Independent modal variable structure fuzzy active vibration control of thin plates laminated with photostrictive actuators

AbstractPhotostrictive actuators can produce photodeformation strains under illumination of ultraviolet lights. They can realize non-contact micro-actuation and vibration control for elastic plate structures. Considering the switching actuation and nonlinear dynamic characteristics of photostrictive actuators, a variable structure fuzzy active control scheme is presented to control the light intensity applied to the actuators. Firstly, independent modal vibration control equations of photoelectric laminated plates are established based on modal analysis techniques. Then, the optimal light switching function is derived to increase the range of sliding modal area, and the light intensity self-adjusting fuzzy active controller is designed. Meanwhile, a continuous function is applied to replace a sign function to reduce the variable structure control (VSC) chattering. Finally, numerical simulation is carried out, and simulation results indicate that the proposed control strategy provides better performance and control effect to plate actuation and control than velocity feedback control, and suppresses vibration effectively

The evolution of magnetic structure driven by a synthetic spin-orbit coupling in two-component Bose-Hubbard model

We study the evolution of magnetic structure driven by a synthetic spin-orbit coupling in a one-dimensional two-component Bose-Hubbard model. In addition to the Mott insulator-superfluid transition, we found in Mott insulator phases a transition from a gapped ferromagnetic phase to a gapless chiral phase by increasing the strength of spin-orbit coupling. Further increasing the spin-orbit coupling drives a transition from the gapless chiral phase to a gapped antiferromagnetic phase. These magnetic structures persist in superfluid phases. In particular, in the chiral Mott insulator and chiral superfluid phases, incommensurability is observed in characteristic correlation functions. These unconventional Mott insulator phase and superfluid phase demonstrate the novel effects arising from the competition between the kinetic energy and the spin-orbit coupling.Comment: 9 fig; English polished, note adde

Concavity property of minimal L2L^{2} integrals with Lebesgue measurable gain VIII -- partial linearity and log-concavity

In this article, we give some necessary conditions for the concavity property of minimal $L^2$ integrals degenerating to partial linearity, a charaterization for the concavity degenerating to partial linearity for open Riemann surfaces, and some relations between the concavity property for minimal $L^2$ integrals and the log-convexity for Bergman kernels.Comment: 37 pages, all comments are welcome! arXiv admin note: text overlap with arXiv:2211.00470, arXiv:2211.0525

Concavity property of minimal L2L^2 integrals with Lebesgue measurable gain V--fibrations over open Riemann surfaces

In this article, we present characterizations of the concavity property of minimal $L^2$ integrals degenerating to linearity in the case of fibrations over open Riemann surfaces. As applications, we obtain characterizations of the holding of equality in optimal jets $L^2$ extension problem from fibers over analytic subsets to fibrations over open Riemann surfaces, which implies characterizations of the fibration versions of the equality parts of Suita conjecture and extended Suita conjecture.Comment: 60 pages. arXiv admin note: substantial text overlap with arXiv:2205.07512, arXiv:2204.0726

The log-plurisubharmonicity of fiberwise ξ−\xi-Bergman kernels for variant functional

In the present paper, we obtain the log-plurisubharmonicity of fiberwise $\xi-$Bergman kernels for variant functional.Comment: 9 pages. All comments are welcome

Free vibration studies of functionally graded magneto-electro-elastic plates/shells by using solid-shel ements

In this article, free vibration studies on functionally graded magneto-electro-elastic plates and cylindrical shells have been carried out by means of finite element method. The functionally graded material is assumed to be exponential in the thickness direction. The present finite element is formulated on the basis of assumed natural strain, enhanced assumed strain method and using displacement components, electric potential and magnetic potentials as nodal degrees of freedom. This element can be used as solid element and can also be applied to model thin curved shell structures. Numerical studies include the influence of the different exponential factor, magnetic and piezoelectric effect on the natural frequencies. Obtained numerical results are in good agreement with the semi-analytical finite element solutions available in the literature

Synchronous charge extraction and voltage inversion (SCEVI): a new efficient vibration-based energy harvesting scheme

This paper presents a new interface technique called synchronous charge extraction and voltage inversion (SCEVI), which consists of a synchronous inductor and a buck-boost converter for vibration-based energy harvesting using piezoelectric elements. The theoretical calculation of the harvested power obtained by using such a technique are proposed and compared with the so-called Standard, SECE (Synchronous Electric Charge Extraction), Parallel-SSHI (Parallel Synchronized Switch Harvesting on Inductor) and Series-SSHI (Series Synchronized Switch Harvesting on Inductor) methods commonly used in piezoelectric vibration-powered generator considering both constant displacement amplitude and force amplitude. From the harvested power point of view, SCEVI and Parallel – SSHI techniques are the better ones and each has its own merits. But the harvested power of SCEVI is independent of the load connected to the generator and Parallel – SSHI depend on the load resistance. The harvested power of SECE is also independent of the load, but the further experimental results show that the proposed SCEVI interface technique dramatically increases the harvested power by almost up to 150 % compared with the SECE method under the same amplitude of displacement excitation

Detecting multiple cracks in beams using hierarchical genetic algorithms

This study deals with a method to identify multiple cracks in a beam. The novelty of this study is the use of a hierarchical genetic algorithm to detect the number, location, and the extent of multiple cracks. To demonstrate the feasibility of the present method, this algorithm is applied to the identification of double or triple cracks in a beam as well as four cracks. The detected crack locations and sizes are in excellent agreement with the actual ones. The numerical simulation reveal the HGA substantially reduces the total number of FE computation required and they are many orders smaller compared to conventional GA. The results also demonstrate the advantages of HGA from the viewpoints of its ability to avoid premature convergence

Tame maximal weights, relative types and valuations

In this article, we obtain a class of tame maximal weights (Zhou weights), whose relative types (Zhou numbers) satisfy the tropical multiplicativity and tropical additivity, and characterize the multiplier ideal sheaves of plurisubharmonic functions. Especially, the relative types to them are valuations (Zhou valuations) on the ring of germs of holomorphic functions, and characterize the division relations of the ring. We consider a global version of these weights on domains in $\mathbb{C}^n$, and obtain some properties of them, including the continuity and some approximation results.Comment: 51 pages, all comments are welcome