International Journal of Mechanical Sciences最新文献

{"title":"Rigid-foldable spiral origami with compression-torsion coupled motion mode","authors":"","doi":"10.1016/j.ijmecsci.2024.109726","DOIUrl":"10.1016/j.ijmecsci.2024.109726","url":null,"abstract":"<div><p>Rigid foldable origami enables smooth and precise folding without stretching or bending its constituent panels and is promising for applications such as reprogrammable matter, self-folding machines, reconfigurable antennas, and deployable spacecraft. The diverse range of potential applications necessitates the need for the design and detailed analysis of different rigid-foldable origami structures, especially those with intricate motion modes. In this paper, we introduce a rigid-foldable spiral origami design that features a compression-torsion coupled motion mode. This design exhibits rich static and dynamic properties. Under static conditions, the compression-torsion coupled motion mode creates multiple self-locking positions and allows for the development of mechanical static diodes. Under dynamic conditions, the compression-torsion coupling effect in the spiral origami facilitates precise control of wave modes within the origami chain when impacted by a ball with a moderate initial velocity. In the case of large initial velocities of the ball, the spiral origami can function as a wave generator, producing rarefaction solitary waves or compressive solitary waves. The proposed spiral origami design provides an opportunity to explore new applications of rigid-foldable origami with compression-torsion coupling effects.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142232557","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":"Mesoscopic simulation of concrete drying shrinkage with hydration kinetics","authors":"","doi":"10.1016/j.ijmecsci.2024.109716","DOIUrl":"10.1016/j.ijmecsci.2024.109716","url":null,"abstract":"<div><p>Shrinkage-induced cracking significantly impacts the durability of mass concrete structures. Quantitatively evaluating drying shrinkage of concrete proves challenging due to the time-consuming experiments and overlooked microstructure changes during the hydration process. To address this concern, this study initially characterized the long-term hydration products and microstructure of low-heat Portland cement (LHPC) through microstructural experiments. Subsequently, a novel high-resolution mesoscale framework is developed to investigate the drying shrinkage with hydration kinetics. High-resolution models consist of realistic-shaped aggregates are validated by the aggregate morphology and gradation parameters of core sample from mass concrete. Concurrently, the quantitative effects of internal and external factors on LHPC drying shrinkage are explored. Results indicated that LHPC possesses a denser microstructure, lower porosity, higher carbonation resistance, and 20% lower drying shrinkage compared to moderate-heat Portland cement, suggesting promising applications. Furthermore, experimental and computational findings suggested that increasing aggregate volume, controlling aggregate morphology, and adjusting curing time and humidity could be employed to reduce and manage drying shrinkage, ensuring concrete structure durability.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142232558","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":"Elimination of satellite droplets in droplet streams by superposing harmonic perturbations","authors":"","doi":"10.1016/j.ijmecsci.2024.109723","DOIUrl":"10.1016/j.ijmecsci.2024.109723","url":null,"abstract":"<div><div>In tin-droplet laser-produced plasma sources, uniform droplet streams with large droplet spacing are desired to minimize the interference of explosion on neighboring droplets. Such droplet streams can be generated in low wavenumber regimes. However, satellite droplets easily appear among main droplets in those regimes, resulting in plenty of undesirable debris. Herein, a novel odd harmonic superposition perturbation method is proposed to eliminate satellite droplets and enhance droplet spacing of uniform droplet streams. The superposition number (<em>N</em>) and the phase difference (<em>θ</em>) of odd harmonic perturbations are adjusted to facilitate the coalescence of satellite droplets with main droplets. First, the superposed odd-order harmonic components could induce additional disturbance growth in jet surfaces, and finally lead to the asymmetric necking on filaments formed between two adjacent main droplets, featured as various carrot-shaped configurations. This asymmetric necking will cause unbalanced surface tension forces at the two sides of filaments, resulting in a velocity difference between satellite and main droplets. Based on this principle, by setting <em>N</em> and <em>k</em> to 3 and 0.2, respectively, satellite droplets positioned above main droplets accelerate, while those below decelerate, achieving complete coalescence between main and satellite droplets. Furthermore, the phase difference is found to determine the jet breakup location and satellite droplet merging characteristics. As <em>θ</em> varies from 0° to 90°, the droplet size significantly decreases while the droplet spacing remains constant since the perturbation energy increases. The merge direction of satellite droplets reverses from upward to downward due to enhanced unbalanced surface tension forces and velocity differences. As <em>θ</em> continuously increases to 270°, the droplet size further decreases along with a slight decrease in droplet spacing. Finally, by setting <em>N</em> = 3 and <em>θ</em> = 0°, mono-disperse tin droplet streams with a mean diameter of 31.5 μm and a maximum droplet spacing-to-diameter ratio of 17.7 are successfully formed. This work presents a novel approach for eliminating satellite droplets to achieve uniform tin droplet streams with large droplet spacing without increasing the droplet diameter.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445913","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":"Curved-crease origami hybrid structures with tailorable buckling and energy absorption","authors":"","doi":"10.1016/j.ijmecsci.2024.109724","DOIUrl":"10.1016/j.ijmecsci.2024.109724","url":null,"abstract":"<div><div>Origami-inspired structures (OIS), renowned for their lightweight design, encounter energy absorption challenges attributed to global buckling. This paper presents a design and hybridization strategy that integrates origami-inspired structures with existing state-of-the-art cellular lattices to create origami-inspired hybrid structures (OIHS), aimed at addressing buckling concerns and customizing the crushing behavior of thin-walled structures. The investigation explores the compressive response of additively-manufactured curved crease OIS and prismatic structures (PS) with diverse cross-sections, including circular origami structure (COS), triangular origami structure (TOS), square origami structure (SOS), and hexagon origami structure (HOS). The experimental results indicate that the COS design offered the highest specific energy absorption (SEA) of 11 kJ/kg, due to controlled deformation associated with the crease lines. The COS hybridized structure, with cellular lattices, exhibited a yielding-dominated behavior, resulting in a lower peak force, a sustained plateau force and a well-controlled deformation response. Furthermore, the COS hybridized with a plate lattice, exceeded the SEA of the auxetic and BCC OIHS structures by 62 % and 71 %, respectively. The circular origami plate hybrid (COPH) design was selected to investigate the effect of varying the top edge angle (α) and the relative density on the mechanical properties and the SEA. It was found that increasing the value of alpha resulted in a higher peak stress and an increased buckling load. Moreover, with its higher relative density, the vertical plate within the OIS contributed to a greater level of structural stability in the plateau region, resulting in an increase in mechanical properties and SEA. These findings advance the understanding of OIS by presenting effective hybridization strategies to mitigate buckling and achieve stable plateau stresses and higher crushing force efficiencies, particularly at lower relative densities, surpassing those reported in the literature. This contributes significantly to the broader field of lightweight structural design.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020740324007653/pdfft?md5=66d9d3343b2cb4f20f9574e5912d622a&pid=1-s2.0-S0020740324007653-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142313020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Group-random algorithm to generate representative volume element models for composites","authors":"","doi":"10.1016/j.ijmecsci.2024.109714","DOIUrl":"10.1016/j.ijmecsci.2024.109714","url":null,"abstract":"<div><p>One of the most commonly used methods for characterizing the mechanical properties of discontinuous fiber reinforced composites (DFRC) is to establish a Representative Volume Element (RVE) model and perform finite element (FE) analysis. However, FE analysis on RVE models established by traditional sampling algorithms is often computationally expensive due to the large size of RVE that is required to be statistically representative of the composite. To address this issue, this paper proposes a new approach for constructing RVE models with more accurate description of fiber orientation, aiming to make the FE modelling more efficient by using an RVE with small size. When establishing RVE models with given target fiber orientation tensor, it is very challenging to accurately capture the orientation of fibers. In order to mitigate the error between the orientation tensor reconstructed by fibers generated in the RVE and the target orientation tensor, a group-random algorithm is proposed in the current work to generate RVE models. Unlike the traditional algorithm, in which fibers are sampled one by one in the RVE, the group-random algorithm samples a group of four fibers at one time in order to eliminate the error of the off-diagonal components of the reconstructed orientation tensor in the principal coordinate system. Then a modification tensor is further introduced to mitigate the error of the diagonal components of the reconstructed orientation tensor. Simulation results show that the orientation tensor error could be significantly reduced by the group-random algorithm even for the RVE with low number of fibers. The merits of the group-random algorithm are also witnessed by the stability and accuracy of predicting the elastic constants of composite materials through RVE modeling. It is thus concluded that the major advantage of this work is to provide an alternatively feasible strategy to substantially improve computational efficiency of RVE modelling.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142232556","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":"Jet array impingement heat transfer in a rectangular cavity with effusion holes","authors":"","doi":"10.1016/j.ijmecsci.2024.109698","DOIUrl":"10.1016/j.ijmecsci.2024.109698","url":null,"abstract":"<div><p>Various researchers have studied jet array impingement heat transfer in impingement/effusion cooling systems. However, there is a lack of research on impingement/effusion cooling systems installed within rectangular cavities that focus on the impact of the proximity of the jet hole to the cavity sidewalls on cooling performance. The main objective of this study is to investigate the flow and heat transfer characteristics of jet array impingement with effusion holes in a rectangular cavity, considering various spacings between the cavity sidewalls and the outermost jet hole. The design parameters in this study include the ratio of the jet hole pitch to jet hole diameter of 7.1, 10.0, and 16.7, and the ratio of the distance between the jet and impingement plates to jet hole diameter of 2, 6, and 10, with the Reynolds number based on the jet hole diameter ranging from 2500 to 15,000. Heat transfer characteristics in the stagnation region and wall jet region were examined using local Nusselt number distributions on the impingement surface, measured by liquid crystal thermography. The local Nusselt number was high in the stagnation region and decreased radially from the stagnation region as the wall jet region formed. The closer the outermost jet hole is to the sidewall, the higher the Nusselt number on the impingement surface near the sidewall. Moreover, the flow structure in the rectangular cavity was numerically investigated, and the velocity vectors and streamlines showed that primary and secondary vortices were generated in the middle of two neighboring jets and near the sidewall, respectively. This study also assessed previous average Nusselt number correlations. Based on experimentally determined average Nusselt number data with 54 center unit cells and 1296 side unit cells, new correlations to predict the average Nusselt number on the impingement surface in a rectangular cavity with effusion holes were developed.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271733","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":"Embodiment of parallelizable mechanical logic utilizing multimodal higher-order topological states","authors":"","doi":"10.1016/j.ijmecsci.2024.109697","DOIUrl":"10.1016/j.ijmecsci.2024.109697","url":null,"abstract":"<div><p>The dramatic advancement of autonomous engineering systems has fueled a surge of research interest in materials and structures embodying intelligence within the mechanical domain. Fundamental to achieving this mechanical intelligence is the ability to process information using the mechanics and dynamic characteristics of structures, such as wave propagation. While utilizing elastic waves for information processing and computing is a promising concept, a critical issue for current platforms is the lack of robust wave transmission that is insensitive to material or structural imperfections. The goal of this research is to overcome this obstacle by leveraging the extraordinary elastic wave control capabilities of higher-order topological metamaterials. More specifically, this work uncovers a novel approach that harnesses multimodal higher-order topological states to achieve robust and frequency-selective mechanical logic. Multimodal resonance is engineered into a 2D higher-order topological metamaterial to create 0D corner states that emerge in eight distinct frequency bands and have a rich collection of displacement field characteristics. A new phase-engineering strategy is synthesized that encodes binary information within the corner states to achieve eight fundamental mechanical logic gates. Crucially, this approach produces an easily detectable mechanical signal due to the temporal and spatial confinement of the higher-order topological states. The multifaceted frequency-dependent features of the corner states are innovatively employed to provide the logic gates with frequency-selective functionality and parallelize unique logic operations across multiple frequency channels. The mechanical logic uncovered in this study will pave the way for future intelligent structures that are much more resilient to cyberattacks and harsh environments, as compared to current systems that are built solely on electronics-based logic.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142241098","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":"Finishing mechanism of stably rotary ring workpiece by friction driven","authors":"","doi":"10.1016/j.ijmecsci.2024.109695","DOIUrl":"10.1016/j.ijmecsci.2024.109695","url":null,"abstract":"<div><p>High-Performance Ring Parts (HPRPs) are widely used in various critical industrial fields, which require good surface quality and dimensional accuracy. The fine finishing of HPRPs is crucial in modern manufacturing. For traditional finishing methods, it is necessary to process the inner and outer surfaces separately due to the clamping. This paper reports on the floating clamp used in barrel finishing to realize the rotation of the ring workpiece by friction driven and uniform finishing of the outer surface and inner surface simultaneously. This work focuses on the finishing mechanism of the ring workpiece, which was rotated stably by friction driven. The constraint rule for the stable rotation of the ring workpiece was clarified by theoretical, simulation, and experimental methods. Subsequently, the action mode and strength of media on the inner and outer surface were studied by contact pressure distribution. Results show that the action strength of media on the inner surface is more significant than that on the outer surface. The finishing experiment is performed on the GCr15 ring workpiece under the condition that the distribution circle diameter is 70 mm, the number of support bars is 6, the angular speed of vessel is 60 rpm, and the filling level is 70 %. The surface roughness, topography, and morphology of finished and unfinished workpiece were analyzed to understand the finishing mechanism. It was found that the cutting induced by sliding is the dominant finishing mechanism of the inner surface, while the micro-ploughing and plastic deformation induced by impact are the dominant finishing mechanism of the outer surface.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142229667","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":"Deep learning identifies transversely isotropic material properties using kinematics fields","authors":"","doi":"10.1016/j.ijmecsci.2024.109672","DOIUrl":"10.1016/j.ijmecsci.2024.109672","url":null,"abstract":"<div><p>Determining the stress-strain relationship in materials that exhibit complex behaviors, such as anisotropy, is pivotal for applications in structural engineering and materials science, as the behavior of materials under stress directly impacts safety and performance. This study introduces an innovative approach that leverages Artificial Intelligence (AI) through deep learning (DL) techniques to accurately predict transversely isotropic material properties using kinematic fields. These kinematic fields are derived from Finite Element Method (FEM) computations, which can realistically be obtained through advanced image correlation techniques, ensuring high precision and applicability in real-world scenarios. The objective of this research is to precisely characterize the behavioral parameters governing transversely isotropic materials. This methodology can also be applied to other constitutive laws, extending its utility across different material models. The proposed methodology, which utilizes a multi-scale encapsulated AI architecture, not only provides nearly instantaneous analytical solutions but also achieves remarkable accuracy, with average errors in parameter identification remaining below 3 % across all parameters. This sophisticated AI model plays a crucial role in accurately ascertaining the mechanical properties of transversely isotropic materials. By offering a method that is significantly faster and more precise than traditional experimental techniques, this research advances the current understanding of transversely isotropic materials' behavior. Such improvements in analysis speed and accuracy facilitate quicker iterations in material design and testing, potentially accelerating advancements in materials science and engineering applications.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142163263","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":"Optimal design of cavity-free mechanical metamaterials exhibiting negative thermal expansion","authors":"","doi":"10.1016/j.ijmecsci.2024.109693","DOIUrl":"10.1016/j.ijmecsci.2024.109693","url":null,"abstract":"<div><p>In this study, we present a novel topology-optimized design of a two-dimensional cavity-free mechanical metamaterial with a negative coefficient of thermal expansion. We challenge the prevailing hypothesis that cavities are necessary for achieving negative coefficients of thermal expansion. The proposed metamaterial is a periodic lattice of a topology-optimized unit cell comprising three distinct solid materials, analyzed using a homogenization method. To confirm the negative thermal expansion of the optimized structures, we present some numerical experiments of the optimized designs and analyze the deformation of the metamaterial under temperature variations.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020740324007343/pdfft?md5=aeb2249ee914dda9fd3d1b1ffc4d1dea&pid=1-s2.0-S0020740324007343-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142151159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}