Structural Health Monitoring Based on Acoustic Emissions: Validation on a Prestressed Concrete Bridge Tested to Failure

Abstract

The increasing number of bridges approaching their design life has prompted researchers and operators to develop innovative structural health monitoring (SHM) techniques. An acoustic emissions (AE) method is a passive SHM approach based on the detection of elastic waves in structural components generated by damages, such as the initiation and propagation of cracks in concrete and the failure of steel wires. In this paper, we discuss the effectiveness of AE techniques by analyzing records acquired during a load test on a full-size prestressed concrete bridge span. The bridge is a 1968 structure currently decommissioned but perfectly representative, by type, age, and deterioration state of similar bridges in operation on the Italian highway network. It underwent a sequence of loading and unloading cycles with a progressively increasing load up to failure. We analyzed the AE signals recorded during the load test and examined how far their features (number of hits, amplitude, signal strength, and peak frequency) allow us to detect, quantify, and classify damages. We conclude that AE can be successfully used in permanent monitoring to provide information on the cracking state and the maximum load withstood. They can also be used as a non-destructive technique to recognize whether a structural member is cracked. Finally, we noticed that AE allow classifying different types of damage, although further experiments are needed to establish and validate a robust classification procedure.

Review of Structural Health Monitoring Techniques in Pipeline and Wind Turbine Industries

“…In general, at lower frequencies, background noise disturbs the measurement e.g., vibrations from vehicles and noise from pumps or from flowing medium. Acoustic emission is especially used in places where leak size estimation is not as necessary as the accuracy [20,31,32].…”

“…Through combinations of various types of wave modes, coverage, transduction methods, transducer motions, and transducer configurations, a large number of possible configurations of detection of damage can be brought to light. The measurements of the voltages, time, and various other factors are listed in the following equations [31,[33][34][35][36]. The main advantages of this technique are the low power consumption of the sensors and the capability to cover large areas using few sensors.…”

Application of Building Information Modelling (BIM) in the Health Monitoring and Maintenance Process: A Systematic Review

“…Some sensing techniques that rely on radiation, sound, or electromagnetic signals are called Non-Destructive Testing techniques (NDT). They used for health monitoring such as acoustic emissions (AE) for detecting cracks of structures or laser scanning for damage detection in timber structures [ 137 , 138 ]. Integration of various sensors types is a useful approach for covering disadvantages of some sensors by other types for example the electromagnetic NDT sensor has geolocalisation problems which covers by using terrestrial laser scanning (TLS) and Structure-from-Motion (SfM) approaches or combining laser scanning and thermographic images technique is useful for vulnerability detection [ 139 , 140 ].…”

Development of a Low-Cost System for the Accurate Measurement of Structural Vibrations

“…To observe and control them, dynamic SHM Systems are required [ 14 , 15 , 16 ]. Structural system identification is a critical component of SHM that targets to identify the parameters of the structural model [ 17 ].…”