Computational homogenization for dynamic characterization of a square cellular honeycomb vibration energy harvester

The prevailing literature on homogenization of cellular structures mainly focuses on computing their effective properties, but only a few studies demonstrate their subsequent use in practical applications. Moreover, the emphasis is largely on static analysis, and dynamic studies are limited to free vibration analysis with no specific applications. Therefore, this research aims to address these gaps by assessing the effectiveness of finite element based homogenization approach in characterizing cellular vibration energy harvester. In particular, the study considers a square cellular structure in cantilever mode and demonstrates the dynamic characterization using the homogenization approach. The results from free, forced, and random vibration analysis show close conformance between cellular and homogenized models with a maximum error of less than 10%. Further, the homogenized model was used to characterize the electro-mechanical response of the square cellular vibration energy harvester, and the predicted voltages for the cellular and homogenized models were 11 V and 13.8 V, respectively, validating the accuracy of homogenized model. Also, the computational time is reduced by 50-75% when using the homogenized model, thereby providing a computationally efficient alternative to experimental and full-scale time intensive finite element simulations.