Dynamics of Phononic Materials and Structures: Historical Origins, Recent Progress, and Future Outlook

The review outlines modern trends in theoretical developments, novel designs and modern applications of sandwich structures. The most recent work published at the time of writing of this review is considered, older sources are listed only on as-needed basis. The review begins with the discussion on the analytical models and methods of analysis of sandwich structures as well as representative problems utilizing or comparing these models. Novel designs of sandwich structures is further elucidated concentrating on miscellaneous cores, introduction of nanotubes and smart materials in the elements of a sandwich structure as well as using functionally graded designs. Examples of problems experienced by developers and designers of sandwich structures, including typical damage, response under miscellaneous loads, environmental effects and fire are considered. Sample applications of sandwich structures included in the review concentrate on aerospace, civil and marine engineering, electronics and biomedical areas. Finally, the authors suggest a list of areas where they envision a pressing need in further research.

Review of current trends in research and applications of sandwich structures

A review of theories for the modeling and analysis of functionally graded plates and shells

Bending, buckling and free vibration of laminated composite and sandwich beams: A critical review of literature

This paper aims at investigating the effect of Carbon Nanotube (CNT) agglomeration on the free vibrations of laminated composite doubly-curved shells and panels reinforced by CNTs. The great performances of doubly-curved structures are joined with the excellent mechanical properties of CNTs. Several laminations schemes and various CNT exponential distributions along the thickness of the structures are considered. Thus, it is evident that the shell dynamic behavior can be affected by many parameters which characterize the reinforcing phase. A widespread parametric study is performed in order to show the natural frequency variation. The general theoretical model for shell structures is based on the so-called Carrera Unified Formulation (CUF) which allows to consider several Higher-order Shear Deformations Theories (HSDTs). In addition, a complete characterization of the mechanical properties of CNTs is presented. The governing equations for the free vibration analysis are solved numerically by means of the well-known Generalized Differential Quadrature (GDQ) method due to its accuracy, stability and reliability features.

Effect of agglomeration on the natural frequencies of functionally graded carbon nanotube-reinforced laminated composite doubly-curved shells

In this work, a periodic 4 × 4 lay-out of resistive inductive (RL) shunted piezoelectric transducer (PZT) patches is designed and applied to achieve broadband vibration reduction of a flexible isotropic plate over tunable frequency bands. Each surface-bonded PZT patch is connected to a single independent RL circuit and all shunt circuits are tuned at the same frequency. A finite element-based design methodology is used to predict the attenuation properties of the unit cell that characterize the periodic assembly. The predictions are experimentally validated by measuring the spatial average harmonic response of the plate. Significant broadband attenuation is obtained over frequency bands centered at the resonance frequency of the shunting circuit.

https://iopscience.iop.org/article/10.1088/0964-1726/19/1/015002/pdf

Broadband vibration control through periodic arrays of resonant shunts: experimental investigation on plates

The paper outlines the design and implementation of the Real Time Application Interface (RTAI) for Linux, as used for high performance local/distributed control systems implemented on low cost off the shelf general purpose computers. Its native lean real time middleware layer is described along with its use in an advanced tool to easily manage and monitor complex networked control systems.

Lorenzo Dozio

Papers

Broadband vibration control through periodic arrays of resonant shunts: experimental investigation on plates

Real time distributed control systems using RTAI

Periodic shunted arrays for the control of noise radiation in an enclosure

A variable-kinematic model for variable stiffness plates: Vibration and buckling analysis

Free vibration analysis of ribbed plates by a combined analytical-numerical method