Piezoelectric energy harvesters (PEHs) can be used as an additional power supply for a Structural Health Monitoring (SHM) system. Its design can be optimised for the best performance; however, the optimal design depends on the input vibration, e.g. acceleration of a bridge due to wind loads and passing traffic. In previous studies, we have shown that optimal design tunes to some predominant frequency of the signal spectrum. However, our previous study was limited to a single location of a PEH on a bridge. In this work, we extend the rigorous optimisation framework to include the effect of the PEH's location. The optimisation framework uses the PEH plate model discretised by IsoGeometric Analysis (IGA) and coupled with the Particle Swarm Optimisation algorithm to find the designs with maximum energy outputs for many acceleration histories, extracted from the recorded dynamic response data of a real cable-stayed bridge in Australia. Then, clustering is performed to find several best candidates for the entire bridge. An additional study is performed to quantify the effect of traffic intensity on the produced energy. It is shown that variation in traffic volume throughout the 24hr time window leads to variation in optimal PEH designs. The study concludes the impact of location and traffic on energy harvesting by identifying the optimal PEH design and placement throughout the bridge structure. The results indicate that the key factors of maximising energy harvesting efficiency are related to the input excitation and the mode of vibration being excited. The position of maximum displacement in the vibration mode corresponds to the best location for energy harvesting. Also, the change in traffic intensity affects the amount of convertible mechanical energy and also directs the fundamental frequency of a PEH to shift within a specific range of frequencies to achieve the highest energy conversion.

翻译：压电能量采集器（PEHs）可作为结构健康监测（SHM）系统的辅助电源。其设计可通过优化实现最佳性能；然而，最优设计取决于输入振动，例如桥梁因风荷载和通行车辆引起的加速度。在前期研究中，我们证明最优设计会调谐至信号频谱的某个主频率。但前期工作仅限于桥梁上PEH的单一位置。本研究将严格优化框架扩展至包含PEH位置的影响。该优化框架采用等几何分析（IGA）离散化的PEH板模型，并与粒子群优化算法耦合，基于澳大利亚某实桥（斜拉桥）记录的动态响应数据中提取的多种加速度时程，寻找能量输出最大的设计方案。随后通过聚类分析为整座桥梁筛选若干最优候选方案。进一步研究量化了交通强度对产生能量的影响。结果表明，24小时内交通量的变化会导致最优PEH设计产生差异。通过确定全桥范围内PEH的最优设计与布置位置，本研究得出位置与交通对能量采集影响的结论：最大化能量采集效率的关键因素与输入激励及所激发的振动模态有关；振动模态中位移最大处对应能量采集的最佳位置。此外，交通强度的变化不仅影响可转换机械能的量级，还会引导PEH的基频在特定频率范围内偏移，以实现最高能量转换效率。