NUMERICAL INVESTIGATIONS ON PARAMETRIC EXCITATION OF A VERTICAL BEAM UNDER PRESCRIBED AXIAL DISPLACEMENTS

Author(s)

Franzini, Guilherme Rosa ; Neto, Alfredo Gay ; Crocker, MJ ; Pawelczyk, M ; Pedrielli, F ; Carletti, E ; Luzzi, S

• Document type: Journal article
• Source: PROCEEDINGS OF THE 22ND INTERNATIONAL CONGRESS ON SOUND AND VIBRATION; v. N/A, p. 8-pg., 2015-01-01.

Abstract

This paper presents and discusses results of parametric excitation. This is done studying the scenario of a vertical beam, subjected to its self-weight. The excitation is done through prescribed axial harmonic displacements at its upper extremity. Two numerical models were employed, namely, an in-house geometric nonlinear finite element code and a reduced-order model. The first is addressed using 3D beam modeling, while the second constructs a 2D solution composed by the first three vibration modes. The reduced-order model considers small deflections and includes nonlinearites arisen from extensibility of the structure. This leads to a nonlinear system of Duffing-like equations, subjected to parametric excitation. The focus of the paper is the presentation of the reduced-order model, as well as comparisons between the mentioned models in a condition in which the first vibration mode is parametrically excited. Results of time histories of displacement in three points along the beam span are presented and showed both qualitative and quantitative adherence between the the numerical approaches herein presented. (AU)

• FAPESP's process: 12/09912-0 - RISERS NONLINEAR DYNAMICS INCLUDING THE UNILATERAL CONTACT WITH THE SEABED
• Grantee: Alfredo Gay Neto
• Support Opportunities: Scholarships in Brazil - Post-Doctoral