  Vibrational energy harvested from the bridge excitation due to the traffic
flow or the wind load can be supplied to sensors in a Structural Health
Monitoring (SHM) system and help prolong its service life, reduce chemical
battery waste and enable its use in remote locations. A common approach to
designing a Piezoelectric Energy Harvester (PEH) consists in tuning its
fundamental frequency to some target value (e.g., the fundamental frequency of
a bridge). However, such approach does not answer the question if the chosen
target frequency is optimal, and does not take into account the possibility to
have multiple design configurations with the same fundamental frequency. In
this work, we approach the problem of a PEH design optimisation in a rigorous
way, using a PEH model based on the Kirchhoff-Love plate theory and
Isogeometric Analysis (IGA), coupled with the Modal Order Reduction (MOR)
approach and Runge-Kutta time integration method. The model is further equipped
with the Particle Swarm Optimisation (PSO) algorithm that allows finding
geometry which maximises energy output from a given base acceleration signal. A
comprehensive study is conducted to infer the impact of a PEH geometry on its
energy harvesting performance in a real-world setting by considering field
health monitoring data of a large-scale cable-stayed bridge in NSW, Australia.
A shape optimisation framework is developed based on acceleration events, i.e.,
where the level of response exceeds a certain threshold. Designs obtained in
the event-based optimisation are then clustered to propose several best
candidates for continuous energy generation. This work represents the first
study on PEH design optimisation for real operational conditions.
