THE OPTIMIZATION OF FULL BAND-GAPS IN MULTILAYER FILMS
Journal Title: ROMANIAN JOURNAL OF TECHNICAL SCIENCES - APPLIED MECHANICS - Year 2016, Vol 61, Issue 2
Abstract
The multilayer films are consisted of alternating layers of material with different mechanical properties, following a triadic Cantor sequence. The extremely low thresholds for subharmonic generation of ultrasonic waves has a significant importance in the generation of the full band-gaps due to the nonlinear coupling between the extended-mode (phonon) and the localized-mode (fracton) vibration regimes. In this paper, the optimization is performed with respect to most important features of sonic composites, such as the localized modes around interfaces and the size of the full band-gaps. The case of a relevant uncertainty of the design parameters which may change over frequency is taken into consideration. Uncertain parameters are related to the local band-gaps and boundary conditions where the displacement and the traction vectors can be discontinuous. Maximizing the full band-gaps is taken as the objective function, while the constant volume of the structure is taken as the constraint. The results show an unexpected influence of discontinuities upon the generation of the full band-gaps.
Authors and Affiliations
VETURIA CHIROIU, LIGIA MUNTEANU, CRISTIAN RUGINA, DAN DUMITRIU, PIER PAOLO DELSANTO
MECHANICAL WORK REDUCTION DURING MANIPULATION TASKS OF A PLANAR 3-DOF MANIPULATOR
The problem addressed in this paper concerns a planar 3-DOF manipulator operating in horizontal plane, that must move from an initial position characterized by angles θ1(0), θ2(0) and θ3(0) to a required final position c...
THE OPTIMIZATION OF FULL BAND-GAPS IN MULTILAYER FILMS
The multilayer films are consisted of alternating layers of material with different mechanical properties, following a triadic Cantor sequence. The extremely low thresholds for subharmonic generation of ultrasonic waves...
SKILL EVALUATION IN HUMAN ADAPTIVE MECHATRONICS. BIMANUAL OPERATION WITH X-Y STAGES
In this paper, some HAM (Human Adaptive Mechatronics) research results on operator skill evaluation, operation assistance, identification of operator's dynamics, skill acquisition, and coupling phenomenon in bimanual ope...
NUMERICAL SIMULATION OF THE QUASISTATIC CONTACT PROBLEM WITH DAMAGE
This paper deals with the numerical analysis of a quasistatic contact problem with friction between an elastic body and a rigid obstacle. The contact is frictional and is modeled with a version of normal compliance condi...
ON MODELING THE MECHANICAL BEHAVIOR AND TEXTURE EVOLUTION OF ROLLED AZ31 MG FOR COMPLEX LOADINGS INVOLVING STRAIN PATH CHANGES
An accurate description of the deformation response of AZ31 Mg under changing strain paths requires consideration of its strong anisotropy and its evolution with accumulated plastic deformation. In this paper, the viscop...