Vikram Pakrashi

Assistant Professor, University College of Dublin
Headshot of Vikram
Talk Title: 
Energy Harvesters and Structural Health Monitors
Talk Abstract: 
"Built infrastructure (roads, bridges, pipelines) are are degrading globally with inadequate rehabilitation funds and bourgeoning sectors like renewable energy devices add to this pressure. Prioritising safety and intervention through structural health monitoring (SHM) has become popular. On the other hand, vibration energy harvesting (VEH) has also seen significant advancement and scientific engagement in the last decade or so. Both markets are predicted to grow significantly for the next while globally. This paper presents work from out work which focuses on various aspects of combining these two sectors together and use VEH for SHM in their own right. The idea fundamentally lies in using VEH signatures from built infrastructure in their operational conditions directly for SHM. This self-powered/ low energy-demand technology also requires little instrumentation ad leads to improved site-safety. This again leads to long monitoring regimes and better data, which subsequently ensures better decisions taken on our built infrastructure. Several challenges exist around this topic. Dynamic response of the host structure to input excitation by its environment is converted to VEH sensor vibration, which in turn in further converted to voltage through the dynamics related to electromechanical coupling and further effects of circuits. Understanding this 'dynamics of dynamics of dynamics' is a central theme around VEH for SHM. Adapting energy harvesting signatures to SHM and system identification techniques/algorithms through the ‘dynamics of dynamics of dynamics’ approach is another challenge. Finally, there is also a paucity of numerical and experimental data around this nascent idea and a challenge lies in developing a well-designed and comprehensive numerical and experimental benchmarked evidence base. This paper addresses all these challenges and establishes VEH for SHM as a viable option. Demonstrations are provided based on numerical analyses, laboratory scale experiments and full-scale deployments. Recommendations and guidelines are also provided around laboratory experimentation in a scaled and unscaled format, for full scale deployment and for adapting to a range of fields of application including roads, bridges, pipelines and renewable energy devices. The work is expected to be of interest for the researcher as well as for a practitioner."