Journal of Applied Mechanics-Transactions of the Asme最新文献_第2页

Instability of Metamaterial-based Thin Cylindrical Shells under Axial Compression 超材料基薄圆柱壳在轴向压缩下的不稳定性

4区工程技术

Journal of Applied Mechanics-Transactions of the Asme Pub Date : 2023-10-26 DOI: 10.1115/1.4063898

Mitansh Doshi, Xin Ning

{"title":"Instability of Metamaterial-based Thin Cylindrical Shells under Axial Compression","authors":"Mitansh Doshi, Xin Ning","doi":"10.1115/1.4063898","DOIUrl":"https://doi.org/10.1115/1.4063898","url":null,"abstract":"Abstract This paper presents comprehensive numerical studies on the instability behavior of metamaterial-based cylindrical shells (meta-shells) under axial compression. The cylindrical meta-shells are comprised of lattice-like metamaterial unit cells including house unit cells and their variants, cuboid braced, octet truss, and octahedron. Their buckling and post-buckling behavior, effects of dimensional variations, structural mass efficiency in carrying axial compression, and the influences from damaged units are studied in this work. The results show that cylindrical meta-shells can exhibit benign or multi-stable post-buckling behavior rather than catastrophic unstable post-buckling commonly seen for conventional cylindrical shells with continuous surfaces. This work finds that the critical buckling loads scale with the meta-shell dimensions following a quadratic relation. However, the meta-shells' structural mass efficiencies in carrying axial load do not change or slightly increase as their sizes proportionally increase. The study on the effects of defects shows that the critical buckling loads linearly decrease with respect to the mass of total damaged units.","PeriodicalId":54880,"journal":{"name":"Journal of Applied Mechanics-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134909362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Tresca vs. von Mises: Which failure criterion is more conservative in a probabilistic context? Tresca vs. von Mises:在概率背景下哪个失效准则更保守?

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Journal of Applied Mechanics-Transactions of the Asme Pub Date : 2023-10-26 DOI: 10.1115/1.4063894

Americo Cunha, Yasar Yanik, Carlo Olivieri, Samuel da Silva

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Smooth Lagrangian Crack Band Model (slCBM) Based on Spress-Sprain Relation and Lagrange Multiplier Constraint of Displacement Gradient 基于应力-扭伤关系和位移梯度拉格朗日乘子约束的光滑拉格朗日裂纹带模型(slCBM

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Journal of Applied Mechanics-Transactions of the Asme Pub Date : 2023-10-26 DOI: 10.1115/1.4063896

Anh Tay Nguyen, Houlin Xu, Karel Matous, Zdenek P. Bazant

{"title":"Smooth Lagrangian Crack Band Model (slCBM) Based on Spress-Sprain Relation and Lagrange Multiplier Constraint of Displacement Gradient","authors":"Anh Tay Nguyen, Houlin Xu, Karel Matous, Zdenek P. Bazant","doi":"10.1115/1.4063896","DOIUrl":"https://doi.org/10.1115/1.4063896","url":null,"abstract":"Abstract A preceding 2023 study argued that the resistance of a heterogeneous material to the displacement field curvature is the physically most realistic localization limiter for softening damage. The curvature was characterized by the second gradient of the displacement vector field, which includes the material rotation gradient, and was named the ‘sprain’ tensor, while the term ‘spress’ is here proposed as the force variable work-conjugate to ‘sprain’. In this study, the computational obstacles using nodal sprain forces in the previous study are overcome by using finite elements with linear shape functions for both the displacement vector and for an approximate displacement gradient tensor. The actual gradient calculated from the nodal displacement vectors is constrained to the approximate gradient by means of a Lagrange multiplier tensor. The gradient tensor of the approximate gradient tensor then represents the third-order approximate displacement curvature tensor (or Hessian) of the displacement field. Importantly, the Lagrange multiplier behaves as an externally applied generalized moment density that, similar to gravity, does not affect the total strain-plus-sprain energy density of material. The conditions of stationary values of the total free energy of the structure with respect all these unknowns yields the set of equilibrium equations of the structure for each loading step. Examples of crack growth in fracture specimens are given. It is demonstrated that the simulation results are independent of the orientation of a regular square mesh, and capture the width variation of the crack band, and converge as the finite elements are refined.","PeriodicalId":54880,"journal":{"name":"Journal of Applied Mechanics-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134908717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

An electro-chemo-mechanical theory with flexoelectricity: application to ionic conductivity of soft solid electrolytes 柔性电的电化学力学理论:在软固体电解质离子电导率研究中的应用

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Journal of Applied Mechanics-Transactions of the Asme Pub Date : 2023-10-26 DOI: 10.1115/1.4063897

Anand Mathew, Yashashree Kulkarni

{"title":"An electro-chemo-mechanical theory with flexoelectricity: application to ionic conductivity of soft solid electrolytes","authors":"Anand Mathew, Yashashree Kulkarni","doi":"10.1115/1.4063897","DOIUrl":"https://doi.org/10.1115/1.4063897","url":null,"abstract":"Abstract Flexible batteries are gaining momentum in several fields, including wearable medical devices and biomedical sensors, flexible displays, and smartwatches. These energy storage devices are subjected to electro-chemo-mechanical effects. Here, we present a theoretical framework that couples electromechanical theory incorporating flexoelectricity with diffusion. As an example, we investigate the effect of flexoelectricity on the ionic conductivity in soft materials. Our analytical results for a thin film made of a soft material reveal that the ionic conductivity is significantly higher at the nanoscale and decreases exponentially to approach the bulk value with increasing film thickness. Furthermore, we find that flexoelectricity reduces the ionic conductivity dramatically at film thickness smaller than the length scale associated with flexoelectricity. This behavior is attributed to the opposite directions of polarization induced by flexoelectricity and the flow of ions driven by the chemical potential. These findings shed light on the interplay between flexoelectricity and diffusion which would be paramount in designing miniaturized energy storage devices.","PeriodicalId":54880,"journal":{"name":"Journal of Applied Mechanics-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134908086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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2022 Timoshenko Medal Acceptance Lecture: A Trip the Light Fantastic 2022年季莫申科奖牌获奖演讲:梦幻之旅

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Journal of Applied Mechanics-Transactions of the Asme Pub Date : 2023-10-20 DOI: 10.1115/1.4063864

Michael A. Sutton

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Probabilistic Bayesian approach for delamination localization in GFRP composites using nonlinear guided waves 基于非线性导波的GFRP复合材料分层定位概率贝叶斯方法

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Journal of Applied Mechanics-Transactions of the Asme Pub Date : 2023-10-17 DOI: 10.1115/1.4063503

Akhilendra Gangwar, D M Joglekar

{"title":"Probabilistic Bayesian approach for delamination localization in GFRP composites using nonlinear guided waves","authors":"Akhilendra Gangwar, D M Joglekar","doi":"10.1115/1.4063503","DOIUrl":"https://doi.org/10.1115/1.4063503","url":null,"abstract":"Abstract Nondestructive evaluation (NDE) techniques that use nonlinear wave–damage interactions have gained significant attention recently due to their improved sensitivity in detecting incipient damage. This study presents the use of finite element (FE) simulation with the experimental investigation to quantify the effects of guided waves’ propagation through multiple delaminations in unidirectional glass fiber-reinforced polymer (GFRP) composites. Further, it utilizes the outcomes of nonlinear interactions between guided waves and delaminations to locate the latter. This is achieved through probabilistic Bayesian updating with a structural reliability approach. Guided waves interacting with delaminations induce nonlinear acoustic signatures that can be quantified by the nonlinearity index (NLI). The study found that the NLI changes with the interrogation frequency, as confirmed by numerical and experimental observations. By using the numerical outcomes obtained from the nonlinear responses, a Bayesian model-based approach with subset simulation is proposed and subsequently used to locate multiple delaminations. The results indicate that both the log-likelihood and log-evidence are key factors in determining the localization phenomenon. The proposed method successfully localizes multiple delaminations and evaluates their number, interlaminar position, width, and type.","PeriodicalId":54880,"journal":{"name":"Journal of Applied Mechanics-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135945124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Automated Identification of Differential-Variational Equations for Static Systems 静态系统微分变分方程的自动辨识

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Journal of Applied Mechanics-Transactions of the Asme Pub Date : 2023-10-17 DOI: 10.1115/1.4063641

Chunjiang Li, Zhanchao Huang, Zhilong Huang, Yong Wang, Hanqing Jiang

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A two-stage magnetically enhanced buoyancy adjustment actuator based on dielectric elastomer 一种基于介电弹性体的两级磁力增强浮力调节驱动器

4区工程技术

Journal of Applied Mechanics-Transactions of the Asme Pub Date : 2023-10-16 DOI: 10.1115/1.4063399

Xunuo Cao, Jiangshan Zhuo, Weifeng Zou, Xinge Li, Dongrui Ruan, Xuxu Yang, Fanghao Zhou, Tiefeng Li

{"title":"A two-stage magnetically enhanced buoyancy adjustment actuator based on dielectric elastomer","authors":"Xunuo Cao, Jiangshan Zhuo, Weifeng Zou, Xinge Li, Dongrui Ruan, Xuxu Yang, Fanghao Zhou, Tiefeng Li","doi":"10.1115/1.4063399","DOIUrl":"https://doi.org/10.1115/1.4063399","url":null,"abstract":"Abstract The buoyancy adjustment capability is crucial for underwater robots. Dielectric elastomer (DE) is promising to be designed as inflatable actuators to achieve quiet, fast, and effective buoyancy adjustment. However, the buoyancy adjustment of DE actuators is limited by voltage amplification and controllability. This paper presents to solve the limitation of the DE buoyancy adjustment actuator by magnetic enhancement. An actuator is designed with a two-stage buoyancy adjustment capability. The two-stage adjustment strategy allows the actuator to achieve higher buoyancy adjustment at low voltage and controllable buoyancy adjustment at high voltage, where the switch between the two stages is achieved by tuning the snap of the magnet. A theoretical model is developed to assess the performance of the actuator in the two stages and describe the snap behavior. The experiment results agree with the simulation, and the actuator demonstrates the ability to adjust attitude by changing buoyancy at high voltages and rapidly ascending at low voltages. The multiple buoyancy adjustment capabilities of this actuator have the potential to enable the underwater robot to fulfill various complex task demands.","PeriodicalId":54880,"journal":{"name":"Journal of Applied Mechanics-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136077385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Analytical solution for the bending problem of micropolar plates based on the symplectic approach 基于辛方法的微极板弯曲问题解析解

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Journal of Applied Mechanics-Transactions of the Asme Pub Date : 2023-10-16 DOI: 10.1115/1.4063398

Qiong Wu, Long Chen, Qiang Gao

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Perspective: Machine learning in design for 3D/4D printing 视角:3D/4D打印设计中的机器学习

4区工程技术

Journal of Applied Mechanics-Transactions of the Asme Pub Date : 2023-10-05 DOI: 10.1115/1.4063684

Xiaohao Sun, Kun Zhou, Frederic Demoly, Ruike Renee Zhao, H. Jerry Qi

{"title":"Perspective: Machine learning in design for 3D/4D printing","authors":"Xiaohao Sun, Kun Zhou, Frederic Demoly, Ruike Renee Zhao, H. Jerry Qi","doi":"10.1115/1.4063684","DOIUrl":"https://doi.org/10.1115/1.4063684","url":null,"abstract":"Abstract 3D/4D printing offers significant flexibility in manufacturing complex structures with a diverse range of mechanical responses, while also posing critical needs in tackling challenging inverse design problems. The rapidly developing machine learning (ML) approach offers new opportunities and has attracted significant interest in the field. In this perspective paper, we highlight recent advancements of utilizing ML for designing printed structures with desired mechanical responses. First, we provide an overview of common forward and inverse problems, relevant types of structures, and design space and responses in 3D/4D printing. Second, we review recent works that have employed a variety of ML approaches for the inverse design of different mechanical responses, ranging from structural properties to active shape changes. Finally, we briefly discuss the main challenges, summarize existing and potential ML approaches, and extend the discussion to broader design problems in the field of 3D/4D printing. This paper is expected to provide foundational guides and insights into the application of ML for 3D/4D printing design.","PeriodicalId":54880,"journal":{"name":"Journal of Applied Mechanics-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134976039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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