International Journal of Non-Linear Mechanics最新文献_第9页

Hydrodynamic behavior of inertial elongated microswimmers in a horizontal channel 水平水道中惯性伸长微型潜水器的水动力行为

IF 2.8 3区工程技术

International Journal of Non-Linear Mechanics Pub Date : 2024-07-14 DOI: 10.1016/j.ijnonlinmec.2024.104838

{"title":"Hydrodynamic behavior of inertial elongated microswimmers in a horizontal channel","authors":"","doi":"10.1016/j.ijnonlinmec.2024.104838","DOIUrl":"10.1016/j.ijnonlinmec.2024.104838","url":null,"abstract":"<div><p>In the current study, the lattice Boltzmann method was used to explore the motion of an elongated microswimmer in a horizontal channel with finite fluid inertia. By employing an extended squirmer rod model, the swimming velocity, hydrodynamic efficiency, and interaction with the channel wall of the capsule-shaped squirmer rod were simulated. It was found that the aspect ratio <em>α</em> and the swimming Reynolds number Re<sub><em>s</em></sub> of the squirmer rod significantly affect its swimming velocity and efficiency. Specifically, as the Reynolds number increases, the pusher rod's velocity increases, whereas the puller rod's velocity decreases. Moreover, compared with the puller rod, the pusher rod has a higher efficiency with the same power consumption. With the increase of the aspect ratio <em>α</em>, the velocity of the squirmer rod increases gradually, the power consumption of the pusher rod and the puller rod decreases gradually, and the efficiency increases gradually, showing the characteristics of lower energy consumption and higher efficiency. During the interaction of the squirmer rod with the wall, four distinct motion modes were identified, namely, steady linear motion, motion away from the wall, damped swinging motion, and wall-attraction oscillation. The emergence of these motion modes and their transitions could be associated with the pressure distribution formed between the squirmer rod and the wall. The results provide another perspective and theoretical basis for the design of bioinspired microswimming devices and microrobots, especially in medical applications such as precision drug delivery systems.</p></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141708191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Micromechanical modelling of rubbery networks: The role of chain pre-stretch 橡胶网络的微机械建模：链预拉伸的作用

IF 2.8 3区工程技术

International Journal of Non-Linear Mechanics Pub Date : 2024-07-14 DOI: 10.1016/j.ijnonlinmec.2024.104834

{"title":"Micromechanical modelling of rubbery networks: The role of chain pre-stretch","authors":"","doi":"10.1016/j.ijnonlinmec.2024.104834","DOIUrl":"10.1016/j.ijnonlinmec.2024.104834","url":null,"abstract":"<div><p>Discrete Network (DN) models are a useful tool to investigate structure–property relationships in rubbery networks such as elastomers and hydrogels. In a DN model, polymer chains are represented by entropic springs connected at crosslinking points, and the partitioning of stretches among the chains is dictated by the condition of mechanical equilibrium at each crosslink. A key feature of these models is that springs have a zero natural length, and are therefore pre-stretched in the reference configuration. However, the role of chain pre-stretch distribution on the emerging mechanical properties has often been overlooked. In this work we investigate the elastic properties of DNs where the average chain pre-stretch, chain density and chain length distribution can be prescribed independently via a novel network generation algorithm. We show that increasing the average pre-stretch increases the network stiffness and decreases its extensibility limit. We also compare predictions of semi-analytical micromechanical models of rubber elasticity to DN predictions taken as reference. Deviations between analytical model and DN predictions are attributed to the combination of two factors: the loss of affinity at large strain and the initial pre-stretch distribution, which is not taken into account in analytical estimates. DN simulations further show that the assumption of one-to-one mapping between chain stretch and chain orientation on which microsphere models rely is not satisfied.</p></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020746224001999/pdfft?md5=50d4d92402d2317c7e2c48653815b737&pid=1-s2.0-S0020746224001999-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141714742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A modified generalized harmonic function perturbation method and its application in analyzing generalized Duffing–Harmonic–Rayleigh–Liénard oscillator 修正的广义谐函数扰动法及其在分析广义达芬-谐波-雷利-李纳振荡器中的应用

IF 2.8 3区工程技术

International Journal of Non-Linear Mechanics Pub Date : 2024-07-14 DOI: 10.1016/j.ijnonlinmec.2024.104832

{"title":"A modified generalized harmonic function perturbation method and its application in analyzing generalized Duffing–Harmonic–Rayleigh–Liénard oscillator","authors":"","doi":"10.1016/j.ijnonlinmec.2024.104832","DOIUrl":"10.1016/j.ijnonlinmec.2024.104832","url":null,"abstract":"<div><p>A modified generalized harmonic function perturbation method is proposed in this paper. Compared with the classical version of this method, the modified version can execute its procedures pure symbolically without the need to assign any system parameters even for some complicated nonlinear oscillators. This means that the relations between amplitude of limit cycles and system parameters can be derived analytically from the proposed method. Meanwhile, the analytical expression of characteristic quantity of limit cycles can be also obtained. Via these analytical expressions, the evolutional process of limit cycles can be studied quantitatively in amplitude domain. It demonstrates the entire live period of each limit cycle from its generation to bifurcation to destination. To show the feasibility of the proposed method, a complicated oscillator named generalized Duffing–Harmonic–Rayleigh–Liénard oscillator is investigated in this paper. First, the two analytical expressions mentioned above are derived and the global evolution of its limit cycles are analyzed quantitatively. Second, the critical value of homoclinic and heteroclinic bifurcation parameters are also predicted via this two analytical expressions. Moreover, the analytical approximate solutions of both limit cycles and homo-heteroclinic orbits are calculated. To prove the accuracy, all the above results obtained via the proposed methods are confirmed by the Runge–Kutta method, which show a good accordance. Therefore, the proposed method can be considered as an effective modification for a classical perturbation method. It provides another feasible and reliable analytical quantitative method for analyzing global dynamics of strongly nonlinear oscillators.</p></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141702310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Physical forces drive C. elegans embryonic deformation 物理力量驱动秀丽隐杆线虫胚胎变形

IF 2.8 3区工程技术

International Journal of Non-Linear Mechanics Pub Date : 2024-07-14 DOI: 10.1016/j.ijnonlinmec.2024.104833

{"title":"Physical forces drive C. elegans embryonic deformation","authors":"","doi":"10.1016/j.ijnonlinmec.2024.104833","DOIUrl":"10.1016/j.ijnonlinmec.2024.104833","url":null,"abstract":"<div><p>The abnormal development of embryos is closely linked to abnormal cell division and elongation, but the underlying mechanism remains to be elucidated. The embryonic development of <em>C elegans</em> embryo is different because it occurs without cell proliferation or cell rearrangement. Here, we focus on a spectacular 4-fold elongation that is achieved approximately 3 h before the egg shell hatches and results from active filament networks. The body shape is represented by an inhomogeneous cylinder, which allows us to assess the active stresses induced by the actomyosin network located in the cortex and the muscles in ventral position near the epidermis. By considering the specific embryo configuration, we can quantitatively obtain the contractile forces induced by actomyosin filaments and muscles for a bending torsion event with defined curvature. We find that the active stress induced by actomyosin molecular motors or muscles increases with elongation and bending curvature, while also varying with radius. Both elongation and torsional deformation contribute to increased moment magnitudes that explain the dynamics of the embryo in the egg. Our results highlight the complex interplay between biomechanical factors in modulating embryonic deformation.</p></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effective response and microstructure evolution for shape memory alloy laminated composites 形状记忆合金层状复合材料的有效响应和微观结构演变

IF 2.8 3区工程技术

International Journal of Non-Linear Mechanics Pub Date : 2024-07-14 DOI: 10.1016/j.ijnonlinmec.2024.104830

{"title":"Effective response and microstructure evolution for shape memory alloy laminated composites","authors":"","doi":"10.1016/j.ijnonlinmec.2024.104830","DOIUrl":"10.1016/j.ijnonlinmec.2024.104830","url":null,"abstract":"<div><p>A model for the macroscopic mechanical behavior of rank-1 laminates including two shape memory alloy (SMA) phases is presented. The model expresses the general behavior of the composite with phases undergoing rate-independent elastic and inelastic deformations. Homogenization techniques (including the rank-1 laminate model) are used to establish the effective behavior of the SMA laminated composite (SLC) based on the information about the mechanical response of the individual phases and their volume concentrations. A stress-control algorithm is put forward to implement the model. With the aid of the stress-control algorithm, an implicit expression for the effective tangent stiffness and an evolution equation for the effective inelastic strain are derived. Results are compared with the outcomes of an FE-based computational homogenization and a very good agreement is seen. By using a constitutive model with internal variables for the dense SMA, the overall response of the SLC under different mechanical loadings is evaluated. The effective response of the SLC for various volume concentrations of the phases is assessed and exclusive comparisons are illustrated. Furthermore, the influence of different temperatures on the effective superelastic behavior of the SLCs is studied. The findings have implications for the analysis and the design of more complex shape-memory-alloy laminated composites for high-end applications.</p></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141700293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Data-driven methods for the inverse problem of suspension system excited by jump and diffusion stochastic track excitation 针对受跳跃和扩散随机轨道激励的悬挂系统逆问题的数据驱动方法

IF 2.8 3区工程技术

International Journal of Non-Linear Mechanics Pub Date : 2024-07-10 DOI: 10.1016/j.ijnonlinmec.2024.104819

{"title":"Data-driven methods for the inverse problem of suspension system excited by jump and diffusion stochastic track excitation","authors":"","doi":"10.1016/j.ijnonlinmec.2024.104819","DOIUrl":"10.1016/j.ijnonlinmec.2024.104819","url":null,"abstract":"<div><p>Following a lengthy tenure of service, suspension systems may exhibit inaccurate model parameters due to the presence of complex conditions, which can result in a deterioration of control and the potential for operational failures. It is therefore imperative to estimate the key parameters of suspension systems. This paper introduces two data-driven methods for addressing the inverse problem in suspension systems subjected to stochastic track excitations. By employing physics-informed neural networks (PINNs) and Monte Carlo (MC) simulation, we are able to address the resulting integro-differential equation that arises from stochastic jump processes, thus avoiding the necessity for mesh grids. In order to mitigate the numerical challenges that arise from the system parameters, a residual-based adaptive sampling method is proposed. These methods effectively infer unknown parameters, addressing scenarios where data is directly available as a probability density function (PDF) or only sparse trajectories are given. In the latter case, a novel loss function employing Kullback-Leibler divergence facilitates learning from stochastic trajectories. Both methods successfully obtain solutions to the forward Kolmogorov equation, as validated by numerical experiments testing their robustness against added noise. The results demonstrate accurate parameter estimation under varying noise intensities, highlighting the methods’ robustness.</p></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141692810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Establishing a unified viscoplastic constitutive equation for EA4T steel: Comparative analysis with Arrhenius model 为 EA4T 钢建立统一的粘塑性结构方程：与阿伦尼乌斯模型的对比分析

IF 2.8 3区工程技术

International Journal of Non-Linear Mechanics Pub Date : 2024-07-10 DOI: 10.1016/j.ijnonlinmec.2024.104835

{"title":"Establishing a unified viscoplastic constitutive equation for EA4T steel: Comparative analysis with Arrhenius model","authors":"","doi":"10.1016/j.ijnonlinmec.2024.104835","DOIUrl":"10.1016/j.ijnonlinmec.2024.104835","url":null,"abstract":"<div><p>Quasi-static and impact compression experiments were conducted on EA4T steel using a Gleeble-3800 thermal simulation machine. The study aimed to investigate the complex microstructural evolution and thermal deformation behavior of EA4T steel under various experimental conditions, including temperatures ranging from 970 °C to 1170 °C and strain rates ranging from 0.01s<sup>−1</sup> to 1s<sup>−1</sup>. To precisely elucidate these phenomena, we meticulously constructed a unified visco-plastic constitutive model using the internal variable methodology. The model's parameterization was achieved through the effective application of genetic algorithm optimization techniques. Rigorous validation of the model was performed by meticulously comparing its outputs with experimental data, including key metrics such as average grain size, recrystallized fraction, and effective flow stress. In addition,a comparative analysis with the improved Arrhenius model highlights the superior performance of the unified visco-plastic constitutive equation in capturing the intricate microstructural evolution and thermal deformation behavior exhibited by EA4T steel.</p></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141630407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

About regular expansion of a two-phase ball 关于两相球的规则膨胀

IF 2.8 3区工程技术

International Journal of Non-Linear Mechanics Pub Date : 2024-07-09 DOI: 10.1016/j.ijnonlinmec.2024.104824

引用次数: 0

Limit analysis of planar steel frames, in-element plastic-hinge for uniformly distributed loads 均匀分布荷载的平面钢框架、元素内塑性铰链的极限分析

IF 2.8 3区工程技术

International Journal of Non-Linear Mechanics Pub Date : 2024-07-09 DOI: 10.1016/j.ijnonlinmec.2024.104827

引用次数: 0

Vibration isolation platform for large-amplitude-low-frequency excitation by parallel-stack-assembly design of Miura origamis 利用三浦折纸的平行叠装设计实现大振幅低频激励的隔振平台

IF 2.8 3区工程技术

International Journal of Non-Linear Mechanics Pub Date : 2024-07-06 DOI: 10.1016/j.ijnonlinmec.2024.104831

Xiuting Sun , Qian Lv , Jiawei Qian , Jian Xu

{"title":"Vibration isolation platform for large-amplitude-low-frequency excitation by parallel-stack-assembly design of Miura origamis","authors":"Xiuting Sun , Qian Lv , Jiawei Qian , Jian Xu","doi":"10.1016/j.ijnonlinmec.2024.104831","DOIUrl":"https://doi.org/10.1016/j.ijnonlinmec.2024.104831","url":null,"abstract":"<div><p>To achieve an ultralow-frequency vibration isolation platform for simulation of space environment, suspension method is always utilized. However, the natural frequency of the suspension system is inversely proportional to the length of the suspension cable. In order to further reduce the dynamic stiffness, compress the suspension area, and achieve vibration isolation for wide-amplitude excitations, we propose parallel-stack-assembly (PSA) design principle for Origamis to construct absolute zero-stiffness for required intervals. The dynamic model for wide-range amplitude and deformation, design criteria for required low-frequency large-amplitude isolation effectiveness, and analysis for nonlinear vibration isolation property are given. Finally, the prototype is carried out to validate the theoretical analysis and design principle. The PSA design principle of Origamis creates the large-amplitude and ultralow-frequency isolation property, and, the study expands the applicability of isolators for low-frequency excitation with large amplitude for the systems in aviation, marine etc.</p></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141593720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0