Mechanics Research Communications最新文献

{"title":"Transformation of surface H-forces in high grade elasticity","authors":"","doi":"10.1016/j.mechrescom.2024.104331","DOIUrl":"10.1016/j.mechrescom.2024.104331","url":null,"abstract":"<div><p>The expression of the elastic energy, postulated for a given material, specifies through the principle of virtual work which external loadings turn out to be admissible. For the elastic bodies, the energy of which depends on the gradients of the placement higher than <span><math><mrow><mo>(</mo><mi>H</mi><mo>+</mo><mn>1</mn><mo>)</mo></mrow></math></span> (or, equivalently, on the derivatives of the deformation gradient higher than <span><math><mi>H</mi></math></span>), external force densities can be prescribed over the boundary surface, which do work on the <span><math><mi>H</mi></math></span>-th derivative of the virtual displacements along the normal direction. Such generalized forces with <span><math><mrow><mi>H</mi><mo>=</mo><mn>1</mn><mo>,</mo><mn>2</mn><mspace></mspace></mrow></math></span> have been dealt with in the literature, referred to as <em>double</em> and <em>triple forces</em>: when <span><math><mi>H</mi></math></span> is increased, however, the analytical evaluation of these work terms may become prohibitive. Each Eulerian <span><math><mi>H</mi></math></span>-force density of this kind, acting on the current boundary surface, turns out to be equivalent to a set of diverse actions defined in the Lagrangian configuration. These actions include: (i) surface terms doing work on the virtual displacement vector; (ii) surface terms doing work on the higher order derivatives of the virtual displacement along the normal direction; (iii) edge terms, doing work on the virtual displacement or on its higher order gradients, which may be further reduced. In this study, a recursive algorithm is utilized to generate all these Lagrangian contributions for any <span><math><mi>H</mi></math></span>. Such an approach rests on the binomial expansion of the tensor products of complementary surface projectors, symmetrized in the work duality, and on the integration by parts combined with the generalized divergence theorem.</p></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0093641324000910/pdfft?md5=b956b1a0e91599b0aca7aa16be779ade&pid=1-s2.0-S0093641324000910-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142240970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of circumferential SH-wave interaction with a piezoelectric cylinder having pre-stressed viscoelastic imperfect coating","authors":"","doi":"10.1016/j.mechrescom.2024.104323","DOIUrl":"10.1016/j.mechrescom.2024.104323","url":null,"abstract":"<div><p>In this study, the circumferential interaction behaviour of the SH-wave with a piezoelectric cylinder coated with a viscoelastic material is investigated. The coating interface is imperfect and the viscoelastic material is subjected to pre-stress. By applying mathematical methods to the dynamical governing equations, expressions for displacement components and electric potential is obtained. Utilizing the set of boundary conditions, dispersion and damping equations are established for this model. The impacts of perfect &amp; imperfect interfaces, piezoelectric &amp; dielectric constants, initial stress, dissipation factor, attenuation coefficient and radial thickness ratio of materials on the phase and damped velocities of SH-wave are observed by numerical examples and graphical visuals.</p></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142163707","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}

{"title":"Hybrid finite element theory in dynamic analysis of an imperfect plate","authors":"","doi":"10.1016/j.mechrescom.2024.104324","DOIUrl":"10.1016/j.mechrescom.2024.104324","url":null,"abstract":"<div><p>This paper presents a comprehensive vibrational analysis of geometrically imperfect plate under various boundary conditions. To achieve this, an approach combining the finite element method and Sanders’ shell theory is adopted to develop a mathematical model the plate, considering the displacements in form of polynomial functions. The elementary mass and stiffness matrices required for the finite element method are obtained by analytical integration for a single element, thereby enabling the dynamic equations for an entire homogeneous flat plate without needing to determine all the matrices for each individual element of the plate. The modal study specifically focuses on a thin, isotropic, elastic, and homogeneous plate. This study includes the numerical examples to evaluate the accuracy and convergence characteristics of the proposed finite element model. The analysis examines the influence of various parameters such as mechanical properties, boundary conditions, and different imperfection amplitude on the free vibration characteristics of the plate. The comparison between the experimental and theoretical results reveals a significant agreement. Furthermore, the results highlight an increase in the natural frequencies of the structure due to the presence of initial imperfections. Additionally, the theory accurately describes the dynamic behavior of the plate when the imperfection amplitude is less than, equal to or greater than the thickness of the plate.</p></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0093641324000843/pdfft?md5=e9510ba2bc1fe0a0467ebe09de9c23db&pid=1-s2.0-S0093641324000843-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142158214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evolutional behavior of viscoelastic materials: A formulation based on logarithmic approach","authors":"","doi":"10.1016/j.mechrescom.2024.104322","DOIUrl":"10.1016/j.mechrescom.2024.104322","url":null,"abstract":"<div><p>In this paper, a new formulation for large deformation of visco-elastometic materials is derived. The formulation is based on logarithmic strain, and the internal variable is defined as the viscous part of the logarithmic strain. A derivation of thermodynamically consistent formulation for visco-elastomeric materials is provided. The evolution equation which is related to the deviatoric part of the strain for viscoelastic formulation is solved by the implicit trapezoidal integration rule which leads to a recursive relation.</p></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S009364132400082X/pdfft?md5=abb09322c2ab131d2f7e94a767fde829&pid=1-s2.0-S009364132400082X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142149147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flexoelectric anisotropy and shear contributions in lead-free piezocomposites","authors":"","doi":"10.1016/j.mechrescom.2024.104321","DOIUrl":"10.1016/j.mechrescom.2024.104321","url":null,"abstract":"<div><p>Flexoelectricity is the coupling between strain gradients and electric fields. This phenomenon can significantly enhance piezocomposite response in addition to linear piezoelectricity. This enhancement is especially important for lead-free piezocomposites, which generally underperform compared to lead-based counterparts. Flexoelectric enhancement is facilitated by structural anisotropy in piezocomposites. However, challenges in modeling flexoelectric effects arise from several unknowns. Firstly, the shear flexoelectric coefficient is not well-characterized experimentally. Secondly, significant discrepancies exist between theoretical predictions and experimental measurements of flexoelectric coefficients. Thirdly, the influence of matrix mechanical properties on flexoelectric behavior is poorly understood. To address these issues, we construct a parametric flexoelectric model of a lead-free piezocomposite with graded inclusion concentration. We then systematically analyze the impact of each parameter to identify which significantly influence flexoelectric behavior. This study is intended to provide direction to further experimental studies towards understanding and tailoring this subset of parameters.</p></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0093641324000818/pdfft?md5=2e7cbfe9a01c6ebc3b748b3153a80404&pid=1-s2.0-S0093641324000818-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142129992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding and phenomenological modeling of the pinching effect of the load–deflection curve of reinforced concrete beams subjected to bending","authors":"","doi":"10.1016/j.mechrescom.2024.104318","DOIUrl":"10.1016/j.mechrescom.2024.104318","url":null,"abstract":"<div><p>The reliable prediction of the seismic response of reinforced concrete (RC) structures hinges on accurate modeling of the cyclic behavior of their constituent elements. The load–deflection curve in RC beams exhibits a pinched hysteresis pattern corresponding to energy dissipations. This pinching effect, often observed under seismic loading conditions, reflects a reduction in stiffness and energy dissipation capacity at certain loading stages. Despite its significance, the detailed mechanisms underlying this phenomenon remain underexplored in existing literature. This paper aims to address this gap by presenting simplified models that directly represents the pinching effect at the crack scale. The model is grounded in a comprehensive analysis of shear stress interactions and crack closure dynamics, hypothesized as primary contributors to the pinching phenomenon. Our approach involves a meticulous examination of the hysteresis loops’ area and shape, facilitating the estimation of an equivalent viscous damping ratio to represent energy dissipation in seismic simulations, irrespective of changes in the structure’s damage or ductility levels. The paper unfolds in three key sections: The first section underscores the significance of a nuanced understanding of the pinching effect in seismic analysis. The second section presents an extensive literature review, consolidating crucial insights into the nature of the pinching phenomenon. The third section details the development and application of the proposed mesoscopic model, highlighting the impact of various geometrical and material parameters on the pinching effect.</p></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142044328","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}

{"title":"The history and the current state of the art related to structures under stress and corrosion","authors":"","doi":"10.1016/j.mechrescom.2024.104320","DOIUrl":"10.1016/j.mechrescom.2024.104320","url":null,"abstract":"<div><p>The paper deals with the current state of the art arising in the design of the structures, operating under traditional mechanical loading in the aggressive environment causing their corrosion. The express goal in this case is establishing the corrosion rate dependence on the stress state of the structure and considering its durability. Thus, the use of basic mathematical models that describe the effect of corrosion rate depending on the stress state of the structure is considered. The main objective of this paper is to provide a review of useful approximations that have been suggested to deal with interaction of stress and corrosion fields. The first model that considers such a relationship is the Dolinsky model, which uses a linear dependence of the stress effect on the corrosion rate. Additionally, the Gutman model, in which the dependence of the corrosion rate on stress is expressed by an exponential law, is considered. When constructing mathematical models of structures’ corrosion wear, it is also necessary to take into account the protective coatings operation and determine the incubation period duration, which is the durability of the applied protective coatings. In this regard, the use of one of these models, which takes into account the decrease in the polymer coatings’ protective properties and a combined approach to accounting for corrosion and the anti-corrosion coatings’ protective properties are presented. Determining their reliability is an equally important aspect in the design of structures subject to corrosion. Therefore, the main theories of reliability and their practical application were considered on specific examples. A characteristic feature of the work is the coverage of issues related to the optimal design of structures operating in corrosion conditions. Two classes of problems were studied. First, determining the optimal form of structures under various types of mechanical loading and the use of the above corrosion models is considered. In the second class, the use of promising optimization models related to the solution of multi-criteria problems (using the fuzzy sets theory), as well as models with a pronounced economic bias, which allow making a cost estimate of structures failure-free operation during their lifetime, is considered. This article's novelty consists of preparing a comprehensive review of the interaction of stress and corrosion conditions. Researchers are deemed to greatly benefit from knowing the existing literature along with their strengths and weaknesses.</p></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141997980","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}

{"title":"Drag of Rankine bodies embedded in porous media at small Darcy numbers","authors":"","doi":"10.1016/j.mechrescom.2024.104319","DOIUrl":"10.1016/j.mechrescom.2024.104319","url":null,"abstract":"<div><p>This paper studies the flow over a solid inclusion embedded in a porous medium of low permeability. We study Rankine bodies which represent circular cylinders and spheres when the aspect ratio is one, and thin plates and almost uniform rods when the aspect ratio is small. Using boundary layer theory, the flow field and pressure distribution are determined. It is found that the pressure drag dominates the shear drag except for small aspect ratios. Thus, geometry plays a decisive role in the choice of using the Darcy equation or the Darcy-Brinkman equation. The results are important for the determination of flow resistance of a non-homogeneous porous medium which has solid inclusions.</p></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142076682","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}

{"title":"A modified dynamic relaxation form-finding method for symmetrical tensegrity structures with group theory and fuzzy clustering","authors":"","doi":"10.1016/j.mechrescom.2024.104310","DOIUrl":"10.1016/j.mechrescom.2024.104310","url":null,"abstract":"<div><p>For tensegrity structures, there are many groups of cables and bars with symmetrical structures or similar internal forces. In this paper, an application of a fuzzy clustering algorithm in the context of form-finding processes for symmetric tensegrity structures is proposed. This algorithm aims to automate grouping, optimize form-finding strategies, and expedite convergence. Point sets are generated through the segmentation of structural components, and Hausdorff distance is used to extract spatial features. Following this, fuzzy clustering automatically groups components with geometric symmetry. The resultant clustering matrix facilitates the refinement of form-finding processes, thus reducing the computational load associated with solving the equilibrium matrix for internal forces within tensegrity structures. By clustering components with analogous internal forces, computational efficiency is enhanced. Additionally, this methodology refines numerical form-finding outcomes based on symmetrical attributes, improving form-finding precision.</p></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141930303","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}

{"title":"An enhanced multiaxial low-cycle fatigue life model","authors":"","doi":"10.1016/j.mechrescom.2024.104309","DOIUrl":"10.1016/j.mechrescom.2024.104309","url":null,"abstract":"<div><p>To improve the accuracy of predicting multiaxial fatigue life, an enhanced multiaxial low-cycle fatigue life model is proposed based on the FS model. This model introduces a correction parameter for the stress-related term to consider the influence of normal stress and shear stress on the critical plane. The feasibility of the model is investigated, and it is validated using fatigue test data from eight different materials. The results indicate that the proposed model is applicable for both symmetric and asymmetric loading conditions under constant amplitude loading, with highly accurate fatigue life prediction results.</p></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141838868","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}