Non-destructive damage evaluation of a structure from limited modal parameters

1996 ◽  
Vol 33 (5) ◽  
pp. A228
Keyword(s):  
Modal Parameters ◽  
Damage Evaluation ◽  
Non Destructive

Fatigue damage in bending of reinforced concrete frames using non-destructive tests for dynamic strength of the cylinder

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Dragan D. Milašinović ◽  
Aleksandar Landović ◽  
Danica Goleš
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fatigue Damage ◽  
Cross Section ◽  
Modal Parameters ◽  
The Finite Element Method ◽  
Concrete Frames ◽  
Content Type ◽  
Non Destructive

PurposeThe purpose of this paper is to contribute to the solution of the fatigue damage problem of reinforced concrete frames in bending.Design/methodology/approachThe problem of fatigue damage is formulated based on the rheological–dynamical analogy, including a scalar damage variable to address the reduction of stiffness in strain softening. The modal analysis is used by the finite element method for the determination of modal parameters and resonance stability of the selected frame cross-section. The objectivity of the presented method is verified by numerical examples, predicting the ductility in bending of the frame whose basic mechanical properties were obtained by non-destructive testing systems.FindingsThe modal analysis in the frame of the finite element method is suitable for the determination of modal parameters and resonance stability of the selected frame cross-section. It is recommended that the modulus of elasticity be determined by non-destructive methods, e.g. from the acoustic response.Originality/valueThe paper presents a novel method of solving the ductility in bending taking into account both the creep coefficient and the aging coefficient. The rheological-dynamical analogy (RDA) method uses the resonant method to find material properties. The characterization of the structural damping via the damping ratio is original and effective.

EVALUATION OF DAMAGE IN STEELS SUBJECTED TO EXPLOITATION LOADING - DESTRUCTIVE AND NON-DESTRUCTIVE METHODS

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5533-5538 ◽  
Author(s):  
ZBIGNIEW L. KOWALEWSKI ◽  
SŁAWOMIR MACKIEWICZ ◽  
JACEK SZELĄŻEK ◽  
KRYSTYNA PIETRZAK ◽  
BOLESŁAW AUGUSTYNIAK
Keyword(s):  
Plastic Deformation ◽  
Damage Identification ◽  
Ultimate Tensile Stress ◽  
Damage Evaluation ◽  
Damage Development ◽  
Tension Tests ◽  
Magnetic Techniques ◽  
Development Evaluation ◽  
Non Destructive ◽  
Destructive Methods

Damage due to creep and plastic flow is assessed using destructive and non-destructive methods in steels (40HNMA and P91). In the destructive methods the standard tension tests were carried out after prestraining and variations of the selected tension parameters were taken into account for damage identification. In order to assess a damage development during the creep and plastic deformation the tests for both steels were interrupted for a range of the selected strain magnitudes. The ultrasonic and magnetic techniques were used as the non-destructive methods for damage evaluation. The last step of the experimental programme contained microscopic observations. A very promising correlation between parameters of methods for damage development evaluation was achieved. It is well proved for the ultimate tensile stress and birefringence coefficient.

Simultaneous Dynamics-Based Visual Inspection Using Modal Parameter Estimation

2011 ◽  
Vol 23 (1) ◽  
pp. 180-195 ◽  
Author(s):  
Hua Yang ◽  
◽  
Takeshi Takaki ◽  
Idaku Ishii
Keyword(s):  
Parameter Estimation ◽  
Real Time ◽  
Visual Inspection ◽  
Dynamic Properties ◽  
Mode Shapes ◽  
Modal Parameters ◽  
Modal Parameter ◽  
Resonant Frequencies ◽  
Modal Parameter Estimation ◽  
Non Destructive

In this study, we introduce the concept of dynamicsbased visual inspection with High-Frame-Rate (HFR) video analysis as a novel non-destructive active sensing method for verifying dynamic properties of a vibrating object. The HFR video is used for determining the structural dynamic properties of an object, such as its resonant frequencies and mode shapes, which can be estimated as modal parameters by modal analysis only when the object is excited. By improving and implementing a fast output-only modal parameter estimation algorithm on a real-time 2000-fps vision platform, the modal parameters of an excited object are simultaneously estimated as its input-invariant dynamic properties for dynamics-based visual inspection evenwhen the objects undergo different excitation conditions. Our simultaneous 2000-fps visual inspection system can facilitate non-destructive and longterm monitoring of the structures of beam-shaped objects vibrating at dozens or hundreds of hertz, and it can detect small changes in the dynamic properties of these objects caused by internal defects such as fatigue cracks in real time, even when their static appearances are similar. To demonstrate the performance of the proposed 2000-fps simultaneous dynamics-based visual inspection approach, the resonant frequencies and mode shapes for beam-shaped cantilevers with different artificial cracks and weights, excited by human finger tapping, were estimated in real time.

514 Development of Non-Destructive Damage Evaluation Method for Nuclear Graphite

2005 ◽  
Vol 2005 (0) ◽  
pp. 353-354
Author(s):  
Taiju SHIBATA ◽  
Junya SUMITA ◽  
Satoshi HANAWA ◽  
Tatsuya TADA ◽  
Kazuhiro SAWA ◽  
...  
Keyword(s):  
Evaluation Method ◽  
Damage Evaluation ◽  
Nuclear Graphite ◽  
Non Destructive

A Study on Damage Detection Procedure for Existing Piles

2003 ◽  
Author(s):  
Akira Sone ◽  
Arata Masuda ◽  
Taihei Koyama ◽  
Kohei Washida ◽  
Makoto Yamada ◽  
...  
Keyword(s):  
Damage Detection ◽  
Numerical Simulations ◽  
Ground Surface ◽  
Dynamic Compliance ◽  
Evaluation Procedure ◽  
Damage Evaluation ◽  
Impulsive Load ◽  
Non Destructive

In this paper, a non-destructive damage evaluation procedure is presented, which aims at detecting early or fatal cracks in existing piles after severe earthquakes. The bending motion of a target pile excited by an impulsive load, which is induced by hammering at the ground surface nearly, is measured at the top to obtain the dynamic compliance of the pile in one direction. Numerical simulations and experiments show that evaluating the dynamic compliance in every direction can suggest the severity of the cracks as well as their location and orientation.

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