Remember Me
Or use your Academic/Social account:


Or use your Academic/Social account:


You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.


Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message


Verify Password:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
Mierczak, Lukasz
Languages: English
Types: Doctoral thesis
Subjects: TJ
Magnetic non-destructive methods utilising the Magnetic Flux Leakage (MFL) and Magnetic Barkhausen Noise (MBN) phenomena are widely used in the evaluation of the structural integrity of steel components. The MFL method is effectively applied for in-service flaw monitoring of oil and gas pipelines, fuel storage tank floors and rails; whereas the MBN method, due to high sensitivity of Barkhausen emission to residual and applied stress, has become one of the most popular NDE tools for investigating this condition of steels. Despite the affirming research and successful applications, which helped these methods to gain acceptance as a viable non-destructive tools, there is still a requirement for establishing a quantitative links between magnetic and mechanical properties of steel which would enable their further understanding and optimisation.\ud In this thesis the applications of MFL and MBN methods for flaw and stress detection are analysed via analytical and numerical modelling.\ud A new model relating the MBN amplitude and stress for materials having different magnetostrictive behaviour under load is proposed and validated in the quantitative stress evaluation of different grades of steel. Moreover, a new method for determining depth dependence of stress from measured magnetic Barkhausen signals is presented. A complete set of newly derived equations describing the detected Barkhausen signals in terms of the actual emissions that are generated inside the material and how these appear when they propagate to the surface is given.\ud The results from finite element modelling of magnetic flux leakage signals above unflawed and flawed rails energised in various directions are presented. These results enabled to identify the most effective current injection procedure and optimise the probability of transverse flaw detection in the rail inspection. The agreement between modelled and measured electromagnetic signals indicating presence of transverse rail defects has been justified.
  • No references.
  • No related research data.
  • No similar publications.

Share - Bookmark

Cite this article