TY - JOUR
TI - An analytical model for piezoelectric unimorph cantilever subjected to an impulse load
DO - https://doi.org/doi:10.7282/T3KH0Q41
PY - 2015
AB - Researchers have been studying ways to harvest various ambient vibrations using piezoelectric materials to power wireless sensors and portable electronics. Literature review includes several such analytical models to harvest energy from vibrations due to the harmonic base excitation using piezoelectric beams. These models have not explored non-harmonic forcing terms independent of frequency such as an impulse load. Presented in this thesis is an analytical model that provides exact solutions for electrical and mechanical response of a piezoelectric unimorph cantilever beam acted upon by an impulse load at the free end. The beam is modeled using the Euler-Bernoulli assumptions. The impulse load is simulated using the delta function. Damping in the form of strain rate damping and viscous damping is taken into consideration for accurate modeling. This model can also capable of obtaining solutions for the conventional forcing terms which have been previously mentioned in the literature review. Closed form expressions for tip displacement of the beam and voltage generated across a load resistance are derived. These closed form expressions are solved using MATLAB to obtain the instantaneous values for the tip displacement and voltage generated. These instantaneous values for different load resistances are plotted as a function time using MATLAB for better visual perspective. The energy generated by harvester and the mechanical efficiency are found. From the plots it can be inferred that the particular harvester was suited for load resistances between the values of 100 Ω to 1 KΩ. The model is thus used to predict the response of a particular configuration for a piezoelectric unimorph cantilever beam harvester which satisfies the Euler-Bernoulli assumptions and is subjected to impulse loading.
KW - Mechanical and Aerospace Engineering
KW - Piezoelectric materials
LA - eng
ER -