Theoretical and Applied Mechanics Letters最新文献_第10页

Performance improvement of the stochastic-resonance-based tri-stable energy harvester under random rotational vibration 随机旋转振动下基于随机共振的三稳定能量采集器性能改进

IF 3.4 3区工程技术

Theoretical and Applied Mechanics Letters Pub Date : 2022-09-01 DOI: 10.1016/j.taml.2022.100365

Tingting Zhang , Yanfei Jin , Yanxia Zhang

{"title":"Performance improvement of the stochastic-resonance-based tri-stable energy harvester under random rotational vibration","authors":"Tingting Zhang , Yanfei Jin , Yanxia Zhang","doi":"10.1016/j.taml.2022.100365","DOIUrl":"10.1016/j.taml.2022.100365","url":null,"abstract":"<div><p>In this paper, the stochastic-resonance-based tri-stable energy harvester (TEH) is proposed to enhance harvesting performance under random rotational vibration. An electromechanical coupled system interfaced with a standard rectifier circuit driven by colored noise is considered. The stationary probability density function (SPDF) of the harvester is obtained by the improved stochastic averaging. Then, with the adiabatic approximation theory, the analytical expression of signal-to-noise ratio (SNR) for the TEH is deduced to characterize stochastic resonance (SR). To enhance direct current (DC) power delivery from a rotational TEH, the influences of system parameters on SR is discussed. The obtained results suggest that there are damping-induced resonance and noise-intensity-induced SR in the tri-stable system. The TEH has higher harvesting performance under the optimal SR. That is, the optimal parameter combinations can induce optimal SR and maximize harvesting performance. Thus, the stochastic-resonance-based TEH can be optimized to enhance energy harvesting through choosing the optimal parameter.</p></div>","PeriodicalId":46902,"journal":{"name":"Theoretical and Applied Mechanics Letters","volume":"12 5","pages":"Article 100365"},"PeriodicalIF":3.4,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095034922000459/pdfft?md5=cd8380cf1d734d3b4a946026477b57f4&pid=1-s2.0-S2095034922000459-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45838046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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: 2

Mechanical characteristics of composite honeycomb sandwich structures under oblique impact 复合材料蜂窝夹层结构斜冲击力学特性研究

IF 3.4 3区工程技术

Theoretical and Applied Mechanics Letters Pub Date : 2022-09-01 DOI: 10.1016/j.taml.2022.100379

Yuechen Duan , Zhen Cui , Xin Xie , Ying Tie , Ting Zou , Tingting Wang

{"title":"Mechanical characteristics of composite honeycomb sandwich structures under oblique impact","authors":"Yuechen Duan , Zhen Cui , Xin Xie , Ying Tie , Ting Zou , Tingting Wang","doi":"10.1016/j.taml.2022.100379","DOIUrl":"10.1016/j.taml.2022.100379","url":null,"abstract":"<div><p>Carbon fiber reinforced polymer (CFRP) and CFRP-based composite honeycomb sandwich structures are particularly sensitive to impact. The mechanical characteristics of composite honeycomb sandwich structures under oblique impact are studied by numerical simulation and experiment. The oblique impact model is established, and the reliability of the model is verified by the oblique impact test. To further analyze the influence of structural parameters on energy absorption under oblique impact, the influence of impact angle, face sheet thickness and wall thickness of the honeycomb is numerically studied. The results show that the impact angle has an important effect on energy distribution. The structural parameters also have an effect on the peak contact force, contact time, and energy absorption, and the effect is different from normal impact due to the presence of frictional dissipation energy. Compared with normal impact, the debonding of oblique impact will be reduced, but the buckling range of the honeycomb core will be expanded.</p></div>","PeriodicalId":46902,"journal":{"name":"Theoretical and Applied Mechanics Letters","volume":"12 5","pages":"Article 100379"},"PeriodicalIF":3.4,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095034922000599/pdfft?md5=c10805bb1cb2e129b4660b99a4f767b5&pid=1-s2.0-S2095034922000599-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48048459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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: 6

A structure-preserving algorithm for time-scale non-shifted Hamiltonian systems 时间尺度非移位哈密顿系统的结构保持算法

IF 3.4 3区工程技术

Theoretical and Applied Mechanics Letters Pub Date : 2022-09-01 DOI: 10.1016/j.taml.2022.100368

Xue Tian , Yi Zhang

{"title":"A structure-preserving algorithm for time-scale non-shifted Hamiltonian systems","authors":"Xue Tian , Yi Zhang","doi":"10.1016/j.taml.2022.100368","DOIUrl":"https://doi.org/10.1016/j.taml.2022.100368","url":null,"abstract":"<div><p>The variational calculus of time-scale non-shifted systems includes both the traditional continuous and traditional significant discrete variational calculus. Not only can the combination of <span><math><mstyle><mi>Δ</mi></mstyle></math></span> and <span><math><mi>∇</mi></math></span> derivatives be beneficial to obtaining higher convergence order in numerical analysis, but also it prompts the time-scale numerical computational scheme to have good properties, for instance, structure-preserving. In this letter, a structure-preserving algorithm for time-scale non-shifted Hamiltonian systems is proposed. By using the time-scale discrete variational method and calculus theory, and taking a discrete time scale in the variational principle of non-shifted Hamiltonian systems, the corresponding discrete Hamiltonian principle can be obtained. Furthermore, the time-scale discrete Hamilton difference equations, Noether theorem, and the symplectic scheme of discrete Hamiltonian systems are obtained. Finally, taking the Kepler problem and damped oscillator for time-scale non-shifted Hamiltonian systems as examples, they show that the time-scale discrete variational method is a structure-preserving algorithm. The new algorithm not only provides a numerical method for solving time-scale non-shifted dynamic equations but can be calculated with variable step sizes to improve the computational speed.</p></div>","PeriodicalId":46902,"journal":{"name":"Theoretical and Applied Mechanics Letters","volume":"12 5","pages":"Article 100368"},"PeriodicalIF":3.4,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095034922000484/pdfft?md5=8c01629198c97de378bb54b2bb47f619&pid=1-s2.0-S2095034922000484-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137273635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Optimization for vibro-impact nonlinear energy sink under random excitation 随机激励下振动冲击非线性能量汇优化

IF 3.4 3区工程技术

Theoretical and Applied Mechanics Letters Pub Date : 2022-09-01 DOI: 10.1016/j.taml.2022.100364

Jiamin Qian , Lincong Chen

引用次数: 1

An alternative form of energy density demonstrating the severe strain-stiffening in thin spherical and cylindrical shells 能量密度的另一种形式表明在薄球形和圆柱形壳体中严重的应变硬化

IF 3.4 3区工程技术

Theoretical and Applied Mechanics Letters Pub Date : 2022-05-01 DOI: 10.1016/j.taml.2022.100361

Md. Moonim Lateefi , Deepak Kumar , Somnath Sarangi

{"title":"An alternative form of energy density demonstrating the severe strain-stiffening in thin spherical and cylindrical shells","authors":"Md. Moonim Lateefi , Deepak Kumar , Somnath Sarangi","doi":"10.1016/j.taml.2022.100361","DOIUrl":"10.1016/j.taml.2022.100361","url":null,"abstract":"<div><p>The present article investigates an elastic instability phenomenon for internally pressurized spherical thin balloons and thin cylindrical tubes composed of incompressible hyperelastic material. A mathematical model is formulated by proposing a new strain energy density function. In the family of limited elastic materials, many material models exhibit strain-stiffening. However, they fail to predict severe strain-stiffening in a moderate range of deformations in the stress-strain relations. The proposed energy function contains three material parameters and shows substantially improved stain stiffening properties than the limited elastic material models. The model is further applied to explore the elastic instability phenomenon in spherical and cylindrical shells. The findings are compared with other existing models and validated with experimental results. The model shows better agreement with experimental results and exhibits a substantial strain-stiffening effect than the current models.</p></div>","PeriodicalId":46902,"journal":{"name":"Theoretical and Applied Mechanics Letters","volume":"12 4","pages":"Article 100361"},"PeriodicalIF":3.4,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095034922000411/pdfft?md5=4a8359ecc2367d4095aca5b5a5b2f14b&pid=1-s2.0-S2095034922000411-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46418454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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: 2

Independent component analysis of streamwise velocity fluctuations in turbulent channel flows 紊流河道中沿流速度波动的独立分量分析

IF 3.4 3区工程技术

Theoretical and Applied Mechanics Letters Pub Date : 2022-05-01 DOI: 10.1016/j.taml.2022.100349

Ting Wu , Guowei He

{"title":"Independent component analysis of streamwise velocity fluctuations in turbulent channel flows","authors":"Ting Wu , Guowei He","doi":"10.1016/j.taml.2022.100349","DOIUrl":"10.1016/j.taml.2022.100349","url":null,"abstract":"<div><p>Independent component analysis (ICA) is used to study the multiscale localised modes of streamwise velocity fluctuations in turbulent channel flows. ICA aims to decompose signals into independent modes, which may induce spatially localised objects. The height and size are defined to quantify the spatial position and extension of these ICA modes, respectively. In contrast to spatially extended proper orthogonal decomposition (POD) modes, ICA modes are typically localised in space, and the energy of some modes is distributed across the near-wall region. The sizes of ICA modes are multiscale and are approximately proportional to their heights. ICA modes can also help to reconstruct the statistics of turbulence, particularly the third-order moment of velocity fluctuations, which is related to the strongest Reynolds shear-stress-producing events. The results reported in this paper indicate that the ICA method may connect statistical descriptions and structural descriptions of turbulence.</p></div>","PeriodicalId":46902,"journal":{"name":"Theoretical and Applied Mechanics Letters","volume":"12 4","pages":"Article 100349"},"PeriodicalIF":3.4,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095034922000290/pdfft?md5=5ad1051065d835ed0b452a8004b98a60&pid=1-s2.0-S2095034922000290-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42121632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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: 3

On the number of fractured segments of spaghetti breaking dynamics 意大利面断裂动力学中断裂段数的研究

IF 3.4 3区工程技术

Theoretical and Applied Mechanics Letters Pub Date : 2022-05-01 DOI: 10.1016/j.taml.2022.100347

Yi Zhang, Xiang Li, Yuanfan Dai, Bo-Hua Sun

{"title":"On the number of fractured segments of spaghetti breaking dynamics","authors":"Yi Zhang, Xiang Li, Yuanfan Dai, Bo-Hua Sun","doi":"10.1016/j.taml.2022.100347","DOIUrl":"10.1016/j.taml.2022.100347","url":null,"abstract":"<div><p>Why are pieces of spaghetti generally broken into three to ten segments instead of two as one thinks? How can one obtain the desired number of fracture segments? To answer those questions, the fracture dynamics of a strand of spaghetti is modelled by elastic rod and numerically investigated by using finite-element software ABAQUS. By data fitting, two relations are obtained: the number of fracture segments in terms of rod diameter-length ratio and fracture limit curvature with the rod diameter. Results reveal that when the length is constant, the larger the diameter and/or the smaller the diameter-length ratio <span><math><mrow><mi>D</mi><mo>/</mo><mi>L</mi></mrow></math></span>, the smaller the limit curvature; and the larger the diameter-length ratio <span><math><mrow><mi>D</mi><mo>/</mo><mi>L</mi></mrow></math></span>, the fewer the number of fractured segments. The relevant formulations can be used to obtain the desired number of broken segments of spaghetti by changing the diameter-to-length ratio.</p></div>","PeriodicalId":46902,"journal":{"name":"Theoretical and Applied Mechanics Letters","volume":"12 4","pages":"Article 100347"},"PeriodicalIF":3.4,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095034922000277/pdfft?md5=a1ce7fb4eabf51ec3e3eb37f4590a64f&pid=1-s2.0-S2095034922000277-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43475158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Motion of a sphere and the suspending low-Reynolds-number fluid confined in a cubic cavity 球体的运动和限制在立方腔内的低雷诺数悬浮流体

IF 3.4 3区工程技术

Theoretical and Applied Mechanics Letters Pub Date : 2022-05-01 DOI: 10.1016/j.taml.2022.100352

Gaofeng Chen , Xikai Jiang

{"title":"Motion of a sphere and the suspending low-Reynolds-number fluid confined in a cubic cavity","authors":"Gaofeng Chen , Xikai Jiang","doi":"10.1016/j.taml.2022.100352","DOIUrl":"10.1016/j.taml.2022.100352","url":null,"abstract":"<div><p>Dynamics of a spherical particle and the suspending low-Reynolds-number fluid confined by a cubic cavity were studied numerically. We calculated the particle’s hydrodynamic mobilities along <span><math><mi>x</mi></math></span>-, <span><math><mi>y</mi></math></span>-, and <span><math><mi>z</mi></math></span>-directions at various locations in the cavity. The mobility is largest in the cavity center and decays as the particle becomes closer to no-slip walls. It was found that mobilities in the entire cubic cavity can be determined by a minimal set in a unit tetrahedron therein. Fluid vortices in the cavity induced by the particle motion were observed and analyzed. We also found that the particle can exhibit a drift motion perpendicular to the external force. Magnitude of the drift velocity normalized by the velocity along the direction of the external force depends on particle location and particle-to-cavity sizes ratio. This work forms the basis to understand more complex dynamics in microfluidic applications such as intracellular transport and encapsulation technologies.</p></div>","PeriodicalId":46902,"journal":{"name":"Theoretical and Applied Mechanics Letters","volume":"12 4","pages":"Article 100352"},"PeriodicalIF":3.4,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095034922000320/pdfft?md5=2c59c1dcf3939d7fe6aa7c47861d030d&pid=1-s2.0-S2095034922000320-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43815055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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: 1

Design of elliptical underwater acoustic cloak with truss-latticed pentamode materials 桁架五模材料椭圆水声斗篷的设计

IF 3.4 3区工程技术

Theoretical and Applied Mechanics Letters Pub Date : 2022-05-01 DOI: 10.1016/j.taml.2022.100346

Yuanyuan Ge, Xiaoning Liu, Gengkai Hu

引用次数: 2

Mathematical modeling of fractional derivatives for magnetohydrodynamic fluid flow between two parallel plates by the radial basis function method 用径向基函数法建立两平行板间磁流体流动的分数阶导数数学模型

IF 3.4 3区工程技术

Theoretical and Applied Mechanics Letters Pub Date : 2022-05-01 DOI: 10.1016/j.taml.2022.100350

Saman Hosseinzadeh, Seyed Mahdi Emadi, Seyed Mostafa Mousavi, Davood Domairry Ganji

{"title":"Mathematical modeling of fractional derivatives for magnetohydrodynamic fluid flow between two parallel plates by the radial basis function method","authors":"Saman Hosseinzadeh, Seyed Mahdi Emadi, Seyed Mostafa Mousavi, Davood Domairry Ganji","doi":"10.1016/j.taml.2022.100350","DOIUrl":"10.1016/j.taml.2022.100350","url":null,"abstract":"<div><p>Investigations into the magnetohydrodynamics of viscous fluids have become more important in recent years, owing to their practical significance and numerous applications in astro-physical and geo-physical phenomena. In this paper, the radial base function was utilized to answer fractional equation associated with fluid flow passing through two parallel flat plates with a magnetic field. The magnetohydrodynamics coupled stress fluid flows between two parallel plates, with the bottom plate being stationary and the top plate moving at a persistent velocity. We compared the radial basis function approach to the numerical method (fourth-order Range-Kutta) in order to verify its validity. The findings demonstrated that the discrepancy between these two techniques is quite negligible, indicating that this method is very reliable. The impact of the magnetic field parameter and Reynolds number on the velocity distribution perpendicular to the fluid flow direction is illustrated. Eventually, the velocity parameter is compared for diverse conditions α, Reynolds and position (<em>y</em>), the maximum of which occurs at <em>α</em> = 0.4. Also, the maximum velocity values occur in α=0.4 and <em>Re</em>=1000 and the concavity of the graph is less for <em>α</em>=0.8.</p></div>","PeriodicalId":46902,"journal":{"name":"Theoretical and Applied Mechanics Letters","volume":"12 4","pages":"Article 100350"},"PeriodicalIF":3.4,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095034922000307/pdfft?md5=eb97cd3cbc33b517ade10a4ead2c4614&pid=1-s2.0-S2095034922000307-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41853014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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: 2