scholarly journals Static load testing with temperature compensation for structural health monitoring of bridges

2016 ◽  
Vol 127 ◽  
pp. 700-718 ◽  
Author(s):  
Viet Ha Nguyen ◽  
Sebastian Schommer ◽  
Stefan Maas ◽  
Arno Zürbes
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Temperature Compensation ◽  
Static Load ◽  
Load Testing ◽  
Structural Health ◽  
Static Load Testing

In-situ load testing of a WWII era timber Warren truss in the development of a structural health monitoring program

2021 ◽  
Vol 239 ◽  
pp. 112274
Author(s):  
Henry Helmer-Smith ◽  
Nicholas Vlachopoulos ◽  
Marc-André Dagenais ◽  
Bradley Forbes
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Monitoring Program ◽  
Load Testing ◽  
Structural Health

scholarly journals Improving sensitivity and coverage of structural health monitoring using bulk ultrasonic waves

2020 ◽  
pp. 147592172096512
Author(s):  
Stefano Mariani ◽  
Yuan Liu ◽  
Peter Cawley
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Temperature Compensation ◽  
Signal Amplitude ◽  
Guided Wave ◽  
Ultrasonic Waves ◽  
Back Wall ◽  
Environmental Chamber ◽  
Structural Health ◽  
Specific Temperature

Practical ultrasonic structural health monitoring systems must be able to deal with temperature changes and some signal amplitude/phase drift over time; these issues have been investigated extensively with low-frequency-guided wave systems but much less work has been done on bulk wave systems operating in the megahertz frequency range. Temperature and signal drift compensation have been investigated on a thick copper block specimen instrumented with a lead zirconate titanate disc excited at a centre frequency of 2 MHz, both in the laboratory at ambient temperature and in an environmental chamber over multiple 20°C–70°C temperature cycles. It has been shown that the location-specific temperature compensation scheme originally developed for guided wave inspection significantly out-performs the conventional combined optimum baseline selection and baseline signal stretch method. The test setup was deliberately not optimised, and the signal amplitude and phase were shown to drift with time as the system was temperature cycled in the environmental chamber. It was shown that the ratio of successive back wall reflections at a given temperature was much more stable with time than the amplitude of a single reflection and that this ratio can be used to track changes in the reflection coefficient from the back wall with time. It was also shown that the location-specific temperature compensation method can be used to compensate for changes in the back wall reflection ratio with temperature. Clear changes in back wall reflection ratio were produced by the shadow effect of simulated damage in the form of 1-mm diameter flat-bottomed holes, and the signal-to-noise ratio was such that much smaller defects would be detectable.

scholarly journals Simultaneous Influence of Static Load and Temperature on the Electromechanical Signature of Piezoelectric Elements Bonded to Composite Aeronautic Structures

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Marc Rebillat ◽  
Mikhail Guskov ◽  
Etienne Balmes ◽  
Nazih Mechbal
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Static Load ◽  
Full Range ◽  
Bonding Layer ◽  
Static Loads ◽  
Temperature Variations ◽  
Structural Health ◽  
Piezoelectric Elements ◽  
Simultaneous Influence

Electromechanical (EM) signature techniques have raised a huge interest in the structural health-monitoring community. These methods aim at assessing structural damages and sensors degradation by analyzing the EM responses of piezoelectric components bonded to aeronautic structures. These structures are subjected simultaneously to static loads and temperature variations that affect the metrics commonly used for damage detection and sensor diagnostics. However, the effects of load and temperature on these metrics have mostly been addressed separately. This paper presents experimentations conducted to investigate the simultaneous influence of static load and temperature on these metrics for two kinds of piezoelectric elements (lead zirconate titanate (PZT) and macrofiber composite (MFC)) bonded on sandwich composite materials, for the full range of real-life conditions encountered in aeronautics. Results obtained indicate that both factors affect the metrics in a coupled manner in particular due to the variations of the mechanical properties of the bonding layer when crossing its glass transition temperature. Furthermore, both piezoelectric elements globally behave similarly when subjected to temperature variations and static loads. Simultaneous accounting of both temperature and static load is thus needed in practice in order to design reliable structural health-monitoring systems based on these metrics.

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