European Journal of Mechanics A-Solids最新文献_第9页

Buckling of micromorphic Timoshenko columns

IF 4.4 2区工程技术

European Journal of Mechanics A-Solids Pub Date : 2024-12-18 DOI: 10.1016/j.euromechsol.2024.105537

N. Challamel , S. El-Borgi , M. Trabelssi , J.N. Reddy

{"title":"Buckling of micromorphic Timoshenko columns","authors":"N. Challamel , S. El-Borgi , M. Trabelssi , J.N. Reddy","doi":"10.1016/j.euromechsol.2024.105537","DOIUrl":"10.1016/j.euromechsol.2024.105537","url":null,"abstract":"<div><div>This paper presents exact solutions for the buckling of a micromorphic Timoshenko column under general boundary conditions. The shear effect is introduced through Engesser’s shear column theory.This problem can also be formulated as a nonlocal strain gradient Timoshenko column that uses nonlocal kernels for both the strain (curvature and shear strain for the Timoshenko beam) and its derivative. It is shown that both models yield the same governing equations but differ in potential energy definiteness. The micromorphic model predicts hardening effects, while the nonlocal strain gradient model captures both softening and hardening. The buckling problem is formulated as an eighth-order differential eigenvalue problem, associated with eight variationally-consistent boundary conditions. Analytical buckling solutions are obtained for various boundary conditions using Cardano’s method. Closed-form solutions of the buckling load may also be obtained for some specific boundary conditions, including the higher-order nonlocal boundary conditions. The role of variationally-consistent higher-order boundary conditions is specifically addressed. The softening or stiffening contributions of the small length-scale terms are discussed for all the considered boundary conditions, including simply-supported, clamped-free, clamped–clamped, and clamped-simply-supported cases. The role of shear contribution is also analyzed for this micromorphic Engesser–Timoshenko column.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105537"},"PeriodicalIF":4.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136221","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

The snap-through actuation and the dynamic regimes of the morphing bistable laminate-MFC assembly

IF 4.4 2区工程技术

European Journal of Mechanics A-Solids Pub Date : 2024-12-18 DOI: 10.1016/j.euromechsol.2024.105544

Ting Dong , Dongxing Cao , Wensai Ma , Ting Li , Xin Jiang , Ketian Li

{"title":"The snap-through actuation and the dynamic regimes of the morphing bistable laminate-MFC assembly","authors":"Ting Dong , Dongxing Cao , Wensai Ma , Ting Li , Xin Jiang , Ketian Li","doi":"10.1016/j.euromechsol.2024.105544","DOIUrl":"10.1016/j.euromechsol.2024.105544","url":null,"abstract":"<div><div>This paper elaborates on a morphing bistable laminate-macro fiber composite (MFC) assembly with four simply-supported corners. The potential energy curve, featuring two wells and a barrier, is graphically depicted. Due to the added stiffness from the MFC, the two wells become asymmetric, significantly affecting snap-through actuation and dynamic behavior. The static snap-through, driven by a single MFC, is unidirectional unless MFCs are installed on both the upper and lower surfaces of the assembly. Under small excitation amplitudes, the dynamic regimes are governed by single-well vibrations, with frequency-amplitude response curves displaying linear characteristics corresponding to modes. As excitation amplitude increases, the response curves exhibit a softening nonlinear stiffness effect, with hysteresis apparent due to sweep directions. The snap-through regimes during forward frequency sweeps display limit-cycle oscillations and chaotic snap-through, while backward sweeps reveal limit-cycle oscillations, multi-period snap-through, and chaotic snap-through. The dynamic regimes correlate with mode frequencies, with chaotic snap-through occurring at or near the reduced resonance frequency. Limit-cycle oscillations during backward sweeps are observed near low and high mode frequencies on both sides of the reduced resonance frequency. The bandwidth of each dynamic regime expands with increased actuation amplitude. The MFC induces both transversal and parametric excitations, leading to deviations from conventional predictions where bistable structures are actuated solely by transversal excitations.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105544"},"PeriodicalIF":4.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512196","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 propagation of axisymmetric guided waves in cylindrical rods based on fractional order thermo-visco-elastic model

IF 4.4 2区工程技术

European Journal of Mechanics A-Solids Pub Date : 2024-12-17 DOI: 10.1016/j.euromechsol.2024.105541

Lina Zhao, Peijun Wei

引用次数: 0

Analytical solutions of film/substrate structure with film bending under elastic boundary and bifurcation deformation analysis

IF 4.4 2区工程技术

European Journal of Mechanics A-Solids Pub Date : 2024-12-17 DOI: 10.1016/j.euromechsol.2024.105538

Kunjie Sun , Jubing Chen , Chen Sun

{"title":"Analytical solutions of film/substrate structure with film bending under elastic boundary and bifurcation deformation analysis","authors":"Kunjie Sun , Jubing Chen , Chen Sun","doi":"10.1016/j.euromechsol.2024.105538","DOIUrl":"10.1016/j.euromechsol.2024.105538","url":null,"abstract":"<div><div>Axisymmetric film/substrate systems are indispensable in many applications due to their unique structural requirements. Stoney’s formula is widely utilized for analyzing such systems. The existing theories have relaxed the limitations of the Stoney’s formula, but mainly assume that the film thickness can be neglected. This work proposes the theoretical solution of axisymmetric film/substrate structure with elastic boundary considering film bending under non-uniform temperature field. Parameterization and method of constant variation are used to decouple and determine the governing equations. Finite element method validates the influence of elastic support on the stress in each layer of the film. It is found that the boundary supports exert an anti-bending effect on the film. The two-stage calibration method is employed, wherein the first step determines the linear relationships between surface deflection and the deflections of both the film and the substrate, while the second step establishes the linear coefficients and their dependence on material properties. Then the stress inverse solutions for arbitrary specified normal distributions of temperature fields are provided. The curvature bifurcation of the surface deformation from an equi-biaxial spherical shape to a non-equi-biaxial elliptical shape is analyzed using the energy method and variational principle. As the thickness ratio of the film to the substrate increases, higher thermal strain energy is required to reach a critical state of curvature. And it is found that the surface deformation would exhibit a hyperbolic shape as the temperature continued to increase.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105538"},"PeriodicalIF":4.4,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136290","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

In silico actuation performance investigation of dielectric elastomers with TPMS geometries

IF 4.4 2区工程技术

European Journal of Mechanics A-Solids Pub Date : 2024-12-15 DOI: 10.1016/j.euromechsol.2024.105540

Mohammad Ali Safaei , Mostafa Baghani , Majid Baniassadi , Mahdi Bodaghi

{"title":"In silico actuation performance investigation of dielectric elastomers with TPMS geometries","authors":"Mohammad Ali Safaei , Mostafa Baghani , Majid Baniassadi , Mahdi Bodaghi","doi":"10.1016/j.euromechsol.2024.105540","DOIUrl":"10.1016/j.euromechsol.2024.105540","url":null,"abstract":"<div><div>Dielectric Elastomer Actuators (DEAs) are highly efficient soft actuators widely used in soft robotics and artificial muscles due to their superior actuation capabilities. Introducing two-phase structures to DEAs offers potential benefits, particularly in reducing operational voltages. However, this approach poses significant challenges due to both physical and numerical constraints. This study investigates the distinctive actuation performance of two-phase microstructure DEAs, designed using a class of architected materials known as Triply Periodic Minimal Surfaces (TPMS), and compares them with Random Heterogeneous Microstructures. Six well-known TPMS geometries, including Gyroid, Schwarz-P, and IWP structures, are employed. In addition to actuation performance, localized electric fields and blocking forces are analyzed for all microstructures to provide a comprehensive understanding of their behavior. The quasi-static, fully coupled governing equations of DEAs are implemented in ABAQUS software using a reliable in-silico FEM approach. The results reveal that DEAs based on TPMS geometries exhibit intrinsic advantages over their random counterparts in terms of actuation performance. Notably, the microstructure named Octo demonstrates the highest improvement, showing a 9.9% increase in actuation performance compared to Random Microstructures. However, this trend is reversed with respect to blocking forces, where Random Microstructures exhibit higher values. The analysis of localized electric fields indicates that both TPMS- and Random-based microstructures have the potential to offer relatively low localized fields. These findings represent a preliminary step toward the development of multi-phase DEA composites with architected geometries.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105540"},"PeriodicalIF":4.4,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136289","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 analyses of pentamodes metamaterials behavior under harmonic loading conditions

IF 4.4 2区工程技术

European Journal of Mechanics A-Solids Pub Date : 2024-12-12 DOI: 10.1016/j.euromechsol.2024.105536

P.N. Lymperopoulos, E.E. Theotokoglou

引用次数: 0

Tensile strength prediction of fiber-reinforced polymer composites through layered interphase and chemical bonding: A semi-empirical micromechanical model

IF 4.4 2区工程技术

European Journal of Mechanics A-Solids Pub Date : 2024-12-12 DOI: 10.1016/j.euromechsol.2024.105533

Jesus A. Rodriguez-Morales , Chentong Gao , Huiyu Sun

{"title":"Tensile strength prediction of fiber-reinforced polymer composites through layered interphase and chemical bonding: A semi-empirical micromechanical model","authors":"Jesus A. Rodriguez-Morales , Chentong Gao , Huiyu Sun","doi":"10.1016/j.euromechsol.2024.105533","DOIUrl":"10.1016/j.euromechsol.2024.105533","url":null,"abstract":"<div><div>Fiber-reinforced polymer composites (FRPC) are essential for high-performance applications. However, concerns about their reliability persist owing to their heterogeneous structure across multiple length scales and the critical role of interphases in controlling their performance. In this article, we introduce a semi-empirical micromechanical model that quantitatively considers the impact of chemical treatments on improving interfacial adherence without relying on the Interfacial Shear Strength (IFSS), which is commonly known for posing challenges in characterization. The model predictions across a wide range of FRPC systems are validated against experimental data from the literature, indicating its reasonability and accuracy. Moreover, we analyze the role of parameters affecting fiber–matrix interphase performance, along with a comparison between the Kelly–Tyson model and the modified rule of mixtures. This article provides a simple, practical, and accurate approach to estimating the tensile strength of composite polymer systems and offers insights into the complex role of interphases in overall performance.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105533"},"PeriodicalIF":4.4,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136287","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

Vibration attenuation of metamaterial dual-beam with simultaneous acoustic black hole and local resonator

IF 4.4 2区工程技术

European Journal of Mechanics A-Solids Pub Date : 2024-12-10 DOI: 10.1016/j.euromechsol.2024.105535

Yunrui Han , Xinhua Chen , Yuhua Wei , Shuai Jiang , Cong Du , Guoqing Jiang , Han Zhang

{"title":"Vibration attenuation of metamaterial dual-beam with simultaneous acoustic black hole and local resonator","authors":"Yunrui Han , Xinhua Chen , Yuhua Wei , Shuai Jiang , Cong Du , Guoqing Jiang , Han Zhang","doi":"10.1016/j.euromechsol.2024.105535","DOIUrl":"10.1016/j.euromechsol.2024.105535","url":null,"abstract":"<div><div>In this work, a metamaterial dual-beam (MDB) structure with simultaneous acoustic black hole (ABH) and local resonator (LR) is proposed for achieving broadband vibration reduction effects in low frequency range. The MDB consists of periodically arranged dual-beam unit cells, with each unit cell comprising two upper wedge-shaped acoustic black hole beams, two lower wedge-shaped acoustic black hole beams, and spring-mass-spring resonators connecting the upper and lower beams. The dynamic stiffness matrix of the dual-beam is derived and calculated, followed by the calculation of the frequency response under initial excitation. The analysis reveals distinct local resonance band gaps and Bragg scattering band gaps in the frequency response. Finite element method simulations are conducted, showing good agreement between the frequency response curves and dispersion curves. Moreover, the coupling relationship between the local resonance band gaps and Bragg band gaps was investigated. In essence, significant vibration reduction effects in the ultra-low frequency range have been achieved. To study the effects of beam height, beam length, and spring stiffness on the band gaps, parameter analyses are conducted. Moreover, models of multi-span beams are examined, revealing ultra-low frequency band gaps starting from 0 Hz. This study offers guidance in dual-beam structures at broadband vibration reduction effects in low frequency range.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105535"},"PeriodicalIF":4.4,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136207","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

A dual-variable influence function based ring-core method for residual stress prediction at small scales

IF 4.4 2区工程技术

European Journal of Mechanics A-Solids Pub Date : 2024-12-10 DOI: 10.1016/j.euromechsol.2024.105526

Kai Guo , Jianfei Huang , Zhen Zhang

{"title":"A dual-variable influence function based ring-core method for residual stress prediction at small scales","authors":"Kai Guo , Jianfei Huang , Zhen Zhang","doi":"10.1016/j.euromechsol.2024.105526","DOIUrl":"10.1016/j.euromechsol.2024.105526","url":null,"abstract":"<div><div>Understanding the fundamental origins of mechanical failure demands accurate residual stress evaluation at microscale. This makes small scale strain relief based residual stress quantification considerably promising. Single-variable influence function based FIB-DIC ring-core procedure is a competitive residual stress measurement method, especially suitable for small-scale residual stress prediction. The method has been widely used in residual stress assessment of additive manufacturing and welding structure. However, the performance of original single-variable influence function based method becomes unsatisfactory under high stress gradient. In addition, previous work fails to emphasize the uncertainties due to measurement noise, although the accuracy and stability of the method are sensitive to the noise. The solution algorithm of residual stress exhibits significant fluctuations in the presence of measurement noise.</div><div>This study proposes a dual-variable influence function to predict residual stress at small scales. This will allow informatively characterizing the relationship between strain relief and eigenstrain. Then, a calibration method of dual-variable influence function is proposed based on the variable separation approach. Compared with original single-variable influence function based method, the proposed method performs encouragingly well by reducing the error considerably to 12%, and increasing the effective measurement range by 7 times when predicting the residual stress with high gradient. In addition, a solution algorithm is proposed based on Tikhonov regularization to deal with measurement noise induced evaluation uncertainties, the regularization algorithm further promotes the solution stability.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105526"},"PeriodicalIF":4.4,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136211","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

A new drop weight tensile testing system for soft matter at intermediate strain rates

IF 4.4 2区工程技术

European Journal of Mechanics A-Solids Pub Date : 2024-12-09 DOI: 10.1016/j.euromechsol.2024.105507

Juan Carlos Nieto-Fuentes , Adeline Wihardja , Paul Stovall , Trent Wilson , Kaushik Bhattacharya , Daniel Rittel

{"title":"A new drop weight tensile testing system for soft matter at intermediate strain rates","authors":"Juan Carlos Nieto-Fuentes , Adeline Wihardja , Paul Stovall , Trent Wilson , Kaushik Bhattacharya , Daniel Rittel","doi":"10.1016/j.euromechsol.2024.105507","DOIUrl":"10.1016/j.euromechsol.2024.105507","url":null,"abstract":"<div><div>This paper presents a novel and versatile tensile testing system based on the drop weight technique, specifically designed for materials that can undergo significant tensile deformation, such as elastomers. The core apparatus comprises of a hanging slender bar, from which a steel sleeve (referred to as the striker) is released under controlled conditions. Accelerated in free fall, the striker impacts a stationary plate, initially held in place by a mechanical detent. The specimen, secured by a gripping system between the hanging bar and the stationary support, undergoes controlled stretching at a nearly constant velocity upon the release of the detent triggered by the striker’s impact. Full-field strain measurement is obtained using a high-speed camera in conjunction with digital image correlation. Additionally, strategically located piezoresistive force sensors enable real-time force measurements. By achieving strain rates ranging from 100 s<sup>−1</sup> to 500 s<sup>−1</sup>, this system addresses a notable gap in the literature concerning intermediate strain rate testing for soft materials.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105507"},"PeriodicalIF":4.4,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136205","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