbert marginal energy spectrum, the Hilbert damage feature vector spectrum was created. On the basis of the damage feature vector spectrum, a damage identification index was proposed. Based on the damage feature vector spectrum and damage index, the damage state of the retaining wall was detected by the damage feature vector spectrum, damage locations of the wall were diagnosed by the damage index trend surface, and the damage intensity of the wall was identified by the quantitative relationship between the damage index and damage intensity. Based on this, a damage diagnosis method for retaining wall structures was proposed. To verify the feasibility and validity of the damage diagnosis method, both model tests and field tests on a pile plate retaining wall are performed under ambient excitations. Test results show that the damage state of the wall can be detected sensitively, damage locations can be diagnosed validly, and damage intensity can be identified quantitatively via this damage diagnosis method.

Review of the Rapid Damage Diagnosis of Medium and Short-Span Bridges

2015 ◽  
Vol 648 ◽  
pp. 45-52
Author(s):  
Feng Ma ◽  
Xian Zhi Shao ◽  
Zhi Cheng Tan
Keyword(s):  
Rapid Diagnosis ◽  
Future Research ◽  
Structural Dynamic ◽  
Damage Diagnosis ◽  
Development Direction ◽  
Bridge Structures ◽  
Diagnosis Method ◽  
Load Tests ◽  
Solid Foundation ◽  
Resistance Decrease

Damage accumulation and resistance decrease inevitably happen to bridge structures due to the effects of earthquakes, impact loads, wind load and corrosion during their service time. Once the damages of the key components accumulate to a certain level, they would spread promptly, causing the sudden destruction of the whole structure if not found and dealt with in time. So the structural damages would not only shorten the operation life of structure but also threaten the human lives and financial safety. Therefore, the technology of damage diagnosis of bridge structure holds supreme significance. This paper summarized the current research situation of the existing bridge diagnosis methods and analyzed the characteristics of each method through the reading and studying of the related material both domestically and internationally. Among those methods, only the diagnosis method based on load tests is the most direct and effective one for current bridge diagnosis, the diagnosis results of which shows higher reliability. And the structural dynamic characteristic method based on dynamic load tests could beautifully avoid the disadvantages of the static load tests, becoming the main development direction of rapid diagnosis of bridge. Furthermore, lastly it elaborated the analysis of the key problems of breaking through the development bottleneck of current rapid diagnosis methods of bridge, creating a solid foundation for the future research.

Cross Modal Strain Energy Method for Damage Localization and Severity Estimation

2007 ◽  
Author(s):  
Shuqing Wang ◽  
Huajun Li ◽  
Sau-Lon James Hu
Keyword(s):  
Strain Energy ◽  
Numerical Study ◽  
Element Model ◽  
Damage Localization ◽  
Modal Strain Energy ◽  
Damage Diagnosis ◽  
Damage Scenarios ◽  
Severity Estimation ◽  
Modal Strain Energy Method ◽  
Diagnosis Method

A cross modal strain energy (CMSE) damage diagnosis method, which is capable of localizing the damages and estimating their severities, is presented. The numerical study uses measurements synthesized from a finite element model of a laboratory-scaled offshore platform. Several damage scenarios are investigated, including: single/double damaged element(s), with/without measurement noise. Numerical results suggest that good performance on both damage location and severity assessment can be achieved by implementing the CMSE method.

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