Structural vibration testing might be a promising method to study the mechanical properties of spinal motion segments as an alternative to imaging and spinal manipulation techniques. Structural vibration testing is a non-destructive measurement technique that measures the response of a system to an applied vibration as a function of frequency, and allows determination of modal parameters such a...

A complete investigation on the free vibration and stability analysis of beams made of functionally graded materials (FGMs) containing open edge cracks utilizing four beam theories, Euler-Bernoulli, Rayleigh, shear and Timoshenko, is performed in this research. It is assumed that the material properties vary along the beam thickness exponentially and the cracked beam is modeled as two segments ...

Abstract A study of smart functionally graded (FG) beams made carbon nanotube (CNT) reinforced composites combined with piezoelectric materials is presented. The material parameters the composite are assumed to vary along their thickness following extended rule mixture. finite element (FE) model was developed for FG nanotube-reinforced beam materials. This tested against previously published st...

In this paper, a displacement-based, variationally consistent, two variable refined theory for shear deformable beams is presented. The beam is assumed to be of linearly elastic, homogeneous, isotropic material and has a uniform rectangular cross-section. In this theory, the beam axial displacement and beam transverse displacement consist of bending components and shearing components. The assum...

Abstract A three-dimensional (3D), multi-directional and multimodal broadband vibration energy harvester using L-shaped curved beams is proposed in this paper. The composed of an cylindrical bending beam a piezoelectric beam. free ends the are respectively fixed with magnet. These two coupled by nonlinear magnetic force introduced magnets. results show that prototype can collect 3D energies has...

Energy balance method is an effective and simple method which is used in the amplitude calculation of Aeolian vibration in transmission lines with Stockbridge damper. However, the accuracy of the results obtained by this method, heavily depends on the assumed mode shapes of the conductor vibration. In this study, by considering an appropriate model for the conductor vibration, a comprehensive m...

In this paper, free longitudinal vibration of nanorods is investigated from the wave viewpoint. The Eringen’s nonlocal elasticity theory is used for nanorods modelling. Wave propagation in a medium has a similar formulation as vibrations and thus,  it can be used to describe the vibration behavior. Boundaries reflect the propagating waves after incident. Firstly, the governing quation of nanoro...

because of production process and constrains conditions, circular graphene sheet may be opposed to structural defect and pin hole, respectively. some of the defects and pin hole on a circular graphene sheet can be considered as an eccentric hole on the sheet. hence, analyzing behavior of circular graphene sheet with an eccentric hole is important. free vibration of an eccentric annular graphene...

In this note, small amplitude free vibration of a double-beam system in presence of inner layer nonlinearity is investigated. The nonlinearity is due to inner layer material and is not related to large amplitude vibration. At first, frequencies of a double-beam system with linear inner layer are studied and categorized as synchronous and asynchronous frequencies. It is revealed that the inner l...