Continuum Mechanics and Thermodynamics最新文献_第2页

Stability of rectangular bar with distributed dislocations 分布位错矩形杆的稳定性

IF 1.9 4区工程技术

Continuum Mechanics and Thermodynamics Pub Date : 2025-03-27 DOI: 10.1007/s00161-025-01377-w

Evgeniya V. Goloveshkina, Leonid M. Zubov

{"title":"Stability of rectangular bar with distributed dislocations","authors":"Evgeniya V. Goloveshkina, Leonid M. Zubov","doi":"10.1007/s00161-025-01377-w","DOIUrl":"10.1007/s00161-025-01377-w","url":null,"abstract":"<div><p>The problem of the influence of distributed dislocations on the equilibrium stability of a rectangular bar loaded with a longitudinal force is investigated. In the subcritical (unperturbed) state, the body experiences a finite plane inhomogeneous deformation. The dislocation density tensor depends on the coordinate measured along the bar thickness and has only one nonzero component corresponding to the distribution of edge dislocations. Within the framework of the compressible semilinear material model, the unperturbed state is defined as an exact solution to the equations of the nonlinear continuum theory of dislocations. Stability analysis is performed using the Euler bifurcation method, which consists in finding nontrivial solutions to the linearized homogeneous boundary value problem of the equilibrium of a prestressed elastic body. The influence of different types of dislocation distribution on the critical values of the longitudinal force and the form of stability loss of the bar is studied. It is established, in particular, that dislocations significantly affect the number of waves along the length of the bar, characterizing the form of stability loss.</p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"37 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143717047","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

Exact hydrodynamic manifolds for the linear Boltzmann BGK equation II: spectral closure 线性Boltzmann BGK方程的精确流体动力流形II：谱闭包

IF 1.9 4区工程技术

Continuum Mechanics and Thermodynamics Pub Date : 2025-03-25 DOI: 10.1007/s00161-025-01379-8

Florian Kogelbauer, Ilya Karlin

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Visual tracking of plate compactor trajectories and soil compaction through metamaterial-inspired approach 通过超材料启发方法对板式压实机轨迹和土壤压实进行视觉跟踪

IF 1.9 4区工程技术

Continuum Mechanics and Thermodynamics Pub Date : 2025-03-21 DOI: 10.1007/s00161-025-01374-z

A. Kwaśniewski, S. Bak, P. Ciężowski, L. Knap, J. Maciejewski, M. Bialas, M. Spagnuolo

引用次数: 0

Compatibility equations, generalized Cesaro’s equations and expansion effects of spacetime 相容方程，广义Cesaro方程和时空的膨胀效应

IF 1.9 4区工程技术

Continuum Mechanics and Thermodynamics Pub Date : 2025-03-18 DOI: 10.1007/s00161-025-01370-3

P. Belov, S. Lurie

{"title":"Compatibility equations, generalized Cesaro’s equations and expansion effects of spacetime","authors":"P. Belov, S. Lurie","doi":"10.1007/s00161-025-01370-3","DOIUrl":"10.1007/s00161-025-01370-3","url":null,"abstract":"<div><p>A kinematic model of 4D continuum with different types of symmetry is introduced and a unified kinematic model of long-range electromagnetic and gravitational fields is proposed. We define the 4D vector potential, introduce 4D distortion tensor, and show that its antisymmetric part gives the classical definition of the electric field intensity vector and the pseudovector of magnetic induction. On the other hand, the symmetric part of the distortion tensor is interpreted as the gravitational field intensity. The structure of the gravitational field kinematic model is analyzed. For the 4D continuum, generalized compatibility equations are established including homogeneous Papkovich and Saint-Venant relations. It is shown that homogeneous Saint-Venant relations can be also integrated in quadrature’s respect to the 4D spherical deformation tensor, which can be defined through an integro-differential operator applied only to the components of the deviator tensor. We show that 4D Cesaro equations indicate the existence of two kinematic states in the spacetime in the absence of the strain deviator tensor. The first kinematic state proves the existence of an expansion metric effect of the 4D continuum since the speed of the observed point is always proportional to the distance to it. The second kinematic state indicates a purely geometric effect of uniformly accelerated expansion of event space.</p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"37 2","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638553","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

Analysis of stripe domains in nematic LCEs by means of a dynamic numerical framework 用动态数值框架分析向列LCEs的条纹域

IF 1.9 4区工程技术

Continuum Mechanics and Thermodynamics Pub Date : 2025-03-14 DOI: 10.1007/s00161-025-01376-x

Francesca Concas, Michael Groß

{"title":"Analysis of stripe domains in nematic LCEs by means of a dynamic numerical framework","authors":"Francesca Concas, Michael Groß","doi":"10.1007/s00161-025-01376-x","DOIUrl":"10.1007/s00161-025-01376-x","url":null,"abstract":"<div><p>Liquid crystal elastomers are a class of materials which shows unusual characteristics due to its dual nature, i.e. the orientational behavior of liquid crystals combined with the intrinsic features of elastomers. Apart from inhomogeneities, the mesogens, which are linked to the polymer chains in LCEs and are modeled as a unit nematic director, are oriented along a unique direction in case of a monodomain sample. Among other remarkable properties, LCEs exhibit a particular behavior under mechanical stretching, such as the semisoft elastic response and the onset of stripe domains in the originally monodomain sample under certain conditions. As observed in experiments, in a sample with stripe domains the mesogens of two adjacent stripes are rotated through the same angle but with opposite senses of rotation. We aim to reproduce the stripe domains in nematic LCEs under mechanical stretch and high strain rates by using a dynamic three-dimensional mixed finite element formulation, which is based on the usage of a mixed principle of virtual power, local drilling degrees of freedom for LCE-network and mesogens and frame-indifferent free energy density functions based on tensor invariants associated with the mixed fields.</p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"37 2","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00161-025-01376-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612337","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}

引用次数: 0

On the approximate schemes for the evaluation of the acoustic radiation by a thin elastic layer 用弹性薄层评价声辐射的近似格式

IF 1.9 4区工程技术

Continuum Mechanics and Thermodynamics Pub Date : 2025-03-12 DOI: 10.1007/s00161-025-01365-0

Julius Kaplunov, Ludmila Prikazchikova, Sheeru Shamsi

引用次数: 0

Modeling the kinetics of stress–strain state and damage accumulation in structural alloys under the mutual influence of fatigue and creep 建立了疲劳和蠕变共同作用下结构合金应力-应变状态和损伤积累动力学模型

IF 1.9 4区工程技术

Continuum Mechanics and Thermodynamics Pub Date : 2025-03-12 DOI: 10.1007/s00161-025-01371-2

L. A. Igumnov, I. A. Volkov, A. I. Yudintseva, A. I. Volkov

{"title":"Modeling the kinetics of stress–strain state and damage accumulation in structural alloys under the mutual influence of fatigue and creep","authors":"L. A. Igumnov, I. A. Volkov, A. I. Yudintseva, A. I. Volkov","doi":"10.1007/s00161-025-01371-2","DOIUrl":"10.1007/s00161-025-01371-2","url":null,"abstract":"<div><p>The corresponding mathematical model of cyclic viscoplastic deformation of damaged material, a structural element counteracting multiaxial disproportionate modes of hybrid thermomechanical loading, is considered. The model is determined by the relations between viscoplastic deformation and failure, as well as the evolution equations of damage accumulation kinetics and the material strength criterion. The description of viscoplastic deformation is based on the existence of plasticity and creep surfaces in the stress space and the principle of gradient of the velocity vectors of the corresponding deformations at the loading point. Such a description distinguishes the main effects of the cyclic behaviour of the material for complex loading trajectories. The description of kinetic damage accumulation is based on the scalar damage parameter. The formation, growth and coalescence of micro-defects are considered. A coupled formulation of the evolution equations for low-cycle fatigue and long-term strength is proposed. The condition that the damage value reaches a critical value is taken as the strength criterion. In the work, material parameters and scalar functions of the mathematical model are obtained. Based on the model, the results of the numerical simulation of the behaviour of the alloys are presented. It is shown that the model describes the durability of the materials with practical reliability.</p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"37 2","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143602099","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

A three-dimensional, continuum mechanical model for additively manufactured polyamide 12 增材制造聚酰胺12的三维连续力学模型

IF 1.9 4区工程技术

Continuum Mechanics and Thermodynamics Pub Date : 2025-03-11 DOI: 10.1007/s00161-025-01369-w

Dominik Hahne, Michael Johlitz, Alexander Lion

{"title":"A three-dimensional, continuum mechanical model for additively manufactured polyamide 12","authors":"Dominik Hahne, Michael Johlitz, Alexander Lion","doi":"10.1007/s00161-025-01369-w","DOIUrl":"10.1007/s00161-025-01369-w","url":null,"abstract":"<div><p>Polyamide 12 (PA12) is a semi-crystalline thermoplastic used in the automotive and aerospace industries due to its high resistance to chemicals and abrasion and its good thermal stability. The material can be processed with various manufacturing technologies, including selective laser sintering (SLS), which offers great potential for industrial production due to its excellent and reproducible mechanical properties and thus motivates a detailed understanding of the mechanical behavior. This paper presents an approach for modeling the mechanical behavior of selectively laser-sintered polyamide 12. A continuum mechanical model is developed based on a comprehensive temperature and velocity-controlled experimental program, and its parameters are identified. After presenting the test specimens developed in-house, which utilized the geometric freedom of the SLS process, the kinematic description of the test specimens and the digital image correlation technique used for this purpose are discussed. The experimental test results are then presented, which consist of relaxation tests and experiments with a constant strain rate at various temperatures. After the two material-theoretical approaches of linear viscoelasticity and endochronic plasticity have been presented, the material model is derived in three dimensions, and the parameters are identified.</p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"37 2","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143594771","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

Love wave scattering by an interface crack between an orthotropic layer and an isotropic half-space 正交各向同性层与各向同性半空间间界面裂纹对Love波的散射

IF 1.9 4区工程技术

Continuum Mechanics and Thermodynamics Pub Date : 2025-03-10 DOI: 10.1007/s00161-025-01375-y

Sourav Kumar Panja, Samim Alam, Subhas Chandra Mandal, Eduard-Marius Craciun

{"title":"Love wave scattering by an interface crack between an orthotropic layer and an isotropic half-space","authors":"Sourav Kumar Panja, Samim Alam, Subhas Chandra Mandal, Eduard-Marius Craciun","doi":"10.1007/s00161-025-01375-y","DOIUrl":"10.1007/s00161-025-01375-y","url":null,"abstract":"<div><p>This research investigates the scattering behavior of Love waves, also known as Q waves in seismology, induced by an interface crack between an orthotropic elastic layer and an isotropic elastic half-space where the orthotropic layer serves as a wave guide medium. The Dispersion relation and phase velocity have been obtained by using convenient boundary conditions for the Love wave propagation. Using the method of Fourier transform and integral equation, the study derives the conditions governing wave propagation and scattering phenomena in the interfaced medium. The expression of the most important fracture quantities, such as dynamic stress intensity factor (DSIF) and crack opening displacement (COD) have been obtained and demonstrated graphically. Results demonstrate the dependence of scattering characteristics on the material properties, crack dimensions, layer height and wave frequencies. The findings contribute to a deeper understanding of Love wave propagation in composite materials, with implications for non-destructive testing and evaluation of structural integrity in engineering applications.</p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"37 2","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00161-025-01375-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143583628","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}

引用次数: 0

Research on multi-oscillator locally resonant seismic metamaterials and the uniform and gradient design for broadband Rayleigh wave attenuation 多振子局部共振地震超材料研究及宽带瑞利波衰减均匀梯度设计

IF 1.9 4区工程技术

Continuum Mechanics and Thermodynamics Pub Date : 2025-03-09 DOI: 10.1007/s00161-025-01368-x

Weikai Xu, Hongyang Sun, Hong Hai, Wei Wang, Chunli Zhou

{"title":"Research on multi-oscillator locally resonant seismic metamaterials and the uniform and gradient design for broadband Rayleigh wave attenuation","authors":"Weikai Xu, Hongyang Sun, Hong Hai, Wei Wang, Chunli Zhou","doi":"10.1007/s00161-025-01368-x","DOIUrl":"10.1007/s00161-025-01368-x","url":null,"abstract":"<div><p>The dimensions of seismic metamaterials pose limitations that make attenuating ultra-low frequency seismic surface waves (with a starting frequency near 0 Hz) in confined spaces through structural design a significant challenge. This paper introduces a locally resonant seismic metamaterial (SM) characterized by an ultra-low frequency wide bandgap, created by placing a nylon barrier embedded with steel oscillators between two steel plates. The bandgap is calculated using dispersion analysis and phononic crystals method, delineating the attenuation range of the seismic metamaterial. Parameter analysis results show that greater oscillator mass, thinner nylon barrier thickness, and higher external barrier height favor broader bandgap width and reduced bandgap frequency. By introducing the concept of multiple oscillators and “uniform and gradient,” the isolation performance of the SM is significantly enhanced, while the impact of the Fano-like phenomenon on attenuation is simultaneously reduced. This indicates that multi-oscillator and “uniform and gradient” are ideal solutions for opening ultra-low frequency bandgaps. Finally, the dynamic response of the SM is clarified through time-domain analysis, further validating the effectiveness of the research. We hope that this study can promote the engineering application of common building materials in the shielding of deep subwave length frequency seismic waves.</p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"37 2","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143576276","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