AXLES USING NON-DESTRUCTIVE TESTING
A company for the maintenance of railway vehicles in Slovenia carried out, in collaboration with the Institute of Metal Structures (IMK), Ljubljana, testing and relevant analyses of the state of carriage axles. In order to detect cracks at carriage axles and to evaluate the quality of axles surfaced, ultrasonic and magnetic particle testing methods were used. Ultrasonic testing with normal and angle probes was used to detect internal cracks in the carriage axles using the distance gain size (DGS) diagram and the distance amplitude correction (DAC) method for reference specimens. Additionally, the magnetic particle testing method, with an apparatus permitting the detection of transverse and longitudinal cracks, was used to search for surface cracks. The tests performed at numerous railway carriages provided results, which make it possible to predict a premature axle fracture in further service. The non-destructive testing methods used permitted the detection of the cracks present, causes for the crack initiation were established, and the risks of crack propagation were evaluated. A critical evaluation of the carriage axles in terms of crack initiation and size is given. The prediction of the remaining life of an axle with reference to the potential propagation of the existing cracks is given taking into account the load axle acting on the axle and the axle age.
Inspection reliability and periodicity for rail axle inspection
Periodic inspection of railway axles is carried out to avoid axle failures. Analytical methods for determining the periodicity of inspection require knowledge of load conditions, materials properties and inspection reliability. The Wheelset Integrated Design and Maintenance (WIDEM) Project is being carried out to acquire some of this data and to develop methodologies for axle design. An example is given in this paper of the measurement of inspection reliability from a set of 11 cracked axles. The method estimates the POD of the in-situ inspection technique from the response versus size method, the size in this case being measured with Alternating Current Potential Drop (ACPD), phased array ultrasonics and time-offlight diffraction. The results show that useful information is generated by such methods and a further experiment is planned on a different range of axles to obtain wider applicability of the data obtained.
Repressive coping before and after diagnosis of breast cancer
Objective: The aim was to investigate to which extent emotional repression is a premorbid coping tendency of cancer patients and/or a coping response to the threat posed by a cancer diagnosis. The results of one previous study of breast cancer patients suggest the latter possibility, and our aim was to replicate and extend these findings.