Damage identification method based on structural dynamic characteristics and strain measurements

2009 ◽  
Author(s):  
Jun Teng ◽  
Wei Lu
Keyword(s):  
Dynamic Characteristics ◽  
Damage Identification ◽  
Structural Dynamic ◽  
Strain Measurements ◽  
Identification Method ◽  
Structural Dynamic Characteristics

Identification and Prediction of Frame Structure Dynamics by Spatial Matrix Identification Method

2000 ◽  
Author(s):  
Masaaki Okuma ◽  
Ward Heylen ◽  
Hisayoshi Matsuoka ◽  
Paul Sas
Keyword(s):  
Boundary Condition ◽  
Dynamic Characteristics ◽  
Structural Modification ◽  
Test Structure ◽  
Frame Structure ◽  
Structural Dynamic ◽  
Identification Method ◽  
Input Multiple Output ◽  
Structural Dynamic Characteristics ◽  
Single Input

Abstract This paper presents the result of using an experimental spatial matrix identification method to predict the dynamics of a frame structure under a different boundary condition. The single-input-multiple-output frequency response functions of the test structure under the free-free boundary condition are measured by hammer testing. Using the FRFs, a set of spatial matrices is determined to represent its structural dynamic characteristics by the method. Then, using the identified spatial matrices, the dynamic characteristics of the test structure under the boundary condition of clamping 4 points is predicted. The prediction is practically accurate. The result of the prediction demonstrates that the spatial matrices identified by the method can be used for structural modification and substructure synthesis in the field of computer aided mechanical engineering.

Identification and Prediction of Frame Structure Dynamics by Spatial Matrix Identification Method

2001 ◽  
Vol 123 (3) ◽  
pp. 390-394 ◽  
Author(s):  
Masaaki Okuma ◽  
Ward Heylen ◽  
Hisayoshi Matsuoka ◽  
Paul Sas
Keyword(s):  
Boundary Condition ◽  
Dynamic Characteristics ◽  
Test Structure ◽  
Frame Structure ◽  
Structural Dynamic ◽  
Various Boundary Conditions ◽  
Identification Method ◽  
Input Multiple Output ◽  
Structural Dynamic Characteristics ◽  
Single Input

This paper presents the results of using an experimental spatial matrix identification method to predict the dynamics of a frame structure under various boundary conditions. The single-input-multiple-output frequency response functions (FRFs) of the test structure under the free-free boundary condition are measured by hammer testing. Using the FRFs, a set of spatial matrices is constructed in order to represent the structural dynamic characteristics of the system by the new method. Using the spatial matrices, the dynamic characteristics of the test structure under the boundary condition of clamping 4 points is predicted. The prediction is adequately accurate for practical application. The results of the prediction demonstrate that the spatial matrices identified by this method can be used for structural modification and substructure synthesis in the field of computer-aided mechanical engineering.

Study on Flow-Induced Vibration Characteristics of Hydraulic Hoist of Large-Span Upwelling Radial Steel Gate

2011 ◽  
Vol 117-119 ◽  
pp. 241-246
Author(s):  
Zhen Hai Gao ◽  
Gen Hua Yan ◽  
Peng Liu ◽  
Fa Zhan Chen ◽  
Fei Ming Lv
Keyword(s):  
Dynamic Characteristics ◽  
Vibration Characteristics ◽  
Vibration Response ◽  
Flow Induced Vibration ◽  
Structural Dynamic ◽  
Large Span ◽  
Response Characteristics ◽  
Lever Action ◽  
Structural Dynamic Characteristics ◽  
Steel Gate

In this paper we conduct study on flow-induced vibration of large-span upwelling radial steel Gate and its hydraulic hoist. Place an emphasis on vibration response characteristics under two working conditions of diversion and drainage, which proves the safety of hydraulic hoist gate vibration caused by gate vibration. Firstly, we study on dynamic characteristics of fluid-structure interaction of association system of gate and start and stop lever, reveals the discipline of the effect fluid having on structural dynamic characteristics. On this basis, flow-induced vibration characteristics under two conditions of with and without start and stop lever action considered. The results indicate that the gate vibration response with hydraulic hoist used decreases, which explains start and stop lever has certain effect of restraining vibration on gate vibration. In addition, under the working condition of drainage the vibration magnitude of start and stop lever is smaller than that of gate body, which explains there is damping action during transference of gate vibration through start and stop lever. The results find out that on the assumption of optimized gate structure and hydraulic arrangement, it is practicable, safe and reliable to adopt hydraulic hoist. The achievement has directive significance on similar projects construction in the future

Serviceability design factors for wind-sensitive structures

2010 ◽  
Vol 37 (5) ◽  
pp. 728-738 ◽  
Author(s):  
A. Pozos-Estrada ◽  
H. P. Hong ◽  
J. K. Galsworthy
Keyword(s):  
Standard Deviation ◽  
Dynamic Characteristics ◽  
Human Perception ◽  
Wind Loading ◽  
Peak Acceleration ◽  
Structural Dynamic ◽  
Annual Probability ◽  
Structural Dynamic Characteristics ◽  
Wind Characteristics ◽  
Design Factors

Wind-sensitive buildings can experience excessive vibrations that cause discomfort and interruption of the activities of the inhabitants of the buildings. To ensure the desired serviceability, codes, standards, and their commentaries have proposed perception curves that limit the expected (or mean) peak acceleration or standard deviation of the acceleration of the buildings. These perception curves are developed based on perceived vibration alone and do not consider the uncertainty in structural dynamic characteristics (i.e., natural frequency of vibration and ratio of damping) and loads such as the wind loading. Therefore, the annual probability that the perception curve is not exceeded for a building whose design is based on the perception curve is unknown. In this study, serviceability design factors are calibrated for selected targeted annual probability of perception levels by considering the uncertainty in the structural dynamic characteristics, wind characteristics, as well as in the human perception of motion. These serviceability design factors are to be used with the estimated mean peak acceleration caused by along-wind and cross-wind excitations given in the commentaries of the current National building code of Canada. The use of calibrated serviceability design factors for design checking is illustrated with a numerical example.

scholarly journals A Sequence-Based Damage Identification Method for Composite Rotors by Applying the Kullback–Leibler Divergence, a Two-Sample Kolmogorov–Smirnov Test and a Statistical Hidden Markov Model

Entropy ◽  
2019 ◽  
Vol 21 (7) ◽  
pp. 690 ◽  
Author(s):  
Angelos Filippatos ◽  
Albert Langkamp ◽  
Pawel Kostka ◽  
Maik Gude
Keyword(s):  
Markov Model ◽  
Hidden Markov Model ◽  
Composite Structures ◽  
Damage Identification ◽  
Hidden Markov ◽  
Structural Dynamic ◽  
Identification Method ◽  
Leibler Divergence ◽  
Kolmogorov Smirnov ◽  
Smirnov Test

Composite structures undergo a gradual damage evolution from initial inter-fibre cracks to extended damage up to failure. However, most composites could remain in service despite the existence of damage. Prerequisite for a service extension is a reliable and component-specific damage identification. Therefore, a vibration-based damage identification method is presented that takes into consideration the gradual damage behaviour and the resulting changes of the structural dynamic behaviour of composite rotors. These changes are transformed into a sequence of distinct states and used as an input database for three diagnostic models, based on the Kullback–Leibler divergence, the two-sample Kolmogorov–Smirnov test and a statistical hidden Markov model. To identify the present damage state based on the damage-dependent modal properties, a sequence-based diagnostic system has been developed, which estimates the similarity between the present unclassified sequence and obtained sequences of damage-dependent vibration responses. The diagnostic performance evaluation delivers promising results for the further development of the proposed diagnostic method.

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