A new piezoelectric higher-order shell element to design energy harvesters by using topology optimization

• Grant number: 15/06334-3
• Support type: Scholarships abroad - Research Internship - Post-doctor
• Effective date (Start): July 22, 2015
• Effective date (End): July 21, 2016
• Field of knowledge: Engineering - Mechanical Engineering
• Principal Investigator: Emílio Carlos Nelli Silva
• Grantee: Cesar Yukishigue Kiyono
• Supervisor abroad: J.N. Reddy
• Home Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Local de pesquisa : Texas A&M University, United States
• Associated to the scholarship: 12/14576-9 - Design of piezoelectric energy harvesting devices using topology optimization method, BP.PD

Abstract

Piezoelectric energy harvesters have received great attention in the past decade, thanks to their intrinsic characteristic of converting mechanical vibrations into usable electrical energy. In general, the design of energy harvesters aims to maximize the generated electric power due to harmonic vibration. The structural design of these devices is very complex, and trial-and-error methods are ineffective. However, they can be efficiently designed by using topology optimization method, which is a structural design tool to find the optimal layout of material to satisfy design requirements. In this sense, the piezoelectric material is systematically distributed over a metallic substrate in order to maximize the generated electric power. Nevertheless, the topology optimization method combines optimization algorithms with numerical analysis tools, such as finite element method (FEM). However, most studies of piezoelectric energy harvesters have used low-order shell elements. These elements assume many simplifications, such as plane stress state or small deformations, and artificial approaches or numeric conditioning are applied, such as reduced integration or stabilization, to make the element behave correctly. Even though, these type of elements can be inaccurate and may still suffer from locking or other numerical instabilities. Thus, this work proposes the formulation of a new piezoelectric high-order shell element with Lagrangian interpolations, which provides more accurate mechanical and electrical responses without any artificial approaches or numerical instabilities. Finally, this element is used in the topology optimization procedure to design resonant energy harvesters. Besides energy harvesting applications, this element is suitable for any linear or nonlinear piezoelectric application. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

KIYONO, C. Y.; SILVA, E. C. N.; REDDY, J. N. A novel fiber optimization method based on normal distribution function with continuously varying fiber path. COMPOSITE STRUCTURES, v. 160, p. 503-515, JAN 15 2017. Web of Science Citations: 21.

KIYONO, C. Y.; VATANABE, S. L.; SILVA, E. C. N.; REDDY, J. N. A new multi-p-norm formulation approach for stress-based topology optimization design. COMPOSITE STRUCTURES, v. 156, p. 10-19, NOV 15 2016. Web of Science Citations: 13.

KIYONO, C. Y.; PEREZ, N.; SILVA, E. C. N. Determination of full piezoelectric complex parameters using gradient-based optimization algorithm. Smart Materials and Structures, v. 25, n. 2 FEB 2016. Web of Science Citations: 8.