Two wheel ultrasonic rail testing system and method

• US 4,174,636 A
• Filed: 08/01/1977
• Issued: 11/20/1979
• Est. Priority Date: 07/25/1977
• Status: Expired due to Term

• Current Assignee: Dominick A. Pagano
• Original Assignee: Dominick A. Pagano
• Inventors: Pagano, Dominick A.
• Primary Examiner(s): Kreitman, Stephen A.
• Application Number:
  US05/820,588
• Time in Patent Office: 841 Days
• Field of Search: 73/618, 73/620, 73/624, 73/625, 73/627, 73/628, 73/629, 73/632, 73/634, 73/635, 73/636, 73/639, 73/641
• US Class Current: 73/636
• CPC Class Codes: G01N 2291/02854 Length, thickness
• CPC Class Codes: G01N 2291/0421 Longitudinal waves
• CPC Class Codes: G01N 2291/0422 Shear waves, transverse waves, horizontally polarised waves
• CPC Class Codes: G01N 2291/0428 Mode conversion
• CPC Class Codes: G01N 2291/048 Transmission, i.e. analysed material between transmitter and receiver
• CPC Class Codes: G01N 2291/105 two or more emitters, two or more receivers
• CPC Class Codes: G01N 2291/2623 Rails; Railroads
• CPC Class Codes: G01N 29/043 in the interior, e.g. by shear waves
• CPC Class Codes: G01N 29/2493 Wheel shaped probes

Abstract

A system and method for performing ultrasonic inspection of a length of test material with ultrasonic transducing means emitting a beam of ultrasonic energy from within sealed wheel means containing a coupling fluid therein and having a flexible cylindrical surface member transparent to the ultrasonic beam and arranged for rolling contact along the test material. The system and method are characterized by spaced leading and trailing wheel means arranged for rolling contact along the length of test material. Ultrasonic transducer means in each of the leading and trailing wheel means are oriented so that a beam of ultrasonic energy emitted from the transducer means in one wheel means will enter the test material, be reflected from the bottom surface thereof, and be directed to and received by the transducer mean in the other wheel means. Each wheel means further includes ultrasonic transducers emitting ultrasonic energy longitudinally in front of and behind the two wheels, and side-looking transducer means for emitting ultrasonic energy into the test material transversely to the direction of travel. Additional transducers emit radiation perpendicularly through the test material. Accordingly, the test material is fully probed and many different kinds of defects can be detected. The transducers are positioned away from the test material by a distance which is substantially the near field distance of the ultrasonic beam. Means are provided for adjusting the spacing between two wheels, to allow different thicknesses of test material to be tested by interwheel transmission of the ultrasonic beam.

Claims

1. In a system of the type for performing ultrasonic inspection of a length of test material, such as a rail, with ultrasonic transducing means emitting a beam of ultrasonic energy from within sealed wheel means containing a coupling liquid therein and having a flexible membrane transparent to the ultrasonic beam and arranged for rolling contact along the test material, rail inspection apparatus comprising:

leading wheel means arranged for rolling contact along the length of rail,

trailing wheel means spaced behind the leading wheel means and arranged for rolling contact along the length of rail,

first ultrasonic transducer means mounted in the leading wheel means aimed at an angle downwardly and rearwardly and second ultrasonic transducer means mounted in the trailing wheel means aimed at an angle downwardly and forwardly for transmitting ultrasonic energy from one of said transducer means to the other longitudinally through the rail at an angle to the top surface thereof,

third ultrasonic transducer means mounted in one of said wheel means aimed at an angle downwardly and laterally for transmitting ultrasonic energy in the rail in a side-looking direction substantially perpendicularly to the side surface of the rail and at a resultant angle of approximately 40°

to the perpendicular to the top surface of the rail toward the lower gage corner of the rail head and for obtaining optimum reflection of ultrasonic energy from the lower gage corner, regardless of the various sizes of rail heads encountered, to detect loss of amplitude of the energy caused by impingement with a defect,

fourth ultrasonic transducer means mounted in the other wheel means aimed at an angle downwardly and laterally for transmitting ultrasonic energy in the rail in a side-looking direction substantially perpendicularly to the side surface of the rail and at a resultant angle of approximately 40°

to the perpendicular to the top surface of the rail toward the lower field corner of the rail head and for obtaining optimum reflection of ultrasonic energy from the lower field corner, regardless of the various sizes of the rail heads encountered, to detect loss of amplitude of the energy caused by impingement with a defect, and

fifth ultrasonic transducer means in at least one of said wheel means aimed downwardly at a zero angle to the perpendicular to the top surface of the rail,

thereby effectively probing the rail for various kinds and orientations of defects regardless of whether the rail is welded or jointed.

2. In a method for performing ultrasonic inspection of a length of test material, such as a rail, with ultrasonic transducing means emitting a beam of ultrasonic energy from within sealed wheel means containing a coupling liquid therein and having a membrane transparent to the ultrasonic beam and arranged for rolling contact along the test material, the rail inspection method comprising the steps of:

providing leading and trailing wheel means,

providing first ultrasonic transducer means in said leading wheel means mounted in a fixed location relative to the axis thereof aimed at an angle downwardly and rearwardly and providing second ultrasonic transducer means in said trailing wheel means mounted in a fixed location relative to the axis thereof aimed at an angle downwardly and forwardly for directing ultrasonic energy in a beam from one of said transducer means to the other in the through-transmission mode wherein the beam of energy travels from one at an angle downwardly and longitudinally within the rail for reflection from the bottom of the rail to travel upwardly and longitudinally within the rail to be received by the other,

providing means for changing the longitudinal spacing between said leading and trailing wheel means,

providing third ultrasonic transducer means within one of said wheel means aimed downwardly perpendicular to the top surface of the rail,

sensing the time required for ultrasonic energy from the third transducer means to travel down through the rail to be reflected from the bottom surface and to travel back to the third transducer means, to sense the height of the rail along which said wheel means are rolling, and

automatically and continuously changing the longitudinal spacing between said wheel means in response to changes in rail height for compensating for such changes to maintain the first and second transducer means in alignment with the beam of energy to be transmitted and received between them.

3. The rail inspection method as claimed in claim 2 further comprising the steps of:

utilizing each of said transducer means in turn as a transmitter and as a receiver in predetermined sequence, and

also utilizing the transmitter as a receiver for operation in the reflection mode.

4. The rail inspection method as claimed in claim 3, wherein

said predetermined sequence comprises alternating the roles of transmitter and receiver in each successive cycle.

5. In a method for performing ultrasonic inspection of a length of test material, such as a rail, with ultrasonic transducing means emitting a beam of ultrasonic energy from within sealed wheel means containing a coupling liquid therein and having a membrane transparent to the ultrasonic beam and arranged for rolling contact along the test material, the rail inspection method comprising the steps of:

providing leading and trailing wheel means,

providing first and second ultrasonic transducer means in the respective wheel means aimed laterally downwardly toward opposite lower corners of the rail head substantially perpendicularly to the side surface thereof,

transmitting ultrasonic energy from the first transducer means for reflection from the one lower corner of the rail head toward which it is aimed and receiving the reflected energy therefrom to detect loss of amplitude of energy caused by impingement with a defect, and

transmitting ultrasonic energy from the second transducer means for reflection from the other lower corner of the rail head toward which it is aimed and receiving the reflected energy therefrom to detect loss of amplitude of energy caused by impingement with a defect, said ultrasonic energy further being transmitted in the rail head from each of said first and said second transducer means at a resultant angle of approximately 40°

to the perpendicular to the top surface of the rail for obtaining optimum reflection of ultrasonic energy from the lower corner of the rail head toward which each of said first and second transducer means is respectively aimed regardless of various sizes in rail heads encountered.

6. In a system of the type for performing ultrasonic inspection of a length of test material, such as a rail, with ultrasonic transducing means emitting a beam of ultrasonic energy from within sealed wheel means containing a coupling liquid therein and having a flexible membrane transparent to the ultrasonic beam and arranged for rolling contact along the test material, rail inspection apparatus which comprises:

leading wheel means arranged for rolling contact along the length of rail,

trailing wheel means spaced behind said leading wheel means and arranged for rolling contact along the length of rail,

first ultrasonic transducer means mounted in said leading wheel means aimed laterally downwardly toward the lower gage corner of the rail head for transmitting a beam of ultrasonic energy in the rail in a side-looking direction substantially perpendicularly to the side surface of the rail and at a resultant angle of approximately 40°

to the perpendicular to the top surface of the rail and for obtaining optimum reflection of ultrasonic energy from the lower gage corner, regardless of various sizes of rail heads encountered, to detect loss of amplitude of the energy caused by impingement with a defect, and

second ultrasonic transducer means mounted in said trailing wheel means aimed laterally downwardly toward the lower field corner of the rail head for transmitting a beam of ultrasonic energy in the rail in a side-looking direction substantially perpendicularly to the side surface of the rail and at a resultant angle of approximately 40°

to the perpendicular to the top surface of the rail and for obtaining optimum reflection of ultrasonic energy from the lower field corner, regardless of various sizes of rail heads encountered, to detect loss of amplitude of energy caused by impingement with a defect.