Vibration analysis of continua using substructure change and elimination methods

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K04037
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 20010:Mechanics and mechatronics-related
• Research Institution: Kansai University
• Principal Investigator: Yamada Keisuke 関西大学, システム理工学部, 准教授 (80456798)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: モード解析 / 連続体 / 波動 / 連成振動 / 振動解析 / 消音器 / 開口端補正

Outline of Final Research Achievements

In this study, we proposed the substructure elimination method as a method to analyze vibration of a continuum without discretization. This method has the advantage of requiring fewer degrees of freedom. In this method, the desired structure is obtained by eliminating substructures from the whole structure, which is a subtractive concept. We also proposed a method to analyze vibration of a continuum by changing the characteristics of the substructures instead of eliminating them. These proposed methods are categorized into modal analysis of a continuum, and in this study, we further proposed several methods: extraction of traveling waves using modal analysis, coupled vibration analysis of acoustic field including continuous structure, and optimal tuning of damped side-branch silencer and damped Helmholtz silencer.

Free Research Field

機械力学・制御

Academic Significance and Societal Importance of the Research Achievements

本研究では，連続体のモード解析を発展させることにより，連続体を空間的に離散化することなく，その振動解析を行うことができる手法を確立した．これにより，任意の座標で振動変位等の情報を得ることができる．モード解析では固有モードの重ねあわせを用いるが，これは言い換えれば定在波の重ねあわせである．この定在波の重ねあわせで進行波である前進波と後退波を抽出することができることも示した．この方法を用いて連続体内部の波動の伝播を可視化することにより，新たな視点で振動を抑制するための対策を立てることができる．