1. ๏ฉ๏ฎ๏ด๏ฒ๏ฏ๏ค๏ต๏ฃ๏ด๏ฉ๏ฏ๏ฎ
Some numerical and experimental results on the dynamics of two-dimensional, linear truss structures are presented. It is well-known that such periodic systems act as wave filters, possessing propagation and attenuation zones (PZs and AZs) in the frequency-wavenumber domain [1][2][3][4]. Structural waves with frequencies and wavenumbers contained inside PZs, travel unattenuated through the periodic system, whereas waves inside AZs are near field solutions with spatially confined envelopes. What gives rise to these PZs and AZs is a complicated interference pattern of reflected and transmitted waves at each junction between periodic sets, resulting in complex wave interaction phenomena that either enhance or prohibit wave propagation through the periodic structure. Chen and Pierre [5,6] developed a computational scheme to study mode localization and wave conversion effects in two-dimensional trusses by modelling each structural member by exact linear partial differential equations governing the longitudinal and transverse vibrations, and coupling the members' dynamic responses to form overall transfer matrices. Experimental studies of truss structures have been recorded in references [7][8][9].
The aim of the present contribution is two-fold. The numerical part is based on the computational procedure of references [5,6] and analyzes the PZs and AZs of truss structures of infinite spatial extent with clamped and pinned joints. The truss studied in reference [5,6] is revisited and some missing wave conversion phenomena are discussed. The experimental part aims to verify the theoretical findings by testing a practical flexible truss of finite spatial extent.