scholarly journals 8‐node hexahedral unsymmetric element with rotation degrees of freedom for modified couple stress elasticity

2020 ◽  
Vol 121 (12) ◽  
pp. 2683-2700
Author(s):  
Yan Shang ◽  
Chen‐Feng Li ◽  
Kang‐Yu Jia
Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1404 ◽  
Author(s):  
Farajollah Zare Jouneghani ◽  
Hamidraza Babamoradi ◽  
Rossana Dimitri ◽  
Francesco Tornabene

Due to the large application of tapered beams in smart devices, such as scanning tunneling microscopes (STM), nano/micro electromechanical systems (NEMS/MEMS), atomic force microscopes (AFM), as well as in military aircraft applications, this study deals with the vibration behavior of laminated composite non-uniform nanobeams subjected to different boundary conditions. The micro-structural size-dependent free vibration response of composite laminated Euler–Bernoulli beams is here analyzed based on a modified couple stress elasticity, which accounts for the presence of a length scale parameter. The governing equations and boundary conditions of the problem are developed using the Hamilton’s principle, and solved by means of the Rayleigh–Ritz method. The accuracy and stability of the proposed formulation is checked through a convergence and comparative study with respect to the available literature. A large parametric study is conducted to investigate the effect of the length-scale parameter, non-uniformity parameter, size dimension and boundary conditions on the natural frequencies of laminated composite tapered beams, as useful for design and optimization purposes of small-scale devices, due to their structural tailoring capabilities, damage tolerance, and their potential for creating reduction in weight.


2010 ◽  
Vol 37-38 ◽  
pp. 667-670
Author(s):  
Kai Wang ◽  
Shen Jie Zhou ◽  
Zhi Feng Nie

Based on the constrained variational principle, the mixed multi-variable natural neighbor Galerkin method for couple-stress elasticity is proposed for three-dimensional problems. The displacements and micro-rotations are taken to be independent nodal degrees of freedom, and the geometrical constraints between them are enforced through Lagrange multipliers. The C0-continuous non-Sibsonain interpolation is used to obtain the discrete equations. The proposed method is tested by the numerical example and the results show that strong size effects are observed when the length of deformation field and the characteristic length of the material are comparable.


2020 ◽  
Vol 245 ◽  
pp. 112294
Author(s):  
V. Sladek ◽  
J. Sladek ◽  
M. Repka ◽  
L. Sator

2018 ◽  
Vol 73 ◽  
pp. 129-147 ◽  
Author(s):  
Farajollah Zare Jouneghani ◽  
Payam Mohammadi Dashtaki ◽  
Rossana Dimitri ◽  
Michele Bacciocchi ◽  
Francesco Tornabene

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