초록 ▼

A method for determining the longitudinal loading acting on a beam, such as a rail of a railway track subjected to longitudinal loading and, in particular, for determining the neutral temperature of railway tracks. The beam is energized longitudinally in the acoustic frequency range, and the level o

A method for determining the longitudinal loading acting on a beam, such as a rail of a railway track subjected to longitudinal loading and, in particular, for determining the neutral temperature of railway tracks. The beam is energized longitudinally in the acoustic frequency range, and the level of magnetic Barkhausen noise at the surface of the energized region is measured. Measurements of the magnetic Barkhausen noise are taken for different longitudinal stress states and used for plotting the calibration curve of the magnetic Barkhausen noise as a function of longitudinal stress, the Barkhausen noise being measured at least at three points on the face of the built-in beam, and the calibration curve is used for determining the longitudinal loading on the cross-section in question using weighted averaging. The neutral temperature of the railway track is then calculated considering the modulus of elasticity, coefficient of thermal expansion and temperature of the rail.

대표청구항 ▼

[ We claim:] [1.] A method for determining in situ a longitudinal load acting on a beam exposed to a longitudinal load, wherein the beam is energized longitudinally in an acoustic frequency range, and a level of magnetic Barkhausen noise is measured at a surface of the energized region, then a calib

[ We claim:] [1.] A method for determining in situ a longitudinal load acting on a beam exposed to a longitudinal load, wherein the beam is energized longitudinally in an acoustic frequency range, and a level of magnetic Barkhausen noise is measured at a surface of the energized region, then a calibration curve of Barkhausen noise versus longitudinal loading is established by measuring Barkhausen noise at different longitudinal stress states, the method comprising the steps of:establishing the calibration curve by measuring in situ the level of the magnetic Barkhausen noise at least at two different loadings and at least at three points on a periphery of a cross section of the beam;plotting a function of a value of the Barkhausen noise versus the change in Barkhausen noise for the change of the local stresses of said at least two different loadings, furtheronassigning the value of the Barkhausen noise belonging to zero stress to the value at the location of maximal change of the function,establishing the curve of Barkhausen noise versus stress by integrating the function of change of the Barkhausen noise versus Barkhausen noise,defining the stress at the given point of the cross section of the beam, thenrepeating the previous steps at further similarly loaded cross sections and for each point defining a weighting factor providing a weighted average of stresses in the same cross section corresponding to the given loading, anddefining the longitudinal loading falling onto said given cross section on the basis of said calibration curve and by carrying out a weighted average calculation.