Keywords: ultrasonic testing, phased array, rotation scanner, hollow axle, sleeve shaft, WOLAXIM.

This paper describes the investigations, carried out during the ongoing European Project WOLAXIM. It presents the development of the non-destructive testing system for hollow axle inspection. The phased array probe is designed, the inspection parameters are determined and the required test equipment is planned according to the specifications.

As a part of the probe design, a detailed model to calculate the sound field of the conical phased array is developed. With this model the optimal geometric parameters for bore diameters from 30mm up to 70mm are determined. The first design of a conical probe with forty-eight elements is realised. Based on this design a mock-up with ten elements is produced. The first practical tests with the calculated delay laws show high sensitivity for small test flaws and offer good agreement with the modelling results. The effectiveness as well as the sensitivity with a good signal to noise ratio is verified.

The parameters for a short inspection time less than five minutes per axle are determined. A raw scanning with 1.5° circumferential and 2mm axial resolution is feasible within two minutes. That is significantly faster than comparable mechanically rotated probe systems. The remaining three minutes are sufficient for the other steps in the inspection process. The required features will be fulfilled by the COMPAS® phased array device.

The feasibility of the ultrasonic system is shown. The specification and the theoretical probe design are complete and sufficient knowledge is present that the system will be viable. The results of the modelling and first practical tests show a good agreement with the objectives. The determined probe parameters satisfy the requirements.

purchase the full-text of this paper (price £20)

go to the previous paper
go to the next paper
return to the table of contents
return to the book description
purchase this book (price £110 +P&P)