Development of vibration absorbing device utilizing chaotic vibrations of buckled curved plate for reduction of low-frequency sound

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06145
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Dynamics/Control
• Research Institution: Gunma University
• Principal Investigator: Nagai Ken-ichi 群馬大学, その他部局等, 名誉教授 (00110403)
• Co-Investigator(Kenkyū-buntansha): 丸山 真一 群馬大学, 大学院理工学府, 准教授 (60344925)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 非線形振動

Outline of Final Research Achievements

Aiming at developing a low-frequency sound-absorbing device utilizing chaotic vibrations of a buckled curved plate accompanied by dynamic snap through transition, experiments are conducted on nonlinear vibrations of a rectangular unsymmetrically laminated CFRP plate. The CFRP plate is fixed at center with bolts. The CFRP plate has two stable equilibrium configurations which is an upward convex and a downward convex. The CFRP plate is exited with periodic acceleration by an electromagnetic shaker. Sweeping the excitation frequency, responses of the plate are measured by laser displacement sensors. In a specific condition of fiber orientation with respect to the rectangular boundary and attached concentrated masses, it was shown that chaotic vibrations are induced accompanied with dynamic snap-through transition.

Free Research Field

機械力学

Academic Significance and Societal Importance of the Research Achievements

非対称積層CFRP板に動的飛び移りを伴うカオス振動が生じる条件を明らかにすることで，広帯域の低周波音と簡素な仕組みで吸音できる装置への応用可能性が飛躍的に高まった．