Mechanics of Materials最新文献

{"title":"Material extrusion additive manufacturing of Acrylonitrile-Butadiene-Styrene: Experiments and anisotropic model for the orientation angle","authors":"Wilco M.H. Verbeeten,&nbsp;Miriam Lorenzo-Bañuelos","doi":"10.1016/j.mechmat.2025.105408","DOIUrl":"10.1016/j.mechmat.2025.105408","url":null,"abstract":"<div><div>The yield stress as a function of both strain rate and orientation angle was measured for material extrusion additively manufactured (ME-AM) Acrylonitrile-Butadiene-Styrene (ABS). Unidirectional test specimens were extracted by waterjet-cutting at different orientation angles from ME-AM processed plates. By printing rectangular plates, a strand trajectory of constant length can be applied. Thus, the thermo-mechanical history of the material was as similar as possible across the plate. By determining an average sample porosity using Archimedes’ principle, yield stress values could be compensated for the voids present in ME-AM specimen. A time- and orientation-dependent model, which combines an Eyring flow rule with Hill anisotropy, was used to describe the yield stresses as a function of strain rate and orientation angle. The model uses a factorizable approach, <em>i.e.</em> both effects are decoupled, which simplifies the determination of model parameters. This anisotropic continuum-based viscoelastic Eyring-Hill model is able to adequately predict the complex experimental yield stress behavior, which is a challenging task. Scanning Electron Microscope fractography revealed macroscopically more ductile behavior due to failure in the strand direction. Macroscopically brittle behavior was related to inter-strand failure. The present study is an important step towards the prediction of structural integrity of ME-AM parts, as time- and orientation-dependency are also important in creep and fatigue behavior.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"208 ","pages":"Article 105408"},"PeriodicalIF":3.4,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144313196","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 physically-based thermo-viscoelastic constitutive model of phantom and entangled networks in amorphous shape memory polymers","authors":"Jianwei Deng ,&nbsp;Haibao Lu ,&nbsp;Yong Qing Fu","doi":"10.1016/j.mechmat.2025.105417","DOIUrl":"10.1016/j.mechmat.2025.105417","url":null,"abstract":"<div><div>Amorphous shape memory polymers (SMPs) are one of the most prominent smart and intelligent materials, whose constitutive models play important roles for their engineering designs and applications. Over the past decades, various thermo-viscoelastic constitutive models have been developed to simulate their shape memory behaviors, but these models are mostly phenomenological and often unable to explain the underlying mechanisms of their viscoelasticity and shape memory effects. Herein we propose a physically-based thermo-viscoelastic constitutive model to describe SMPs’ shape memory behaviors. We propose that the SMPs are composed of both hard and soft phase chains. The hard phase chains form a backbone network showing strong elastic responses, which can be modeled with a phantom network model. Whereas the soft phase chains form transient networks and entangled networks exhibiting viscoelastic behaviors, which can be explained using contour length relaxation and disentanglement relaxation phenomena. Time-temperature superposition principle is then incorporated to capture critical time-temperature dependence of the viscoelasticity and thermally induced shape memory effect. The proposed model has been implemented numerically and validated using shape memory experimental results at different recovery temperatures and heating rates, during the shape memory processes of amorphous SMPs. This work presents a good understanding of the viscoelasticity and shape memory effects of amorphous SMPs at the polymer chain level, and also provides an effective constitutive model for practical applications.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"208 ","pages":"Article 105417"},"PeriodicalIF":3.4,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144291418","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":"Modeling of glass-fiber-reinforced 3D-printed filaments using micro-computed tomography data","authors":"E. Polyzos,&nbsp;Y. Zhu,&nbsp;L. Pyl","doi":"10.1016/j.mechmat.2025.105396","DOIUrl":"10.1016/j.mechmat.2025.105396","url":null,"abstract":"<div><div>The use of 3D printing technology for composites has gained increased attention due to their high mechanical properties and their rapid manufacturing. However, accurately predicting the mechanical response of the 3D-printed composite parts remains challenging due to their complex internal morphology. In this article, a hybrid methodology is presented for the direct modeling of 3D-printed composites of polylactic acid (PA) reinforced with continuous glass fibers. The methodology includes micro-computed tomography images to visualize the fibers and create ideal models using analytical effective field methods (EFMs). The EFMs are used to predict the effective elastic properties of the composite, which compared with experimental results and demonstrate a great agreement.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"208 ","pages":"Article 105396"},"PeriodicalIF":3.4,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144297119","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":"Multi-field induced reconfigurable point defect state of flexural waves in magnetostrictive phononic crystals plates","authors":"Shunzu Zhang,&nbsp;Lichao Su","doi":"10.1016/j.mechmat.2025.105415","DOIUrl":"10.1016/j.mechmat.2025.105415","url":null,"abstract":"<div><div>Point defect state of phononic crystals (PCs) has attracted increasing interest owing to the unique characteristics of wave localization. However, the effectively and dynamically multi-field realization of point defect state of elastic waves in complex environments is still a challenge. We propose a magnetostrictive PC plate aiming to dynamically achieve the reconfigurable point defect state of flexural waves by adjusting magnetic, mechanical and thermal loadings. The controllable band gap can be successfully induced by changing the multi-field loadings. Subsequently, we design three Schemes to induce the reconfigurable point defect without altering the structure, i.e., magnetic-induced, thermal-induced and multi-field (magnetic and thermal) induced Schemes, respectively. The numerical and experimental results show that for the magnetic and thermal-induced Schemes, the frequency of point defect state increases monotonically with the increase of the defect magnetic field and temperature, respectively. By adjusting the magnetic and thermal distributions, the reconfigurable location of point defect can be obtained, the frequency decreases as the number of cells increases. This study provides a guidance for realizing the reconfigurable point defect state of elastic waves, which can be beneficial for the customized requirement of wave localization devices like wave guiding, monitoring and energy harvesting.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"208 ","pages":"Article 105415"},"PeriodicalIF":3.4,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144271417","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":"On deformation and structural twins in the shape memory alloys","authors":"Anatoli A. Rogovoy","doi":"10.1016/j.mechmat.2025.105393","DOIUrl":"10.1016/j.mechmat.2025.105393","url":null,"abstract":"<div><div>Using the Ni<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>MnGa shape memory alloy as an example, the article substantiates an approach to describing at the microstructural level the processes of twinning and detwinning of the martensitic phase. The coordinated twinned martensitic structure is described by the Hadamard compatibility equation for deformations, the solution of which made it possible to determine the surfaces along which the shift occurs, the directions and the magnitude of sliding in a tetragonal crystal cell corresponding to the material under consideration in the martensitic state, leading to the appearance and disappearance of the twinned structure. It is shown that two types of twins simultaneously and inseparably exist in an alloy with shape memory: deformation and structural. The first is related to the deformation of a simple shear, that occurs in accordance with the Hadamard compatibility condition in a martensitic plate, which leads to the kink of this straight plate and the appearance of two elements rotated at a certain angle relative to each other, which form this twin. The structural twin is formed from two parts, in each of which the tetragonal crystal cells of martensite are identically oriented, but the short axes of all these tetragonal cells make up an angle of <span><math><mrow><mn>9</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>0</mn></mrow></msup></mrow></math></span> when these cells are located in different parts of the twin. The positions of the structural twin elements relative to the shear plane, determined as a result of solving the twinning equation, are in good agreement with the experimental data. The formation of a deformation twin as a result of a shift in the material leads to the occurrence of a corresponding strain. The formation of a structural twin initiates a structural strain. It is shown that a certain position of the structural twin in the deformation one leads to the equality of these strains.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"208 ","pages":"Article 105393"},"PeriodicalIF":3.4,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144242488","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":"Indentation of a non-equal biaxially stretched elastomer by an elliptic cone","authors":"Le Du ,&nbsp;Jianmin Long ,&nbsp;Rui Xiao","doi":"10.1016/j.mechmat.2025.105412","DOIUrl":"10.1016/j.mechmat.2025.105412","url":null,"abstract":"<div><div>By assuming the contact pressure follows an inverse hyperbolic cosine function and employing the surface Green's function method, we investigated the indentation of a non-equal biaxially stretched elastomer by an elliptic cone. We considered different rotation angles of the elliptic cone relative to the principal stretching directions of the elastomer and proposed a semi-analytical method to solve this problem. The rotation angle of the elliptic cone influences the relationship between the indentation force and the indentation depth. Additionally, we investigated the effects of the rotation angle of the elliptic cone and the pre-stretches of the elastomer on the rotation angle and eccentricity of the contact ellipse. By applying a pre-defined stress field to the elastomer, we performed finite element simulations of the present problem and found that the simulation results are in good agreement with the theoretical predictions. This work contributes to the application of indentation experiments to characterize the mechanical properties of pre-stretched soft materials, as well as to the design of contact or printing patterns.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"208 ","pages":"Article 105412"},"PeriodicalIF":3.4,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144242487","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":"Fully implicit crystal plasticity models representing orientations with modified Rodrigues parameters","authors":"Mark C. Messner,&nbsp;Tianchen Hu","doi":"10.1016/j.mechmat.2025.105388","DOIUrl":"10.1016/j.mechmat.2025.105388","url":null,"abstract":"<div><div>This work describes a crystal plasticity formulation combining several mathematical, numerical, and implementation choices to produce a highly efficient model. Specifically, the key choices in the implementation are (1) representing orientations with modified Rodrigues parameters, (2) implementing a fully coupled implicit time integration for the elastic stretch, the crystal orientations, and the model internal variables, (3) implementing the model in the NEML2 constitutive modeling framework, based on PyTorch, to vectorize the calculations and port the computation to GPUs and other hardware accelerators, and (4) an exact implementation of the consistent tangent matrix, even for arbitrary coupling to other field variables beyond the displacements, like temperature, neutron fluence, etc. The first two features of the model are, to our knowledge, novel. The paper considers each of these choices individually as well as the final model as a whole. This includes a full description of modified Rodrigues parameters, their advantages over other representations of orientations, the mathematical formulae and tools required to implement a model with modified Rodrigues parameters, and a detailed description of the geometry of the space of modified Rodrigues parameters (in an appendix). It also includes a description of a fully implicit time integration scheme for the orientations and the advantages in representing orientations with modified Rodrigues parameters in implementing such a model. The work then assess, via numerical examples, the advantages of fully coupled implicit time integration versus more common decoupled and explicit time integration schemes. These studies demonstrate the computational advantages of fully coupled integration versus other time integration algorithms, though the performance of the competing models depends on the complexity of the underlying single crystal model. The study concludes by demonstrating that the choice of time integration method affects the sharpness of the predicted texture, with explicit methods for integrating the orientations overestimating texture sharpness and implicit methods underestimating texture sharpness.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"208 ","pages":"Article 105388"},"PeriodicalIF":3.4,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144253393","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":"CRSS evolution with changing grain size for a dual-phase Ti-6Al-2Sn-4Zr-2Mo-Si alloy having a martensite structure","authors":"Irvin Séchepée ,&nbsp;Hiroaki Matsumoto ,&nbsp;Hugo Rousseaux ,&nbsp;Vincent Velay ,&nbsp;Vanessa Vidal","doi":"10.1016/j.mechmat.2025.105407","DOIUrl":"10.1016/j.mechmat.2025.105407","url":null,"abstract":"<div><div>Duplex martensitic microstructures have recently attracted significant attention due to their unique ability to combine high strength, excellent ductility, and superior work-hardening properties, making them ideal for structural applications. This study explores the micromechanisms underlying the tensile properties of a Ti-6Al-2Sn-4Zr-2Mo-Si alloy with hot-rolled T-split textures and various microstructures, tested along two tensile directions: TensileD//RD (referred to as 0°) and TensileD⊥RD (referred to as 90°). A comparative analysis highlights the superior work-hardening capacity and isotropic behavior of duplex (α+α′) and (α+α\") microstructures containing martensite, compared to equiaxed (α+β) microstructures. The enhanced work-hardening observed in the duplex microstructures is attributed to mechanisms such as variant reorientation in the martensitic phases, the pronounced mechanical contrast between the harder α phase and the softer α'/α\" phases, and the interactions between α slipping and α'/α\" twinning. Macroscopic Hall-Petch relations further clarify how microstructures influence strength and ductility. Specifically, duplex (α+α′) microstructures exhibit improved ductility due to lower Hall-Petch constants and diminished grain boundary effects. Interestingly, reverse Hall-Petch behavior is observed in the duplex (α+α\") microstructure at 90°, which is associated with the presence of α\" martensite. Slip trace analysis is conducted to determine the experimental Critical Resolved Shear Stress (CRSS) ratios and qualitatively assess the impact of grain size and tensile direction on the activation of slip systems. Multiscale simulations are then utilized to calculate CRSS values and investigate the roles of deformation modes and crystallographic texture in shaping the macroscopic behavior of duplex (α+α\") microstructures. At 0°, the T-split texture and the facilitation of prismatic&lt;a&gt; slip between adjacent prismatic grains result in a low Hall-Petch constant and minimal grain boundary effects, acting as soft grains. In contrast, basal&lt;a&gt; and pyramidal&lt;c+a&gt; systems exhibit much higher Hall-Petch constants, behaving as hard grains and significantly contributing to work hardening. At 90°, basal&lt;a&gt; slips uniquely display reverse Hall-Petch behavior, which is linked to the macroscopic reverse Hall-Petch phenomenon. This behavior is thought to stem from the presence of α\" martensite and the hot-rolled texture, combined with the tensile direction of 90°, which triggers a shift in the dominant mechanism around basal grains from intragrain dislocation movement to grain boundary sliding.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"208 ","pages":"Article 105407"},"PeriodicalIF":3.4,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144242486","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":"Full-field elastic strain tensor evolution of 3D polycrystals with recurrent neural networks and transfer learning","authors":"Ashley Lenau ,&nbsp;Reeju Pokharel ,&nbsp;Alexander Scheinker ,&nbsp;Stephen Niezgoda","doi":"10.1016/j.mechmat.2025.105389","DOIUrl":"10.1016/j.mechmat.2025.105389","url":null,"abstract":"<div><div>High energy X-ray diffraction microscopy (HEDM) is a non-destructive characterization technique that enables the study of material evolution under in situ thermo-mechanical conditions. While HEDM provides valuable insights, successful experiments require extensive planning, data collection, and data reduction, making them time-intensive and expensive. Crystal plasticity simulations could improve experimental planning and reduce the time required for experimental data reconstruction, but they are too computationally intensive for real-time experimental feedback. Deep learning models offer the speed needed for real-time feedback that could optimize data collection and data reconstruction while expanding the experimental design space. However, these models are currently limited by the small size of available training datasets. This work develops a surrogate crystal plasticity model using a U-Net architecture with recurrent and recursive connections to predict the evolution of full-field elastic strain tensors in 3D polycrystalline materials—properties directly measured during HEDM experiments. Using a Cu polycrystal as the baseline material, the trained network can make predictions instantaneously, representing a significant step towards real-time crystal plasticity predictions for HEDM experiments and potentially enabling more efficient and adaptive experimental designs. However, training such a 3D network for different materials system is computationally expensive due to its numerous trainable parameters and the cost of generating training data. To address this challenge, we investigate transfer learning techniques that enable the network to predict the evolution of different materials without training from scratch, while using the Cu-trained network as a foundation for expanding the model’s capabilities. The transfer learning approach successfully reduced training time and data requirements while maintaining prediction accuracy for materials with similar microstructures, demonstrating the potential for rapid adaptation to new material systems.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"208 ","pages":"Article 105389"},"PeriodicalIF":3.4,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144189306","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":"Model of enhanced flexural strength of ceramics at elevated temperatures","authors":"A.G. Sheinerman","doi":"10.1016/j.mechmat.2025.105398","DOIUrl":"10.1016/j.mechmat.2025.105398","url":null,"abstract":"<div><div>We suggest a model that describes the observed non-monotonous temperature dependences of the flexural strength of ceramics. Within the model, the flexural strength is affected by the sliding of the intergranular boundaries, which can blunt the crack tip and increase the flexural strength at certain temperatures. At the same time, at high enough temperatures, enhanced boundary sliding results in the transition from the brittle to ductile failure, which reduces the flexural strength. It is demonstrated that the fracture strength of ceramics at elevated temperatures can be strongly affected by the sliding properties of the intergranular boundaries and the loading time. The ceramics with the highest fracture strength should have low sliding resistance at short-term loading and high sliding resistance in the case of long-term loading. The results of the model quantitatively agree with experimental data.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"208 ","pages":"Article 105398"},"PeriodicalIF":3.4,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144213204","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}