Grant: Discovery Grants Program - Individual

Excessive vibration causes machines to malfunction and leads to failure; therefore, vibration control is important to ensure that machines operate properly. Recently, harvesting the energy from vibrations, instead of dissipating it through damping, has become a fruitful area of study. Much of this work has been driven by the need to power wireless sensors. The optimal outcome would be to achieve vibration suppression and energy harvesting (VSEH) simultaneously. The existing research has focused on using a linear mass-spring-damper system for this purpose. The shortcoming of such a device is that it is effective only in a narrow vibrational frequency band. Many studies have been conducted on broadband vibration suppression or broadband energy harvesting. However, few studies on simultaneous VSEH under broadband ambient vibration environment have been reported. Recently the applicant and his graduate students have initiated a new research direction that focuses on simultaneous VSEH. Inspired by the concept of the nonlinear energy sink, a nonlinear energy sink and harvester (NESH) was developed. This proposal will enhance the broadband capability of simultaneous VSEH by exploiting features of nonlinear systems. Three objectives will be addressed. (1) Develop new NESH devices by exploiting the features of nonlinear systems and varying their configurations and attachment schemes. (2) Model, analyze, and test developed NESHs. Modelling will be tackled both analytically and experimentally. Analysis approaches will primarily include numerical integration, nonlinear normal mode analysis, and the mixed Multiple Scale/Harmonic Balance algorithm. Testing will validate the results of the analytical studies. (3) Optimize developed NESHs through multi-objective optimization, in which two conflicting goals, minimizing vibration and maximizing energy, will be combined into a single objective function by properly choosing weight factors. Research on simultaneous VSEH is a relatively new area. The proposed research is novel, because the NESH is different from existing devices. The outcomes of the proposed research will be new VSEH devices with many potential applications, such as monitoring the integrity of machines and structures using self-powered wireless sensors. The study is driven both by academic curiosity and industrial need. New knowledge and techniques will be gained. Because the study covers a wide spectrum of mechatronics, it will provide excellent opportunities for the training of highly qualified personnel. It is highly anticipated that the knowledge and techniques generated from this research program will have a strong potential to benefit to Canadas industry and society in the areas of safer machines and structures.