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Applied Mathematics and Mechanics(English Edition) 2025年第01期 81-100页

作者： S.SAURABH R.KIRAN D.SINGH R.VAISH V.S.CHAUHAN School of Mechanical and Materials Engineering Indian Institute of Technology Mandi

Bio-inspired helicoidal composite laminates, inspired by the intricate helical structures found in nature, present a promising frontier for enhancing the mechanical properties of structural designs. Hence, this study provides a comprehensive investigation into the nonlinear free vibration and nonlinear bending behavior of bio-inspired composite plates. The inverse hyperbolic shear deformation theory(IHSDT) of plates is employed to characterize the displacement field, with the incorporation of Green-Lagrange nonlinearity. The problem is modeled using the C0finite element method(FEM), and an in-house code is developed in the MATLAB environment to solve it numerically. Various helicoidal layup configurations including helicoidal recursive(HR), helicoidal exponential(HE), helicoidal semi-circular(HS), linear helicoidal(LH), and Fibonacci helicoidal(FH)with different layup sequences and quasi-isotropic configurations are studied. The model is validated, and parametric studies are conducted. These studies investigate the effects of layup configurations, side-to-thickness ratio, modulus ratios, boundary conditions, and loading conditions at different load amplitudes on the nonlinear vibration and nonlinear bending behaviors of bio-inspired composite plates. The results show that the laminate sequence exerts a substantial impact on both nonlinear natural frequencies and nonlinear bending behaviors. Moreover, this influence varies across different side-to-thickness ratios and boundary conditions of the bio-inspired composite plate.

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Universal converse flexoelectricity in dielectric materials via varying electric field direction

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International Journal of Smart and Nano Materials 2021年第1期12卷 107-128页

作者： Saurav Sharma Rajeev Kumar Rahul Vaish School of Engineering Indian Institute of Technology MandiMandiIndia

Flexoelectricity is a symmetry independent electromechanical cou-pling phenomenon that outperforms piezoelectricity at micro and nanoscales due to its size-dependent behavior arising from gradi-ent terms in its constitutive ***,due to this gradient term flexoelectricity,to exhibit itself,requires specially designed geometry or material composition of the dielectric *** of its kind,the present study put forward a novel strategy of achieving electric field gradient and thereby converse flexoelectri-city,independent of geometry and material composition of the *** spatial variation of the electric field is established inside the dielectric material,Ba_(0.67)Sr_(0.33)TiO_(3)(BST),by manipulating electrical boundary *** unique patterns of electrode placement are suggested to achieve this spatial *** varying direction of electric field gives rise to electric field gradient,the prerequisite of converse flexoelectricity.A multi-physics cou-pling based theoretical framework is established to solve the flexo-electric actuation by employing isogeometric analysis(IGA).Electromechanically coupled equations of flexoelectricity are solved to obtain the electric field distribution and the resulting displace-ments *** maximum displacements of 0.2 nm and 2.36 nm are obtained with patterns I and II,respectively,while pattern III can yield up to 85 nm of maximum displacement.

关键词： Converse flexoelectricity electrical boundary conditions electric field direction isogeometric analysis

Existence and controllability results to second order neutral differential equation with non-instantaneous impulses

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Journal of Control and Decision 2020年第3期7卷 286-308页

作者： Muslim Malik Avadhesh Kumar School of Basic Sciences Indian Institute of Technology MandiMandiIndia

In this paper,existence and uniqueness of the solutions of the second order neutral differential equation with non-instantaneous impulses in a Hilbert space X are *** is followed by a brief discussion on the exact and trajectory ***,the strongly continuous cosine family of linear operators and Banach fixed point theorem are used to establish the ***,an example is given to illustrate the analytical findings.

关键词： Non-instantaneous impulsive system neutral differential equations deviated argument Banach fixed point theorem controllability

Transfer Matrix Approach for Two-State Scattering Problem with Arbitrary Coupling

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Chinese Physics Letters 2015年第7期32卷 5-8页

作者： Diwaker Aniruddha Chakraborty School of Basic Sciences Indian Institute of Technology Mandi

The present work deals with the calculation of transition probability between two diabatic potentials coupled by any arbitrary coupling. The method presented in this work is applicable to any type of coupling while for numerical calculations we have assumed the arbitrary coupling as Gaussian coupling. This arbitrary coupling is expressed as a collection of Dirac delta functions and by the use of the transfer matrix technique the transition probability from one diabatic potential to another diabatic potential is calculated. We examine our approach by considering the case of two constant potentials coupled by Gaussian coupling as an arbitrary coupling.

关键词： Transfer Matrix Approach for Two-State Scattering Problem with Arbitrary Coupling

Maximization of Acoustic Levitating Force for a Single-Axis Acoustic Levitation System Using the Finite Element Method

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Chinese Physics Letters 2019年第3期36卷 49-52页

作者： Saurabh Yadav Arpan Gupta Acoustic and Vibration Laboratory School of Engineering Indian Institute of Technology Mandi

We investigate single-axis acoustic levitation using standing waves to levitate particles freely in a medium bounded by a driver and a reflector. The acoustic pressure at the pressure antinode of the standing wave counteracts the downward gravitational force of the levitating object. The optimal relationship between the air gap and the driving frequency leads to resonance and hence maximization of the levitating force. Slight deviation from the exact resonance condition causes a reduction in acoustic pressure at the pressure antinodes. This results in a significant reduction of the levitating force. The driving frequency is kept constant while the air gap is varied for different conditions. The optimal air gap for maximizing the levitation force is studied for first three resonance modes. Furthermore, a levitating particle is introduced between the driver and the reflector. The dependence of the resonance condition on the size of the levitating particle as well as the position of the particle between the driver and the reflector has also been studied. As the size of the levitating particle increases, the resonance condition also gets modified. Finite element results show a good agreement with the validated results available in the literature. Furthermore, the finite element approach is also used to study the variation of acoustic pressure at the pressure antinode with respect to the size of the reflector. The optimum diameter of the reflector is calculated for maximizing the levitating force for three resonance modes.

关键词： Maximization Levitating Acoustic Levitation Method

TasselGAN:An Application of the Generative Adversarial Model for Creating Field-Based Maize Tassel Data

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Plant Phenomics 2020年第1期2卷 210-224页

作者： Snehal Shete Srikant Srinivasan Timothy A.Gonsalves School of Computing and Electrical Engineering Indian Institute of TechnologyMandiIndia

Machine learning-based plant phenotyping systems have enabled high-throughput,non-destructive measurements of plant *** such as object detection,segmentation,and localization of plant traits in images taken in field conditions need the machine learning models to be developed on training datasets that contain plant traits amidst varying backgrounds and environmental ***,the datasets available for phenotyping are typically limited in variety and mostly consist of lab-based images in controlled ***,we present a new method called TasselGAN,using a variant of a deep convolutional generative adversarial network,to synthetically generate images of maize tassels against sky *** foreground tassel images and background sky images are generated separately and merged together to form artificial field-based maize tassel data to aid the training of machine learning models,where there is a paucity of field-based *** effectiveness of the proposed method is demonstrated using quantitative and perceptual qualitative experiments.

关键词： qualitative typically traits

Trajectory controllability of fractional dynamical systems

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Journal of Control and Decision 2017年第2期4卷 114-130页

作者： Venkatesan Govindaraj Muslim Malik Raju K.George Department of Mathematics Indian Institute of Space Science and TechnologyTrivandrumIndia School of Basic Sciences Indian Institute of Technology MandiMandiIndia

In this paper,we discuss the trajectory controllability of linear and nonlinear fractional dynamical systems represented by the fractional differential equations in the sense of Caputo fractional derivative by using the Mittag-Leffler function and Gronwall-Bellman *** the nonlinear system,we assume Lipschitz-type conditions on the *** are given to illustrate the theoretical results.

关键词： Fractional derivative trajectory controllability Mittag-Leffler function Gronwall-Bellman inequality Lipschitz continuity

Piezoelectric material selection for transducers under fuzzy environment

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Journal of Advanced Ceramics 2013年第2期2卷 141-148页

作者： Gaurav VATS Rahul VAISH School of Engineering Indian Institute of Technology MandiHimachal Pradesh 175001India

Piezoelectric ceramics are extensively investigated materials for transducer *** selection of optimal piezoelectric material for this particular application is a tedious *** depends upon various physical properties,including piezoelectric charge coefficient(d33),electromechanical coupling factor(K_(p)),dielectric constant(ε_(r)),and dielectric loss(tanδ).The classical multiple attribute decision making(MADM)can be used for decision making if these properties are known ***,these properties cannot be expressed by exact numerical values,since they are dependent upon the microstructure and fabrication ***-based MADM approaches can be helpful in such *** this paper,we have determined the ranks and rank indices(for degree of closeness)of important piezoelectric materials using fuzzy VlseKriterijumska Optimisacija I Kompromisno Resenje(VIKOR)***(8/65/35)((Pb_(1-x)La_(x))(Zr_(y)Ti_(1-y))O_(3))and KNN-LT-LS((K_(0.44)Na_(0.52)Li_(0.04))-(Nb0_(.84)Ta_(0.10)Sb_(0.06))O_(3))consecutively are found to be the top-rank piezoelectric *** indicates that KNN-LT-LS can be used on behalf of lead-based piezo-ceramics.

关键词： piezoceramics selection MADM fuzzy approach transducer application

Predicting suitability of different scale-dependent dispersivities for reactive solute transport through stratified porous media

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Journal of Rock Mechanics and Geotechnical Engineering 2016年第6期8卷 921-927页

作者： Deepak Swami Abhimanyu Sharma Pramod Kumar Sharma Dericks P.Shukla School of Engineering Indian Institute of Technology Mandi School of Engineering Indian Institute of Technology Roorkee

In this paper,the behavior of breakthrough curves(BTCs) for reactive solute transport through stratified porous media is investigated.A physical laboratory model for layered porous media was constructed,in which thin layer of gravel was sandwiched in between two thick layers of natural *** layer and natural soil layers were hydraulically connected as single porous continuum.A constant source of tracer was connected through gravel layer and elucidated at different sampling points in the direction of *** multiprocess non-equilibrium(MPNE) transport equation with scale-dependent dispersivity function was used to simulate experimental BTCs of reactive solute transport through layered porous *** values of equilibrium sorption coefficient and other input parameters were obtained *** simulation of BTC was performed using MPNE model with scale-dependent *** simulation of different scale-dependent dispersivities was then compared and it was found that for field scale of estimation of dispersivity,asymptotic and exponential dispersivity functions performed *** continuation to the comparison of simulated BTCs obtained using different models,spatial moment analysis of each aforesaid scale-dependent dispersivity model was also *** moment analysis provides the information related to mean solute mass,rate of mass travel,and mean plume *** and constant dispersivities showed higher variance as compared to asymptotic and exponential dispersion *** supports the field applicability of asymptotic and exponential dispersivity *** BTCs were also found to elucidate a nonzero concentration with time,which was clearly affected by physical *** natural condition,such information is required in effective aquifer remediation process.

关键词： Multiprocess non-equilibrium(MPNE) Scale-dependent dispersivity Stratified porous media Spatial moment

EXISTENCE AND ATTRACTIVITY OF k-ALMOST AUTOMORPHIC SEQUENCE SOLUTION OF A MODEL OF CELLULAR NEURAL NETWORKS WITH DELAY

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Acta Mathematica Scientia 2013年第1期33卷 290-302页

作者： Syed ABBAS 夏永辉 School of Basic Sciences Indian Institute of Technology MandiMandiH.P.-175001India Department of Mathematics Zhejiang Normal University

In this paper we discuss the existence and global attractivity of k-almost automorphic sequence solution of a model of cellular neural networks. We consider the corresponding difference equation analogue of the model system using suitable discretization method and obtain certain conditions for the existence of solution. Almost automorphic function is a good generalization of almost periodic function. This is the first paper considering such solutions of the neural networks.

关键词： almost automorphic sequence difference equations neural networks