Analysis of Vibration of 2-D Periodic Cellular Structures

Grid-like structures;Periodic lattices;Directionality;Mechanical pass-band filters;Phononic band-gaps

Jeong, Sang Min ; Aerospace Engineering

University:Georgia Institute of Technology

Department:Aerospace Engineering

关键词: Grid-like structures;    Periodic lattices;    Directionality;    Mechanical pass-band filters;    Phononic band-gaps;   

Others  :  https://smartech.gatech.edu/bitstream/1853/7122/1/jeong_sangmin_200508_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

The vibration of and wave propagation in periodic cellular structuresare analyzed. Cellular structures exhibit a number of desirablemultifunctional properties, which make them attractive in a variety ofengineering applications. These include ultra-light structures, thermaland acoustic insulators, and impact amelioration systems, among others.Cellular structures with deterministic architecture can be consideredas example of periodic structures. Periodic structures feature uniquewave propagation characteristics, whereby elastic waves propagate onlyin specific frequency bands, known as "pass band", while they areattenuated in all other frequency bands, known as "stop bands". Suchdynamic properties are here exploited to provide cellular structureswith the capability of behaving as directional, pass-band mechanicalfilters, thus complementing their well documented multifunctionalcharacteristics.This work presents a methodology for the analysis of the dynamicbehavior of periodic cellular structures, which allows the evaluationof location and spectral width of propagation and attenuation regions.The filtering characteristics are tested and demonstrated forstructures of various geometry and topology, including cylindricalgrid-like structures, Kagom and eacute; and tetrhedral truss core lattices.Experimental investigations is done on a 2-D lattice manufactured outof aluminum. The complete wave field of the specimen at variousfrequencies is measured using a Scanning Laser Doppler Vibrometer(SLDV). Experimental results show good agreement with the methodologyand computational tools developed in this work. The results demonstratehow wave propagation characteristics are defined by cell geometry andconfiguration. Numerical and experimental results show the potential ofperiodic cellular structures as mechanical filters and/or isolators ofvibrations.