A method is presented by which the wavenumbers for a one-dimensional waveguide can be predicted from finite element (FE) model. The involves postprocessing conventional, but low order, FE model, mass and stiffness matrices of are typically found using conventional package. This in contrast to most popular previous waveguide/FE approach, sometimes termed spectral requires new developed. In approach described here, section modeled software dynamic matrix formed. periodicity condition applied,...

The dispersion curves describe wave propagation in a structure, each branch representing mode. As frequency varies the wavenumbers change and number of phenomena may occur. This paper characterizes, analyzes, quantifies these general terms illustrates them with examples. Two classes Weak coupling phenomena—veering locking—arise when branches interact. These occur vicinity at which, for undamped waveguides, uncoupled waveguides would cross: if two (representing either propagating or...

An internal resonance based broadband vibration energy harvester is proposed by introducing an auxiliary oscillator to the main nonlinear harvesting oscillator. Compared conventional harvesters, natural frequencies of this two-degree-of-freedom system can be easily adjusted commensurable which will result in more resonant peaks and better wideband performance. Experimental measurements equivalent circuit simulations demonstrate that design outperforms its linear counterpart. In addition...

In this paper a tuned vibration absorber (TVA) is realized using shape memory alloy (SMA) elements. The elastic modulus of SMA changes with temperature and effect exploited to develop continuously tunable device.

This paper concerns wave reflection, transmission, and propagation in Timoshenko beams together with analysis of vibrations beam structures. The transmission reflection matrices for various discontinuities on a are derived. Such include general point supports, boundaries, changes section. matrix relations between the injected waves externally applied forces moments also These can be combined to provide concise systematic approach vibration or complex structures consisting components. is...

This paper describes a wave finite element method for the numerical prediction of characteristics cylindrical and curved panels. The combines conventional elements theory propagation in periodic structures. mass stiffness matrices small segment structure, which is typically modeled using either single shell or, especially laminated structures, stack solid meshed through cross-section, are postprocessed periodicity conditions. found commercial FE package. solutions resulting eigenproblem...

This work investigates the effects of fiber content and orientation on impact behavior flax fiber‐reinforced polypropylene (PP) composites. The laminates various contents were manufactured by a vacuum bagging process; their properties then measured using Charpy (i.e., in‐plane load) drop weight out‐of‐plane tests. Experiments conducted range samples with different volume fractions orientations. results show significant variations in energy absorption according to orientation. Composites...