Acta Mechanica Sinica最新文献

{"title":"The stress transfer mechanism of nacre-like composites under off-axis tensile loading","authors":"Peng Jiang \u0000 (,&nbsp;),&nbsp;Guangming Xia \u0000 (,&nbsp;),&nbsp;Shi Bai \u0000 (,&nbsp;),&nbsp;Dongfang Xu \u0000 (,&nbsp;),&nbsp;Jixiang Qi \u0000 (,&nbsp;),&nbsp;Xun Xiong \u0000 (,&nbsp;),&nbsp;Xianben Ren \u0000 (,&nbsp;),&nbsp;Ying Li \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24547-x","DOIUrl":"10.1007/s10409-024-24547-x","url":null,"abstract":"<div><p>Nacre exhibits excellent mechanical properties attributed to the staggered alignment of inorganic minerals and bio-organic materials. This study aims to understand how stress transfers from macro-scale loading conditions to the staggered architecture, revealing multiple stress transfer modes in nacre-like composites under off-axis tensile loading conditions. We propose an innovative off-axis tension-shear chain model, which predicts the trend of the equivalent modulus. Systematic optimization reveals a counter-intuitive result: the equivalent modulus at a certain angle can be smaller than the equivalent moduli in both principal directions, and this phenomenon differs from the monotonic behavior commonly observed in continuous fiber composite materials.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 2","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144125513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Post-buckling analysis of square film under in-plane torsion: experiment and simulation comparisons","authors":"Yiming Shan \u0000 (,&nbsp;),&nbsp;Liang Wang \u0000 (,&nbsp;),&nbsp;Wenwang Wu \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24609-x","DOIUrl":"10.1007/s10409-024-24609-x","url":null,"abstract":"<div><p>Thin-film structures are widely used in industry due to their advantages in lightweight, flexibility and deployability. This paper investigates the wrinkling deformation pattern of square film subjected to in-plane torsion through the post-buckling theory of shell, with the geometric nonlinear behavior derived by energy principle and analyzed with finite element method. An equal-sized experimental verification platform is designed and fabricated, and the wrinkling surface of polyimide film driven by rotary motor is reconstructed by 3D-digital image correlation measurement and verified with finite element simulation comparisons. Wrinkling region within the film expands continuously as the torsion proceeds, accompanied by multiple wrinkling configuration transitions throughout the complete evolutionary process. Due to the non-axial symmetry between structure and loading, significant discrepancies arise in amplitude, span and wavelength between different stripes, effects of thickness, torsion radius and pre-stretch on wrinkling pattern configuration are further discussed. This study can provide valuable references for understanding the wrinkling mechanism of hard film under complex torsion loading.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144125512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the dynamic mechanical properties of additive manufactured Ti-6Al-4V alloys: the effect of impact orientation and heat treatment","authors":"Yihang Cui \u0000 (,&nbsp;),&nbsp;Zhiguo Li \u0000 (,&nbsp;),&nbsp;Ling Hu \u0000 (,&nbsp;),&nbsp;Yuying Yu \u0000 (,&nbsp;),&nbsp;Jianbo Hu \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24138-x","DOIUrl":"10.1007/s10409-024-24138-x","url":null,"abstract":"<div><p>Ti-6Al-4V is a high-strength alloy widely used in various industries due to its exceptional mechanical properties. This study focuses on the dynamic mechanical behavior of Ti-6Al-4V alloys manufactured through additive manufacturing techniques, specifically selective laser melting (SLM), which enables the production of complex structures with high precision. The microstructure of Ti-6Al-4V is influenced by the thermal conditions during solidification, resulting in variations in grain size, morphology, and crystallographic texture. We investigate the effects of impact direction and heat treatment processes on the dynamic mechanical properties of SLM Ti-6Al-4V alloys through one-dimensional plate impact loading experiments. Our microscopic characterizations reveal two types of spall damage mechanisms in the SLM samples, influenced by the impact directions and velocities. Interestingly, the strength of SLM samples exhibits minimal anisotropy, indicating little difference in spall strength between different impact directions. Moreover, we found that the Hugoniot elastic limit of SLM samples shows greater sensitivity to impact velocity than the traditionally wrought samples. Wrought Ti-6Al-4V demonstrates superior dynamic tensile strength compared to SLM counterparts. Furthermore, we analyze the impact of heat treatment on the SLM Ti-6Al-4V samples. The phase composition and texture undergo changes during recrystallization, with the non-equilibrium acicular <i>α</i>′ martensite transforming into an equilibrium (<i>α</i>+<i>β</i>) microstructure. This recrystallization process leads to a decline in the dynamic tensile properties of the SLM samples. Our findings contribute to a better understanding of the dynamic behavior and spallation damage mechanisms of SLM Ti-6Al-4V alloys.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 2","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144125750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructure and properties of selective laser melted Alx CoCrFeNi high entropy alloy via molecular dynamics simulation","authors":"Jiajun Liu \u0000 (,&nbsp;),&nbsp;Jing Peng \u0000 (,&nbsp;),&nbsp;Weipeng Li \u0000 (,&nbsp;),&nbsp;Hui Feng \u0000 (,&nbsp;),&nbsp;Shenyou Peng \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24311-x","DOIUrl":"10.1007/s10409-024-24311-x","url":null,"abstract":"<div><p>Selective laser melting (SLM), as an additive manufacturing technology, has garnered widespread attention for its capability to fabricate components with complex geometries and to tailor the microstructure and mechanical properties under specific conditions. However, the intrinsic influence mechanism of microstructure formation under non-equilibrium solidification conditions in SLM processes has not been clearly revealed. In the present work, the influence of Al concentration and process parameters on the microstructure forming mechanism of Al_<i>x</i>CoCrFeNi HEAs prepared by SLM is investigated by molecular dynamics simulation method. The simulation results show that the difference in Al content significantly affects the microstructure formation of HEAs, including the growth rate and morphology of columnar crystals, stress distribution at grain boundaries, and defect structure. In addition, the results show that increasing the substrate temperature improves the solidification formability, reduces microstructural defects, and helps reduce residual stress in Al_<i>x</i>CoCrFeNi HEAs. By analyzing the influence of heat and solute flow in the molten pool on the growth of columnar crystals, it is found that spatial fluctuations in Al concentration during the non-equilibrium solidification process inhibit the high cooling rates induced by steep temperature gradients. These findings promote the understanding of the forming mechanism of microstructure in HEAs prepared by SLM and provide theoretical guidance for designing high-performance SLM-fabricated HEAs.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144125821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics and vibration reduction performance of a cross-type motion amplified nonlinear energy sink","authors":"Yu-Fei Shao \u0000 (,&nbsp;),&nbsp;Jin-Chen Ji \u0000 (,&nbsp;),&nbsp;Hu Ding \u0000 (,&nbsp;)","doi":"10.1007/s10409-025-24948-x","DOIUrl":"10.1007/s10409-025-24948-x","url":null,"abstract":"<div><p>Suppressing micro-amplitude vibrations is a critical issue in aerospace engineering. While nonlinear energy sinks (NES) are effective for passive vibration damping, their performance diminishes for micro-amplitude vibrations. This paper introduces a motion-amplified NES (MANES) to address this challenge. The system’s governing equations are derived using Hamilton’s principle, and an approximate analytical solution is validated by numerical methods. The effects of various parameters are explored, with higher vibration reduction efficiency achievable through parameter adjustments. Compared to cubic NES, MANES shows superior vibration suppression and a broader reduction bandwidth for micro-amplitude excitations. Additionally, MANES enters the effective vibration reduction range at lower excitation levels, indicating a reduced threshold for vibration suppression. This study provides insight into the vibration suppression mechanism of MANES, offering a theoretical foundation for mitigating micro-amplitude vibrations in engineering applications.</p></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 7","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The potential influence study of a nonlinear layer on a vibroacoustic coupling system","authors":"Yuhao Zhao \u0000 (,&nbsp;),&nbsp;Yilin Chen \u0000 (,&nbsp;),&nbsp;Rongshen Guo \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24570-x","DOIUrl":"10.1007/s10409-024-24570-x","url":null,"abstract":"<div><p>Vibroacoustic coupling systems widely exist in various engineering fields, and controlling their vibration and noise is essential. Unfortunately, the existing literature lacks research on the vibroacoustic coupling system composed of multi-plates and a cavity with nonlinear factors, limiting the application of nonlinear factors in controlling the vibration and noise of the vibroacoustic coupling system. This work aims to explore the effect of the nonlinear layer on the behavior of a vibroacoustic coupling system, where the behavior of the vibroacoustic coupling system motivated by the nonlinear layer and the vibroacoustic behavior under constant frequencies caused by the nonlinear layer is systematically studied. It can be found that the behavior of the vibroacoustic coupling system with a nonlinear layer can be correctly predicted by using the Lagrange method. The nonlinear layer establishes a new vibration-converting pathway of the vibroacoustic coupling system. A reasonable nonlinear layer is suitable for controlling the vibration of plate 2 and the sound pressure of the cavity. In a reasonable variation range, adjusting key parameters of the nonlinear layer is a feasible way to artificially control the unconventional responses under constant frequencies of the vibroacoustic coupling system. Overall, the introduction of the nonlinear layer provides a possible approach to control the vibroacoustic coupling system’s behavior, providing a new perspective to utilize the nonlinear layer in controlling the vibroacoustic coupling system.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 2","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144125724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response of wind turbine loads to multi-scale turbulent structures: a study based on turbulence signals observed in the field","authors":"Yongfen Chai \u0000 (,&nbsp;),&nbsp;Yan Wang \u0000 (,&nbsp;),&nbsp;Haolin Li \u0000 (,&nbsp;),&nbsp;Jingjing Zhang \u0000 (,&nbsp;),&nbsp;Jian Zheng \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24721-x","DOIUrl":"10.1007/s10409-024-24721-x","url":null,"abstract":"<div><p>Accurately assessing the impact of turbulence structures on load fluctuation is crucial for the long-term stable operation of wind turbines. Based on turbulence signals observed at the Qingtu Lake Observed Array in China, the aerodynamic load responses of the wind turbine to different turbulence scales are quantitatively analyzed in this study. The results indicate that very large-scale motions (VLSMs) are associated with significant load fluctuations due to its low frequency and high energy characteristics, increasing the risk of extreme loads. Large-scale motions coupled with the natural frequency of wind turbines in the medium frequency range, result in resonance phenomena. Small-scale motions, due to their high-frequency rapid vibration characteristics, cause instantaneous oscillations in wind turbine loads. Furthermore, correlation analysis indicates that the flapwise moment and thrust are most sensitive to VLSMs, while the edgewise moment is less affected by the scale characteristics. It is worth noting that this study is the first to explore the modulation effects of different scales of turbulent structures on the amplitude of wind turbine load fluctuation. It was found that turbulent structures exceeding a scale of 3<i>δ</i> have the most significant impact on modulating the load amplitudes, where <i>δ</i> is the boundary layer thickness, which is 99% of the flow velocity outside the boundary layer. These findings contribute to the enhancement of understanding regarding the load response of wind turbines in multi-scale turbulent environments and provide important references for the optimization of wind turbine design and load control.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 2","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144125742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling of curing process and residual stress analysis of thick-section thermosetting composites","authors":"Yongshan Li \u0000 (,&nbsp;),&nbsp;Guangchang Chen \u0000 (,&nbsp;),&nbsp;Jingran Ge \u0000 (,&nbsp;),&nbsp;Kai Liu \u0000 (,&nbsp;),&nbsp;Jun Liang \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24411-x","DOIUrl":"10.1007/s10409-024-24411-x","url":null,"abstract":"<div><p>The curing behavior of composites significantly influences their performance, making it crucial to understand the curing process. This study experimentally measured specific heat capacity, thermal conductivity, glass transition temperature, coefficient of thermal expansion, and cure shrinkage of materials. A simulation model of its curing deformation was established and validated against strain data obtained from fiber Bragg grating experiments. The effects of thickness, heating rate, and cooling rate on the curing temperature field and residual stress field during the molding of thick-section composite plates were analyzed.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144135331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights into the role of thalamus interneurons in regulating seizure-like discharges under electromagnetic internal induction and external radiation","authors":"Luyao Yan \u0000 (,&nbsp;),&nbsp;Honghui Zhang \u0000 (,&nbsp;),&nbsp;Zhongkui Sun \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24543-x","DOIUrl":"10.1007/s10409-024-24543-x","url":null,"abstract":"<div><p>A series of experimental findings provide compelling evidence that GABAergic interneurons (TIN) in the thalamus play a potential role in the generation of absence seizures. Recently, we establish a thalamocortical model to investigate the epilepsy mechanism with a primary focus on such interneurons. The proposed model produces epileptic discharges driven by inhibition projections from TIN population, which matches the basic experimental observations. Also, pyramidal (PY) population has excitatory projection to TIN and constructs the feed-forward inhibition circuit PY-TIN-TC which can also result in transition behaviors from background to seizure state. Notably, we explain the seizure production and transition to unveiling intrinsic mechanisms through bifurcation analysis. As an important intervention in epilepsy treatment, the electromagnetic effect on epileptic activity is further explored. It shows the significant role of electromagnetic induction <i>k</i>₀ in controlling generalized seizures, which is strengthened by the feedback gain from populations to magnetic flux <i>k</i>₁ and weakened by the self-feedback gain of magnetic flux <i>k</i>₂. For the weak electromagnetic induction (<i>k</i>₀ &lt; 0.1), the seizure rate is still up to 50%, and we apply external electromagnetic radiation to further regulate. It is observed that the external electromagnetic radiation has a remarkable modulation of absence seizures with optimal stimulus parameters. Overall, this work not only reveals the mechanism of thalamus interneurons in seizures, but, more importantly, provides a theoretical basis for electromagnetic therapy in epilepsy regulation.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 2","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144135352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of morphological profile of dandelion-seed on flight lift force under crosswind","authors":"Lang Qin \u0000 (,&nbsp;),&nbsp;Huasong Qin \u0000 (,&nbsp;),&nbsp;Lifeng Ma \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24496-x","DOIUrl":"10.1007/s10409-024-24496-x","url":null,"abstract":"<div><p>In this paper, the effect of the morphological profile of dandelion seed on flight lift force under crosswind conditions is explored. Existing studies primarily focus on the flight characteristics of dandelion seed during its fall, emphasizing the influence of the complex filament structure on the formation of wake vortices. However, research on the flight lift force due to the dandelion seed’s morphological profile under lateral crosswind conditions is quite limited. This study investigates the aerodynamic behavior of dandelion seed using a novel virtual barrier model. This model is proposed, based on the regular pattern of the filaments’ outer contours and the virtual barrier effect produced by their columnar array. Through elaborate numerical simulations, it is found that the morphological profile of dandelion seed possesses superior aerodynamic properties, particularly in generating lift force under crosswind conditions. This characteristic is a crucial mechanism for the long-distance dispersal of dandelion seed. Subsequently, the study extends to examine the aerodynamic performance of the model at varying degrees of opening angles and inflow attack angles, offering a fresh perspective on understanding the flight characteristics of dandelion seed in natural environments. The findings not only contribute to the field of plant aerodynamics but also provide insights into potential biomimetic applications in engineering.</p></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 12","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}