Modelling, design and analysis of unidimensional periodic structures with a change in the cross-section area

• Grant number: 21/03281-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2021
• End date: May 31, 2022
• Field of knowledge: Engineering - Mechanical Engineering - Mechanics of Solids
• Principal Investigator: Paulo José Paupitz Gonçalves
• Grantee: Eduardo Borges Frateschi
• Host Institution: Faculdade de Engenharia (FE). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil

Abstract

Periodic structural configurations occur in many engineering systems, such as vehicles (terrestrial, naval or aerial) and civil structures. In general, a structure is considered periodic when a whole is formed by the repetition of similar elementary units, called cells. From the point of view of structural dynamics, it is known that there are frequency bands, called band gaps, in which mechanical waves do not propagate or are severely attenuated. This behaviour is directly related to the Bragg scattering phenomenon and occurs when the propagating wavelengths become twice the cell's characteristic length. This project aims to understand the geometric effect of the cross-sectional variation of one-dimensional waveguides, such as bars. By manipulating the cross-section in shape and area, it is possible to attenuate the waves' amplitude in desired regions. In addition, the way the cells forming the structure are arranged can affect the behaviour of the band gaps, which are fundamental in mitigating longitudinal waves. The project foresees the equation by analytical, numerical models and comparisons as traditional methods, such as the finite element method.