Design and Field Validation of an Offline Synchronized Multi-Sensor DAQ System for Bridge Structural Health...

Area of Science:

• Engineering
• Civil Engineering
• Sensor Technology

Background:

• Structural Health Monitoring (SHM) of large-span bridges demands dense sensor networks for accurate dynamic and kinematic analysis.
• Existing commercial systems often face challenges like data loss, high power consumption, and synchronization errors, hindering Operational Modal Analysis (OMA).

Purpose of the Study:

• To design, develop, and validate a custom, offline-synchronized multi-sensor Data Acquisition (DAQ) system tailored for SHM applications.
• To overcome the limitations of traditional SHM systems by providing a robust and cost-effective solution.

Main Methods:

• Developed two specialized sensor nodes: an inertial node with a MEMS accelerometer (ADXL355) and a displacement node with a high-resolution ADC (ADS1220).
• Utilized an ultra-low-power microcontroller (STM32L431), local microSD storage with pseudo-SRAM buffer, and a temperature-compensated Real-Time Clock (DS3231) for offline synchronization.
• Deployed 53 DAQ nodes on the Spyckstraße bridge in Germany, monitoring 118 measurement points using a hybrid fixed and roving setup.

Main Results:

• Achieved reliable, low-noise measurements crucial for SHM.
• Successfully enabled accurate extraction of operational mode shapes from bridge monitoring data.
• Demonstrated the system's effectiveness in a real-world field campaign.

Conclusions:

• The developed offline-synchronized DAQ system offers a viable, cost-effective, and robust solution for large-scale infrastructure monitoring.
• The system addresses key limitations of conventional SHM approaches, improving data acquisition reliability and synchronization accuracy.