International Journal of Mechanical Sciences最新文献

{"title":"Rapid Stress Intensity Factor Evaluation in Cracked Welded Joints","authors":"Liuyang Feng ,&nbsp;Tao Suo ,&nbsp;Zhongbo Yuan ,&nbsp;Cheng Chen ,&nbsp;Xudong Qian","doi":"10.1016/j.ijmecsci.2026.111554","DOIUrl":"10.1016/j.ijmecsci.2026.111554","url":null,"abstract":"<div><div>Accurate determination of stress intensity factors (SIFs) and nonlinear local stress fields in welded plate joints is essential for fatigue life prediction and structural integrity assessment. However, finite element simulations become tedious and computationally expensive when dealing with complex crack geometries, particularly in real-time monitoring or large-scale engineering applications. This study presents a hybrid analytical-optimization framework that integrates analytical structural mechanics with genetic optimization to determine nonlinear local stress fields and stress intensity factors (SIFs) for welded plate joints. The framework formulates a physics-informed objective function derived from global force-moment equilibrium, enabling accurate identification of nonlinear regions and crack-tip parameters for through-width, shallow/deep elliptical, and highly irregular crack geometries. By embedding curvature radius, crack-front orientation, and geometry-dependent stress characteristics into a unified optimization procedure, the proposed method reproduces FEM-level accuracy while reducing computational cost by orders of magnitude.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"318 ","pages":"Article 111554"},"PeriodicalIF":9.4,"publicationDate":"2026-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147587371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hybrid Kresling origami metamaterial for low-frequency longitudinal waves","authors":"Chenyi Bu ,&nbsp;Xiang Fang ,&nbsp;Xiaoxuan Wang ,&nbsp;Kai Wang ,&nbsp;Sixing Xiong ,&nbsp;Huimin Wu ,&nbsp;Jin Qian","doi":"10.1016/j.ijmecsci.2026.111359","DOIUrl":"10.1016/j.ijmecsci.2026.111359","url":null,"abstract":"<div><div>Origami and kirigami offer a distinct alternative to conventional vibration mitigation strategies, demonstrating superior adaptability and tunability under varying dynamic conditions. However, they are still confronted with several challenges in practical applications, including insufficient durability, difficulties in scalable manufacturing, and limited vibration suppression performance in the low-frequency range. In this work, we proposed a novel one-dimensional metamaterial based on Kresling origami, which combines exceptional durability with suitability for scalable manufacturing. The structure incorporates origami-derived elastic struts and local resonant masses positioned at both ends of the creases, forming a unit cell that integrates the axial-torsional coupling characteristics of Kresling origami with the principle of local resonance. Through systematic finite element simulations, we investigate the band structures and wave attenuation capabilities of the proposed Kresling origami metamaterial. Our results indicate that low-frequency longitudinal bandgaps can be effectively tuned by key geometric parameters, including the added resonant mass and the geometries of the Kresling origami. Samples were fabricated using selective laser melting (SLM) with AlSi10Mg alloy. Further vibration experiments showed close agreement with simulation results, accurately capturing both the spectral locations and widths of the bandgaps. Various parameter configurations demonstrated tunable performance for broadband wave attenuation. This study enriches the design methodology for origami-inspired metamaterials and provides theoretical guidance for structural engineering applications, including vibration isolation, noise reduction, and impact mitigation, paving the way for multifunctional and programable structures of next-generation.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"314 ","pages":"Article 111359"},"PeriodicalIF":9.4,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Orientation-induced fluctuations of elastic modulus by Berkovich nanoindentation","authors":"Yaxi Li ,&nbsp;Xin Wang ,&nbsp;Ming Liu ,&nbsp;Tang Gu ,&nbsp;Xu Long","doi":"10.1016/j.ijmecsci.2026.111367","DOIUrl":"10.1016/j.ijmecsci.2026.111367","url":null,"abstract":"<div><div>Nanoindentation is widely employed to evaluate elastic properties of crystalline materials; however, the influence of in-plane rotation of non-axisymmetric indenters on elastic modulus extraction in elastically anisotropic single crystals remains insufficiently quantified. In this study, the effect of Berkovich indenter rotation on elastic modulus measurements performed on the [001] surface of a DD6 Ni-based single-crystal superalloy is systematically investigated. By combining nanoindentation experiments with finite element simulations, it is demonstrated that indenter rotation alone—without any change in crystallographic orientation—induces reproducible, orientation-dependent fluctuations in the apparent elastic modulus. Two finite element frameworks are employed for comparison: a crystal elasticity-based finite element model (CE-FEM) and a macroscopic anisotropic elastic model (Macro-FEM). Their close agreement under purely elastic conditions confirms that the observed modulus fluctuations originate from an intrinsic geometry–crystal coupling between the asymmetric Berkovich indenter and elastic anisotropy, rather than from constitutive modeling artifacts. Experimental results further reveal that the orientation-dependent modulation of the measured modulus persists under realistic testing conditions, indicating that indenter orientation can constitute a non-negligible source of systematic variation in high-precision nanoindentation measurements. By systematically comparing Berkovich and spherical indentation responses and analyzing orientation-dependent trends, this work establishes indenter rotation as an intrinsic, geometry-driven factor affecting elastic modulus extraction in anisotropic single crystals. The findings provide practical guidance for improving the reliability and interpretability of nanoindentation-based elastic characterization in anisotropic materials.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"314 ","pages":"Article 111367"},"PeriodicalIF":9.4,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new physics-motivated constitutive model of hyperelastic polymer networks","authors":"Zichuan Li ,&nbsp;Jiajie Fan ,&nbsp;Guoqi Zhang","doi":"10.1016/j.ijmecsci.2026.111366","DOIUrl":"10.1016/j.ijmecsci.2026.111366","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This study is motivated by a conceptual inconsistency in the physical interpretation of eight-chain hyperelastic theory, which arises from the combined effect of two distinct issues: the use of the marginal projection distribution &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;z&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;|&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;z&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;|&lt;/mo&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; as a surrogate for the full probability density of end-to-end distance &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mover&gt;&lt;mrow&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;̄&lt;/mo&gt;&lt;/mrow&gt;&lt;/mover&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mover&gt;&lt;mrow&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;̄&lt;/mo&gt;&lt;/mrow&gt;&lt;/mover&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, and the subsequent reliance on a root mean square (RMS) approximation step in the micro–macro averaging of chain stretch. We first revisit this probabilistic mismatch by reformulating the probability density function of freely-jointed chains (FJCs) in terms of the squared end-to-end vector &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;, thereby restoring consistency on chain-level statistics. Building on this formulation, the micro–macro mapping averaging of chain conformational free energy is constructed directly in terms of &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;, leading to a one-step mean-field approximation that avoids RMS averaging. The modified probability transformation is examined by Monte Carlo sampling at the microscopic level. To account for interchain interactions, &lt;span&gt;&lt;math&gt;&lt;mi&gt;q&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;-mean statistical description of micro tube confinement was incorporated, leading to the appearance of the general invariant &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;q&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;λ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;q&lt;/mi&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;λ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;q&lt;/mi&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;λ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;q&lt;/mi&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. The resulting continuum constitutive model is assessed against multiaxial experimental data for several polymer networks, including vulcanized natural rubber, Entec Enflex S4035A thermoplastic elastomer, Tetra-PEG, and isoprene rubber vulcanizate. Comparisons with three existing hyperelastic strain energy formulations, the extended eight-chain, extended tube models, and the four-parameter ”comprehensive” model, demonstrate comparable phenomenological accuracy of the current model while providing a clearer and more consistent micro–macro physical interpretation of model parameters. A parametric study further illustrates how the dimensionless parameters &lt;span&gt;&lt;math&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mi&gt;q&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; govern the shape of the macroscopic stress–strain re","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"314 ","pages":"Article 111366"},"PeriodicalIF":9.4,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tunable low-frequency bandgaps in semi-active quasi-zero-stiffness metamaterial beam","authors":"Changqi Cai ,&nbsp;Xin Guo ,&nbsp;Hongye Ma ,&nbsp;Jiaxi Zhou ,&nbsp;Bo Yan","doi":"10.1016/j.ijmecsci.2026.111360","DOIUrl":"10.1016/j.ijmecsci.2026.111360","url":null,"abstract":"<div><div>Low-frequency structural vibrations are subject to frequency shifts due to changing environmental conditions. To suppress the structural vibrations, a semi-active quasi-zero-stiffness (QZS) metamaterial beam is designed by integrating the compliant and electromagnetic mechanisms for flexural wave attenuation within tunable low-frequency bandgaps. The compliant mechanism is responsible for the QZS-based low-frequency bandgap, while the electromagnetic mechanism enables the semi-active modulation of bandgap frequency by varying the overall stiffness. A simplified theoretical model is established to derive the dispersion relations of the metamaterial beam. The formation and modulation mechanisms of the low-frequency bandgaps are revealed using the transfer matrix method (TMM) and further validated by the spectral element method (SEM). Dynamic experiments are performed to confirm its bandgap modulation performance at low frequencies. Both experiment and theory demonstrate that the semi-active metamaterial beam can effectively regulate low-frequency bandgaps and suppress flexural wave propagation at desired frequencies with only a low coil current. Therefore, the proposed QZS metamaterials should be a promising solution for suppressing elastic waves with varying frequencies in engineering structures.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"314 ","pages":"Article 111360"},"PeriodicalIF":9.4,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Degradation mechanism of subway energy absorber crashworthiness under complex boundaries","authors":"Kun He,&nbsp;Jimin Zhang,&nbsp;Hechao Zhou","doi":"10.1016/j.ijmecsci.2026.111371","DOIUrl":"10.1016/j.ijmecsci.2026.111371","url":null,"abstract":"<div><div>Subway trains operate with high passenger density and complex environments. In collisions, anti-climb energy absorbers may bend under uncertain boundaries, leading to crashworthiness degradation. To clarify this degradation mechanism, an explainable machine learning framework is proposed. First, the sources of uncertain boundary conditions are systematically analyzed, and representative collision parameters are extracted. A quadratic sampling strategy based on local response entropy is developed to construct the collision dataset. Several machine learning models are employed to fit the mapping between boundary conditions and energy-absorption performance, with SHapley Additive exPlanations used to provide explainability of feature contributions. Research findings indicate that absorber alignment and lateral slip are critical factors affecting crashworthiness. Under the most severe boundary conditions, energy absorption decreased by 43.6%. Under single boundary variation, energy absorption exhibits a nonlinear decline as boundary conditions deteriorate. However, under coupled boundary variations, the impact of different boundaries on collision safety shows an intertwined positive and negative pattern. Specifically, when the lateral tilt angle is large, energy absorption first increases and then decreases as lateral displacement increases. This is primarily attributed to the inability of anti-creep teeth to effectively constrain lateral slip. Further explainable analysis quantified the relative contributions of boundary conditions, revealing that vertical displacement is the dominant factor causing collision safety degradation, accounting for over 48% of the contribution. These findings provide theoretical insights and data-driven support for optimizing the design of subway anti-climb energy absorbers.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"314 ","pages":"Article 111371"},"PeriodicalIF":9.4,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermohydrodynamic analysis of liquid metal journal bearings in CT tubes","authors":"Yujie Wang,&nbsp;Shuai Huang,&nbsp;JiongGuang Wei,&nbsp;Jian Li,&nbsp;Wenjun Li,&nbsp;Kai Feng","doi":"10.1016/j.ijmecsci.2026.111365","DOIUrl":"10.1016/j.ijmecsci.2026.111365","url":null,"abstract":"<div><div>Liquid metal journal bearings (LMJBs), employing liquid metal (LM) as a highly conductive and thermally stable lubricant, are increasingly used in CT tubes to withstand high temperatures and dissipate heat. This work establishes a three-dimensional thermohydrodynamic model of the LMJB, incorporating its distinctive features, including herringbone grooves, extreme operating environment, and thermal input from the CT system. Specifically, it accounts for the groove pumping effect, fluid–solid heat transfer interface, vacuum thermal radiation, and high-temperature input at the end-face. Boundary conditions are assigned according to the local thermal characteristics. An experimental rig was built to validate the model by comparing temperatures at different rotational speeds. The temperature distribution was analyzed, and the effects of bearing parameters and operating conditions were assessed. The results show that the grooves induce fluctuations in the temperature. Groove geometry and bearing structural parameters significantly influence the peak temperature. High-conductivity LM or enhanced convective heat transfer effectively lowers the temperature, with the bush as the primary heat dissipation path. Moreover, the heat input from the end-faces has a decisive influence on the bearing temperature. These findings provide guidance for LMJB design and cooling strategies to ensure reliable operation in high performance CT applications.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"314 ","pages":"Article 111365"},"PeriodicalIF":9.4,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predictive model for cutting forces in ultrasonic-assisted friction drilling of Ti-6Al-4V","authors":"Kechuang Zhang,&nbsp;Xian Wu,&nbsp;Shaolong Lin,&nbsp;Yong Zhang,&nbsp;Jianyun Shen,&nbsp;Fuyin Huang","doi":"10.1016/j.ijmecsci.2026.111385","DOIUrl":"10.1016/j.ijmecsci.2026.111385","url":null,"abstract":"<div><div>The precision machining of titanium alloy thin-walled components presents significant challenges in aerospace manufacturing due to intricate cutting force variations during friction drilling machining. To address these challenges, this study proposes and comprehensively investigates an ultrasonic-assisted friction drilling (UAFD) process. An equivalent model of a friction drill bit during ultrasound-assisted friction drilling machining is established, simplifying its complex geometry for analytical tractability while preserving the essential physics of force generation. Based on the intermittent machining mechanism of UAFD machining and the friction drilling mechanism of Ti-6Al-4V, a seven-phase drilling cutting force model is innovatively developed to predict the evolution of cutting forces and torque throughout the entire process. Subsequently, the accuracy of the cutting force prediction of this model is verified by ultrasonic-assisted friction drilling machining experiments. Finally, experiments were conducted on conventional drilling and ultrasonic-assisted friction drilling. The results demonstrate that 28.00 kHz ultrasonic vibration reduces the axial force by 4.31% and the torque by 10.01% through the intermittent cutting mechanism and thermal softening effects, while the peak temperature increases by 1.27%. The accuracy of the model predictions was also validated by experimental results. This research provides theoretical foundations and practical guidelines for implementing energy-field assisted machining in aerospace titanium component manufacturing.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"314 ","pages":"Article 111385"},"PeriodicalIF":9.4,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146152944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-velocity perforation of medium-entropy CrCoNi thin plates by spherical projectiles","authors":"J.C. Cheng ,&nbsp;T. Yang ,&nbsp;L. Wang ,&nbsp;J.Y. Hua ,&nbsp;J.Y. Huang ,&nbsp;L.X. He ,&nbsp;W. Feng ,&nbsp;Y. Cai ,&nbsp;Q.Y. Wang ,&nbsp;S.N. Luo","doi":"10.1016/j.ijmecsci.2026.111364","DOIUrl":"10.1016/j.ijmecsci.2026.111364","url":null,"abstract":"<div><div>High-speed ballistic impacts are carried out with high-speed photography on 2-mm thick CrCoNi alloy plates with 5-mm spherical stainless steel projectiles within the impact velocity range of 514<span><math><mo>−</mo></math></span>1436 m<!--> <!-->s⁻¹. Post-impact samples are characterized by optical imaging, microhardness, electron backscatter diffraction and transmission electron microscopy. With increasing impact velocity, bulging, complete plugging and fragmentation occur sequentially. The ballistic limit velocity for the investigated projectile–target combination is 530 m<!--> <!-->s⁻¹, significantly higher than that of CrMnFeCoNi plate (495 m<!--> <!-->s⁻¹). The area of the crater/bullet hole exhibits a linear relationship with projectile kinetic energy loss. Dislocations, stacking faults, Lomer–Cottrell locks, deformation bands and various twin variants, contribute to enhanced strain-hardening capacity and penetration resistance. The bending of the target plate induced by low-velocity impact leads to additional plastic deformation and higher microhardness. Based on the Johnson–Cook constitutive model and the damage criterion, the finite element simulations effectively reproduce the ballistic impact experiments. Molecular dynamics simulations reproduce microstructural evolution at the atomic scale. The <span><math><mrow><mfenced><mrow><mn>111</mn></mrow></mfenced><mfenced><mrow><mn>11</mn><mover><mrow><mn>2</mn></mrow><mrow><mo>̄</mo></mrow></mover></mrow></mfenced></mrow></math></span> and <span><math><mrow><mfenced><mrow><mn>11</mn><mover><mrow><mn>1</mn></mrow><mrow><mo>̄</mo></mrow></mover></mrow></mfenced><mfenced><mrow><mn>112</mn></mrow></mfenced></mrow></math></span> twin variants are simultaneously activated, because of the equivalence of the twin planes and twin directions of these two variants relative to the <span><math><mfenced><mrow><mover><mrow><mn>1</mn></mrow><mrow><mo>̄</mo></mrow></mover><mn>10</mn></mrow></mfenced></math></span> impact direction. This study presents the high-velocity perforation failure behavior of this medium-entropy alloy, elucidates the deformation and damage mechanisms, and provide valuable insights for its safety assessment and material/structural optimization design in extreme loading environments.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"314 ","pages":"Article 111364"},"PeriodicalIF":9.4,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A pretraining-finetuning computational framework for material homogenization","authors":"Yizheng Wang ,&nbsp;Xiang Li ,&nbsp;Ziming Yan ,&nbsp;Shuaifeng Ma ,&nbsp;Jinshuai Bai ,&nbsp;Bokai Liu ,&nbsp;Xiaoying Zhuang ,&nbsp;Timon Rabczuk ,&nbsp;Yinghua Liu","doi":"10.1016/j.ijmecsci.2026.111388","DOIUrl":"10.1016/j.ijmecsci.2026.111388","url":null,"abstract":"<div><div>Homogenization is a fundamental tool for studying multiscale physical phenomena. Traditional numerical homogenization methods, heavily reliant on finite element analysis, demand significant computational resources, especially for complex geometries, materials, and high-resolution problems. To address these challenges, we propose PreFine-Homo, a novel numerical homogenization framework comprising two phases: pretraining and fine-tuning. In the pretraining phase, a Fourier Neural Operator (FNO) is trained on large datasets to learn the mapping from input geometries and material properties to displacement fields. In the fine-tuning phase, the pretrained predictions serve as initial solutions for iterative algorithms, drastically reducing the number of iterations needed for convergence. The pretraining phase of PreFine-Homo delivers homogenization results up to 1000 times faster than conventional methods, while the fine-tuning phase further enhances accuracy. Moreover, the fine-tuning phase grants PreFine-Homo improved generalization capabilities, enabling continuous learning and improvement as data availability increases. We validate PreFine-Homo by predicting the effective elastic tensor for 3D periodic materials, specifically Triply Periodic Minimal Surfaces (TPMS). The results demonstrate that PreFine-Homo achieves high precision, exceptional efficiency, robust learning capabilities, and strong extrapolation ability, establishing it as a powerful tool for multiscale homogenization tasks. The source code is publicly available at: <span><span>https://github.com/yizheng-wang/HomoGenius</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"314 ","pages":"Article 111388"},"PeriodicalIF":9.4,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146160873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}