International Journal of Mechanical Sciences最新文献

{"title":"An intelligent design system for tailored metamaterial properties","authors":"","doi":"10.1016/j.ijmecsci.2024.109595","DOIUrl":"10.1016/j.ijmecsci.2024.109595","url":null,"abstract":"<div><p>Metamaterials are widely studied for their ability to carry human designs and realize exotic, specific physical properties. However, the existing metamaterial design methods are highly dependent on the experience and expertise of the designers. Unlocking the potential of metamaterials requires efficient design methods accessible beyond expert users. This work presents a novel intelligent design system (IDS) for fabricating metamaterials with designated mechanical properties without extensive expertise. The IDS leverages a combined approach of particle swarm and moving morphable components topology optimization, capitalizing on swarm intelligence for efficient material structure generation. The proposed IDS successfully generates tailored metamaterial matrices exhibiting desired elastic properties like Poisson's ratio and elastic modulus for orthotropic and isotropic materials. Innovative development of fuzzy models is achieved to optimize convergence mapping of isotropic mechanical metamaterials for user guidance. Notably, it achieves this even without requiring an initial design, completing the process within minutes and offering seamless integration with MATLAB for portability. From the pre-determination of convergence before design to the export of fabrication models after design, IDS provides a new path to designing metamaterials without needing research experience. This comprehensive, user-friendly system holds immense potential for expansion into 3D design and various metamaterial classes, acting as a valuable bridge for non-experts to achieve metamaterial design.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141842663","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 energy absorption design of porous metals using deep learning","authors":"","doi":"10.1016/j.ijmecsci.2024.109593","DOIUrl":"10.1016/j.ijmecsci.2024.109593","url":null,"abstract":"<div><p>Due to its remarkable energy absorption properties, porous metals have widespread applications in engineering. However, the high randomness of pore morphology greatly hinders the effective design and analysis of high energy absorption structures. To address this challenge, this paper first introduces a deep learning-based framework for high energy absorption-oriented design of random porous metals structures. The framework comprises two steps: (i) a generator powered by Wasserstein deep convolutional generative adversarial network is developed to swiftly generate a vast design space (∼one million samples) of porous metals with real random pore morphology. (ii) an inverse search strategy based on convolutional neural network is applied to quickly pick out the optimal structure with the best energy absorption from the design space. Results show that the optimal energy absorption is about 17.71 % higher than the maximum value of initial structures from CT scan. Additionally, a 575-fold increase in computational efficiency is achieved compared to the traversal search using finite element method. Subsequently, the deformation process of the optimal structure is analyzed focusing on the pore morphology and compression performance, showing that random porous metals with uniformly sized pores are capable of withstanding higher stress under the same strain and exhibit no yield band during compression. Inspired by this, a structural homogenization method is introduced and validated to create porous metal structure with stable microstructure evolution, extended plateau stress and high energy absorption.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141849048","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":"Design and analysis of rigid-elastic coupling origami flashers with bistable characteristics","authors":"","doi":"10.1016/j.ijmecsci.2024.109602","DOIUrl":"10.1016/j.ijmecsci.2024.109602","url":null,"abstract":"<div><p>Origami flashers are frequently used in the design of deployable structures due to their large storage ratio and simple structure. However, origami flashers are not foldable without the flexible deformation of the structural components. On the other hand, conventional origami flashers could not be maintained in the deployed configuration with enough supporting stiffness because of the flexibility of the facets and creases, which limits their practical applications. By analyzing the mobility of the rigid origami flashers, we find that the origami flashers have a bistability-like property. Based on this, we propose a method to design rigid-elastic coupling origami flashers with bistable characteristics. The rigid-elastic coupling origami flashers consist of rigid facets, zero-stiffness creases, and elastic ropes. The bistable folding characteristics are analyzed by theoretical models, and demonstrated by numerical methods and experiments. Such bistable characteristics allow for the deployment of the origami with less energy consumption, while achieving greater supporting stiffness in the deployed configuration. The effect of different parameters on the dynamic performance is also investigated. A fabrication method of the novel system is proposed and verified by a physical prototype. The rigid-elastic coupling origami flashers facilitate their potential applications in space engineering.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141930989","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":"Hamiltonian formalism for bistable-multilayered plates under non-mechanical stimuli","authors":"","doi":"10.1016/j.ijmecsci.2024.109603","DOIUrl":"10.1016/j.ijmecsci.2024.109603","url":null,"abstract":"<div><p>Bistable multilayered plates have attracted significant attention as morphing and adaptive structures, renowned for their unprecedented exceptional performance. However, accurately predicting both their shape and internal stresses poses formidable challenges due to their geometrically nonlinear nature. For the first time, this paper introduces a Hamiltonian formalism aimed at achieving high-resolution analysis of nonlinear multilayered plates subjected to non-mechanical stimuli, including hygro-thermo-electro-magneto-elastic responses. A canonical system is strategically developed to compute membrane behaviors, yielding symplectic dual differential equations for in-plane field variables. This method elegantly decouples out-of-plane variables from the full-state vector, leading to an exact analytical solution in the membrane problem. To predict the bending behaviors, the first variation of the Hamiltonian energy density function, expressed as a power series of the transverse deflection, ensures flexural equilibrium. The power series effectively captures all admissible out-of-plane deformations, enabling a smooth transition between linear and nonlinear plate responses, including pitchfork bifurcation and limit points. The validity and accuracy of the proposed method are rigorously assessed through convergence tests and satisfaction of boundary conditions across various equilibria, ranging from monostability to bistability. It is cross-verified with high-fidelity finite-element methods (FEM), showing excellent agreements in both deformations and stress resultants. This research presents a physics-based methodology that unveils a parametric interplay between in-plane and out-of-plane field variables, serving as an efficient approach for analyzing adaptive and morphing structures.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141842385","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":"Self-aware active metamaterial cell 3D-printed in a single process","authors":"","doi":"10.1016/j.ijmecsci.2024.109591","DOIUrl":"10.1016/j.ijmecsci.2024.109591","url":null,"abstract":"<div><p>Metamaterials are capable of attenuating undesired mechanical vibrations within a narrow band-gap frequency range; however, real-world applications often require adjustments due to varying loads and frequency content. This study introduces a self-aware, thermo-active metamaterial, 3D-printed in a single process using thermoplastic material extrusion. The adjustment of the natural frequency and band-gap region is achieved through resistive heating of conductive paths, which alters the stiffness of the base cell’s resonator. Additionally, these conductive paths facilitate the detection of the resonator’s excitation frequency and temperature, thereby eliminating the need for external sensors. This dynamic adaptability, experimentally demonstrated by achieving a band-gap tuning range from 505 Hz to 445 Hz with a 17 °C temperature difference, highlights the potential of these metamaterials for applications in smart structures across the aerospace, civil, and automotive industries.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020740324006325/pdfft?md5=69137ba988fa333361e587bc7a43c68d&pid=1-s2.0-S0020740324006325-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141841539","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":"Nonlinear dynamic analysis of high-speed precision grinding considering multi-effect coupling","authors":"","doi":"10.1016/j.ijmecsci.2024.109604","DOIUrl":"10.1016/j.ijmecsci.2024.109604","url":null,"abstract":"<div><p>The aerostatic spindle is widely used in the field of precision grinding because of its excellent machining stability and machining accuracy. The spindle is jointly affected by multiple excitation effects in the high-speed grinding process. In order to study the dynamic characteristics of the aerostatic spindle under high-speed precision machining, it is necessary to analyse the nonlinear response of the aerostatic spindle with multi-physical field coupling. In this paper, the nonlinear dynamic model of the aerostatic spindle system under multi-effect coupling is established by considering three aspects: fluid-structure coupling, mass eccentricity excitation coupling, and vibration-grinding force coupling. Firstly, the instantaneous nonlinear air film force excitation is calculated by the derivation of the dynamic air film thickness model with multi-degree-of-freedom vibration responses coupling. The mass eccentricity excitation considering dynamic deflection angle is derived through the eccentric-load relationship. Afterwards, the dynamic precision grinding force model under the full surface of the tool is established based on judging the material removal mode, which considers the grain-workpiece interaction relationship under the influence of the nonlinear vibration. Finally, the accuracy and effectiveness of the coupled model is verified by high-speed precision grinding experiments, and the nonlinear dynamic behaviour under different operating parameters is analysed.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141846747","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":"Uncertainty quantification for locally resonant coated plates and shells","authors":"","doi":"10.1016/j.ijmecsci.2024.109587","DOIUrl":"10.1016/j.ijmecsci.2024.109587","url":null,"abstract":"<div><p>The effect of uncertainty in design parameters on the acoustic performance of coated plates and coated shells for maritime applications is presented. The locally resonant coatings are designed using a viscoelastic material with an impedance similar to water and embedded with layers of inclusions. Both voids and hard inclusions, which respectively exhibit monopole and dipole resonance scattering, are considered. Effective medium approximation theory is employed to characterise the layers of inclusions as homogenised layers with effective material and geometric properties. The coating is then modelled as a multilayered equivalent fluid composed of alternating layers of the homogeneous viscoelastic material and the homogenised layers of inclusions. The coating is bonded to a rigid backing plate and the acoustic response is calculated using the transfer matrix method. The coating is also externally applied to an elastic cylindrical shell. The acoustic response is calculated by expressing the shell displacements and acoustic pressures in the coating and exterior domain in terms of Fourier series expansions, and applying continuity equations at each interface between the shell surface, coating layers and the surrounding water. Efficient stochastic models based on the non-intrusive polynomial chaos expansion (PCE) method are developed by transforming the analytical models for the coated plates and shells into computationally efficient surrogate models using point collocation. Uncertainty in dominant design parameters associated with the geometry of the inclusions and material properties of the coating is examined. The influence of the design parameters for inclusions tuned to different resonance frequencies and for multiple layers of inclusions is also reported. Strong acoustic performance of coating designs occurs in a broad frequency range around local resonance of the inclusions. For all coating models, uncertainty in parameters which predominantly influence the local resonance of the inclusions were observed to yield the greatest variation in the acoustic responses of the coated plates and shells.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020740324006283/pdfft?md5=69801deb3353cfcead8a7849814c2db5&pid=1-s2.0-S0020740324006283-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141853653","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":"Micromorphic FE2 simulation of plastic deformations of foam structures","authors":"","doi":"10.1016/j.ijmecsci.2024.109551","DOIUrl":"10.1016/j.ijmecsci.2024.109551","url":null,"abstract":"<div><p>Capturing and predicting the effective mechanical properties of highly porous cellular media still represents a significant challenge for the research community, due to their complex structural interdependencies and known size effects. Micromorphic theories are often applied in this context to model the inelastic deformation behavior of foam-like structures, in particular to incorporate such size effect into the investigation of structure–property correlations. This raises the problems of formulating appropriate constitutive relations for the numerous non-classical stress measures and determining the corresponding material parameters, which are usually difficult to assess experimentally.</p><p>The present contribution therefore alternatively employs a hierarchical micromorphic multi-scale approach within the direct FE² framework to simulate the complex irreversible behavior of foam-like porous solids. The predictions of Cosserat (micropolar) and a fully-micromorphic theory are compared with conventional FE² results and direct numerical simulations (DNS) for complex loading scenarios with elastic, elastic–plastic, and creep deformations. Therein, non-classical deformation modes of the microstructure resulting from the introduced micromorphic kinematics are visualized, as are the macroscopic hyperstresses and deformations.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020740324005939/pdfft?md5=12f5aabdc9b988fe967eac3e0efc6783&pid=1-s2.0-S0020740324005939-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141931023","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":"Unveiling microstructure effect on nanoscratch behavior of gold-platinum alloys","authors":"","doi":"10.1016/j.ijmecsci.2024.109594","DOIUrl":"10.1016/j.ijmecsci.2024.109594","url":null,"abstract":"<div><p>The microstructural effect on the mechanical behaviors of gold-platinum alloys during nanoscratch is revealed. By adjusting the microstructures (crystallographic orientation, interface type, grain size, twinning thickness), the hardness, plasticity, removal rate and surface roughness of the alloys are significantly improved. The nanoscratch is performed by molecular dynamics (MD). For the single-crystal (SC) alloys, the <span><math><mrow><mrow><mo>[</mo><mrow><mn>1</mn><mover><mn>1</mn><mo>¯</mo></mover><mn>0</mn></mrow><mo>]</mo></mrow><mrow><mo>(</mo><mn>111</mn><mo>)</mo></mrow></mrow></math></span>-oriented SC alloy shows the high hardness, wear resistance and low roughness. The high dislocation density induces the strong work hardening while the horizontal twinning boundaries (HTBs) effectively improve the surface quality by hindering the elastic recovery. For the bi-crystal (BC) alloys, the BC alloy with TB exhibits the excellent plasticity and low roughness. TB can uniformly limit the dislocation slip and promote the dislocation nucleation to strengthen the plasticity and surface quality. For the polycrystal (PC) and nanotwinned-polycrystal (NTPC) alloys, the alloys with small grain size or small twinning thickness show the high removal rate and low roughness. The reduction in grain size or twinning thickness inhibits the dislocation motion and promotes the GB or TB migration to improve the surface quality and atomic removal. These results provide an important theoretical basis for the microstructural design and nanofabrication of gold-platinum alloys with smooth surface and remarkable mechanical property, expanding the application for the bimetallic materials.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141851708","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":"Detection of breathing cracks using physics-constrained hybrid network","authors":"","doi":"10.1016/j.ijmecsci.2024.109568","DOIUrl":"10.1016/j.ijmecsci.2024.109568","url":null,"abstract":"<div><p>During the operational lifespan of mechanical structures, the occurrence of “breathing” cracks in structural components due to long-term dynamic loading poses a significant risk of catastrophic failure to the overall mechanical system. In this research, we propose an innovative approach for detecting breathing cracks by leveraging the physics-constrained hybrid network (PCHN). The fundamental concept is embedding the implicit governing equations into the network training process. This integration constrains the solution space and results in a closed-form dynamical model, which reveals the index for breathing crack detection. Firstly, the state-constrained parallel networks (SCPNs) capable of making full-state predictions with partial labels are constructed by introducing state dependency constraints to the outputs of three parallel networks. Subsequently, a portable sparse regression layer (SRL) is built to recover the governing formulation, wherein the function library is constructed with the full-state predictions of the SCPNs. Finally, the SCPNs and SRL are synthesized to constitute the PCHN framework, providing both full-state predictions and the dynamical model of the breathing beam. An alternate optimization (AO) method is developed to optimize the two components sequentially. The effectiveness, robustness, and applicability of the proposed method are demonstrated through comprehensive numerical simulations, finite element simulations, and experimental studies. Our results indicate that the proposed PCHN method accurately identifies the dynamical model of the breathing beam and evaluates the degree of damage even when only partial noisy state observations are available. Notably, the robustness and sensitivity of the proposed approach make it a promising tool for practical damage detection applications. The code of PCHN is available on <span><span>https://github.com/latexalpha/PCHN</span><svg><path></path></svg></span>.</p></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141836769","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}