Design Strategies for Stack-Based Piezoelectric Energy Harvesters near Bridge Bearings

Area of Science:

• Energy Harvesting
• Structural Health Monitoring
• Mechanical Engineering
• Electrical Engineering

Background:

• Many bridges require condition monitoring due to significant deterioration.
• Wireless sensors powered by energy harvesting systems (EHSs) are crucial for monitoring dynamically loaded structures.
• Piezoelectric energy harvesters (pEHs) offer a direct relationship between exciting force and electrical signal output.

Purpose of the Study:

• To present a novel co-optimization approach for mechanical and electrical components of stack-based piezoelectric energy harvesting systems (pEHSs).
• To maximize energy output for powering wireless sensors in bridge monitoring applications.
• To explore the potential of pEHSs for traffic observation and structural condition assessment.

Main Methods:

• Developed a co-optimization approach using a nonlinear solver for mechanical and electrical components.
• Estimated mechanical excitation via finite element simulation.
• Modeled electric circuitry in Simulink, incorporating nonlinear characteristics of rectifying diodes.
• Utilized real traffic data for statistical randomized scenarios and variation analysis.

Main Results:

• Revealed a strong dependence of energy output on the interaction between bridge, harvester, and traffic dynamics.
• Established design criteria for pEHSs to maximize energy output.
• Demonstrated the feasibility of harvesting several milliwatts of time-averaged power on a medium-sized bridge.
• Validated the suitability of pEHSs for powering wireless sensor nodes and for traffic observation (vehicle frequency, weight, axle load).

Conclusions:

• The co-optimization methodology effectively maximizes energy harvesting from dynamic bridge loads.
• pEHSs are a viable solution for powering wireless sensor nodes for structural health monitoring and traffic analysis.
• The developed approach provides essential design insights for future pEHS implementations in civil infrastructure.