
今日更新:International Journal of Solids and Structures 1 篇,Journal of the Mechanics and Physics of Solids 1 篇,Mechanics of Materials 1 篇,Thin-Walled Structures 6 篇
An alytical model for open-ended cylinder elastoplastic expansion
Rongzhi Wei, Murilo Augusto Vaz, Xuefeng Hu
doi:10.1016/j.ijsolstr.2025.113751
开口筒体弹塑性膨胀的解析模型
This paper presents a theoretical model for the elastoplastic stress–strain ana lysis of an internally pressurized, open-ended, thick-walled cylinder made of strain-hardening material. The mathematic model is derived within the framework consisting of Hencky deformation theory and von Mises yielding criterion. By assuming the Ludwik Power Law (LPL) constitutive model, an alytical elastoplastic expressions of stress and strain components can be obtained. The derivation process of the theoretical models is performed and demonstrated, and both models are validated through Finite Difference Method (FDM) and Finite Element Method (FEM), for a typical thick-walled cylinder, which considers the strain-hardening behavior. Good correlation between results using different methods for strain evolution before and after the full plastification can be observed. For the s tress an alysis and production design involving partial plastic and post-yield expansion of single cylinder, such as the liner hydraulic expansion in mechanically lined pipe fabrication process, the presented models can be regarded as a new and practical method for theoretical an alysis.
本文提出了一种内压、开口、厚壁圆筒弹塑性应力-应变分析的理论模型。在henky变形理论和von Mises屈服准则的框架下,推导了该模型。通过假设Ludwik幂律(LPL)本构模型,可以得到应力和应变分量的解析弹塑性表达式。对理论模型的推导过程进行了验证,并以考虑应变硬化行为的典型厚壁圆柱体为例,采用有限差分法和有限元法对两种模型进行了验证。在完全塑化前后,不同方法的应变演化结果具有良好的相关性。对于单缸局部塑性和屈服后膨胀的应力分析和生产设计,如机械衬管制造过程中衬垫的水力膨胀,所建立的模型可作为理论分析的一种新的实用方法。
Mechanical instabilities and snapping phenomena in helical rods with perversion
Émilien Dilly, Sébastien Neukirch, Julien Derr, Williams Brett, Dražen Zanchi
doi:10.1016/j.jmps.2025.106402
扭曲螺旋杆的力学不稳定性和断裂现象
The mechanical instabilities of clamped helical elastic rods under controlled rotation and extension, featuring perversion, are studied experimentally, numerically and theoretically. Perversion appears at a winding lower than the intrinsic one. When the extension and winding are varied, the perversion is involved in three main instabilities. They can all be identified visually as abrupt qualitative modifications of the conformation. Singularities in the axial force and torque acting on the clamps are observed at critical winding and/or extension. (i) Transitioning from a pure helix to a configuration with perversion (and vice versa) is accompanied by a snapping instability. (ii) At zero net turns, the rod undergoes a writhing bifurcation from a straight to a writhed configuration. (iii) The perversion jumps to self-contact at critical extension. While the transitions (i) and (iii) are subcritical bifurcations, the writhing bifurcation is continuous and supercritical. The singularity at the creation of the perversion is reproduced numerically by incorporating clamping effects within path-following methods. A shooting technique, path-following method and finite element simulations are employed to assess the stability of the perversion and the associated snapping towards self-contact. An ana logy with first-order phase transitions is discussed.
本文从实验、数值和理论三个方面研究了夹持螺旋弹性杆在具有扭转特性的可控旋转和拉伸作用下的力学不稳定性。畸变出现在比固有绕组低的一个绕组上。当延伸和绕组变化时,扭曲涉及三个主要的不稳定性。它们都可以从视觉上识别为构象的突然质的改变。在临界缠绕和/或延伸时,观察到作用在夹钳上的轴向力和扭矩的奇异性。(1)从纯螺旋过渡到扭曲构型(反之亦然)是伴随着断裂不稳定性的。(ii)净转数为零时,杆由直向扭向分叉。(iii)变态在临界扩展时跳到自接触。过渡(i)和(iii)是亚临界分岔,而扭动分岔是连续的超临界分岔。通过在路径跟踪方法中合并夹紧效应,在数值上再现了变态产生的奇点。采用射击技术、路径跟踪方法和有限元模拟来评估扭曲的稳定性和相关的自接触断裂。讨论了与一阶相变的类比。
Fractional order strain and viscosity in the Moore Gibson Thompson thermoelastic diffusion model: A study of transient responses in one-dimensional half-space
Geetanjali Geetanjali, Pawan Kumar Sharma
doi:10.1016/j.mechmat.2025.105542
摩尔-吉布森-汤普森热弹性扩散模型中的分数阶应变和黏度:一维半空间瞬态响应的研究
In the mathematical modelling of viscoelastic materials such as biological tissues, polycrstalline metals, and high polymers, fractional order strain is widely adopted to highlight their rheological properties. Moreover, models incorporating fractional calculus provide more rational results. In this light, we consider fractional Moore Gibson Thompson model of generalized visco-thermoelastic-diffusion to study the transient responses of a one dimensional half space. The novelty of the present work lies in considering fractional order strain and fractional viscosity in the considered framework. Initially, the medium is kept at rest and at the boundary, thermal shock is applied in a stress free state. The basic equations and relations governing the problem are non-dimensionalized and solved in a Laplace transformed domain using the boundary restrictions. The solution of the problem is obtained in the original domain via a numerical inversion technique. This work aims to underline the impact of different models, fractional order strain, and viscosity parameters on physical quantities. Graphical representation of the results elucidates that fractional viscosity softens the stiffness in the distribution of field variables and fractional order strain eliminates the sudden increment in their peak points. Also, different models have varying degree of influence on all the field variables.
在生物组织、多晶金属和高聚物等粘弹性材料的数学建模中,广泛采用分数阶应变来突出其流变性能。此外,结合分数阶微积分的模型提供了更合理的结果。在这种情况下,我们考虑分数阶Moore - Gibson - Thompson广义粘-热弹-扩散模型来研究一维半空间的瞬态响应。本工作的新颖之处在于在考虑的框架中考虑分数阶应变和分数阶粘度。最初,介质保持静止,在边界处,热冲击以无应力状态施加。控制问题的基本方程和关系是无量纲化的,并在拉普拉斯变换域中利用边界限制进行求解。通过数值反演技术在原域得到了问题的解。这项工作的目的是强调不同的模型,分数阶应变和粘度参数对物理量的影响。结果的图形表示表明,分数阶粘度软化了场变量分布中的刚度,分数阶应变消除了其峰值点的突然增量。不同的模型对各场变量的影响程度也不同。
Dynamic an alysis and design of axially functionally graded lattice sandwich structures based on dynamic substructuring method
Ziqiang Zhao, Haonan He, Zhiguang Song
doi:10.1016/j.tws.2025.114176
基于动态子结构法的轴向功能梯度格芯结构动力分析与设计
Lattice sandwich structures are ideal for functionally graded material (FGM) applications because their highly customizable core designs (geometries and topologies) enable continuous spatial variation of mechanical properties. To fully exploit this potential and achieve optimal gradient performance, the lattice core must be carefully optimized, which in turn requires efficient and accurate dynamic ana lysis. However, existing dynamic a nalysis methods present key trade-offs. The assumed mode method (AMM), while computationally efficient, lacks the accuracy needed for ana lyzing non-uniform structures. In contrast, the finite element method (FEM) provides high fidelity but is computationally intensive, especially when applied within iterative optimization loops for large-scale lattice structures. To solve this problem, this study introduces a substructuring-based method, aiming to improve the efficiency of structural optimization for axially functionally graded lattice sandwich structures, while maintaining the accuracy of dynamic modeling. To implement this approach, an integrated an alysis framework is developed, combining high-fidelity finite element (FE) modeling, Craig-Bampton model reduction, and a genetic algorithm-based optimization. The effectiveness of the proposed method is validated through both numerical simulations and experimental testing on the pyramidal lattice sandwich structure. In the case studies, the proposed method achieved a 97% reduction in degrees of freedom (DOFs) compared to the traditional FEM modeling while maintaining less than 5% error in the first four resonance frequencies. Building upon this advantage, the proposed method was further applied to optimize the structure’s modal behavior, successfully achieving the desired operational mode shapes with a maximum Modal Assurance Criterion (MAC) value of up to 94%. The proposed method provides a robust and efficient tool for functionally graded design of lattice sandwich structures.
晶格夹层结构是功能梯度材料(FGM)应用的理想选择,因为其高度可定制的核心设计(几何形状和拓扑结构)可以实现机械性能的连续空间变化。为了充分利用这一潜力并实现最佳的梯度性能,晶格核心必须仔细优化,这反过来又需要有效和准确的动态分析。然而,现有的动态分析方法存在关键的权衡。假设模态法虽然计算效率高,但缺乏分析非均匀结构所需的精度。相比之下,有限元法(FEM)提供了高保真度,但计算量大,特别是在大规模晶格结构的迭代优化循环中应用时。为了解决这一问题,本研究引入了一种基于子结构的方法,旨在提高轴向功能梯度晶格夹层结构的结构优化效率,同时保持动态建模的准确性。为了实现这种方法,开发了一个集成的分析框架,结合高保真有限元(FE)建模,Craig-Bampton模型约简和基于遗传算法的优化。通过对金字塔晶格夹层结构的数值模拟和实验验证了该方法的有效性。在案例研究中,与传统的FEM建模相比,该方法实现了97%的自由度降低(dof),同时在前四个共振频率上保持小于5%的误差。基于这一优势,提出的方法进一步应用于优化结构的模态行为,成功地实现了期望的工作模态形状,最大模态保证准则(MAC)值高达94%。该方法为晶格夹层结构的功能梯度设计提供了一种稳健、高效的工具。
Nonlinear thermo-mechanical forced vibration of nonlocal FG-CNTRC adsorber with 2D PSH network and vdW interactions across wide frequency spectrum
Soumia Khouni, Hicham Bourouina, Abir Lamari, Lamine Elaihar
doi:10.1016/j.tws.2025.114216
二维PSH网络和宽频谱vdW相互作用下非局部FG-CNTRC吸附器的非线性热机械强迫振动
This work explores the nonlinear vibrational behavior of a novel sandwich microbeam system that integrates functionally graded carbon nanotube-reinforced composite (FG-CNTRC) face sheets with a core that is perforated with a longitudinal arrangement of periodic square holes (PSH). The framework simultaneously incorporates the combined effects of thermal loading, adatom adsorption, and nonlocal strain gradient phenomena. By capturing these multiphysics interactions under nonlinear thermal fields, the study introduces a more realistic representation of nanoscale resonator behavior that extends beyond conventional adsorption–nonlocal beam models. Two distribution patterns are considered: uniform distribution (UD-CNTRC) and functionally graded distribution (FG-CNTRC) of carbon nanotubes (CNTs) in the FG-CNTRC layers. The effective material characteristics are found by applying the mixing rule in the thickness direction. The size-dependent response of the FG-CNTRC sandwich microbeam is investigated using nonlocal strain gradient theory (NLSGT), which incorporates two independent scale parameters to capture both nonlocal effects and strain gradient contributions, while geometrical nonlinearity is treated using the von Kármán nonlinear assumption. In addition, the Lennard-Jones (6-12) potential is used to capture van der Waals (vdW) interactions between the adatoms and the microstructure substrate, accounting for adsorption-induced energy. The dynamic model is expressed as a fourth-order nonlinear partial differential equation formulated using the Euler–Bernoulli beam model (EBM) and the Levinson beam model (LBM). The system is reduced to an ordinary differential equation (ODE) with cubic nonlinearity using the Galerkin method, and the resonance shift response is ana lytically determined using the multiple scales method (MMS). The H/Si (100) system's frequency shift was evaluated, and numerical results showed that perforation properties, CNT distribution, thermal loads, and s mall-scale impacts all significantly affect the microsystem's dynamic response. This work introduces a novel configuration that combines FG-CNTRC face sheets with a perforated PSH core under thermo-adsorptive coupling, providing deeper insight into multiphysics interactions. The findings establish practical guidelines for the design and optimization of next-generation Micro/Nano-Electro-Mechanical Systems (M/NEMS)-based mass sensors with enhanced sensitivity and tunability.
本研究探索了一种新型夹层微梁系统的非线性振动行为,该系统集成了功能梯度碳纳米管增强复合材料(FG-CNTRC)面片,其核心上穿孔有周期性方孔(PSH)的纵向排列。该框架同时结合了热载荷、吸附原子吸附和非局部应变梯度现象的综合效应。通过捕获非线性热场下的这些多物理场相互作用,该研究引入了一种更真实的纳米级谐振器行为表示,超越了传统的吸附-非局部光束模型。考虑了碳纳米管(CNTs)在FG-CNTRC层中的均匀分布(UD-CNTRC)和功能梯度分布(FG-CNTRC)两种分布模式。通过在厚度方向上应用混合规律,找到了有效的材料特性。采用非局部应变梯度理论(NLSGT)研究了FG-CNTRC夹层微梁的尺寸相关响应,该理论采用两个独立的尺度参数来捕获非局部效应和应变梯度贡献,而几何非线性则采用von Kármán非线性假设来处理。此外,Lennard-Jones(6-12)势用于捕获吸附原子与微结构底物之间的范德华(vdW)相互作用,计算吸附诱导能量。采用欧拉-伯努利梁模型(EBM)和莱文森梁模型(LBM)建立了四阶非线性偏微分方程。利用伽辽金方法将系统简化为具有三次非线性的常微分方程(ODE),并利用多尺度法(MMS)解析确定了共振位移响应。对H/Si(100)体系的频移进行了评估,数值结果表明,射孔特性、碳纳米管分布、热载荷和小尺度影响都对微系统的动态响应有显著影响。这项工作介绍了一种新的配置,将FG-CNTRC面片与热吸附耦合下的穿孔PSH岩心结合在一起,为多物理场相互作用提供了更深入的了解。研究结果为下一代基于微/纳米机电系统(M/NEMS)的质量传感器的设计和优化提供了实用指南,该传感器具有更高的灵敏度和可调性。
Effects of ply clustering on failure mechanis m and residual compressive strength of CFRP laminated composites subjected to edge-on impact
Nian Li, Weijie Ma, Siyu Tong, Weiling Liu
doi:10.1016/j.tws.2025.114225
铺层聚类对CFRP层合复合材料沿边冲击破坏机理及残余抗压强度的影响
This study systematically investigates the effects of ply clustering on the low-velocity edge-on impact (LVEI) resistance and subsequent compression after edge-on impact (CAEI) behavior of carbon fiber reinforced polymer (CFRP) laminated composites. Four distinct layup configurations, representing varying degrees of ply and sub-laminate clustering, are subjected to controlled edge-on impacts at three energy densities using a hemispherical drop-weight impactor. Post-impact damage is characterized by visual inspection, ultrasonic C-scan, and X-ray micro-computed tomography (μCT), while CAEI performance is evaluated using digital image correlation (DIC) and strain gauges. Results show that the baseline configuration (L_B: [45/0/-45/90]4S) consistently exhibits the highest CAEI residual strength, outperforming other configurations by up to 27%, while the highly clustered configuration (L_A2: [45/0/-45/90]3S) shows the lowest but most stable strength, with less than 2% fluctuation across all impact energies. Neither ply clustering nor increased laminate thickness improves CAEI damage tolerance; in fact, both lead to greater strength reductions under higher impact energies. Correlation an alysis indicates that absorbed energy during LVEI is the most reliable predictor of residual compressive strength.
本研究系统地研究了层序聚类对碳纤维增强聚合物(CFRP)层合复合材料低速抗冲击性能(LVEI)和冲击后压缩性能(CAEI)的影响。四种不同的铺层结构,代表不同程度的铺层和亚层压板集群,在三种能量密度下使用半球形落锤撞击器进行受控的边对冲击。通过目视检查、超声c扫描和x射线微计算机断层扫描(μCT)对撞击后损伤进行表征,通过数字图像相关(DIC)和应变片对CAEI性能进行评估。结果表明,基线配置(L_B: [45/0/-45/90]4S)始终表现出最高的CAEI残余强度,比其他配置高出27%,而高度聚集配置(L_A2: [45/0/-45/90]3S)表现出最低但最稳定的强度,在所有冲击能量中波动小于2%。聚类厚度和层压厚度的增加都不能提高CAEI的损伤容限;事实上,在更高的冲击能量下,两者都会导致更大的强度降低。相关分析表明,LVEI过程中吸收能量是剩余抗压强度最可靠的预测指标。
Electrochemical pre-treatment of aluminum alloy in environmentally friendly medium: Parameter optimization and bonding strengthening mechanis m
Qifan Hu, Zhenghui Ge, Kai Pang, Yongwei Zhu, Xiaonan Hou
doi:10.1016/j.tws.2025.114226
铝合金在环保介质中的电化学预处理:参数优化及强化机理
The electrochemical treatment of adhesive surfaces in neutral salt solutions is a promising novel method for improving the bonding performance of aluminum alloys. However, the mechanis m through which this treatment improves interfacial bonding strength remains poorly understood. This study systematically investigates the relationship among electrochemical parameters, microstructure, property evolution, and the bonding strength of thin-walled aluminum adhesive joints. Multi-scale characterization techniques were employed to elucidate the strengthening mechanis m from the perspectives of chemical bonding and mechanical interlocking. The results demonstrated that a current density of 0.8 A·cm−2 applied for 100 s increased the bonding strength by 170% compared to untreated joints. Furthermore, the effect of electrochemical treatment, sandblasting, and grinding on the surface characteristics and bonding properties was compared. XPS and FTIR a nalyses revealed that the electrochemical treatment significantly increased the surface density of hydroxyl groups, which promoted the opening of epoxy rings and the subsequent formation of covalent bonds. This finding confirms the critical role of chemical bonding in enhancing interfacial strength. Eventually, a qualitative model was developed to illustrate the mechanis m by which electrochemical treatment enhances the adhesive performance of aluminum alloy joints. These insights are valuable for exploring the potential application of electrochemical treatment to thin-walled, lightweight alloy components.
在中性盐溶液中对粘接表面进行电化学处理是一种很有前途的提高铝合金粘接性能的新方法。然而,通过这种处理提高界面结合强度的机制仍然知之甚少。本研究系统地研究了薄壁铝粘接接头的电化学参数、微观结构、性能演变与粘接强度之间的关系。采用多尺度表征技术,从化学键和机械联锁的角度阐明了强化机理。结果表明,施加0.8 a·cm−2的电流密度100 s,与未处理的接头相比,结合强度提高了170%。比较了电化学处理、喷砂处理和磨削处理对表面特性和结合性能的影响。XPS和FTIR分析表明,电化学处理显著提高了羟基的表面密度,促进了环氧环的打开和共价键的形成。这一发现证实了化学键在提高界面强度方面的关键作用。最后,建立了一个定性模型来解释电化学处理提高铝合金接头粘接性能的机理。这些见解对于探索电化学处理在薄壁轻质合金部件上的潜在应用是有价值的。
Experimental an alysis of axially compressively loaded GFRP-confined grout short columns
Ruilin Xia, Yordan Garbatov, Qing Hu, Changyong Liu
doi:10.1016/j.tws.2025.114191
gfrp约束短柱轴向受压试验分析
The corrosion of steel pipe piles, subsea pipelines, and offshore structures poses a significant challenge in marine environments. This has increased demand for effective reinforcement and repair methods. One promising technique is the use of glass fibre reinforced polymer (GFRP) grouting, which has gained popularity in engineering due to its excellent adaptability to environmental conditions and its long-term, maintenance-free performance. To explore the basic mechanical properties of this reinforcement method, 45 specimens were designed, custom-fabricated, and subjected to axial compression testing. Key parameters considered during testing included the grout's compressive strength, the diameter-to-thickness ratio of the GFRP tubes, and the fibre winding angle. The failure modes, load-axial displacement curves, strain development, and the effects of these parameters on the axial load capacity of the short columns were examined. Based on the experimental results, three axial load-displacement models were proposed: a three-stage model for specimens with 89° winding angle; a five-stage model for those with a 45° winding angle; and a four-stage model for specimens with a 30° winding angle. Additionally, an an alytical formula was developed to estimate the axial load capacity of GFRP-confined grout short columns. The predicted results from this formula showed good agreement with the experimental data.
在海洋环境中,钢管桩、海底管道和海上结构物的腐蚀是一个重大挑战。这增加了对有效加固和修复方法的需求。玻璃纤维增强聚合物(GFRP)注浆是一种很有前途的技术,由于其对环境条件的良好适应性和长期免维护的性能,在工程中得到了广泛的应用。为了探索这种加固方法的基本力学性能,设计、定制了45个试件,并进行了轴压试验。试验中考虑的关键参数包括浆液抗压强度、GFRP管的径厚比和纤维缠绕角。研究了短柱的破坏模式、荷载-轴向位移曲线、应变发展情况,以及这些参数对短柱轴向承载能力的影响。基于试验结果,提出了三种轴向载荷-位移模型:89°缠绕角试件的三阶段模型;45°绕组角的五阶段模型;并建立了绕组角为30°的试件的四级模型。此外,还建立了估算gfrp约束短柱轴向承载力的解析公式。该公式的预测结果与实验数据吻合较好。
Geometrically Nonlinear Thermal-Induced Vibration of FG-GPL RC Conical Shells resting on partial Elastic Foundation
Yi Zhang, Biao Zhang, Linqing Liu, Xiangwen Deng
doi:10.1016/j.tws.2025.114217
部分弹性基础上FG-GPL RC锥形壳的几何非线性热激振动
This work examines the transient thermo-mechanical behavior of conical shells made from functionally graded composites reinforced with graphene platelets (FG-GPLRC) and partially supported on an elastic substrate. In contrast to traditional laminated materials, the effective properties of FG-GPLRC vary s moothly across the thickness direction according to a defined dispersion pattern of graphene nanofillers. The shell is exposed to a thermal shock under different boundary constraints, such as instantaneous temperature changes, prescribed heat flux, or adiabatic surface conditions. A transient heat transfer model across the thickness is established and solved under the requirement of continuous thermal flux and temperature. The time-dependent temperature solution is then employed to determine the resulting thermal stresses and moments. The equations of motion are formulated based on the first-order shear deformation theory (FSDT) and Donnell kinematics relations; and solved numerically using the generalized differential quadrature (GDQ) technique. A parametric ana lysis explores the influence of factors such as shell geometry (e.g., semi-vertex angle, thickness-to-radius ratio), grading scheme (power-law exponent), GPL content and dispersion pattern, thermal environments, and elastic support models (Winkler or Pasternak). The numerical approach is validated against existing solutions for homogeneous conical shells. Findings highlight the considerable effect of localized foundation stiffness and transient thermal gradients on the system's nonlinear dynamic response.
本研究研究了由石墨烯片增强的功能梯度复合材料(FG-GPLRC)制成的锥形壳的瞬态热力学行为,并部分支撑在弹性衬底上。与传统的层压材料相比,FG-GPLRC的有效性能根据石墨烯纳米填料的特定分散模式在厚度方向上平滑变化。在不同的边界约束下,如瞬时温度变化、规定的热流密度或绝热表面条件下,壳暴露于热冲击中。建立了在连续热流密度和温度条件下的跨厚度瞬态传热模型,并对其进行了求解。然后采用与时间相关的温度解来确定产生的热应力和力矩。基于一阶剪切变形理论(FSDT)和Donnell运动学关系建立了运动方程;并采用广义微分正交(GDQ)技术进行数值求解。参数分析探讨了壳体几何形状(如半顶角、厚度与半径比)、分级方案(幂律指数)、GPL含量和色散模式、热环境和弹性支撑模型(Winkler或Pasternak)等因素的影响。数值方法与已有的均匀圆锥壳解进行了验证。研究结果强调了局部基础刚度和瞬态热梯度对系统非线性动力响应的重要影响。