Advanced Evaluation of Fatigue Phenomena Using Non-Destructive Testing Methods

2016 ◽  
Vol 879 ◽  
pp. 1841-1846 ◽  
Author(s):  
Peter Starke ◽  
Hao Ran Wu ◽  
Christian Boller
Keyword(s):  
Fatigue Life ◽  
Damage Evolution ◽  
Structural Integrity ◽  
Residual Life ◽  
Fatigue Behavior ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Physically Based ◽  
Damage Condition ◽  
Non Destructive

The comprehensive characterization of the change in metallic materials’ microstructure due to an applied load is of prime importance for the understanding of basic fatigue mechanisms or more general damage evolution processes. If those mechanisms and processes are to be understood to a much greater extent, advanced fatigue life calculation methods being far away from linear damage accumulation models, have to be realized providing more than “classic fatigue data” only. Among others the PHYBAL (physically based fatigue life calculation) method including current enhancements and a thereon-based development named SteBLife (step-bar fatigue life approach) have been developed over the last 10 years. These methods allow the efforts in experimentation to be reduced by more than 90 % and therefore offer the possibility to take further fatigue relevant parameters into account. This therefore allows a variety of S,N-curves dependent on those fatigue relevant parameters to be generated with those methods easily establishing a multidimensional dataset. To just name a few examples of those parameters such as the influence of temperature, loading conditions, geometry as well as thermal and mechanical ageing processes on the fatigue behavior can now be calculated in accordance to a process being straightforward leading to an important step with regard to improving the efficiency of assessing structural components. Consequently, safety factors can be defined more in accordance to structural needs, being of highest interest with respect to the increasing number of ageing infrastructure such as highways, bridges or others. A lot of this ageing infrastructure has a strong need to be managed with respect to its structural integrity and the engineering community therefore tries the residual life of this infrastructure to be determined as appropriate as possible. In that context non-destructive testing parameters are increasingly considered to characterize a metallic material’s microstructure allowing more precise information to be obtained regarding the actual damage condition and the integrity of a component. The paper will address the high capability of non-destructive testing techniques for the evaluation of damage evolution processes also with respect to mechanism based fatigue as well as residual life calculations according to PHYBAL and SteBLife.

A Review of Ultrasonic Application on Non-destructive Testing Method for Concrete Structure

2014 ◽  
Vol 70 (3) ◽  
Author(s):  
Nasarudin Ahmad ◽  
Ruzairi Abdul Rahim ◽  
Herlina Abdul Rahim ◽  
Mohd Hafiz Fazlul Rahiman
Keyword(s):  
Concrete Structure ◽  
High Speed ◽  
Structural Integrity ◽  
Surface Hardness ◽  
Concrete Surface ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Surface Absorption ◽  
Processing Techniques ◽  
Non Destructive

Although the technique of using ultrasound has reached maturity by given the extent of the development of sensors, but the use of the various areas still can be explore. Many types of ultrasonic sensors are still at conventional in use especially for measurement equipment in the industry. With the advancement of signal processing techniques, high-speed computing, and the latest techniques in image formation based Non-destructive testing (NDT) methods, the usage of ultrasound in concrete NDT testing is very extensive because the technique is very simple and should not damage the concrete structure to be investigated. Many of the parameters need to be tested using ultrasound techniques to concrete can be realized. Starting with the initial process for of concrete mixing until the concrete matured to the age of century old. Various tests are available to test a variety of non-destructive of concrete completely, in which there is no damage to the concrete, through those where the concrete surface is damaged a bit, to partially destructive testing, such as core tests and insertion and pull-off test, which surface to be repaired after the test. Testing parameter features that can be evaluated using non-destructive testing and destructive testing of some rather large and include basic parameters such as density, elastic modulus and strength and surface hardness and surface absorption, and reinforcement location, size and distance from the surface. In some cases it is also possible to check the quality of the workmanship and structural integrity of the ability to detect voids, cracks and delamination. A review of NDT using ultrasound on concrete are presented in this paper to highlight the important aspect to consider when one to consider the application and development of ultrasound testing on concrete by considering ultrasound signal capturing, processing and presenting.

scholarly journals Non-destructive testing and evaluation for structural integrity

Sadhana ◽  
1995 ◽  
Vol 20 (1) ◽  
pp. 5-38 ◽  
Author(s):  
Baldev Raj ◽  
T Jayakumar ◽  
B P C Rao
Keyword(s):  
Structural Integrity ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Non Destructive ◽  
Testing And Evaluation

Technical Note: Detection of delamination in tyres using eddy currents

1997 ◽  
Vol 211 (1) ◽  
pp. 79-82 ◽  
Author(s):  
X. E. Gros
Keyword(s):  
Eddy Currents ◽  
Structural Integrity ◽  
Low Cost ◽  
Technical Note ◽  
Quality And Safety ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Safety Standards ◽  
Current Testing ◽  
Non Destructive

Non-destructive testing (NDT) is a useful tool to assess the structural integrity of components in order to maintain quality and safety standards. A low-cost electromagnetic technique based on eddy currents induced into a material appeared promising for the inspection of composite materials. Experiments were carried out in order to assess the potential of eddy currents in detecting delamination in rubber tyres. Infrared thermography was used to verify inspection results achieved with eddy currents. Non-destructive examination results are presented in this paper; these confirm that eddy current testing is an economically viable alternative for the inspection of steel reinforced truck tyres.

scholarly journals Risk Based Inspection of Jackets Submitted to Through-Wall Cracks

2003 ◽  
Author(s):  
Franck Schoefs ◽  
Mustapha Rguig
Keyword(s):  
Decision Aid ◽  
Structural Integrity ◽  
Offshore Structures ◽  
Probability Of Detection ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Probability Of False Alarm ◽  
The Impact ◽  
Non Destructive ◽  
Rational Process

The actual challenge for the requalification of existing offshore structures through a rational process of reassessment leads to state the importance of Risk Based Inspection methodology. This paper points out the inspection results modelling and their contribution to decision aid tools. The study of the impact of through cracks on structural integrity of jacket platforms is still a challenge. The detection of large cracks is first addressed. In order to minimize inspections and maintenance costs, all the available data from inspection results, such as probability of detection and probability of false alarm, must be addressed, as well as the probability of crack presence. This can be achieved by the use of the decision theory. These capabilities of Non Destructive Testing give a first input for the risk study. A cost function is suggested to introduce this modelling into a risk analysis and is devoted to help rank the NDT tools. The case of large through-wall cracks is specifically addressed.

scholarly journals Piezoelectric Impedance-Based Non-Destructive Testing Method for Possible Identification of Composite Debonding Depth

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 621 ◽  
Author(s):  
Wongi S. Na ◽  
Jongdae Baek
Keyword(s):  
Composite Materials ◽  
Composite Structures ◽  
Structural Integrity ◽  
Structural Safety ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Electromechanical Impedance ◽  
Testing Method ◽  
Piezoelectric Impedance ◽  
Non Destructive

Detecting the depth and size of debonding in composite structures is essential for assessing structural safety as it can weaken the structure possibly leading to a failure. As composite materials are used in various fields up to date including aircrafts and bridges, inspections are carried out to maintain structural integrity. Although many inspection methods exist for detection damage of composites, most of the techniques require trained experts or a large equipment that can be time consuming. In this study, the possibility of using the piezoelectric material-based non-destructive method known as the electromechanical impedance (EMI) technique is used to identify the depth of debonding damage of glass epoxy laminates. Laminates with various thicknesses were prepared and tested to seek for the possibility of using the EMI technique for identifying the depth of debonding. Results show promising outcome for bringing the EMI technique a step closer for commercialization.

scholarly journals Laboratory stand for development of method and system for continuous non-contact non-destructive testing of technical condition of insulation equipment

2021 ◽  
pp. 80-87
Author(s):  
T. G. Galieva ◽  
◽  
D. A. Ivanov ◽  
M. F. Sadykov ◽  
A. V. Golenishchev-Kutuzov ◽  
...  
Keyword(s):  
Residual Life ◽  
Electrical Equipment ◽  
Technical Condition ◽  
Contact Method ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Electromagnetic Methods ◽  
On Line ◽  
Offline Testing ◽  
Non Destructive

Measurement of partial discharges (PD) is a generally accepted method of diagnosing the insulation of electrical equipment worldwide. Today, the trend is to move from conventional offline testing to online monitoring to predict the service life of insulation. For testing and calibration of the developed new methods with the contact method, a laboratory stand has been developed in accordance with GOST R 55191-2012 (IEC 60270:2000). The article suggests the use of acoustic and electromagnetic methods for a system of continuous non-contact non-destructive testing of the technical condition of insulation equipment, which will allow monitoring insulation equipment online and predicting its residual life. On their basis, a system of «on-line» diagnostics of high-voltage insulators has been developed.

scholarly journals Fatigue Life of RC Bridge Decks Affected by Non-Uniformly Dispersed Stagnant Water

2019 ◽  
Vol 9 (3) ◽  
pp. 607 ◽  
Author(s):  
Eissa Fathalla ◽  
Yasushi Tanaka ◽  
Koichi Maekawa
Keyword(s):  
Fatigue Life ◽  
Great Influence ◽  
Severe Case ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Stagnant Water ◽  
Fatigue Lifetime ◽  
Testing Technology ◽  
Non Destructive ◽  
Remaining Fatigue Life

Stagnant water on reinforced concrete (RC) decks reduces their life significantly compared to the case of dry states. Fully submerged states have been investigated as the most severe case, which is however rarely experienced in reality. Currently, it is possible to simulate concrete–water interactions for lifetime prediction of RC decks. In this study, fatigue lifetime is systematically computed for various locations of stagnant water at the upper layer of RC decks. It is found that the patterns of wet and dry areas have a great influence on the remaining fatigue life even though the same magnitude of cracking develops. Then, a hazard map for the wetting locations with regard to the remaining fatigue life is presented based on the systematically arranged simulation. Finally, a nonlinear correlation is introduced for fatigue life prediction based upon site inspected wetting locations, which can be detected by non-destructive testing technology.

The structural integrity of flash-butt welded premium rail steel – Evaluation of strength, microstructure and defects

2020 ◽  
pp. 095440972097313
Author(s):  
Anthony Micheletto ◽  
John Cookson ◽  
Yong Pang ◽  
Bernard Chen ◽  
Peter Mutton
Keyword(s):  
Structural Integrity ◽  
Rail Steel ◽  
Experimental Testing ◽  
Non Destructive Testing ◽  
Testing Methods ◽  
Destructive Testing ◽  
Integrity Assessment ◽  
Catastrophic Failures ◽  
Non Destructive ◽  
Microstructural Examination

Experimental testing of flash-butt welded premium rail steel samples was undertaken to quantify the variation in strength through the cross-section of the weld, with results showing a general correlation between the width of the heat-affected-zone and the ultimate tensile strength. Microstructural examination and fractography revealed the presence of defects in some samples. Large defects can be identified by non-destructive testing methods as part of routine structural integrity assessment; however, small defects may escape detection but could propagate under cyclic loading in service leading to catastrophic failures. This work demonstrates the requirement for stringent control of heat input to prevent the development of defects in premium rail steels with high alloying content.

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