Ultrasonic guided wave inspection techniques are well-known for the inability to scan a long range axial distance of a pipe from a single transducer position. A phased array focusing technique was developed to improve the ultrasonic guided wave inspection results by concentrating the energy onto a defect. Focusing can increase the energy impinging onto the defects, reduce false alarm ratio, locate the defects, and enhance the propagation distance of the guided waves. An ultrasonic system with n (n>1) individual excitation channels is required to achieve phased array focusing. When phased array focusing was carried out, time delays and amplitude factors were applied to control the input signals for each excitation channel. Different from the time delays for bulk wave linear array focusing, the time delays and amplitude factors for guided wave array focusing are non-linear functions of the focal distance, the pipe size, excitation conditions, and the active frequency. A challenge of this technique is to focus beyond welds, defects, or other obstructions. The influence of axisymmetric welds is investigated with 3D FEM simulations and an experimental example. The theoretical analysis and experiments shows that although welds usually decrease the penetration energy, a limited number of welds rarely affects the phased array focal location.


    Access

    Access via TIB

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Ultrasonic guided wave focusing beyond welds in a pipeline


    Additional title:

    Geführte Ultraschallwellen fokussiert hinter Schweißungen in einer Pipeline


    Contributors:
    Zhang, L. (author) / Luo, W. (author) / Rose, J.L. (author)


    Publication date :

    2006


    Size :

    8 Seiten, 6 Bilder, 9 Quellen





    Type of media :

    Conference paper


    Type of material :

    Storage medium


    Language :

    English




    Pipe testing with ultrasonic guided wave synthetic focusing techniques

    Mu, Jing / Zhang, Li / Hua, Jia et al. | Tema Archive | 2010


    Advanced ultrasonic techniques in pipeline girth welds examination

    Cataldo, Giuseppina / Legori, Roberto | Tema Archive | 2003


    An ultrasonic guided wave tomography approach for pipeline health monitoring

    Royer, R.L. jun. / Velsor, J. van / Rose, J.L. | Tema Archive | 2009



    Simulation supported POD curves for automated ultrasonic testing of pipeline girth welds

    Chapuis, B. / Jenson, F. / Calmon, P. et al. | Tema Archive | 2014