Forces in mechanics最新文献

The Analytical Artificial Neural Networks Method 分析人工神经网络方法

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2026-06-01 Epub Date: 2026-02-23 DOI: 10.1016/j.finmec.2026.100360

Ali Ahmadi Azar

This study introduces the Analytical Artificial Neural Networks Method (AANNM), a groundbreaking framework that systematically converts the discrete, black-box outputs of neural network solvers into closed-form analytical solutions. The efficacy of AANNM is demonstrated by solving the differential equation governing the Kelvin-Voigt viscoelastic model. First, a high-fidelity numerical solution is obtained using a Physics-Informed Neural Network (PINN). The core innovation of AANNM is then deployed: the discrete PINN data is used to construct a system of algebraic equations, the solution of which yields the coefficients for a precise polynomial analytical expression. The derived AANNM solution is directly validated against the known exact analytical solution, demonstrating exceptional agreement and providing a more rigorous benchmark than comparisons with purely numerical methods. Crucially, while demonstrated with PINNs, the AANNM framework is solver-agnostic, designed to convert discrete solutions from any artificial neural network into analytical form. This inherent flexibility ensures the method's applicability to future ANN advancements, making it both timeless and adaptable. The proposed framework establishes AANNM as a transformative pipeline that bridges data-driven numerical models with rigorous analytical mathematics, significantly enhancing the interpretability, utility, and trustworthiness of machine learning in computational science.

本研究介绍了分析人工神经网络方法（AANNM），这是一个开创性的框架，系统地将神经网络解算器的离散黑箱输出转换为封闭形式的分析解。通过求解Kelvin-Voigt粘弹性模型的微分方程，证明了AANNM的有效性。首先，利用物理信息神经网络（PINN）获得高保真的数值解。然后部署AANNM的核心创新：使用离散的PINN数据构建代数方程系统，其解产生精确多项式解析表达式的系数。推导的AANNM解直接针对已知的精确解析解进行验证，证明了异常的一致性，并提供了比纯数值方法比较更严格的基准。至关重要的是，虽然用pin进行了演示，但AANNM框架是求解器不可知论的，旨在将任何人工神经网络的离散解转换为解析形式。这种固有的灵活性确保了该方法对未来人工神经网络发展的适用性，使其具有永恒和适应性。提出的框架将AANNM建立为一个变革性的管道，将数据驱动的数值模型与严格的分析数学连接起来，显著提高了计算科学中机器学习的可解释性、实用性和可信度。

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引用次数: 0

Effect of weld profiling on the fatigue strength of thin-walled rectangular hollow section T-joints made of high strength steel 焊缝成形对高强钢薄壁矩形空心截面t形接头疲劳强度的影响

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2026-06-01 Epub Date: 2026-02-18 DOI: 10.1016/j.finmec.2026.100359

Benjamin Laher , Christian Buzzi , Peter Brunnhofer , Martin Leitner

In this study, a thin-walled high-strength S960 rectangular hollow section T-joint is cyclically tested at a stress ratio of R=0.1. The work focuses on the effect of weld profiling conducted as post-weld treatment by grinding of the weld seam. Numerical simulations using the real weld seam geometry are carried out and compared with strain gauge measurements. Thereby, it is shown that the stress states of both methods are in sound agreement and the crack initiation site can be assessed well by the numerical approach. The resulting nominal S/N curves reveal an increase of the fatigue strength by about 33% at two million load-cycles due to weld profiling, which represents a high potential for this post-weld treatment technique. Furthermore, the notch stress approach using the common procedure by modelling a reference radius of r_ref=1 mm at the weld toe as well as modelling the real weld toe geometry after weld profiling are applied. The results are compared to the recently published values in the Recommendations for Fatigue Design of Welded Joints and Components by the International Institute of Welding (IIW) and highlight that both different modelling methods lead to a sound notch stress fatigue assessment of the weld-profiled condition.

在应力比R=0.1的条件下，对S960矩形空心截面薄壁高强t形节点进行了循环试验。本文的工作重点是对焊缝进行磨削处理后焊缝轮廓的影响。采用实际焊缝几何形状进行了数值模拟，并与应变片测量结果进行了比较。结果表明，两种方法的应力状态吻合较好，可以较好地评价裂纹起裂位置。由此产生的标称S/N曲线显示，在200万次载荷循环下，由于焊接轮廓，疲劳强度增加了约33%，这表明这种焊后处理技术具有很大的潜力。此外，缺口应力方法采用通用程序，通过在焊缝脚趾处建模参考半径rref=1 mm，以及在焊缝轮廓后模拟真实的焊缝脚趾几何形状。结果与国际焊接学会（IIW）最近发布的焊接接头和部件疲劳设计建议值进行了比较，并强调两种不同的建模方法都可以对焊缝轮廓状态进行良好的缺口应力疲劳评估。

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引用次数: 0

Comparative numerical studies of the mechanical efficiency of sandwich-panels with different non-/auxetic prismatic and lattice cores subjected to ballistic loading 弹道力作用下不同非/不对称棱柱芯和格子芯夹层板力学效率的数值比较研究

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2026-03-01 Epub Date: 2026-01-31 DOI: 10.1016/j.finmec.2026.100354

Marcel Walkowiak, Denis Anders, Ulf Reinicke

Civil as well as military facilities, vehicles and applications must increasingly meet higher safety standards to ensure the highest possible protection against extraordinary stresses such as ballistic and/or air-blast loading. The use of lightweight sandwich constructions is considered an efficient and promising measure for enhancing passive safety and maintaining structural integrity. In addition to increased bending stiffness compared to monolithic plates of the same weight, they also exhibit a more favorable behavior under dynamic loading scenarios. The influence of open and closed auxetic core geometries on the relevant mechanical parameters under impact loads of spherical rigid projectiles (r_sph = 15 mm, m_sph = 10 g) with velocities of 200 ms⁻¹ will be analyzed in the present study in order to be able to draw principal conclusions on the auxetic mechanisms and their effectiveness. A new performance indicator is suggested in this context. Numerical studies were performed using the commercial finite element code ABAQUS/Explicit. This included a validated material model for the aluminum alloy EN AW-7108 T6, which considers strain-rate dependent plastic material behavior and typical failure criteria. A comparison with a monolithic reference plate of the same mass and conventional non-auxetic core topologies allows a final efficiency assessment of the sandwich designs with a modified internal structure. The displacements of the rear face surfaces as well as the resulting stresses on supporting structures can be reduced by up to 90 percent and the plastically dissipated energy can be increased by up to 15 percent for some core variants.

民用和军用设施、车辆和应用必须越来越多地满足更高的安全标准，以确保对弹道和/或空气爆炸载荷等特殊应力的最高保护。使用轻质夹层结构被认为是一种有效和有前途的措施，以提高被动安全性和保持结构的完整性。除了与相同重量的单片板相比增加的抗弯刚度外，它们在动态加载场景下也表现出更有利的行为。在速度为200 ms−1的球形刚性弹丸（rsph = 15 mm, msph = 10 g）的冲击载荷下，本研究将分析开放和封闭的消磁芯几何形状对相关力学参数的影响，以便能够得出消磁机理及其有效性的主要结论。在这方面，建议设立一个新的业绩指标。采用商业有限元代码ABAQUS/Explicit进行数值研究。其中包括针对铝合金EN AW-7108 T6的验证材料模型，该模型考虑了应变率相关的塑性材料行为和典型的失效准则。与相同质量的单片参考板和传统的非辅助核心拓扑进行比较，可以对具有修改内部结构的夹层设计进行最终的效率评估。后表面的位移以及由此产生的对支撑结构的应力可以减少高达90%，对于一些核心变体，塑性耗散能量可以增加高达15%。

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引用次数: 0

Vibration analysis of a rotating FGM cracked beam under a tangent follower force 切线随动力作用下旋转FGM裂纹梁的振动分析

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2026-03-01 Epub Date: 2026-02-06 DOI: 10.1016/j.finmec.2026.100355

Ayaa H. Fadhel , Talib EH. Elaikh , Ali Hasan Ali , Husam A. Neamah

In the current study, we investigate the dynamic response of cracked rotating FG-beams with two variable boundary conditions. The crack is considered to be simulated by a massless torsional spring model. The beam motion equation is obtained based on Hamilton’s concept. In this study, a power-law exponent describes graded beam materials as they vary through the beam's thickness. The beam's natural frequencies are established by solving the vibration equations with the Galerkin method. The study investigates the effect of geometrical and material properties, rotating speed, distributed force, hub length, and crack parameters on these frequencies. The analysis shows that the power index decreases the dimensionless natural frequencies for all end conditions, with or without a crack. In the absence of cracks, the ratio of the reduction in frequency of the double-simply supported FG beam is 17.58%, and the ratio of the reduction in frequency of the clamped-free end conditions is 15.95%. The frequency decreases by 22.75% and 19.60% in S-S and C-F, respectively, with a crack.

Also, the dimensionless vibration frequency decreases with increasing tangent follower force, by 14.97% in S-S and 10.65% in C-F. Also, the results exhibit that crack depth lowers the dimensionless vibration frequencies. Moreover, the analysis shows that the hub radius ratio raises the dimensionless vibration frequencies, irrespective of the presence of a crack, across all end conditions. The findings provide useful insight for the vibration analysis and design of rotating FG structures in practical applications.

在本研究中，我们研究了裂纹旋转fg梁在两种可变边界条件下的动力响应。考虑用无质量扭簧模型来模拟裂缝。根据汉密尔顿的概念，得到了梁的运动方程。在这项研究中，幂律指数描述了随着光束厚度的变化而变化的梯度光束材料。利用伽辽金法求解振动方程，建立了梁的固有频率。研究考察了几何和材料特性、转速、分布力、轮毂长度和裂纹参数对这些频率的影响。分析表明，无论有无裂纹，功率指标都降低了无量纲固有频率。在无裂纹条件下，双简支FG梁的频率降低率为17.58%，无端部夹紧条件下的频率降低率为15.95%。随着裂纹的出现，S-S和C-F的频率分别下降了22.75%和19.60%。随着切向从动力的增大，无量纲振动频率降低，S-S降低14.97%，C-F降低10.65%。结果还表明，裂纹深度降低了无量纲振动频率。此外，分析表明，轮毂半径比提高无量纲振动频率，而不考虑裂纹的存在，在所有的末端条件。研究结果为实际应用中旋转FG结构的振动分析和设计提供了有益的见解。

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引用次数: 0

Experimental investigation of mechanical properties of hybrid sisal fiber and sheep wool reinforced epoxy composite material 剑麻纤维与羊毛混杂增强环氧复合材料力学性能的实验研究

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2026-03-01 Epub Date: 2026-01-17 DOI: 10.1016/j.finmec.2026.100353

Zewditu Aschalew Tarekgne , Teshome Mulatie Bogale , Velmurugan Paramasivam

Hybrid two or more fiber-reinforced composites are generally prepared to enhance different properties as compared to single-fiber reinforced composites. Sheep wool and sisal fibers are natural fibers that can be obtained from animal and plant sources respectively. After extracted and treated the fibers, the woven yarn fiber mat was prepared. The woven hybrid composite was fabricated with a 20% weight fraction of fiber by using hand layup fabrication techniques. Composites samples were prepared under five different weight percentage ratios of sheep wool to sisal fiber 0:20, 5:15, 10:10, 15:5, and 20:0. And each weight percentage of a sample was fabricated with two different angles (0°-90° and ±45°) of orientations. From the experimental test results, it was observed that the tensile, compressive, flexural strengths increase directly with increase sisal fiber weight percentage of composite samples in both 0-90° and ±45°angle of orientations. However, between the two angles of orientation, the tensile and flexural strengths of the hybrid sheep wool and sisal fiber epoxy composite samples were highest in 0-90°angle orientations composite samples. On other hand, the compressive and impact strengths were highest in ±45°angle orientation of the composite samples. Overall, the composite sample with a 15:5 sisal fiber-sheep wool ratio (SA4 and SB4) demonstrated the best mechanical performance. The maximum tensile and flexural strengths of 95.73 MPa and 358.80 MPa, respectively, were obtained for the 0°–90° oriented composite, whereas the highest compressive strength of 95.73 MPa and impact strength is 746.77 kJ/m² were observed in the ±45° oriented composite. The experimental test result shows that the hybrid sheep wool and sisal fiber epoxy composite are alternative materials for the interior part of automotive applications like interior roof and door panels.

与单纤维增强复合材料相比，通常制备两种或多种纤维增强复合材料以增强不同的性能。羊毛和剑麻纤维是天然纤维，分别可以从动物和植物中获得。对纤维进行提取处理后，制备了机织纱纤维垫。采用手工叠层法制备了纤维质量分数为20%的机织杂化复合材料。在羊毛与剑麻的重量百分比为0:20、5:15、10:10、15:5、20:0的条件下制备复合材料样品。样品的每一个重量百分比采用两种不同角度（0°-90°和±45°）的取向制备。试验结果表明，在0-90°和±45°取向角下，复合材料的抗拉、抗压、抗弯强度均随剑麻纤维重量百分比的增加而直接增加。而在两种取向角度之间，0 ~ 90°取向的混合羊毛/剑麻环氧复合材料的拉伸和弯曲强度最高。另一方面，复合材料样品的抗压和冲击强度在±45°角取向时最高。综上所述，剑麻纤维与羊毛（SA4和SB4）比为15:5的复合材料的力学性能最好。0°-90°取向复合材料的最大拉伸强度为95.73 MPa，最大弯曲强度为358.80 MPa，±45°取向复合材料的最大抗压强度为95.73 MPa，最大冲击强度为746.77 kJ/m²。实验测试结果表明，混合羊毛和剑麻纤维环氧复合材料是汽车内饰件的替代材料，如车顶和门板。

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引用次数: 0

Dynamic load localization and time history identification using blind source separation and structural modal shape matching 基于盲源分离和结构模态振型匹配的动载荷定位与时程识别

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2026-03-01 Epub Date: 2026-01-03 DOI: 10.1016/j.finmec.2026.100350

Kun Li , Zhuo Fu , Xianfeng Man , Shuai Wang , Yixiang Chen , Nuo Chen

Accurate knowledge of dynamic load locations and time histories is a critical input for structural design but is often infeasible to measure directly. While numerous load identification methods exist, they predominantly address the localization and time-history reconstruction separately, relying on the prior assumption that one of the two is known. This paper introduces a novel and efficient integrated approach that combines Blind Source Separation (BSS) with Structural Modal Shape Matching (SMSM) to concurrently identify both the spatial location and temporal profile of dynamic loads. The proposed methodology is founded on the principle that modal loads and physical loads are mutually convertible. Initially, truncated modal loads are stably reconstructed in the modal space using a shape function method with Tikhonov regularization. These recovered modal loads are then interpreted as blind mixtures of the unknown physical load source signals, with the structural modal shape coefficients acting as the mixing matrix. BSS is subsequently employed to separate the equivalent load time histories and estimate the mixing matrix. Since the mixing coefficient vector is linearly related to the structural mode shape vector at the load application point, SMSM is implemented by quantifying the intersection angles between the estimated mixing vectors and candidate modal shape vectors to pinpoint the most probable load locations. Finally, the actual load time histories are accurately retrieved using the reconstructed modal loads and the identified modal shape matrix. The efficacy of the proposed method is rigorously demonstrated through two numerical examples involving a complex ropeway tower and a rectangular plate.

动态荷载位置和时程的准确知识是结构设计的关键输入，但通常无法直接测量。虽然存在许多载荷识别方法，但它们主要是分别处理定位和时程重建，依赖于先验假设两者之一是已知的。提出了一种将盲源分离（BSS）和结构模态振型匹配（SMSM）相结合的新型高效集成方法，可同时识别动载荷的空间位置和时间分布。所提出的方法是建立在模态荷载和物理荷载相互转换的原则之上的。首先，利用带Tikhonov正则化的形函数方法在模态空间中稳定重构截短的模态载荷。然后将这些恢复的模态载荷解释为未知物理载荷源信号的盲混合，结构模态振型系数作为混合矩阵。然后利用BSS分离等效荷载时程并估计混合矩阵。由于混合系数矢量与加载点的结构模态振型矢量线性相关，因此SMSM通过量化估计的混合矢量与候选模态振型矢量之间的交角来确定最可能的加载位置。最后，利用重构的模态荷载和识别出的模态振型矩阵准确地检索出实际荷载时程。通过两个复杂索道塔和矩形板的数值算例，验证了该方法的有效性。

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引用次数: 0

Chemomechanical modeling of lithiation-induced failure based on strain gradient plasticity theory 基于应变梯度塑性理论的锂化破坏化学力学建模

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2026-03-01 Epub Date: 2025-12-13 DOI: 10.1016/j.finmec.2025.100343

Zengsheng Ma

Porous silicon (Si) anodes in lithium-ion batteries (LIBs) experience significant diffusion-induced stress gradients during electrochemical cycling, leading to crack propagation and active material pulverization. To systematically predict such failure behaviors, this study proposes a chemo-mechanical coupling framework by integrating strain gradient plasticity (SGP) theory with damage mechanics. The theoretical model explicitly resolves the interplay among lithiation kinetics, dislocation-mediated plasticity, and progressive damage accumulation in porous Si structures. Finite element method (FEM) simulations reveal the spatiotemporal evolution of lithium concentration fields, stress-strain distributions, and microcrack patterns. Parametric analyses identify critical structural parameters (e.g., pore radius, porosity) governing stress localization and interfacial delamination. Additionally, this work constructs a quantitative failure mechanism diagram that correlates state-of-charge (SOC), porosity, and pore geometry with fracture thresholds. The diagram offers actionable guidance for optimizing electrode architectures to mitigate stress-induced degradation in high-capacity LIB anodes.

锂离子电池（LIBs）多孔硅（Si）阳极在电化学循环过程中会产生明显的扩散诱导应力梯度，导致裂纹扩展和活性物质粉末化。为了系统地预测这种破坏行为，本研究将应变梯度塑性（SGP）理论与损伤力学相结合，提出了一个化学-力学耦合框架。该理论模型明确地解决了多孔硅结构中锂化动力学、位错介导的塑性和渐进损伤积累之间的相互作用。有限元模拟揭示了锂离子浓度场、应力-应变分布和微裂纹模式的时空演化规律。参数分析确定了控制应力局部化和界面分层的关键结构参数（如孔隙半径、孔隙度）。此外，该工作还构建了定量破坏机理图，将荷电状态（SOC）、孔隙度和孔隙几何形状与破裂阈值相关联。该图为优化电极结构提供了可行的指导，以减轻高容量锂离子电池阳极的应力诱导退化。

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引用次数: 0

An improved Bayesian model updating framework using an enriched spring-based finite element model for structural health monitoring 基于弹性有限元模型的结构健康监测改进贝叶斯模型更新框架

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2026-03-01 Epub Date: 2026-02-17 DOI: 10.1016/j.finmec.2026.100357

Masoomeh Farrokhtar, Reza Saleh Jalali, Morteza Sohrabi Gilani

Classical finite‐element model updating (FEMU) requires iterative updates of the structural model. Alternative approaches are often computationally expensive or oversimplify the actual physical behavior of the structures. This paper introduces a novel approach, an enriched spring-based Bayesian finite element model updating (ES-BFEMU) method, which reduces computational cost while preserving high fidelity. In the proposed model, each structural element is divided into two beam-like sub-elements and a rotational spring. The stiffness matrix is derived by enriching the strain energy of both the sub-elements and the spring. This formulation enhances the physical interpretability of local stiffness degradation by explicitly representing rotational flexibility in potential damage zones. The enriched stiffness matrix is updated to provide a more realistic finite element model by detecting stiffness reductions within a Bayesian FEMU framework that considers the uncertainties. The computational efficiency is improved by adopting an adaptive transitional Markov chain Monte Carlo (TMCMC) algorithm to obtain the posterior probability of parameters. The proposed model is applied to the Salar Bridge, a six-span structure instrumented with accelerometers, displacement transducers, and strain gauges. Structural damage is simulated by introducing stiffness reduction coefficients into the elastic modulus of selected elements, with scenarios defined at reduction levels of 2%, 5%, 10%, and 15%. The introduced damages were successfully detected with a deviation of <2%. The proposed ES-BFEMU was also compared with surrogate and reduced-order FEMU approaches, demonstrating improved computational efficiency and higher accuracy in damage identification. The proposed model serves as a bridge between the surrogate and reduced-order FEMU. It reduces the computational cost associated with the reduced-order FEMU by a factor of 3.57 and enhances the accuracy of the surrogate method by 33%. The stress-time results of ES-BFEMU show a prediction error of <6.15% when compared to experimental results. These results demonstrate that ES-BFEMU provides a computationally efficient, physically interpretable, and reliable framework for structural health monitoring and damage identification.

经典有限元模型更新（FEMU）需要对结构模型进行迭代更新。替代方法通常在计算上昂贵或过度简化结构的实际物理行为。本文介绍了一种新颖的方法——基于丰富弹簧的贝叶斯有限元模型更新（ES-BFEMU）方法，该方法在降低计算成本的同时保持了较高的保真度。在该模型中，每个结构单元被划分为两个类梁子单元和一个旋转弹簧。通过丰富子单元和弹簧的应变能，推导出刚度矩阵。该公式通过明确表示潜在损伤区域的旋转柔韧性，增强了局部刚度退化的物理可解释性。通过在考虑不确定性的贝叶斯FEMU框架内检测刚度降低，更新了丰富的刚度矩阵，以提供更真实的有限元模型。采用自适应过渡马尔可夫链蒙特卡罗（TMCMC）算法获得参数的后验概率，提高了计算效率。提出的模型应用于Salar大桥，这是一个六跨结构，配有加速度计，位移传感器和应变计。通过在选定元素的弹性模量中引入刚度折减系数来模拟结构损伤，并定义了2%、5%、10%和15%的折减水平。引入的损伤以2%的偏差成功地检测到。将ES-BFEMU方法与替代方法和降阶FEMU方法进行了比较，结果表明ES-BFEMU方法在损伤识别方面具有更高的计算效率和准确性。该模型是代理模型和降阶FEMU之间的桥梁。该方法将降阶FEMU的计算成本降低了3.57倍，将替代方法的精度提高了33%。与实验结果相比，ES-BFEMU的应力-时间预测误差为6.15%。这些结果表明，ES-BFEMU为结构健康监测和损伤识别提供了一个计算效率高、物理可解释且可靠的框架。

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引用次数: 0

Experimental and numerical damage assessment of PLA based on young’s modulus reduction using the bonora damage model 采用bonora损伤模型对基于杨氏模量折减的聚乳酸损伤进行实验和数值评估

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2026-03-01 Epub Date: 2025-12-13 DOI: 10.1016/j.finmec.2025.100345

Mohammad Ali Kazemi , Seyedsajad Jafari , Mostafa akbari

The goal of this paper is to experimentally and numerically investigate damage evolution in PLA+ materials, based on the reduction of Young’s modulus during cyclic loading–unloading tests. Standard tensile specimens were fabricated via FDM 3D printing and tested under displacement-controlled cyclic loading, while strain was measured using both extensometer and digital image correlation. The Bonora damage model was calibrated for PLA+ by fitting the damage parameter to experimental plastic strain data. The obtained constants (D_cr=0.20, ε_th=0.012, ε_f=0.042, α=0.76) were implemented in a custom VUSDFLD subroutine in ABAQUS. The finite element simulations successfully predicted final failure, showing good agreement with the experimental damage parameter evolution. The numerical predictions deviated <5 % from experimental results, confirming the high accuracy of the Bonora-based model implementation. This combined experimental–numerical framework provides a reliable basis for predicting progressive damage in PLA+ components under quasi-static loading. The novelty of this work lies in the calibration of the Bonora model for PLA+, which shows enhanced ductility compared to conventional PLA, and in demonstrating its potential for reliable application in both engineering load-bearing structures and biodegradable biomedical devices.

本文的目的是通过实验和数值研究基于循环加载-卸载试验中杨氏模量降低的PLA+材料的损伤演变。通过FDM 3D打印制作标准拉伸试件，在位移控制的循环加载下进行测试，同时使用伸量计和数字图像相关测量应变。通过将损伤参数拟合到实验塑性应变数据中，对PLA+的Bonora损伤模型进行了标定。得到的常数（Dcr=0.20, εth=0.012, εf=0.042, α=0.76）在ABAQUS自定义的VUSDFLD子程序中实现。有限元模拟成功地预测了最终破坏，与试验损伤参数的演变符合较好。数值预测与实验结果偏差5%，证实了基于bonora模型实现的高精度。这种实验-数值结合的框架为预测PLA+构件在准静态载荷作用下的渐进损伤提供了可靠的依据。这项工作的新颖之处在于校准了PLA+的Bonora模型，与传统PLA相比，PLA+显示出增强的延展性，并展示了其在工程承重结构和可生物降解生物医学设备中的可靠应用潜力。

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引用次数: 0

Analytical investigation of nonlinear response of single-walled carbon nanotube resting on elastic foundation subjected to casimir-electrostatic-van der waals forces 弹性基础上单壁碳纳米管在卡西米尔-静电-范德华力作用下的非线性响应分析研究

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2026-03-01 Epub Date: 2025-12-13 DOI: 10.1016/j.finmec.2025.100344

E.H. Abubakar , A.A. Yinusa , M.G. Sobamowo , O.M. Sadiq

This paper presents analytical investigation into the nonlinear dynamic response of single-walled carbon nanotube (SWCNT) resting on elastic foundation and subjected to magneto-thermal and electrostatic environment under the influence of Casimir and intermolecular forces. The Euler-Bernoulli beam theory, the nonlocal elasticity theory and Hamilton’s principle of nonlinear mechanistic motion are applied in the theoretical formulation of the governing differential equation and the Galerkin decomposition technique is used to decompose the formulated equation of motion into spatial and temporal parts. The duffing equation which describes the temporal part of the equation of motion of the SWCNT is then solved analytically. Subsequently, the frequency ratios of the nanotube for end conditions including simple-simple, clamped-clamped, clamped-simple, and clamped-free are obtained. Furthermore, parametric study is carried out to show the influences of Casimir force, intermolecular force, electrostatic force, magnetic term, elastic foundation and thermal term on the nanotube’s stability. The stability response solution obtained from the parametric study reveals that an increase in Casimir force enables CNTs to experience an additional attractive pressure that decreases their stability and may result in buckling or collapse. Meanwhile, increase in Van der Waals force reduces critical buckling load. Additionally, increasing the electrostatic force results in an increased frequency ratio and vibration amplitude. These parameters need to be carefully monitored or controlled to prevent instabilities due to their sensitivities.

本文分析研究了单壁碳纳米管（SWCNT）在弹性基础上，在卡西米尔力和分子间作用力的影响下，在磁热和静电环境下的非线性动力响应。应用欧拉-伯努利梁理论、非局部弹性理论和Hamilton非线性机械运动原理对控制微分方程进行理论推导，并利用伽辽金分解技术将运动方程分解为空间和时间两个部分。然后对描述swcnts运动方程时间部分的duffing方程进行解析求解。随后，得到了纳米管在简单-简单、夹紧-夹紧、夹紧-简单和无夹紧等末端条件下的频率比。此外，还对卡西米尔力、分子间力、静电力、磁项、弹性基础和热项对纳米管稳定性的影响进行了参数化研究。从参数化研究中得到的稳定性响应解表明，卡西米尔力的增加使碳纳米管承受额外的吸引压力，从而降低其稳定性，并可能导致屈曲或坍塌。同时，范德华力的增大降低了临界屈曲载荷。此外，增加静电力会导致频率比和振动幅值的增加。这些参数需要仔细监测或控制，以防止因其敏感性而产生不稳定。

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引用次数: 0