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  • Open Access


    Hybrid Strategy of Partitioned and Monolithic Methods for Solving Strongly Coupled Analysis of Inverse and Direct Piezoelectric and Circuit Coupling

    Daisuke Ishihara*, Syunnosuke Nozaki, Tomoya Niho, Naoto Takayama

    CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.2, pp. 1371-1386, 2024, DOI:10.32604/cmes.2024.049694

    Abstract The inverse and direct piezoelectric and circuit coupling are widely observed in advanced electro-mechanical systems such as piezoelectric energy harvesters. Existing strongly coupled analysis methods based on direct numerical modeling for this phenomenon can be classified into partitioned or monolithic formulations. Each formulation has its advantages and disadvantages, and the choice depends on the characteristics of each coupled problem. This study proposes a new option: a coupled analysis strategy that combines the best features of the existing formulations, namely, the hybrid partitioned-monolithic method. The analysis of inverse piezoelectricity and the monolithic analysis of direct piezoelectric and circuit interaction are strongly… More >

  • Open Access


    Inkjet-printed Myoglobin based H2S Sensor


    Journal of Polymer Materials, Vol.38, No.3-4, pp. 309-325, 2021, DOI:10.32381/JPM.2021.38.3-4.11

    Abstract The objective of this research work is to investigate the feasibility of fabricating bio-based visual sensor indicators to detect the presence of H2S using inkjet printing. Myoglobin and chitosan were used as indicating and immobilizing materials respectively. 30 mg of myoglobin dissolved in 1 mL of tris buffer with 10% glycerol gave optimum jettability properties. Similarly, drop formation was optimal for 0.50% m/v chitosan solution diluted to 10 cP viscosity. The samples were fabricated in layer-by-layer approach and indicator with 2 layers of chitosan and 4 layers of myoglobin gave maximum sensitivity with 14.42 for 0.7 mg/L of H2S. The… More >

  • Open Access


    An Effective Meshless Approach for Inverse Cauchy Problems in 2D and 3D Electroelastic Piezoelectric Structures

    Ziqiang Bai1, Wenzhen Qu2,*, Guanghua Wu3,*

    CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.3, pp. 2955-2972, 2024, DOI:10.32604/cmes.2023.031474

    Abstract In the past decade, notable progress has been achieved in the development of the generalized finite difference method (GFDM). The underlying principle of GFDM involves dividing the domain into multiple sub-domains. Within each sub-domain, explicit formulas for the necessary partial derivatives of the partial differential equations (PDEs) can be obtained through the application of Taylor series expansion and moving-least square approximation methods. Consequently, the method generates a sparse coefficient matrix, exhibiting a banded structure, making it highly advantageous for large-scale engineering computations. In this study, we present the application of the GFDM to numerically solve inverse Cauchy problems in two-… More >

  • Open Access


    Algorithm Selection Method Based on Coupling Strength for Partitioned Analysis of Structure-Piezoelectric-Circuit Coupling

    Daisuke Ishihara*, Naoto Takayama

    CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.2, pp. 1237-1258, 2024, DOI:10.32604/cmes.2023.030211

    Abstract In this study, we propose an algorithm selection method based on coupling strength for the partitioned analysis of structure-piezoelectric-circuit coupling, which includes two types of coupling or inverse and direct piezoelectric coupling and direct piezoelectric and circuit coupling. In the proposed method, implicit and explicit formulations are used for strong and weak coupling, respectively. Three feasible partitioned algorithms are generated, namely (1) a strongly coupled algorithm that uses a fully implicit formulation for both types of coupling, (2) a weakly coupled algorithm that uses a fully explicit formulation for both types of coupling, and (3) a partially strongly coupled and… More >

  • Open Access


    Giant Flexoelectric Effect of Polymeric Porous Composite and Its Applications

    Dongze Yan1, Jianxiang Wang2, Lihua Shao1,*

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.1, pp. 1-2, 2023, DOI:10.32604/icces.2023.09357

    Abstract Non-uniform strains produce a localized break in the microscopic inverse symmetry of materials, which leads to the electromechanical coupling phenomenon known as flexoelectricity in all dielectric materials. However, the size-dependent flexoelectric effect typically only manifests at small scales. Creating a considerable flexoelectric output at the macroscopic scale remains a bottleneck. Micro- and nano-porous materials own a significant number of randomly distributed microscopic pores and ligamentous structures, which can deform non-uniformly under arbitrary forms of macroscopic loading. Moreover, since the small size effect of flexoelectricity, the entire flexoelectricity of the micro- and nano-porous materials will be much more significant than that… More >

  • Open Access


    Direct FE2 Method For Concurrent Multilevel Modeling of Piezoelectric Structures

    Leilei Chen2,3, Haozhi Li3,4, Lu Meng5, Pan Chen3, Pei Li1,*

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.4, pp. 1-2, 2023, DOI:10.32604/icces.2023.010584

    Abstract In this paper, a Direct FE2 method is proposed to simulate the electromechanical coupling problem of inhomogeneous materials. The theoretical foundation for the proposed method, downscaling and upscaling principles, is the same as that of the FE2 method. The two-level simulation in the Direct FE2 method may be addressed in an integrative framework where macroscopic and microscopic degrees of freedom (DOFs) are related by multipoint constraints (MPCs) [1]. This critical characteristic permits simple implementation in commercial FE software, eliminating the necessity for recurrent data transfer between two scales [2-4]. The capabilities of Direct FE2 are validated using four numerical examples,… More >

  • Open Access


    Size Dependent Structures and Properties of Na0.5Bi0.5TiO3-Based Ceramics for Piezoelectric Sensors

    Pan Chen1,2,3, Baojin Chu1,*

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.4, pp. 1-1, 2023, DOI:10.32604/icces.2023.09199

    Abstract Generally, film dielectric materials often exhibit size-dependent structure and electric properties. In this work, we demonstrate a similar behavior in bulk Na0.5Bi0.5TiO3 (NBT)-based polycrystalline ceramics. According to the results from X-ray diffraction, the (Na0.5Bi0.5)0.92Ba0.08Ti0.99Mg0.01O2.99 (NBT8M1.0) ceramic showed a complex structure that consists of rhombohedral, tetragonal and cubic symmetries. We found, when decreasing the thickness of a ϕ 10 mm NBT8M1.0 ceramic from 1230 μm to 230 μm, the ceramic showed increased content of cubic symmetry (CC) from 28% to 56%. Meanwhile, the piezoelectric response (d33) increased from 107 pC/N to 134 pC/N and the depolarization temperature (Td) decreased from 170… More >

  • Open Access


    Mixed Finite Element Approach for Semiconductor Structures

    Qiufeng Yang1, Xudong Li2, Zhaowei Liu3, Feng Jin1,*, Yilin Qu1,*

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.3, pp. 1-2, 2023, DOI:10.32604/icces.2023.09073

    Abstract Compared to piezoelectric effects restricted to noncentrosymmetric crystalline structures, flexoelectric effects exist universally in all crystalline structures [1,2]. Meanwhile, some crystals, say silicon, are also semiconductive, which raises interest in studying the interactions between mechanical fields and mobile charges in semiconductors with consideration of piezoelectricity or flexoelectricity [3,4]. In order to explain these coupling effects, macroscopic theories on elastic semiconductors considering piezoelectricity or flexoelectricity were proposed by Yang and co-authors [5,6]. For piezoelectric semiconductors, the formulation of finite elements is relatively straightforward since the governing partial derivative equation (PDE) is twice-order. As for elastic semiconductors with consideration of flexoelectricity, it… More >

  • Open Access


    Wireless Self-Powered Vibration Sensor System for Intelligent Spindle Monitoring

    Lei Yu1, Hongjun Wang1,*, Yubin Yue1, Shucong Liu1, Xiangxiang Mao2, Fengshou Gu3

    Structural Durability & Health Monitoring, Vol.17, No.4, pp. 315-336, 2023, DOI:10.32604/sdhm.2022.024899

    Abstract In recent years, high-end equipment is widely used in industry and the accuracy requirements of the equipment have been risen year by year. During the machining process, the high-end equipment failure may have a great impact on the product quality. It is necessary to monitor the status of equipment and to predict fault diagnosis. At present, most of the condition monitoring devices for mechanical equipment have problems of large size, low precision and low energy utilization. A wireless self-powered intelligent spindle vibration acceleration sensor system based on piezoelectric energy harvesting is proposed. Based on rotor sensing technology, a sensor is… More >

  • Open Access



    Jason Velardoa, Randeep Singha,*, Mohammad Shahed Ahameda, Masataka Mochizukib, Abhijit Datec, Aliakbar Akbarzadehc

    Frontiers in Heat and Mass Transfer, Vol.17, pp. 1-11, 2021, DOI:10.5098/hmt.17.1

    Abstract Thermal solutions play an integral role in managing heat loads for electronic devices. As these electronics become more compact and portable, improved thermal management solutions need to be introduced. Thin flattened heat pipes (0.8mm – 2.0mm thick) and piezoelectric fans (1mm thick) have been proposed here for this purpose. The maximum heat carrying capacity of the flattened heat pipe was experimentally determined and found to be a function of the flattened heat pipe thickness. Reductions from 48W at 2.0mm to 7W at 0.8mm were observed. This was expected to be due to capillary limitations. The piezoelectric fan could be operated… More >

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