Applied Mathematical Modelling最新文献_第9页

Stress-constrained concurrent multiscale topological design of porous composites based on discrete material optimisation 基于离散材料优化的多孔复合材料应力约束并发多尺度拓扑设计

IF 4.4 2区工程技术

Applied Mathematical Modelling Pub Date : 2024-09-30 DOI: 10.1016/j.apm.2024.115730

Guangkai Wei , Yuan Chen , Xu Han , Guixing Li , Yingchun Bai , Kunkun Fu

{"title":"Stress-constrained concurrent multiscale topological design of porous composites based on discrete material optimisation","authors":"Guangkai Wei , Yuan Chen , Xu Han , Guixing Li , Yingchun Bai , Kunkun Fu","doi":"10.1016/j.apm.2024.115730","DOIUrl":"10.1016/j.apm.2024.115730","url":null,"abstract":"<div><div>Porous composites have attracted increasing attention in recent decades. This study develops a concurrent multiscale topology optimisation (CMTO) method under a prescribed stress constraint for designing porous composites with multi-domain microstructures. First, to address the difficulty of predicting local stress due to varying of microstructural type throughout the optimisation process, a continuous and differentiable stress measure is proposed to effectively approximate the local stress. Second, an inverse homogenisation method based on isogeometric analysis (IGA) is developed to improve the accuracy of stress prediction, and then it is integrated into a CMTO which is developed based on the discrete material optimisation (DMO) interpolation scheme. Third, a stress constraint which is differentiable with respect to both macro and micro design variables is proposed to enable the stress-constrained concurrent optimisation of the macrostructural configuration, microstructural configuration and distribution. Fourth, a novel post-processing approach is established to achieve smooth while volume preserving contour of unit cells with layouts. Finally, two benchmark design examples, namely l-bracket and Crack problems, are implemented using the presented CMTO under a global stress constraint to demonstrate the effectiveness of the proposed method. The result indicates that the proposed method can effectively decrease the stress concentration via three design manners, i.e., the macrostructural configuration, microstructural configuration and distribution. Also, an “interface-enlarging” phenomenon was interestingly but reasonably found in those cases when subjected to stress-constraint considerations.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"137 ","pages":"Article 115730"},"PeriodicalIF":4.4,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Flexoelectronics of a centrosymmetric semiconductor cylindrical nanoshell 中心对称半导体圆柱纳米壳的柔性电子学

IF 4.4 2区工程技术

Applied Mathematical Modelling Pub Date : 2024-09-29 DOI: 10.1016/j.apm.2024.115725

Ziwen Guo , Gongye Zhang , Changwen Mi , Yilin Qu

{"title":"Flexoelectronics of a centrosymmetric semiconductor cylindrical nanoshell","authors":"Ziwen Guo , Gongye Zhang , Changwen Mi , Yilin Qu","doi":"10.1016/j.apm.2024.115725","DOIUrl":"10.1016/j.apm.2024.115725","url":null,"abstract":"<div><div>Cylindrical shell-type semiconductors are essential for sensing and energy harvesting when integrated into surfaces of certain equipment, such as spacecraft, marine devices, and portable electronics, where mechanical forces play a significant impact on charge transport. Traditionally, such functionalities are only manifested in piezoelectric or pyroelectric crystals that possess non-centrosymmetry. Here, we theoretically investigate electronic behaviors driven by strain gradient-induced flexoelectric polarization in a centrosymmetric semiconductor cylindrical nanoshell, expanding the flexoelectronics in shell structures. The governing equations and accompanying boundary conditions are formulated simultaneously using the principle of virtual work and the fundamental lemma of the calculus of variation. Electromechanical interactions through static bending and forced vibration analyses of the newly developed model are systematically investigated. Under localized force excitation, the distribution of mobile charges is manipulated by tuning loading magnitudes and areas. The effects of doping levels on electric potentials and mobile charges are explored to show the interaction mechanism between flexoelectric and semiconducting properties. Moreover, the natural frequencies and modes of all mechanical displacements, electric potentials, and carrier concentration perturbations within the shell are identified. This paper provides a new approach for designing shell-shaped sensors and energy harvesters specifically for centrosymmetric semiconductors.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"137 ","pages":"Article 115725"},"PeriodicalIF":4.4,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Bending-torsional vibration response of modified Timoshenko thin-walled beams under moving harmonic loads 移动谐波载荷下改良季莫申科薄壁梁的弯曲扭转振动响应

IF 4.4 2区工程技术

Applied Mathematical Modelling Pub Date : 2024-09-28 DOI: 10.1016/j.apm.2024.115724

Yong Cai , Laifu Zhang , Jiajia Zhang , Xiaoyue Fan , Xiaoyong Lv , Haijun Chen

{"title":"Bending-torsional vibration response of modified Timoshenko thin-walled beams under moving harmonic loads","authors":"Yong Cai , Laifu Zhang , Jiajia Zhang , Xiaoyue Fan , Xiaoyong Lv , Haijun Chen","doi":"10.1016/j.apm.2024.115724","DOIUrl":"10.1016/j.apm.2024.115724","url":null,"abstract":"<div><div>In this paper, a new method is proposed for calculating the bending-torsional vibration response of modified Timoshenko thin-walled beams under moving harmonic loads. The boundary conditions of the beams are considered to be simply supported at both ends. By using Fourier and Laplace transformations, analytical solutions for vibration responses are derived. For the validation of the proposed method, the results obtained using the proposed method are compared with those acquired by the finite element method (FEM). Through the parametric analysis, the effects of cross-sectional properties as well as the load magnitude, velocity, and eccentricity are further investigated. The results indicate that: (1) compared to the method that ignores shear rotary inertia, the vertical displacement of the beam at the midspan calculated by the proposed method shows an accuracy improvement of up to 6.87%; (2) the bending-torsional vibration frequency increases with the growth of the torsional moment of inertia; (3) when the velocity increases from 20 m/s to 80 m/s, the difference in the maximum displacement at the midspan is essentially within 5%; (4) the bending-torsional vibration response is significantly influenced by the load magnitude and eccentricity, whereas the vibration frequency of the beam remains unaffected by these variations; (5) an increase in load velocity does not always lead to a greater response from the beam, which can be explained from the perspective of resonance.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"137 ","pages":"Article 115724"},"PeriodicalIF":4.4,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Three-dimensional nonlinear vortex-induced vibrations of risers under internal gas-liquid and external shear flows 内部气液流和外部剪切流下立管的三维非线性涡流诱导振动

IF 4.4 2区工程技术

Applied Mathematical Modelling Pub Date : 2024-09-28 DOI: 10.1016/j.apm.2024.115728

Bin Zhang , Yongxin Chen , Yuyang Chai , Fengming Li

{"title":"Three-dimensional nonlinear vortex-induced vibrations of risers under internal gas-liquid and external shear flows","authors":"Bin Zhang , Yongxin Chen , Yuyang Chai , Fengming Li","doi":"10.1016/j.apm.2024.115728","DOIUrl":"10.1016/j.apm.2024.115728","url":null,"abstract":"<div><div>A novel three-dimensional (3D) dynamic model is proposed to explore the nonlinear vortex-induced vibration (VIV) characteristics of top-tension risers under the combined action of internal gas-liquid two-phase flow and external shear flow. The van der Pol equation is used to evaluate the interaction between the riser and the external shear flow. The nonlinear governing equations are established through Hamilton's principle, and they are discretized by the Galerkin method and solved via the Runge-Kutta method. The VIV responses calculated by the proposed nonlinear dynamic model are compared with the previously experimental and computational fluid dynamics (CFD) results, demonstrating the effectiveness and accuracy of the present theoretical method. The influences of the internal flow effect, the tension and the shear parameter of the external flow on the VIV responses of the riser are analyzed. The results show that when the internal flow effect is not considered, the transition of the external flow from uniform flow to shear flow leads to an increase in excited modes and a decrease in resonance responses of the riser in the cross-flow (CF) direction. Furthermore, with the increase of the external shear flow velocity, resonances at different positions of the riser are not synchronized, which is different from that of the riser in uniform flow. In the case of the riser conveying gas-liquid two-phase flow and being subjected to external uniform or shear flow, the increase in the velocity of the liquid phase leads to an increase in the maximum response amplitudes of the riser in the in-line (IL) and axial directions. When the internal flow changes from single-phase to gas-liquid two-phase, the maximum VIV responses of the riser in the IL and axial directions tend to decrease regardless of whether the riser is in uniform flow or shear flow.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"137 ","pages":"Article 115728"},"PeriodicalIF":4.4,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Green's functions of two-dimensional piezoelectric quasicrystal semi-infinite crack and finite crack 二维压电准晶体半无限裂缝和有限裂缝的格林函数

IF 4.4 2区工程技术

Applied Mathematical Modelling Pub Date : 2024-09-28 DOI: 10.1016/j.apm.2024.115732

Xiang Mu , Zhaowei Zhu , Liangliang Zhang , Yang Gao

引用次数: 0

Dynamics of rational and semi-rational solutions of the general N-component nonlinear Schrödinger equations 一般 N 分量非线性薛定谔方程的有理解和半有理解的动力学特性

IF 4.4 2区工程技术

Applied Mathematical Modelling Pub Date : 2024-09-27 DOI: 10.1016/j.apm.2024.115726

Wei-Qi Peng

引用次数: 0

Dynamics of Love-type wave propagation in composite transversely isotropic porous structures 复合横向各向同性多孔结构中爱型波传播的动力学特性

IF 4.4 2区工程技术

Applied Mathematical Modelling Pub Date : 2024-09-27 DOI: 10.1016/j.apm.2024.115723

Komal Gajroiya, Jitander Singh Sikka

{"title":"Dynamics of Love-type wave propagation in composite transversely isotropic porous structures","authors":"Komal Gajroiya, Jitander Singh Sikka","doi":"10.1016/j.apm.2024.115723","DOIUrl":"10.1016/j.apm.2024.115723","url":null,"abstract":"<div><div>The present study aims to analyze the propagation behavior of Love-type wave in a composite transversely isotropic porous structure. The structure comprises an inhomogeneous sandy porous layer lying between a non-homogeneous magneto-poroelastic layer and a heterogeneous fractured porous half-space. Analytic solutions of the field equations of the respective media involve the application of the variable separable method and Wentzel-Kramers-Brillouin (WKB) asymptotic approach for the conversion of partial differential equations into ordinary differential equations. Through careful imposition of boundary conditions and subsequent elimination of arbitrary constants, we derive a complex dispersion relation governing the propagation of Love-type waves. This dispersion equation yields both the phase velocity curve, corresponding to the real expression, and the damping velocity curve, derived from the imaginary expression. To represent our findings, we conduct extensive calculations and graphical simulations illustrating the influence of various material parameters such as heterogeneity, porosity, volume fraction of fractures, sandiness, magnet-oelastic coupling, angle at which wave crosses the magnetic field, and layer thickness on the dispersive nature of Love-type waves using MATHEMATICA software. Furthermore, we conduct case-specific analyses, revealing instances where the dispersion equation simplifies to the standard Love wave equation, thereby validating our mathematical framework. Our findings underscore the significant influence of the aforementioned material parameters on the phase and damping velocities of Love-type wave. This interdisciplinary investigation into different porous media opens new avenues for future research and has significant implications in various disciplines, ranging from engineering and geophysics to environmental science and beyond.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"137 ","pages":"Article 115723"},"PeriodicalIF":4.4,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cylindrical cavity expansion-contraction solutions in undrained MCC soils with the auxiliary variable approach 用辅助变量法求解未排水 MCC 土中的圆柱形空腔膨胀-收缩问题

IF 4.4 2区工程技术

Applied Mathematical Modelling Pub Date : 2024-09-26 DOI: 10.1016/j.apm.2024.115722

Li Pang, Chong Jiang, Chaoyang Zhang

{"title":"Cylindrical cavity expansion-contraction solutions in undrained MCC soils with the auxiliary variable approach","authors":"Li Pang, Chong Jiang, Chaoyang Zhang","doi":"10.1016/j.apm.2024.115722","DOIUrl":"10.1016/j.apm.2024.115722","url":null,"abstract":"<div><div>Cylindrical cavity exhibits non-self-similarity during contraction process following expansion. Previous studies solve this problem with total strain approach and simple constitutive models, but the approach is not applicable when using an advanced constitutive model. This paper presents a semi-analytical solution for a cylindrical cavity undergoing expansion-contraction in undrained soils with auxiliary variable approach, incorporating the Modified Cam-Clay (MCC) model. The stress states around the cavity are formed by the superposition of initial and superimposed stress states. By treating superimposed effective stresses as self-similar, a semi-analytical solution is derived for solving the cavity expansion-contraction problem. The elastoplastic stress-strain relationship is formulated as a set of first-order differential equations, which can be solved as an initial value problem though Runge-Kutta (RK) method. Then the stress distribution around the cavity during expansion-contraction process can be determined. To validate the proposed approach, a series of well-conduced self-boring pressuremeter (SBP) tests are used to verify the proposed approach, which shows good agreements. Additionally, a FEM simulation incorporating the MCC model is performed, and the simulation results are presented to carry out parametric studies on soil parameters. A significant influence on the range of the plastic and reverse plastic zones is shown for overconsolidation ratio, while the <em>in-situ</em> coefficient of the earth pressure only quantitatively affects the stress distribution.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"137 ","pages":"Article 115722"},"PeriodicalIF":4.4,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Solution for time-dependent resilience in the presence of gradual deterioration of performance 性能逐渐恶化时随时间变化的弹性解决方案

IF 4.4 2区工程技术

Applied Mathematical Modelling Pub Date : 2024-09-23 DOI: 10.1016/j.apm.2024.115716

Cao Wang

{"title":"Solution for time-dependent resilience in the presence of gradual deterioration of performance","authors":"Cao Wang","doi":"10.1016/j.apm.2024.115716","DOIUrl":"10.1016/j.apm.2024.115716","url":null,"abstract":"<div><div>In this paper, a closed-form method is developed for the evaluation of time-dependent resilience (so named as it is a function of the service time of interest) of an aging object (e.g., a structure or system). These structures and systems often suffer from the deterioration of performances in a harsh service environment, causing the decline of serviceability. They are thus expected to be sufficiently resilient during their service lives, i.e., to have the ability to withstand disruptions to their performances. The proposed method takes into account the uncertainty associated with the performance deterioration process, the availability of resources that support the performance recovery, and the impact of a changing environment. The accuracy and improved efficiency of the proposed method are demonstrated through three examples. It is also shown through sensitivity analysis that the impact of a changing environment, and the availability of recovery-supporting resources play an essential role in the time-dependent resilience. The proposed resilience method can also be used to efficiently guide the design of new structures that meet predefined resilience goals.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"137 ","pages":"Article 115716"},"PeriodicalIF":4.4,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical analysis of small-strain elasto-plastic deformation using local Radial Basis Function approximation with Picard iteration 利用皮卡尔迭代的局部径向基函数近似对小应变弹塑性变形进行数值分析

IF 4.4 2区工程技术

Applied Mathematical Modelling Pub Date : 2024-09-23 DOI: 10.1016/j.apm.2024.115714

Filip Strniša, Mitja Jančič, Gregor Kosec

{"title":"Numerical analysis of small-strain elasto-plastic deformation using local Radial Basis Function approximation with Picard iteration","authors":"Filip Strniša, Mitja Jančič, Gregor Kosec","doi":"10.1016/j.apm.2024.115714","DOIUrl":"10.1016/j.apm.2024.115714","url":null,"abstract":"<div><div>In this paper, we discuss a von Mises plasticity model with nonlinear isotropic hardening assuming small strains in a plane strain example of internally pressurised thick-walled cylinder subjected to different loading conditions. The elastic deformation is modelled using the Navier-Cauchy equation. In regions where the von Mises stress exceeds the yield stress, corrections are made locally through a return mapping algorithm. We present a novel method that uses a Radial Basis Function-Finite Difference (RBF-FD) approach with Picard iteration to solve the system of nonlinear equations arising from plastic deformation. This technique eliminates the need to stabilise the divergence operator and avoids special positioning of the boundary nodes, while preserving the elegance of the meshless discretisation and avoiding the introduction of new parameters that would require tuning. The results of the proposed method are compared with analytical and Finite Element Method (FEM) solutions. The results show that the proposed method achieves comparable accuracy to FEM while offering significant advantages in the treatment of complex geometries without the need for conventional meshing or special treatment of boundary nodes or differential operators.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"137 ","pages":"Article 115714"},"PeriodicalIF":4.4,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0