Mechanics of Materials最新文献

{"title":"Crystallization-induced residual deformation evolution in thermoplastics during material extrusion and subsequent annealing","authors":"Shuailong Ren ,&nbsp;Zhihong Han ,&nbsp;Yulin Xiong ,&nbsp;Hongqiu Wei ,&nbsp;Jinyou Xiao ,&nbsp;Lihua Wen ,&nbsp;Ming Lei ,&nbsp;Xiao Hou","doi":"10.1016/j.mechmat.2025.105345","DOIUrl":"10.1016/j.mechmat.2025.105345","url":null,"abstract":"<div><div>Thermomechanical histories in material extrusion (MEX) and subsequent high-temperature service strongly influence the geometric accuracy of semi-crystalline thermoplastic structures. The crystallization-induced residual stress generated in MEX manufacturing process is partially released during subsequent annealing at moderate temperatures. However, high-temperature annealing induces further cold crystallization and additional residual deformation. Therefore, releasing and generating of residual stress in subsequent annealing would affect the high-temperature performance of structural components made by MEX. Tracing the crystallization history during manufacturing and subsequent annealing plays a key role in design and evaluation of components made by MEX throughout the entire lifecycle. To address this issue, we developed a process simulation method for MEX based on the element activation technology of the finite element method and a continuous phase evolution constitutive model of thermoplastic crystallization. In the simulation, the elements of the target object are sequentially activated following the real manufacturing path, and the thermomechanical boundary conditions are updated stepwise. In the constitutive model, crystal growth is modeled by a series of continuously formed crystal phases that are sequentially added to the initial amorphous medium to memorize the crystallization history coupled with the entire deformation history. Therefore, during subsequent annealing, the crystallization-induced bi-directional bending of the polylactic acid frame structure is observed in the simulation, and then verified by experiments. The square frame structure after MEX is observed first to bend downward and finally to bend upward during subsequent annealing. The initial downward bending is induced by the release of the residual stress generated by crystallization during MEX manufacturing, and the final upward bending is induced by the orientation difference of the crystals formed during manufacturing and subsequent annealing. Overall, the good agreement indicates that the developed method can accurately describe the inheritance of the crystalline state during manufacturing on the subsequent high-temperature service performance.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"206 ","pages":"Article 105345"},"PeriodicalIF":3.4,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143790803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of the shape of cohesive zone models on the peeling of stiff film/soft substrate systems: A theoretical perspective","authors":"Hao Long ,&nbsp;Yanwei Liu ,&nbsp;Hanbin Yin ,&nbsp;Yueguang Wei","doi":"10.1016/j.mechmat.2025.105343","DOIUrl":"10.1016/j.mechmat.2025.105343","url":null,"abstract":"<div><div>Peel tests have been widely used to measure the interfacial properties of thin film/substrate systems. With the emergence of soft materials and structures, there is a growing need to characterize the interface of stiff film/soft substrate systems. The accurate prediction of their peeling behaviors relies on cohesive zone models (CZMs), but the influence of the shape of CZMs remains unclear. Herein, we propose a theoretical model based on the trapezoidal CZM to characterize the 90-degree peeling of stiff film/soft substrate systems, and this model can degenerate into those based on Dugdale’s and bilinear CZMs. We validate the theoretical solutions for different shapes of CZMs by finite element simulations, and reveal that the maximum peeling force (<span><math><mrow><msub><mi>P</mi><mi>max</mi></msub></mrow></math></span>) and the corresponding cohesive zone length (<span><math><mrow><msubsup><mi>l</mi><mtext>CZ</mtext><mi>max</mi></msubsup></mrow></math></span>) are significantly affected by the shape of CZMs. We further obtain the unified power scaling laws of <span><math><mrow><msub><mi>P</mi><mi>max</mi></msub></mrow></math></span> and <span><math><mrow><msubsup><mi>l</mi><mtext>CZ</mtext><mi>max</mi></msubsup></mrow></math></span> for different shapes of CZMs, where the scaling exponents depend on substrate elasticity and the shape of CZMs. By a simple extension of the present model, we find that the presence of a small initial interfacial crack can lead to a significant decrease of <span><math><mrow><msub><mi>P</mi><mi>max</mi></msub></mrow></math></span>. When the initial interfacial crack is long, the influences of the substrate modulus, the shape of CZMs and the interfacial strength on <span><math><mrow><msub><mi>P</mi><mi>max</mi></msub></mrow></math></span> can be ignored, and the peeling is governed by the interfacial fracture energy. With the present theoretical solutions, the interfacial strength and fracture energy of stiff film/soft substrate systems can be extracted simultaneously via 90-degree peel tests as long as the shape of CZMs is given and the initial interfacial crack is not very long. We expect that the present model can be extended to the case of arbitrary multi-linear CZMs, which can approximate arbitrarily shaped CZMs. These results can help us measure the interfacial properties of stiff film/soft substrate systems via peel tests, and understand the influence of the shape of CZMs on the interfacial fracture from a theoretical perspective.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"206 ","pages":"Article 105343"},"PeriodicalIF":3.4,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermo-mechanical modeling and behavior analysis of titanium-matrix composites via laser powder bed fusion","authors":"Yang Yang ,&nbsp;Zhi-Jian Li ,&nbsp;Yuan Yao ,&nbsp;Hong-Liang Dai","doi":"10.1016/j.mechmat.2025.105342","DOIUrl":"10.1016/j.mechmat.2025.105342","url":null,"abstract":"<div><div>Laser powder bed fusion (LPBF) gives new insights into the effective fabrication of multi-material parts. However, they have not reached mechanical reliability due to undesirable physical defects such as porosity related to powder spatter. The effect of a powder bed-substrate system with such defects on the thermo-mechanical behavior of multi-material parts is still unclear. In this paper, considering porosity due to powder spatter, a multi-material property model of titanium-matrix composites (TMCs) is established based on the mixture method. Considering temperature-dependent thermal properties, an integrated thermo-mechanical modeling of TMCs is developed to predict the residual stress and deformation of the as-built parts. The three-dimensional transient thermal and stress fields are predicted using the differential quadrature method (DQM). The predicted results show excellent agreement with the predictions and experimental results in the literature. Furthermore, the effect of process parameters, ceramic, part dimension, and porosity on the thermo-mechanical responses of TMCs is analyzed. The results show that the interface between the powder bed and substrate is subjected to the highest thermal gradient and residual stress. In addition, the thermal gradient, residual stress, and interfacial deformation increase with the increased energy density, porosity, and substrate thickness. These results can provide a guide for the design and manufacturing of multi-material parts via LPBF.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"206 ","pages":"Article 105342"},"PeriodicalIF":3.4,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A constitutive model of temperature gradient driving diffusion in solids with stress effect","authors":"Feng Xie,&nbsp;Xin Xu,&nbsp;Weixu Zhang","doi":"10.1016/j.mechmat.2025.105340","DOIUrl":"10.1016/j.mechmat.2025.105340","url":null,"abstract":"<div><div>In the presence of temperature gradient, the non-uniform redistribution of solute atom usually occurs in an initially uniform solid, e.g. the segregation of alloy element in the gas turbine blade, and this phenomenon is called as Ludwig-Soret effect. The redistribution process of solute atom accompanies a significant stress in solids, which was not taken into account in previous theories. In this paper, in the framework of the irreversible thermodynamics, we establish a constitutive model of temperature gradient driving diffusion. The redistribution process of solute atom and the effect of stress are investigated, respectively. The results reveal that our established model describes the redistribution law of solute atom and clarifies the implied mechanism. And the redistribution of solute atom firstly starts at the hot end and gradually extends towards the cold end. Stress retards the diffusion driven by the temperature gradient and then reduces the non-uniform redistribution of solute atom. Moreover, the obtained quantitative relationship predicts the direction and magnitude of the formed concentration gradient. According to our results, researchers can optimize the distribution of element and evaluate the service performance of engineering materials.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"206 ","pages":"Article 105340"},"PeriodicalIF":3.4,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143790802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitatively predicting and evaluating the hardness of amorphous ribbons via a deep learning-symbolic regression approach","authors":"Bo Pang ,&nbsp;Zhilin Long ,&nbsp;Tao Long ,&nbsp;Zhonghuan Su","doi":"10.1016/j.mechmat.2025.105341","DOIUrl":"10.1016/j.mechmat.2025.105341","url":null,"abstract":"<div><div>Amorphous ribbons are applicable across various fields due to their advantageous mechanical, physical, and electromagnetic properties. One such property, Vickers hardness (<em>H</em>_v), is foundational and intimately linked with other properties, which have attracted a growing amount of attention from researchers. However, there is a paucity of a well-performed expression for amorphous ribbons that could quantitatively guide the design of new ones with the desired <em>H</em>_v. In the present study, nine machine learning (ML) algorithms were executed on a dataset previously collected by the authors. By comparing the coefficients of determination (<em>R</em>²) of these algorithms on the test sets, the descriptor ranking of the model with the highest accuracy was obtained. Then, the final expression was successfully explored by utilizing three key descriptors, which was accomplished by synthesizing the <em>R</em>² values, descriptor ranking, and Pearson Correlation Coefficient (PCC) for different feature subsets. Furthermore, the intricate relationship between these features and <em>H</em>_v was elucidated during exploration. The efficacy of this framework may also offer insights into the discovery of other properties of novel amorphous ribbons.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"206 ","pages":"Article 105341"},"PeriodicalIF":3.4,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stimuli–responsive programmable mechanics of bi-level architected nonlinear mechanical metamaterials","authors":"S. Ghuku ,&nbsp;S. Naskar ,&nbsp;T. Mukhopadhyay","doi":"10.1016/j.mechmat.2025.105333","DOIUrl":"10.1016/j.mechmat.2025.105333","url":null,"abstract":"<div><div>Mechanical metamaterials which are often conceptualized as a periodic network of beams have been receiving significant attention over the last decade, wherein the major focus remains confined to the design of micro-structural configurations to achieve application-specific multi-functional characteristics in a passive framework. It is often not possible to actively modulate the metamaterial properties post-manufacturing, critically limiting the applications for a range of advanced intelligent structural systems. To achieve physical properties beyond conventional saturation limits attainable only through unit cell architectures, we propose to shift the design paradigm towards more innovative bi-level modulation concepts involving the coupled design space of unit cell geometries, architected beam-like members and their stimuli–responsive deformation physics. On the premise of revolutionary advancements in additive manufacturing technologies, we introduce hard magnetic soft (HMS) material architectures in the beam networks following physics-informed insights of the stress resultants. Through this framework, it is possible to achieve real-time on-demand control and modulation of fundamental mechanical properties like elastic moduli and Poisson’s ratios based on a contactless far-field stimuli source. A generic semi-analytical computational framework involving the large-deformation geometric non-linearity and material non-linearity under magneto-mechanical coupling is developed for the effective elastic properties of HMS material based bi-level architected lattices under normal or shear modes of mechanical far-field stresses, wherein we demonstrate that the constitutive behaviour can be programmed actively in an extreme-wide band based on applied magnetic field. Under certain combinations of the externally applied mechanical stress and magnetic field depending on the residual magnetic flux density, it is possible to achieve negative stiffness and negative Poisson’s ratio with different degrees of auxecity, even for the non-auxetic unit cell configurations. The results further reveal that a single metamaterial could behave like extremely stiff metals to very soft polymers through contactless on-demand modulation, leading to a wide range of applicability in statics, stability, dynamics and control of advanced mechanical, aerospace, robotics and biomedical systems at different length scales.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"206 ","pages":"Article 105333"},"PeriodicalIF":3.4,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143808562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anisotropic tensile properties and microstructure of SS316LSi fabricated using wire-based laser directed energy deposition","authors":"Ritam Pal,&nbsp;Nathan Dreyer,&nbsp;Ajay Kushwaha,&nbsp;Nandana Menon,&nbsp;Brady A. Sawyer,&nbsp;Amrita Basak","doi":"10.1016/j.mechmat.2025.105338","DOIUrl":"10.1016/j.mechmat.2025.105338","url":null,"abstract":"<div><div>This paper investigates the anisotropic mechanical properties and microstructures of two austenitic stainless steel 316LSi vertical wall components fabricated using laser wire-directed energy deposition (LW-DED). ASTM standard tensile specimens were extracted from different locations of these twin walls. The specimens’ mechanical properties in longitudinal and transverse orientations relative to the build direction were assessed under uniaxial tension. A select number of speciments were subjected to heat treatment at 1100 ^oC to evaluate its impact on anisotropy, ultimate strength, and ductility. Digital image correlation (DIC) was employed to analyze strain field evolution in two representative horizontal and vertical specimens. Fractured surfaces were examined using scanning electron microscopy. The results showed an average ultimate tensile strength of 550 MPa in both directions, with a maximum strength of 680 MPa in specimens from the median location. This variation was attributed to residual stress differences across the printed wall, as confirmed by finite element analysis. The average elongations were 25 % and 35 % for vertically and horizontally extracted specimens, respectively. Heat treatment enhanced ductility by 15–20 % for both categories due to grain structure coarsening. The anisotropy in ductility was primarily because of the differences in columnar grain orientation with the coarser grains aligned with the tension direction in horizontally extracted specimens. This alignment facilitated damage accumulation, leading to tensile fracture. This study provides insights into the anisotropic behavior of LW-DED SS316LSi components and the influence of heat treatment on tensile properties.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"206 ","pages":"Article 105338"},"PeriodicalIF":3.4,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143785272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of NiTi under low-amplitude cyclic loading by means of thermographic harmonic analysis","authors":"V. Pinto ,&nbsp;R. Cappello ,&nbsp;S. Di Leonardo ,&nbsp;G. Catalanotti ,&nbsp;G. Burriesci ,&nbsp;G. Pitarresi","doi":"10.1016/j.mechmat.2025.105334","DOIUrl":"10.1016/j.mechmat.2025.105334","url":null,"abstract":"<div><div>Nitinol is a shape memory alloy exhibiting superelastic behaviour above a specific temperature. This property has allowed the design of a new breed of collapsible/expandable cardiovascular medical devices, which are generally characterised by high-risk classes. Therefore, it is crucial to gain a comprehensive understanding of the material behaviour under in-vivo operating conditions. These are typically characterised by large pre-straining and small strain amplitude cyclic loading (high-cycle fatigue). In the present study, nitinol strips are monitored by two full-field sensing techniques: digital image correlation (DIC) and infrared thermography (IRT). The latter in particular was used to sample temperature during small-strain amplitude sinusoidal loading at various mean strains. Results show that the analysis of the frequency domain content of the temperature signal can provide useful information to characterise the material under operating conditions. In particular, it is found that temperature modulation is mainly characterised by its <em>first</em> and <em>second harmonics</em>, i.e. the harmonics at the load frequency and at twice the load frequency. These are shown to be correlated to the local stress field, the actual material phase status and the phase transformation history. The proposed harmonic analysis can be performed in near-real-time, and has the potential to be a convenient and highly informative tool when monitoring nitinol devices under structural fatigue testing. The paper also discusses the nature of the load-induced temperature modulation, and the direct applicability of the thermoelastic effect theory to interpret the observed behaviour.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"206 ","pages":"Article 105334"},"PeriodicalIF":3.4,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The dual phase lag model for thermoelastic microbeams embedded in an elastic foundation incorporating fractional Kelvin–Voigt viscoelasticity","authors":"Ahmed E. Abouelregal ,&nbsp;Salman S. Alsaeed ,&nbsp;Murat Yaylacı ,&nbsp;Mohamed E. Elzayady ,&nbsp;Zafer Kurt ,&nbsp;Ecren Uzun Yaylacı","doi":"10.1016/j.mechmat.2025.105336","DOIUrl":"10.1016/j.mechmat.2025.105336","url":null,"abstract":"<div><div>This research presents the dual-phase lag model (DPL) for thermoelastic microbeams. The model, supported by Winkler foundations, incorporates fractional Kelvin–Voigt viscoelasticity. The model addresses the complexities of heat transfer and mechanical behavior in micro-scale structures by accounting for phase lags in both temperature and heat flux, which are crucial for accurate predictions at small scales. By integrating fractional Kelvin–Voigt viscoelasticity, the study improves the comprehension of time-dependent material responses, capturing the unique behaviors of viscoelastic materials at the micro-level. The governing equations combine the dual-phase lag mechanism with Winkler foundation assumptions for a comprehensive analysis of thermoelastic behavior. Advanced mathematical techniques, including the Laplace transform, are applied to derive expressions for key parameters such as temperature distribution, deflection, and stress profiles. Numerical simulations provide graphical representations that evaluate the effects of factors like fractional order, foundation stiffness, and viscoelastic properties on microbeam behavior. This model is a valuable tool for engineers and researchers designing advanced materials and structures for dynamic thermal and mechanical conditions, promoting innovation in nanotechnology, materials science, and structural engineering.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"205 ","pages":"Article 105336"},"PeriodicalIF":3.4,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143681518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A multi-physics coupled beam model for ionic polymers: Solutions for static and dynamic responses","authors":"Yiming Fan ,&nbsp;Luke Zhao ,&nbsp;Qiufeng Yang ,&nbsp;Feng Jin","doi":"10.1016/j.mechmat.2025.105335","DOIUrl":"10.1016/j.mechmat.2025.105335","url":null,"abstract":"<div><div>Ionic polymers, with Nafion as a typical representative, have been widely applied in various fields. In this paper, we develop a new model that reveals the multi-physics coupling properties of ionic polymer beams. A key advantage of this model is its ability to provide analytical solutions, eliminating the need for finite element methods while effectively capturing the various responses of ionic polymer beams. Through this model, we systematically investigate the static and harmonic vibration characteristics of ionic polymer-metal composites (IPMCs) as force sensors and perform a comprehensive parametric analysis. Specifically, we explore how diffusion coefficient, permittivity, molar volume of hydrated cations, and anion concentration influence IPMC performance. The results highlight the strong applicability of the model in describing the multi-physics coupled behavior of ionic polymers, making it a powerful tool for the design and optimization of this class of sensors.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"206 ","pages":"Article 105335"},"PeriodicalIF":3.4,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}