A Wayside System for In-Situ Measurement of Rail Neutral Temperature by Nonlinear Ultrasonic Guided Waves

2012 ◽  
Author(s):  
Claudio Nucera ◽  
Robert Phillips ◽  
Francesco Lanza di Scalea ◽  
Mahmood Fateh ◽  
Gary Carr
Keyword(s):  
Thermal Stress ◽  
Temperature Measurement ◽  
Guided Waves ◽  
Thermal Stresses ◽  
Numerical Models ◽  
In Situ Measurement ◽  
Ultrasonic Guided Waves ◽  
Test Bed ◽  
Neutral Temperature

The University of California at San Diego (UCSD), under a Federal Railroad Administration (FRA) Office of Research and Development (R&D) grant, is conducting research to develop a system for in-situ measurement of the rail Neutral Temperature in Continuous-Welded Rail (CWR). It is known that CWR can break in cold weather and can buckle in hot weather. Currently, there is a need for the railroads to know the current state of thermal stress in the rail, or the rail Neutral Temperature (rail temperature with zero thermal stress), to properly schedule slow-order mandates and prevent derailments. UCSD has developed a prototype for wayside rail Neutral Temperature measurement that is based on non-linear ultrasonic guided waves. Numerical models were first developed to identify proper guided wave modes and frequencies for maximum sensitivity to the thermal stresses in the rail web, with little influence of the rail head and rail foot. Experiments conducted at the Large-scale Rail NT Test-bed indicated a rail Neutral Temperature measurement accuracy of a few degrees. Field tests are planned at the Transportation Technology Center (TTC) in Pueblo, CO in June 2012 in collaboration with the Burlington Northern Santa Fe (BNSF) Railway.

Nonlinear Guided Waves for Structural Health Monitoring: Numerical Algorithm and Application to Railroad Track

2012 ◽  
Author(s):  
Claudio Nucera ◽  
Francesco Lanza di Scalea
Keyword(s):  
Thermal Stress ◽  
Temperature Measurement ◽  
Large Scale ◽  
Guided Waves ◽  
Thermal Stresses ◽  
Numerical Models ◽  
Guided Wave ◽  
Cold Weather ◽  
Test Bed ◽  
Neutral Temperature

The University of California at San Diego (UCSD), under a Federal Railroad Administration (FRA) Office of Research and Development (R&D) grant, is conducting research to develop a system for in-situ measurement of the rail Neutral Temperature in Continuous-Welded Rail (CWR). It is known that CWR can break in cold weather and can buckle in hot weather. Currently, there is a need for the railroads to know the current state of thermal stress in the rail, or the rail Neutral Temperature (rail temperature with zero thermal stress), to properly schedule slow-order mandates and prevent derailments. UCSD has developed a prototype for wayside rail Neutral Temperature measurement that is based on non-linear ultrasonic guided waves. Numerical models were first developed to identify proper guided wave modes and frequencies for maximum sensitivity to the thermal stresses in the rail web, with little influence of the rail head and rail foot. Experiments conducted at the Large-scale Rail NT Test-bed indicated a rail Neutral Temperature measurement accuracy of a few degrees. Field tests are planned at the Transportation Technology Center (TTC) in Pueblo, CO in June 2012 in collaboration with the Burlington Northern Santa Fe (BNSF) Railway.

Nonlinear guided waves for neutral temperature measurement in continuous welded rails: results from laboratory and field tests

2013 ◽  
Author(s):  
Claudio Nucera ◽  
Robert Phillips ◽  
Peter Zhu ◽  
Stefano Mariani ◽  
Francesco Lanza di Scalea ◽  
...  
Keyword(s):  
Temperature Measurement ◽  
Guided Waves ◽  
Field Tests ◽  
Neutral Temperature

Rail Neutral Temperature Estimation Using Field Data, Numerical Models, and Machine Learning

2021 ◽  
Author(s):  
Yuning Wu ◽  
Xuan Zhu ◽  
Chi-Luen Huang ◽  
Sangmin Lee ◽  
Marcus Dersch ◽  
...  
Keyword(s):  
Machine Learning ◽  
Field Data ◽  
Thermal Stresses ◽  
Numerical Models ◽  
Estimation Method ◽  
Supervised Machine Learning ◽  
Estimation Accuracy ◽  
Optimization Approach ◽  
Neutral Temperature ◽  
Wide Range

Abstract Effective Rail Neutral Temperature (RNT) management is needed for continuous welded rail (CWR). RNT is the temperature at which the longitudinal stress of a rail is zero. Due to the lack of expansion joints, CWR develops internal tensile or compressive stresses when the rail temperature is below or above, respectively, the RNT. Mismanagement of RNT can lead to rail fracture or buckling when thermal stresses exceed the limits of rail steel. In this work, we propose an effective RNT estimation method structured around four hypotheses. The work leverages field-collected vibration test data, high-fidelity numerical models, and machine learning techniques. First, a contactless non-destructive and non-disruptive sensing technology was developed to collect real-world rail vibrational data. Second, the team established an instrumented field test site at a revenue-service line in the state of Illinois and performed multi-day data collection to cover a wide range of temperature and thermal stress levels. Third, numerical models were developed to understand and predict rail vibration behavior under the influence of temperature and longitudinal load. Excellent agreement between model and experimental results were obtained using an optimization approach. Finally, a supervised machine learning algorithm was developed to estimate RNT using the field-collected rail vibration data. Sensitivity studies and error analyses were included in this work. The system performance with field data indicates that the proposed framework can support reasonable RNT estimation accuracy when measurement or model noise is low.

Ultrasonic Guided Wave Monitoring of Railroad Tracks

2012 ◽  
Vol 83 ◽  
pp. 198-207 ◽  
Author(s):  
Claudio Nucera ◽  
Robert Phillips ◽  
Francesco Lanza di Scalea
Keyword(s):  
Guided Waves ◽  
Thermal Stresses ◽  
Flaw Detection ◽  
Guided Wave ◽  
Ultrasonic Guided Waves ◽  
Rail Transportation ◽  
Railroad Tracks ◽  
Ultrasonic Guided Wave ◽  
The Us ◽  
Inspection Systems

Among structural concerns for the safety of rail transportation are internal flaws and thermal stresses, both of which can cause disruption of service and even derailments. Ultrasonic guided waves lend themselves to addressing both of these problems. This paper reports on two inspection systems for rails being developed at UCSD under the auspices of the US Federal Railroad Administration. Both systems utilize ultrasonic guided waves as the main probing mechanism, for the two different applications of flaw detection and thermal stress detection.

MODEL-BASED IN SITU PARAMETER ESTIMATION OF ULTRASONIC GUIDED WAVES IN AN ISOTROPIC PLATE

2010 ◽  
Author(s):  
James S. Hall ◽  
Jennifer E. Michaels ◽  
Donald O. Thompson ◽  
Dale E. Chimenti
Keyword(s):  
Parameter Estimation ◽  
Guided Waves ◽  
Isotropic Plate ◽  
Ultrasonic Guided Waves ◽  
Model Based

In Situ Observation of Thermal Stress in Nano-Size Thin Aluminum Films

2005 ◽  
Vol 490-491 ◽  
pp. 577-582
Author(s):  
Hanabusa Takao ◽  
Kazuya Kusaka ◽  
Shozo Shingubara ◽  
Osamu Sakata
Keyword(s):  
Thin Films ◽  
Thermal Stress ◽  
Thermal Stresses ◽  
In Situ Observation ◽  
Heating Cycle ◽  
Cooling Cycle ◽  
Aluminum Films ◽  
Thin Aluminum ◽  
Nano Size

In-situ observation of thermal stress in thin films deposited on a silicon substrate was made by synchrotron radiations. The specimens prepared in this experiment were nano-size thin aluminum films with SiO2 passivation. The thickness of the films was 10 nm, 20 nm and 50 nm. Residual stress in the as-deposited state was tensile. Compressive stress was developed in the heating cycle up to 300 oC and tensile stresses developed in the cooling cycle. The thermal stresses in the 50 nm film showed non-linear behavior in the first heating cycle from the room temperature to 300 oC. However, they linearly behaved in the first cooling cycle and the second thermal cycle. On the other hand, the thermal stresses in the 10 nm film behaved almost linearly without any hysteresis in the first and the second thermal cycles. The mechanism of thermal stress behavior of thin films is discussed.

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