International Journal of Plasticity最新文献

{"title":"Gurson revisited and multiscale-multimechanisms modeling","authors":"Gilles Rousselier,&nbsp;Thilo F. Morgeneyer,&nbsp;Jean-Michel Scherer","doi":"10.1016/j.ijplas.2025.104490","DOIUrl":"10.1016/j.ijplas.2025.104490","url":null,"abstract":"<div><div>Ductile fracture of metallic alloys is mainly attributed to initiation, growth and coalescence of micrometric voids. In 1977, Gurson’s kinematic limit analysis of the hollow sphere provided an analytical upper bound of the yield surface in the case of fully plastic flow: Gurson’s famous porous plasticity model. But in the case of flow with a conical rigid section, Gurson only fitted an empirical equation to his ”data points”. In 2004, the numerical limit analysis methods developed by Pastor et al. pointed out the existence of a corner of the yield surface on the hydrostatic axis that is not obtained with the empirical equation. The two parameters of Rousselier’s thermodynamically-derived model provide a good fit to Gurson’s data points in both cases of fully plastic flow and flow with rigid section, simultaneously. It is of utmost importance for ductile fracture modeling as void coalescence involves a transition from fully plastic flow to flow with rigid section. This model yield surface shows a corner with the right slope <span><math><mrow><mo>−</mo><mn>3</mn><mo>/</mo><mn>2</mn></mrow></math></span> corresponding to void coalescence and strain localization in a band normal to the main loading direction. In shear-dominated loadings, rotation and flattening of micrometric voids is also observed. It is usually modeled either with uncoupled failure criteria or with porous plasticity. In the first approach, criteria depending on the third invariant of the stress tensor: the Lode variable, have been developed. In porous plasticity, a second porosity was added to the yield criterion by Gologanu, Madou, Leblond and Morin (1993, 1994, 2012). In this work, the two approaches are combined with a very simple equation for the second porosity evolution depending on the Lode variable. The novelty lies in applying void nucleation, growth, rotation and flattening models also to the secondary nanometric voids that are observed inside the grains and in microscopic shear bands. At this latter scale, a modified Lode variable is used depending on the resolved shear and normal stresses of each slip system. Multiscale modeling is thus required. The dissipative Coulomb-Rousselier-Luo (2014) failure model at the slip system scale is also considered for ductile fracture without voids observed in aluminum alloys. The use of reduced texture polycrystalline models is a good compromise between macroscopic plasticity and crystal plasticity finite element method. Finite element calculations of a notched specimen are performed to illustrate the effects of the various damage models.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"194 ","pages":"Article 104490"},"PeriodicalIF":12.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145195418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 cross-scale stress gradient plasticity theory for length-scale effects on hardening behaviors of microbeam bending","authors":"Xu Zhang, Takashi Sumigawa","doi":"10.1016/j.ijplas.2025.104494","DOIUrl":"https://doi.org/10.1016/j.ijplas.2025.104494","url":null,"abstract":"Understanding and defining intrinsic length-scales is the key to developing continuum plasticity theories that accurately capture size-dependent behaviors. This study presents a cross-scale stress gradient plasticity (C-σGP) theory that couples the dynamics of soft dislocation pile-up in stress gradients with continuum mechanics without resorting to phenomenological evolution (hardening) laws. The theory explicitly incorporates four material length-scales: slip-band spacing, dislocation source length, dislocation pile-up length, and boundary layer thickness. We implemented the C-σGP model using an implicit algorithm to simulate the pure bending behavior of single-crystalline microbeams. Results show that only two intrinsic length-scales are required to capture the size-dependent bending strength at different strain stages. One is the source length that controls the yield strength, and the other is the slip-band spacing which governs the post‑yield hardening. Moreover, this study reveals for the first time how the evolution of slip-band spacing with plastic strain significantly affect the strain‑hardening rate and flow intermittency observed at micro‑ and sub‑micron scales. By identifying and quantifying these intrinsic lengths, the C-σGP framework provides a physically grounded foundation for future gradient‑enhanced plasticity models of small‑scale structures.","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"113 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145195420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revealing the underlying slip/twinning mechanisms of tension-compression asymmetry and anisotropy in Mg-Gd-Y-Zn-Zr alloys with heterostructure","authors":"Chen Zhou ,&nbsp;Wenyi Hu ,&nbsp;Qichi Le ,&nbsp;Yingbin Lin ,&nbsp;Tong Wang ,&nbsp;Hansol Jeon ,&nbsp;Qiyu Liao ,&nbsp;Chenglu Hu ,&nbsp;Long Liu ,&nbsp;Yatong Zhu ,&nbsp;Xiuzhen Xie","doi":"10.1016/j.ijplas.2025.104493","DOIUrl":"10.1016/j.ijplas.2025.104493","url":null,"abstract":"<div><div>This study investigates the underlying slip/twinning mechanisms in an extruded Mg-Gd-Y-Zn-Zr alloy with a fiber coarse grain-ultrafine grain (FCG-UFG) heterostructure under various strain paths, combining experimental characterization and Visco-Plastic Self-Sonsistent modeling incorporating Predominant Twin Reorientation (VPSC-PTR). The material constants in the VPSC-PTR model were inversely calibrated using Schmid factor (SF)-corrected grain reference orientation deviation (GROD) data. The VPSC-PTR model was skillfully employed to quantitatively distinguish deformation mechanisms and texture evolution between coarse and fine grains in bimodal Mg alloys, demonstrating its strong potential for broader applications in heterostructured alloys. The results show that under both tension and compression, the UFG region initially accommodates plastic strain mainly through basal 〈a〉 slip. This produces a pronounced strain gradient at FCG grain boundaries, stimulating adjacent FCG grains—initially in hard orientations for basal 〈a〉 slip—to activate prismatic 〈a〉 slip and pyramidal 〈<em>c</em> + <em>a</em>〉 slip. The divergence in deformation mechanisms between FCG and UFG regions and the resulting mechanical incompatibility act synergistically to enhance hetero-deformation induced (HDI) strengthening, leading to simultaneous improvements in strength and ductility. Furthermore, the alloy exhibits an uncommon reversed tension-compression yield asymmetry (<span><math><msubsup><mi>σ</mi><mi>y</mi><mi>C</mi></msubsup></math></span>/<span><math><msubsup><mi>σ</mi><mi>y</mi><mi>T</mi></msubsup></math></span> &gt; 1). This behavior originates from the high critical stress required for kinking deformation of LPSO phases under compression, coupled with the suppression of conventional {10–12} extension twinning, which collectively reverse the typical twin-dominated yield asymmetry seen in conventional Mg alloys. Owing to its weak basal texture, the UFG region deforms mainly via basal 〈a〉 slip under various strain paths, contributing little to compressive anisotropy. In contrast, the orientation-dependent competition between basal and non-basal 〈a〉 slip within FCG grains, along with the distribution characteristics of LPSO phases, governs compressive mechanical anisotropy. GROD analysis further indicates that {10–12} extension twins promote the activation of pyramidal 〈<em>c</em> + <em>a</em>〉 slip. The introduction of twins and associated 〈<em>c</em> + <em>a</em>〉 dislocations effectively alleviates local stress concentrations and enhances plasticity in FCG regions, thereby delaying fracture. These findings provide new insights into the deformation mechanisms of heterostructured Mg alloys under multi-directional loading and will facilitate the design of high-performance Mg alloys with reduced tension-compression asymmetry and mechanical anisotropy.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"194 ","pages":"Article 104493"},"PeriodicalIF":12.8,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrogen–vacancy effects on the elastic and plastic behaviour of Ni<100> probed by nanoindentation","authors":"S.P. Murugan,&nbsp;Y. Ben Jedidia,&nbsp;X. Feaugas,&nbsp;A. Oudriss","doi":"10.1016/j.ijplas.2025.104492","DOIUrl":"10.1016/j.ijplas.2025.104492","url":null,"abstract":"<div><div>One of the fundamental aspects of hydrogen embrittlement is based on the impacts of hydrogen on the elementary mechanisms of plasticity. Even though it is well known that the solute hydrogen generally deteriorates the ductility of nickel, it highlighted the existence of antagonistic processes in the hydrogen effect as well, i.e., hydrogen-induced hardening and/or softening without a relevant universal explanation. These effects may also reflect an implication of hydrogen on the modification of the elasticity properties. In this work, the impact of hydrogen on elastic modulus, dislocation nucleation (i.e., pop-in), and hardness was investigated in nickel 〈100〉 single crystal using nanoindentation. The evolution of the different properties during hydrogen desorption offers the opportunity to distinguish the direct impact of hydrogen from those associated with solute-induced defects. The deformed sub-surfaces by nanoindentation were analyzed by TEM to characterise the development of dislocation structures and any other defects, and hence to establish the hydrogen-defect-elasticity-plasticity correlations. Hertz’s theory was used to model the elastic regime and Oliver and Pharr's model (Oliver and Pharr, 1992) was used to analyze the elastoplastic regime of the nanoindentation load-displacement curve. Hydrogen-induced impacts on maximum shear stress to activate dislocations, hardness and elastic modulus were observed. An irreversible reduction in elastic modulus with hydrogen absorption revealed the influence of hydrogen-induced vacancy clusters on elasticity. In addition, the increase in pop-in load and hardness with hydrogen absorption indicated a hardening behaviour in the plastic regime, resulting from the interaction of interstitial hydrogen and vacancy clusters with dislocation nucleation and mobility.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"194 ","pages":"Article 104492"},"PeriodicalIF":12.8,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145153659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanics-informed neural networks for modeling constitutive relation for nonlinear elastoplastic materials","authors":"Jin-Cheng Wang ,&nbsp;Zhen Liu ,&nbsp;Xue-Yang Zhang ,&nbsp;De-Shan Cui ,&nbsp;Xian-Fang Li","doi":"10.1016/j.ijplas.2025.104479","DOIUrl":"10.1016/j.ijplas.2025.104479","url":null,"abstract":"<div><div>Identifying constitutive relations for materials with complex behaviors remains a persistent challenge in computational mechanics. Unlike metals, granular materials exhibit pressure hardening, where increasing hydrostatic pressure enhances both shear strength and stiffness through reinforced interparticle contact forces and frictional resistance. For nonlinear elastoplastic granular materials, traditional approaches rely on empirical constitutive models derived from extensive experimental datasets, but they lack flexibility and dependent heavily on parameter calibration. This study proposes a mechanics-informed neural network (MINN) framework, leveraging physics-informed learning principles, to identify nonlinear constitutive relations for geotechnical granular materials under diverse deformation path. By embedding the second-order work criterion and enforcing time consistency for path-dependent responses, MINN significantly outperforms traditional neural networks in robustness, particularly for materials with complex loading history. By integrating finite element solvers, numerical cases further validates the framework’s efficacy, demonstrating close alignment between numerical predictions and experimental data. The dual capabilities of MINN in balancing physical constraints and data-driven adaptability enhance its versatility in elastic–plastic constitutive modeling.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"194 ","pages":"Article 104479"},"PeriodicalIF":12.8,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145182944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 cohesive–frictional phase-field model for hybrid fracture in quasi-brittle materials incorporating strength criteria","authors":"Hanzhang Li ,&nbsp;Tao You ,&nbsp;Keita Yoshioka ,&nbsp;Yuhao Liu ,&nbsp;Yi Rui ,&nbsp;Fengshou Zhang","doi":"10.1016/j.ijplas.2025.104489","DOIUrl":"10.1016/j.ijplas.2025.104489","url":null,"abstract":"<div><div>Fracture nucleation with phase-field models has recently gained significant attention as classical phase-field models often fall short in capturing the onset of fracture in the bulk material with small cracks under multi-axial loading conditions. In this study, we propose a micromechanics-based cohesive phase-field approach with a stress-dependent characteristic length for accurately modeling fracture nucleation in quasi-brittle materials subjected to multi-axial loading. Our analytical solutions reveal that the fracture nucleation criterion is independent of the phase-field length scale parameter and aligns with the material’s strength surface. Compared with available experimental data under biaxial and triaxial loading, we demonstrate that the proposed model is capable of predicting the strength surfaces that transition from extension to compression, while the existing models fail to represent these failure surfaces. Our three-dimensional numerical simulation shows that the proposed model reproduces the transition of fracture pattern from extension to compression.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"194 ","pages":"Article 104489"},"PeriodicalIF":12.8,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145140725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature-mediated extraordinary rate insensitivity of strongly textured titanium","authors":"Zhuangzhuang Liu ,&nbsp;Yu Zhang ,&nbsp;Hao Wu ,&nbsp;Guohua Fan","doi":"10.1016/j.ijplas.2025.104491","DOIUrl":"10.1016/j.ijplas.2025.104491","url":null,"abstract":"<div><div>Strain rate sensitivity is a critical parameter influencing mechanical behaviors, typically resulting in increased flow stress at higher strain rates across most metallic materials. In the present study, we report an unusual phenomenon of strain rate insensitivity in hexagonal titanium deformed at 77 K, independent of strain rates ranging from 0.001 to 0.1 s⁻¹. Through detailed characterization using synchrotron Laue microdiffraction, transmission electron microscopy, and <em>in situ</em> electron backscatter diffraction, we attribute this unusual behavior to the consistency in the type and density of defects. Specifically, at the yield stage, strain rate insensitivity is linked to the prevalence of &lt;<em>a</em>&gt; dislocations, while the insensitivity during initial deformation stages correlates with the dynamics of dislocations and twins both of which are evolved in concert. These findings not only provide new insights into cryogenic deformation theory, but also identify new challenges and prospects for the development of high-speed cryogenic forming or extrusion.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"194 ","pages":"Article 104491"},"PeriodicalIF":12.8,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145134223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hierarchical nanoporous-based design strategy towards ductile ceramics with excellent strain hardening capability","authors":"Zhuochen Chen ,&nbsp;Wanghui Li ,&nbsp;Oluwafunmilola Ola ,&nbsp;Lanxi Feng ,&nbsp;Xiaoqing Zhang ,&nbsp;Yong-Wei Zhang ,&nbsp;Xiaohu Yao","doi":"10.1016/j.ijplas.2025.104487","DOIUrl":"10.1016/j.ijplas.2025.104487","url":null,"abstract":"<div><div>Overcoming the inherent brittleness of ceramics is a longstanding, unsolved challenge in materials science and engineering. Here, we demonstrate a new effective strategy to achieve a brittle-ductile transition in ceramics by introducing a hierarchical spinodal structure. Combining phase field method and molecular dynamics (MD) method, we first constructed nanoporous SiC samples with 1-level and hierarchical 2-level structures separately using a phase field method whose rationality is well validated, featuring spinodal topologies. Then, the mechanical response of the nanoporous ceramics under compression is investigated by all-atom MD simulations to discover the underlying nanoscale deformation mechanisms. The results revealed that the 1-level nanoporous SiC samples exhibited conventional brittleness due to stress-concentration-induced cracking; in stark contrast, the hierarchical 2-level samples displayed a ductile, strain-hardening, metal-like behavior, which is attributed to the presence of dispersed nuclei of defects like stacking faults, which effectively dispersed stress and prevented stress-concentration-induced failure. The strength of the hierarchical nanoporous ceramics follows Shi's law rather than classical Gibson-Ashby law. Our study not only elucidates the two distinct deformation mechanisms but also introduces a highly effective hierarchical nanoporous strategy for the design of ductile ceramics with excellent strain hardening capability, addressing the enduring challenge of brittleness in ceramics.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"194 ","pages":"Article 104487"},"PeriodicalIF":12.8,"publicationDate":"2025-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145093672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Architecting micro-and nanoscale heterostructure for exceptional strength-ductility synergy in additively manufactured titanium alloy","authors":"Fu Chen ,&nbsp;Huaqiang Liu ,&nbsp;Yuanfei Han ,&nbsp;Jiaming Zhang ,&nbsp;Xiaoyan Wang ,&nbsp;Yongqiang Ye ,&nbsp;Chunyu Shen ,&nbsp;Yimin Zhuo ,&nbsp;Jianwen Le ,&nbsp;Guangfa Huang ,&nbsp;Weijie Lu ,&nbsp;Di Zhang","doi":"10.1016/j.ijplas.2025.104488","DOIUrl":"10.1016/j.ijplas.2025.104488","url":null,"abstract":"<div><div>Strength-ductility trade-off in additively manufactured titanium alloys has been a critical bottleneck, significantly limiting their engineering applications. Our work demonstrated that this dilemma was overcome by tailoring a hierarchical heterostructure (HHS) in laser-directed energy deposited titanium alloy (Ti-6.5Al-3.5Mo-1.5Zr-0.3Si). The designed HHS consisted of coarse micro-sized α phases (α_p, soft region) and ultrafine nano-sized α precipitates (α_s, hard region), generating hierarchical heterointerfaces including microscale α_p/β_t and nanoscale α_s/β_r interfaces. The HHS enhanced the total elongation to failure by 476.2 % without sacrificing strength compared to the conventional α-β lamella structure, achieving exceptional strength-ductility synergy. Micro/nano-scale mechanical deformation analyses showed that hetero-deformation between coarse α_p and ultrafine α_s regions caused noticeable accumulation of geometrically necessary dislocations (GNDs) at heterointerfaces, inducing the pronounced hetero-deformation induced (HDI) strengthening effect on the soft α_p, and the HDI hardening effect improving ductility. The HDI stress facilitated the formation and growth of dislocation networks in soft α_p, promoting the accumulation of interfacial GNDs, enhancing the HDI hardening effect. Compared to single-level α/β interfaces, hierarchical heterointerface generated higher GND density with a dual-gradient distribution, further improving the HDI stress and producing multiscale HDI hardening. This resultant high HDI stress activated high-proportioned pyramidal 〈<em>c</em> + <em>a</em>〉 slip modes with significant increment of GND density, overcoming deformation incompatibility. Moreover, hierarchical heterointerface exhibited a multi-scale crack buffering effect, synergistically contributing to the excellent ductility. Finally, a two-level homogenization model was established to comprehensively elucidate the intrinsic strengthening-toughening mechanism of the HHS. This work provided theoretical guidance for developing additively manufactured titanium alloys with high-performance.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"194 ","pages":"Article 104488"},"PeriodicalIF":12.8,"publicationDate":"2025-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145093671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 novel constitutive model emphasizing disclination-induced back stress in strain hardening","authors":"Jinzhao Li ,&nbsp;Zhiping Guan ,&nbsp;Junfu Chen ,&nbsp;Yongsen Yu","doi":"10.1016/j.ijplas.2025.104486","DOIUrl":"10.1016/j.ijplas.2025.104486","url":null,"abstract":"<div><div>Back stress hardening is a component of strain hardening during plastic deformation. Traditionally, the theory of dislocations has attributed the microscopic origin of back stress in polycrystalline metal materials to the long-range stress fields generated by geometrically necessary dislocations (GNDs), which accommodate the translational lattice incompatibility of the crystal. However, the lattice incompatibility also contains a rotational component, associated with disclinations. Similar to GNDs, disclinations also generate long-range internal stress fields, yet their role in back stress remains insufficiently understood. This study introduces a disclination-induced back stress mechanism and proposes a novel single-ended disclination pile-up model, analogous to the single-ended GND pile-up model. This model accounts for the reduction in the average distance of long-range stress fields due to the growth of disclinations within grains. Integrating back stress contributions from both GNDs and disclinations, a new constitutive model is developed. Uniaxial tension simulations of 6061-T5 aluminum alloy sheets demonstrate that the predicted back stress from this model closely aligns with experimental results from tension-compression tests, thereby validating its accuracy. The simulation results show that while GND-induced back stress rapidly increases initially and then stabilizes, disclination-induced back stress continues to rise, constituting 65% of the total back stress at a strain of 0.16. This work not only advances our understanding of the origins of back stress in disclinations but also underscores the significance of incorporating disclinations in back stress calculations, offering new insights into the relationship between microstructure evolution and strain hardening behavior.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"194 ","pages":"Article 104486"},"PeriodicalIF":12.8,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145089182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}