Modal analysis for macroelement modeling: natural frequencies and modes of vibration

• Grant number: 19/05299-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2019
• End date: May 31, 2020
• Field of knowledge: Engineering - Civil Engineering - Structural Engineering
• Principal Investigator: Rodrigo Provasi Correia
• Grantee: Vinícius Massaki Kanaoka Benevides
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Vibrations occur in all types of structures, either due to natural loads or the structure's own functioning. Although it is often desirable or does not lead to problems, there are cases where the structure responds improperly to vibrations. For certain frequencies, the amplitudes of vibration increase and are amplified, which can lead to the failure of these structures. These frequencies are called natural frequencies. In view of this type of problem, this work plan proposes the obtainment of natural frequencies in flexible tubes simplified through finite macroelements modeling. In the finite macroelements, stiffness matrices are already defined. It will be part of this work to obtain the mass matrices of the cylindrical and helix elements. These matrices will be implemented in the MacroFEM tool, which contains the current models, as well as a solver that allows obtaining the natural frequencies and modes of vibration, utilizing calculus libraries. For the verification of the values obtained, the results will be compared to those obtained through ANSYS modal analysis.