Mechanics of Materials最新文献

{"title":"Failure induced by a dynamic anti-plane slip pulse in flexoelectric materials","authors":"A.E. Giannakopoulos ,&nbsp;Ch. Knisovitis ,&nbsp;Ares J. Rosakis","doi":"10.1016/j.mechmat.2025.105587","DOIUrl":"10.1016/j.mechmat.2025.105587","url":null,"abstract":"<div><div>Failure models related to dynamic slip pulses have been extensively used in seismology as for example the models of Yoffe (1952), Freund (1979) and Rice et al. (2005). The models of Freund and Rice et al. describe a finite mode III crack of constant length that propagates at constant (subsonic) rapture velocity <span><math><mrow><mi>V</mi><mo>&lt;</mo><msub><mi>c</mi><mi>s</mi></msub></mrow></math></span> whereas the trailing edge leaves behind a dislocation as a permanent irreversible deformation. The driving forces of such models are far field shear tractions, whereas at the same time a frictional traction acts along the crack line due to the contacting crack surfaces that allow only shear slip. Yoffe's model on the other hand assumes a complete healing and thus rendering the trailing edge to behave as a crack-tip, just as the leading edge does. An important difference between Freund's and Rice et al.’s models is that Rice et al.’s model includes additionally the effect of the static friction, whereas Freund's model incorporates only the kinetic friction. The present work extends the models of Freund and Rice et al. to flexoelectric materials under steady state anti-plane loading. The problem is formulated so that the mechanical problem is casted as a strain gradient elasticity problem. Our analytical results point out that the well known influence of the cohesive zone in classic dynamic fracture can be established in the context of flexoelectricity (and strain gradient elasticity) without the need for a cohesive zone. An interesting analogy with the Rice et al. analysis can be established and, in this way, a flexoelectric material can be used for laboratory work in earthquake and friction studies.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"214 ","pages":"Article 105587"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145881438","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":"Simple models of viscoelastic fibrillar adhesion between rigid rough surfaces","authors":"X.M. Liang ,&nbsp;G.F. Wang ,&nbsp;M. Ciavarella","doi":"10.1016/j.mechmat.2025.105582","DOIUrl":"10.1016/j.mechmat.2025.105582","url":null,"abstract":"<div><div>Adhesive interactions between rigid rough surfaces commonly occur in biological attachment systems and bioinspired adhesives, often facilitated by fibrillar contact structures composed of soft, viscoelastic materials. In this study, we analytically investigate the behavior of such systems using two distinct models for detachment criteria: the Schapery model, which assumes a rate-independent bond energy and failure initiated by defects; and the Shrimali–Lopez-Pamies (SLP) model, which assumes failure occurs at a critical fibril elongation. The model gives reduction of pull-off pressure with increasing amplitude of roughness, although not as strongly as in the elastic case and further depending on the loading protocols: starting from a fully relaxed state leads to the highest enhancements of pull-off pressure. These findings provide insights into biological adhesion mechanisms and offer design principles for engineered adhesive systems capable of functioning on rough, rigid substrates.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"214 ","pages":"Article 105582"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841197","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":"3D finite element investigation of hyperelastic foam behavior. I. Voronoi closed-cell microstructures","authors":"Thomas C. Merlette,&nbsp;Julie Diani","doi":"10.1016/j.mechmat.2025.105566","DOIUrl":"10.1016/j.mechmat.2025.105566","url":null,"abstract":"<div><div>The mechanical behavior of isotropic, elastomeric, Classical Voronoi closed-cell foams is investigated numerically using 3D finite element simulations under finite-strain uniaxial compression, and infinitesimal-strain shear and hydrostatic loading conditions. Foam microstructures with porosities ranging from 77% to 95% and narrow pore volume distributions were generated by subtracting irregular polyhedra, obtained from Voronoi tessellations of well dispersed seed points, from a cubic matrix. Severe finite-strain uniaxial compression, up to 95% nominal strain, was simulated using the Abaqus/Explicit solver. Parametric studies revealed that the compressive response of the foams scales proportionally with the factor <span><math><msup><mrow><mrow><mo>(</mo><mn>1</mn><mo>−</mo><mi>c</mi><mo>)</mo></mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span>, where <span><math><mi>c</mi></math></span> denotes the porosity. Moreover, at high porosities (typically 90%), the influence of the base polymer’s hyperelasticity reduces to its initial shear modulus <span><math><msub><mrow><mi>μ</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>, since the matrix undergoes only limited strain, whereas the effect of the polymer’s large-strain behavior becomes significant at lower porosities (typically 77%). As a result, all stress–strain curves collapse onto a single master curve when the stress is normalized by <span><math><mrow><msub><mrow><mi>μ</mi></mrow><mrow><mn>0</mn></mrow></msub><msup><mrow><mrow><mo>(</mo><mn>1</mn><mo>−</mo><mi>c</mi><mo>)</mo></mrow></mrow><mrow><mn>2</mn></mrow></msup></mrow></math></span>. The effect of internal gas pressure within the closed cells was also assessed numerically and compared against experimental data, validating the simple analytical model proposed by Gibson and Ashby (1997). At small strains, the shear modulus is accurately predicted by the Differential Hollow Sphere Assemblage (DHSA) originally developed for spherical voids. However, the same model was found to overestimate the bulk modulus, and a phenomenological correction is therefore proposed to enable rapid and more accurate estimation of this quantity.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"214 ","pages":"Article 105566"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145750219","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":"An approach to predict long-term rupture life of nickel-based superalloy based on relaxation creep tests","authors":"Wen Kang,&nbsp;Tieshan Cao,&nbsp;Congqian Cheng,&nbsp;Jie Zhao","doi":"10.1016/j.mechmat.2025.105573","DOIUrl":"10.1016/j.mechmat.2025.105573","url":null,"abstract":"<div><div>The measurement of creep rupture life normally requires a relatively long duration, while stress relaxation, with the advantages of fewer specimens and shorter time, is proposed as an effective method for predicting rupture life. However, considerable debate persists regarding the estimation of long-term creep rupture life derived from short-term relaxation creep data. This paper investigates the relationship between relaxation creep and constant-load creep based on a nickel-based superalloy in two states: as-received and aged. The results indicate that the prediction model derived from relaxation creep tests on the as-received specimens tends to overestimate the long-term rupture life. The relaxation creep rate increases with exposure time due to microstructural degradation. In order to account for this effect, a damage parameter <em>D</em>_a is introduced to modify the model. Long-term rupture-life predictions from the modified model closely match the experimental results and are comparable to those of the LM model, thereby confirming its validity at 900 °C. The micro-mechanism of the modified model is discussed in terms of Lifshitz–Slyozov–Wagner theory, and significant variations in the <em>γ</em>′ microstructure are quantified as a function of the damage parameter <em>D</em>_a in a given temperature. Accounting for the temperature dependence of microstructural degradation, the modified model has been validated across a wider temperature range. It underestimates rupture life above 900 °C but remains a useful guide. For higher accuracy, specimens should undergo an additional aging treatment at the target temperature and the modified model recalibrated accordingly.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"214 ","pages":"Article 105573"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799115","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 non-local GTN model with two length scales calibrated for a low alloy steel","authors":"Shuyue Wang ,&nbsp;Pål Efsing ,&nbsp;Jonas Faleskog","doi":"10.1016/j.mechmat.2025.105579","DOIUrl":"10.1016/j.mechmat.2025.105579","url":null,"abstract":"<div><div>This study applies a non-local integral Gurson-Tvergaard-Needleman model, incorporating two characteristic material length scales as regularization parameters, linked to shear deformation and hydrostatic tension, to simulate fracture in low alloy A533B. The model accounts for void growth, nucleation, and coalescence, including a shear-enhanced mechanism. Experiments under various stress triaxialities were used to assess model performance, including: uniaxial tensile test, fracture test, and simple shear test. The aim is to predict both global load-deformation responses and fracture modes using a single, physically motivated parameter set. While some parameters are well-established in the literature and linked to micro-structural observations and micro-mechanical analysis, others are less studied and require calibration against experiments. The calibration process is challenging due to nonlinear parameter interactions causing complex dependencies. A trade-off between competing effects was frequently observed. To address this, three parameter sets were investigated. Set 1 used physically motivated values and successfully reproduced the cup-cone fracture in round smooth bar, but underestimated the strains to failure for round smooth bar and modified Iosipescu specimens. Set 2 employed phenomenological values to closely match all the global load-deformation responses, but failed to replicate the experimentally observed fracture mode. Set 3 slightly adjusted parameters in Set 1, achieving improved failure strain predictions and a more accurate cup-cone pattern.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"214 ","pages":"Article 105579"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841196","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 estimating 3D crack density from crack traces on surfaces or cross-sections of a specimen – problem revisited","authors":"Yulia Pronina ,&nbsp;Mark Kachanov","doi":"10.1016/j.mechmat.2025.105575","DOIUrl":"10.1016/j.mechmat.2025.105575","url":null,"abstract":"<div><div>The crack density parameter (scalar or tensor) controls the effect of cracks on the overall elastic and conductive properties of microcracked materials. However, it cannot, generally, be related to volume fractions and may be difficult to be estimated experimentally. Its estimation from the 2D density of crack traces observed on specimen surfaces or cross-sections is therefore valuable. Note that quantitative 2D–3D connections for various geometric parameters of inhomogeneities have been discussed in literature starting from the nineteenth century. However, they do not cover connections for the crack density parameter. Such 2D–3D relationship is derived for the isotropic case of random crack orientations; it corrects the previously published results that actually referred to the special case of transverse isotropy. In the latter case, the anisotropic elastic and conductive constants are derived directly in terms of the observable 2D density of crack traces.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"214 ","pages":"Article 105575"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799114","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":"Low-cycle fatigue prediction of AM IN718 using a crystal plasticity model with precipitate shear mechanism","authors":"Biao Wang ,&nbsp;Ruiping Lai ,&nbsp;Shijie Song ,&nbsp;Jianfeng Zhao ,&nbsp;Liming Lei ,&nbsp;Lei Shi ,&nbsp;Shengchuan Wu ,&nbsp;Wei Rao ,&nbsp;Zishi Shen ,&nbsp;Xu Zhang","doi":"10.1016/j.mechmat.2025.105574","DOIUrl":"10.1016/j.mechmat.2025.105574","url":null,"abstract":"<div><div>To explore the cyclic softening behavior of additively manufactured (AM) IN718 under low-cycle fatigue, this study develops a crystal plasticity model that incorporates the dislocation shear precipitates mechanisms. By introducing irreversible factor, the model effectively captures the softening behavior by dislocation shear precipitates during cyclic loading. Simulation results reveal that both irreversible dislocations and strain amplitude critically affect softening. Irreversible dislocations shear the precipitate during cycling, resulting in a reduction in the radius of the precipitate and a strengthening of the precipitate, ultimately leading to softening. As the irreversible factor increases, the rate of softening significantly escalates. As the strain amplitude increases, the corresponding rise in dislocation density enhances the shear effect of dislocations on precipitations, accelerates the reduction in the radius of precipitates and weakens precipitation strengthening, ultimately accelerating cyclic softening. Additionally, the FIP, represented in terms of cumulative plastic strain and strain energy dissipation, effectively predicts low cycle fatigue life. The prediction results based on strain energy dissipation criteria offer superior accuracy at high strain amplitudes. The outcomes of this study enhance the understanding of the mechanical properties associated with the AM IN718 alloy, providing a critical basis for optimizing the properties of the alloy.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"214 ","pages":"Article 105574"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799101","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":"Shock compression of additively manufactured high solids loaded polymer composites with aligned porosity","authors":"K.B. Wagner ,&nbsp;G. Kennedy ,&nbsp;D. Montaigne ,&nbsp;B.J. Jensen ,&nbsp;M. Zhou ,&nbsp;N.N. Thadhani","doi":"10.1016/j.mechmat.2025.105571","DOIUrl":"10.1016/j.mechmat.2025.105571","url":null,"abstract":"<div><div>The effects of aligned porosity on the shock-compression response of additively manufactured (AM) composite structures with collinear and log-cabin geometries are investigated. The composites contain two inorganic and two organic particle populations and a UV-curable polymer binder. X-ray phase contrast imaging (X-PCI) is used as an <em>in-material</em> diagnostic in plate-impact experiments performed at the Dynamic Compression Sector of the Advanced Photon Source at the Argonne National Laboratory. Macroscale shock and particle velocities and microscale pore collapse velocities are measured from X-PCI images obtained from samples impacted in various orientations relative to the AM build directions. The linear shock and particle velocity relation for the structures with collinear build geometry shows directional differences, with the build direction exhibiting the highest slope and the filament print direction having the shallowest slope. Composites with log-cabin geometry, due to their slightly lower porosity and smaller sized pores, show higher shock velocities than the collinear structures at the same particle velocity. Microscale directionality effects are also observed, with the pore collapse velocity dependent on the pore configuration. Specifically, the pore collapse velocity is highest for pores elongated along the impact direction which is the case for the colinear structures impacted in the filament print direction, which is consistent with the directionality trend observed in the data for the shock and particle velocity equation of state. The pore collapse velocity approaches ∼80 % of the shock velocity and is several times the average bulk particle velocity, suggesting a highly hydrodynamic mechanism of pore collapse. Overall, both the macroscale response as measured by the shock and particle velocity relationship, and the microscale response as measured by the pore collapse velocity, are found to be anisotropic and dependent on the AM composite structure.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"213 ","pages":"Article 105571"},"PeriodicalIF":4.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733100","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":"Secondary instability development in the post-buckling regime in soft composites","authors":"Dean Chen ,&nbsp;Yuhai Xiang ,&nbsp;Nitesh Arora ,&nbsp;Qi Yao ,&nbsp;Jian Li ,&nbsp;Stephan Rudykh","doi":"10.1016/j.mechmat.2025.105565","DOIUrl":"10.1016/j.mechmat.2025.105565","url":null,"abstract":"<div><div>In this paper, we report the numerical observations of a distinctive phenomenon – the development of <em>secondary</em> buckling in soft particulate composites. After experiencing the first microstructural buckling event and consequent microstructure transformations, the composite re-enters a stable state. However, the composite may undergo a secondary buckling upon exceeding a certain deformation level. This secondary buckling event gives rise to a plethora of distinct instability patterns and behaviors. We conduct the finite-amplitude post-buckling and Bloch Floquet analyses implemented in the post-buckling regime to characterize the development of the secondary buckling. These analyses also characterize the dependence of the critical strain and wavelength of the secondary buckling on the composite's initial microstructure parameters.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"213 ","pages":"Article 105565"},"PeriodicalIF":4.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733101","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 physics-informed neural network model to predict thermo-oxidative/thermal aging of viscoelastic materials","authors":"Hossein Naderi,&nbsp;Roozbeh Dargazany","doi":"10.1016/j.mechmat.2025.105548","DOIUrl":"10.1016/j.mechmat.2025.105548","url":null,"abstract":"<div><div>This study introduces a physics-informed machine-learned constitutive model to predict the behavior of viscoelastic materials (VEMs) and their degradation during thermal-oxidative (TO) aging. The framework integrates the eight-chain model with conditional neural networks, enabling the statistical representation of molecular chain dynamics while capturing progressive microstructural changes induced by aging. The complex 3D stress–strain tensor mapping problem has been simplified into a series of super-constrained 1D mapping problems through sequential order reduction. This reduction is achieved using an ensemble of replicated conditional neural network learning agents, each specifically trained to decompose the high-dimensional mapping into distinct 1D problems, each representing a specialized agent. Unlike conventional data-driven approaches, the proposed model embeds physical constraints from polymer chain mechanics and thermodynamics, ensuring both accuracy and consistency. Validation against experimental data demonstrates that the model successfully reproduces the stress–strain response of VEMs and their stiffness changes across different aging levels. This modeling framework will be integrated into the K-Load degradation module developed by Karax LLC<span><span>¹</span></span> to support digital-twin applications for polymeric materials.The developed model (available in GitHub) provides an open-source tool for modeling degradation in polymeric materials and offers a pathway to combining mechanistic constitutive modeling with machine learning.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"213 ","pages":"Article 105548"},"PeriodicalIF":4.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733102","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}