Forces in mechanics最新文献_第2页

Elastic-damage characterization of fibre-bundle lamina of CFRP composite through 3D digital image correlation and finite element method 基于三维数字图像相关和有限元法的CFRP复合材料纤维束层弹性损伤表征

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2025-10-21 DOI: 10.1016/j.finmec.2025.100337

S․ S. R․ Koloor , A. Farokhi Nejad , N. Yidris , S.M. Sapuan , M.R. Abdullah , M.N. Tamin

Carbon fibers’ exceptional mechanical properties make them the major load-bearing component of CFRP composites, which are rapidly being used in modern aerospace applications. Design of multi-directionally (MD) laminated composite structures for specific operational load requires the exact determination and force analysis of 0°-laminas and their arrangement in the lamina assembly process. The significant property variation between carbon fibers and matrix components indicates that the mechanical behavior of the 0°-laminas is attributed largely to the fiber-bundle at the mesoscale. The elastic properties of fiber have been obtained through standard tests, however, many challenges are encountered in the characterization of fiber damage and fracture processes. In this research, a new experiment is introduced where tensile tests are performed on single edge-notch 0°-CFRP composite monitored by 3D digital image correlation (DIC), to demonstrate the mechanism of deformation and failure and determine the exact elastic-damage properties. A hybrid experimental-computational approach is developed where finite element models representing the experiment, are used to obtain and validate the damage evolution characteristics of fibers in CFRP lamina. In addition, test and simulation results are utilized to describe the mechanism and mechanics of deformation and damage of the composite structure.

碳纤维优异的机械性能使其成为CFRP复合材料的主要承重成分，在现代航空航天应用中得到迅速应用。针对特定工作载荷设计多向层压复合材料结构，需要对0°-层板进行精确的确定和受力分析，并在层板组装过程中对其进行布置。碳纤维和基体组分之间的显著性能差异表明，0°-层板的力学行为主要归因于纤维束在中尺度上的作用。纤维的弹性性能已经通过标准试验得到，但在纤维损伤和断裂过程的表征中遇到了许多挑战。本文采用三维数字图像相关（DIC）技术对0°-CFRP复合材料进行了拉伸试验，验证了0°-CFRP复合材料的变形破坏机理，并确定了其准确的弹性损伤特性。提出了一种实验与计算相结合的方法，利用代表实验的有限元模型，获得并验证了碳纤维复合材料层中纤维的损伤演化特征。此外，利用试验和模拟结果描述了复合材料结构变形和损伤的机理和力学特性。

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引用次数: 0

Nonlinear thermo-mechanical coupling behaviours and damage mechanisms of 3D braided composites subjected to longitudinal and transverse tensile at room and elevated temperatures 室温和高温下纵向和横向拉伸三维编织复合材料的非线性热-力耦合行为和损伤机制

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2025-10-05 DOI: 10.1016/j.finmec.2025.100336

Dong Li, Jun-Jiang Xiong

This paper examines thermo-mechanical coupling behaviours and damage mechanisms of 3D4D (three-dimensional four-directional) braided composites subjected to longitudinal and transverse tensile at room and elevated temperatures. New nonlinear constitution model of 3D braided composites is derived in consideration of thermo-mechanical coupling effect, non-linear shear constitutive relationship of fibre yarn and elastoplastic deformation characteristics of matrix, and novel mixed criterion is then presented based on von-Mises rule, 3D Hashin criterion, B-K energy and quads damage model. After this, an improved progressive damage algorithm is devised for modelling progressive thermo-mechanical coupling damage process of 3D braided composites. Quasi-static longitudinal and transverse tensile tests are respectively performed on 3D4D braided composites at RT (room temperature) and 85

^{\circ} C

, and nonlinear thermo-mechanical coupling behaviours are analyzed and discussed from experiment results. In order to verify the model and algorithm mentioned previously, a high-fidelity full-scale mesoscale finite element (HFFSMFE) model is generated and integrated with improved algorithm for modelling progressive damage process of 3D4D braided composites subjected to longitudinal and transverse tensile at both temperatures, and numerical predictions agree well with experimental findings, demonstrating the apt and effective usage of new model proposed in the paper.

本文研究了三维四向编织复合材料在室温和高温下纵向和横向拉伸的热-力耦合行为和损伤机制。考虑了热机耦合效应、纤维纱线的非线性剪切本构关系和基体的弹塑性变形特性，建立了三维编织复合材料的非线性本构模型，并提出了基于von-Mises规则、三维哈辛准则、B-K能量和四元损伤模型的混合准则。在此基础上，设计了一种改进的渐进损伤算法，用于模拟三维编织复合材料的热-力耦合渐进损伤过程。分别在RT（室温）和85°C下对3D4D编织复合材料进行了准静态纵向和横向拉伸试验，并从实验结果分析和讨论了非线性热-力耦合行为。为了验证上述模型和算法，建立了高保真的全尺寸中尺度有限元（HFFSMFE）模型，并将其与改进算法相结合，对两种温度下纵向和横向拉伸的3D4D编织复合材料的渐进损伤过程进行了模拟，数值预测与实验结果吻合较好，证明了本文提出的新模型的适用性和有效性。

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引用次数: 0

Impact dynamics of mechanical metamaterials: A short review and perspective 机械超材料的冲击动力学：综述与展望

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2025-10-03 DOI: 10.1016/j.finmec.2025.100335

Chuanqing Chen , Yulong He , Yuli Chen , Guoxing Lu , Ming-Hui Lu , Xin Li

Mechanical metamaterials, with their unique properties, have been increasingly investigated as lightweight, high‑strength impact‑resistant solutions for aerospace, military, transportation, and biomedical applications. In this paper, recent advanced studies in mechanical metamaterials under impact loads are briefly reviewed. On the basis of structural form, four primary types of metamaterials are categorized: mass-spring system, rod/beam-based, plate/shell-based and other specialized types of metamaterials. Additionally, their intended energy-absorption mechanisms and loading-rate‑dependent mechanical responses are discussed. Finally, potential future research directions are proposed, including studies of strain rate and inertial effects, stress wave propagation, localized impact, size effect and multi-scale effect, multifunctional design and AI-assisted on-demand design. This paper highlights key strategies and areas for innovation in the development of next-generation impact-resistant mechanical metamaterials.

机械超材料以其独特的性能，作为航空航天、军事、运输和生物医学应用的轻质、高强度抗冲击解决方案，得到了越来越多的研究。本文综述了近年来在冲击载荷作用下机械超材料的研究进展。根据结构形式，可将四种主要类型的超材料分类为：质量-弹簧系统、杆/梁型、板/壳型和其他特殊类型的超材料。此外，他们预期的能量吸收机制和加载速率相关的力学响应进行了讨论。最后，提出了未来可能的研究方向，包括应变速率与惯性效应、应力波传播、局部冲击、尺寸效应与多尺度效应、多功能设计、人工智能辅助按需设计等。本文重点介绍了下一代抗冲击机械超材料发展的关键策略和创新领域。

引用次数: 0

Axially crashworthy performance of thin-walled tubes with various configurations under the same scale 相同尺度下不同结构薄壁管的轴向耐撞性能

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2025-09-27 DOI: 10.1016/j.finmec.2025.100334

Qingliang Zeng , Zhaoji Li , Peng Liu , Naihao Gong , Lirong Wan

Thin-walled tubes with various design strategies as energy absorbers have been widely proposed and applied in the engineering fields. However, the comparison of the crashworthy performance of tubes with various cross-sectional topologies under axial compression remains scarce. In this paper, twelve types of thin-walled tubes (e.g., single-celled, bi-tubular and hierarchical square, hexagonal and circular tubes), which have the identical material, height, apparent area and mass, have been fairly compared. Validation is accomplished through axial quasi-static crushing tests, ensuring the accuracy of the finite element models. The crushing behaviors of all tubes studied are investigated using six crashworthiness indicators. The results show that thin-walled tubes with hierarchical features primarily deform in the preferrable stable deformation mode, with more lobes and higher energy dissipation. Then, hierarchical features can reduce the fluctuations and enhance the load-carrying capacity. In addition, the mean crushing force (MCF) and specific energy absorption (SEA) of bi-tubular tubes also do not increase significantly compared with single-celled tubes. Specifically, the increases in SEA from square tubes to circular tubes for single-celled, bi-tubular and edge-based hierarchical are 65.4 %, 75.0 % and 49.6 %, respectively. Furthermore, all tubes studied are comprehensively evaluated by applying the technique for order preference by similarity to an ideal solution (TOPSIS) method. Considering the effect of dimension, four non-dimensional indicators are selected, namely ESR, EEA, CFE and ULC. EH_C has the best overall performance among all the tubes studied.

薄壁管作为吸能器，其设计策略多种多样，已被广泛提出并应用于工程领域。然而，对不同截面拓扑结构的管材在轴压作用下的耐撞性能的比较研究仍然很少。本文对具有相同材料、高度、表观面积和质量的12种薄壁管（如单细胞、双管和分层方形、六角形和圆形管）进行了比较。通过轴向准静态破碎试验进行验证，保证了有限元模型的准确性。采用6项耐撞性指标对所研究管的破碎性能进行了研究。结果表明：具有分层特征的薄壁管主要以较优的稳定变形模式进行变形，其叶片较多，能量耗散较高；然后，分层特征可以减少波动，提高承载能力。此外，与单细胞管相比，双管的平均破碎力（MCF）和比能吸收（SEA）也没有显著增加。具体来说，对于单细胞、双管和边缘分层，从方形管到圆形管的SEA分别增加了65.4%、75.0%和49.6%。此外，通过应用与理想溶液（TOPSIS）方法相似的顺序偏好技术，对所研究的所有管进行了全面评估。考虑到维度的影响，我们选择了4个无维度指标，分别是ESR、EEA、CFE和ULC。EH_C在所有被研究的管中具有最好的综合性能。

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引用次数: 0

Simplified numerical modeling with experimental validation of molten pool geometry in laser welding 激光焊接熔池几何形状的简化数值模拟与实验验证

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2025-09-25 DOI: 10.1016/j.finmec.2025.100333

Mahdi Ghamari , Pouria Oliazadeh , Mohammad Hossein Farshidianfar

Laser welding is widely adopted for its high speed, precision, and automation capabilities, delivering superior microstructural properties in material joining. However, suboptimal welding parameters can cause defects, necessitating accurate and computationally efficient simulation models. This study introduces a novel simplified numerical model for laser welding that optimizes the prediction of molten pool geometry while minimizing computational cost. By integrating a phase-change model with a calibrated Gaussian heat source, the approach balances accuracy and efficiency, addressing the limitations of complex fluid dynamics models and oversimplified temperature-based simulations. The model was validated against seven experimental cases involving Ti6Al4V and stainless steel 316 L, achieving zero error in melt pool depth prediction and maximum errors in top and bottom widths of <0.2 mm. This computationally efficient model enables rapid parameter optimization, making it ideal for large-scale industrial applications, including residual stress and distortion analysis. By offering a practical alternative to high-cost simulations, this work advances laser welding simulation for precision manufacturing and supports broader adoption in industries such as automotive and railway.

激光焊接以其高速度、高精度和自动化的特点，在材料连接中具有优异的微结构性能而被广泛采用。然而，次优焊接参数可能导致缺陷，因此需要精确且计算效率高的仿真模型。本文介绍了一种新型的激光焊接简化数值模型，该模型在最小化计算成本的同时优化了熔池几何形状的预测。通过将相变模型与校准的高斯热源集成，该方法平衡了精度和效率，解决了复杂流体动力学模型和过于简化的基于温度的模拟的局限性。通过7个涉及Ti6Al4V和316 L不锈钢的实验案例对模型进行了验证，熔池深度预测误差为零，上下宽度最大误差为0.2 mm。这种计算效率高的模型可以快速优化参数，使其成为大规模工业应用的理想选择，包括残余应力和变形分析。通过提供高成本模拟的实用替代方案，这项工作推进了精密制造的激光焊接模拟，并支持在汽车和铁路等行业的更广泛采用。

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引用次数: 0

Effect of stress state on the fracture behavior of Al6061-T6 via combined experimental and numerical approaches 试验与数值结合研究应力状态对Al6061-T6断裂行为的影响

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2025-09-23 DOI: 10.1016/j.finmec.2025.100332

Mohsen Mansouri, Mehdi Ganjiani

This study presents an experimental and numerical investigation into the influence of stress triaxiality, Lode angle parameter, and ductile fracture behavior in Al 6061-T6 aluminum alloy. To explore negative stress triaxiality conditions, uniaxial tensile and compressive tests were conducted on geometrically tailored specimens, including dumbbell-shaped and rectangular samples with elliptical curved holes. Negative triaxiality values ranging from –0.355 to –0.554 were successfully achieved. A hybrid experimental–numerical approach was adopted to characterize the fracture behavior. In the numerical approach, the Ganjiani fracture model incorporating damage parameters, was implemented in finite element simulations using Abaqus via custom VUHARD and VUSDFLD subroutines. Comparative analysis of experimental and numerical results revealed good agreement in fracture strain predictions. Numerical evaluations indicated that the fracture occurs at the site where maximum plastic strain is observed. The results confirm that stress triaxiality significantly influences ductile fracture, and notably, the variation in fracture strain exhibits different trends under positive and negative triaxiality conditions.

本文对应力三轴性、Lode角参数对Al 6061-T6铝合金韧性断裂行为的影响进行了实验和数值研究。为探索负应力三轴性条件，对几何定制的哑铃形和椭圆形弯曲孔矩形试样进行单轴拉伸和压缩试验。成功地获得了负三轴性值，范围从-0.355到-0.554。采用实验-数值混合方法对断裂行为进行表征。在数值方法中，采用Abaqus，通过自定义的VUHARD和VUSDFLD子程序实现了包含损伤参数的Ganjiani断裂模型的有限元模拟。实验结果与数值结果的对比分析表明，断裂应变预测结果吻合较好。数值计算表明，断裂发生在塑性应变最大的部位。结果表明，应力三轴性对韧性断裂有显著影响，且在正、负三轴性条件下，断裂应变的变化趋势不同。

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引用次数: 0

The conversion between thermal snap-through and bifurcation instabilities of metal foam sandwich beams by refined first-order shear theory 用精细一阶剪切理论研究泡沫金属夹层梁热透失稳与分岔失稳的转换

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2025-09-14 DOI: 10.1016/j.finmec.2025.100331

Ying-long Zhao , Chao Fu , Hong-yao Zeng , Qiang Lyu , Neng-hui Zhang

The bending, vibration, and buckling of metal foam structures under thermal loads have consistently attracted significant interest in various engineering applications. However, most theoretical models rely on numerical results, which obscure connections between the system parameters and the system response, and the thermal instability type of metal foam structures has not been clarified. This paper aims to investigates the instability type of metal foam sandwich beams under various temperature fields. The analysis incorporates three models for porosity distribution and two scenarios for temperature fields. Firstly, a nonlinear governing equation for metal foam sandwich beams under uniform and linear temperature fields is formulated by using refined first-order shear theory, Von Karman geometric nonlinearity, and the concept of physical neutral plane. Secondly, an analytical solution to the nonlinear integral-differential boundary value problem for metal foam sandwich beams is obtained by using the Nayfeh’s semi-inverse solution method. Finally, the instability type, post-buckling paths, and corresponding mechanism of metal foam sandwich beams are predicted by the analytical solution and free energy evaluation, respectively. The results indicate that the clamped-supported (CC) metal foam sandwich beam will experience bifurcation instability; however, the instability type of the simply-supported (S-S) metal foam sandwich beam transitions from bifurcation instability to snap-through as the pore distribution and temperature fields vary. Furthermore, the buckling resistance of metal foam sandwich beams can be substantially improved through meticulous optimization of material parameters. These findings are anticipated to provide novel insights and valuable references for the design and regulation of metal foam structures.

金属泡沫结构在热载荷作用下的弯曲、振动和屈曲一直引起了各种工程应用的极大兴趣。然而，大多数理论模型依赖于数值结果，模糊了系统参数与系统响应之间的联系，并且金属泡沫结构的热不稳定类型尚未明确。本文旨在研究金属泡沫夹层梁在不同温度场下的失稳类型。分析采用了三种孔隙度分布模型和两种温度场情景。首先，利用改进的一阶剪切理论、Von Karman几何非线性和物理中性面概念，建立了均匀和线性温度场下金属泡沫夹层梁的非线性控制方程；其次，采用Nayfeh半反解法，得到了金属泡沫夹层梁非线性积分-微分边值问题的解析解。最后，利用解析解和自由能评价分别预测了泡沫金属夹层梁的失稳类型、后屈曲路径和失稳机理。结果表明：夹支金属泡沫夹层梁将发生分岔失稳；然而，随着孔分布和温度场的变化，简支金属泡沫夹层梁的失稳类型由分岔失稳转变为窜穿失稳。此外，通过对材料参数的精心优化，金属泡沫夹层梁的抗屈曲性能可以得到大幅提高。这些发现有望为金属泡沫结构的设计和规范提供新的见解和有价值的参考。

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引用次数: 0

Free vibration analysis of rectangular plates with variable thickness using a meshless method 用无网格法分析变厚度矩形板的自由振动

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2025-08-21 DOI: 10.1016/j.finmec.2025.100328

Reza Pilafkan , Peter D. Folkow

This paper presents a comprehensive study on the free vibration analysis of rectangular plates with variable thickness, utilizing three-dimensional elasticity theory and a meshless method. Traditional plate theories, such as classical and shear deformation theories, often fail to provide accurate results for thick plates or those with complex geometries. To overcome these limitations, the study adopts the three-dimensional elasticity approach, which considers the full material behavior and the entire plate structure. The meshless method, specifically the Radial Point Interpolation Method (RPIM) with multi-quadrics radial basis functions, is employed to solve the vibration problem. This method offers advantages over traditional finite element methods by using scattered nodes and higher-order shape functions, thus eliminating issues related to meshing and re-meshing. The plates’ thickness is assumed to vary linearly and nonlinearly in one or both directions in the plate plane, and the study investigates the impact of different thickness ratios, aspect ratios, and boundary conditions on the natural frequencies of the plate. The results show that the meshless method provides a high degree of accuracy and fast convergence for both thin and thick plates with variable thickness, making it a reliable and efficient tool for free vibration analysis. This work thus contributes with valuable insights to the dynamic behavior of variable-thickness plates, with applications in many engineering fields where weight reduction and structural performance are critical. The work also provides eigenfrequency results on several plate structures with varying thickness, which may serve as a reference using 3D theory.

本文利用三维弹性理论和无网格法对变厚度矩形板的自由振动进行了全面的研究。传统的板理论，如经典和剪切变形理论，往往不能提供准确的结果厚板或具有复杂的几何形状。为了克服这些局限性，本研究采用了三维弹性方法，考虑了材料的整体性能和整个板结构。采用无网格法，即多二次径向基函数径向点插值法（RPIM）求解振动问题。该方法使用分散节点和高阶形状函数，与传统有限元方法相比具有优势，从而消除了网格划分和重新网格划分的问题。假设板的厚度在板平面上沿一个或两个方向呈线性和非线性变化，研究了不同的厚度比、宽高比和边界条件对板固有频率的影响。结果表明，该方法对变厚度薄板和厚板均具有较高的精度和快速收敛性，是一种可靠、高效的自由振动分析工具。因此，这项工作为变厚板的动态行为提供了有价值的见解，在许多工程领域的应用中，减轻重量和结构性能是至关重要的。本文还提供了几种不同厚度板结构的特征频率结果，可作为三维理论的参考。

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引用次数: 0

The spall damage of Al at ultra-high strain rates: A combination of MD simulation and mechanical modelling 超高应变速率下Al的剥落损伤：MD模拟与力学建模的结合

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2025-08-01 DOI: 10.1016/j.finmec.2025.100326

Fuqi Zhao , Tingting Zhou , Anmin He , Pei Wang

Molecular dynamics (MD) and mechanical modelling simulations were used to investigate the dynamic fracture mechanism and damage evolution in single crystal aluminium subjected to shock loadings. MD simulations of shock induced spalling were performed to investigate the effect of strain rate. It is discovered that as the strain rate increases, the critical stress for damage activation, the rate of damage development, and the spall strength increase, whereas the width of the damage region decreases. The time evolution of the void volume fraction obtained from MD simulations was then used to determine the parameters of several theoretical models, including the nucleation-and-growth (NAG) model and Kanel’s model. Coupled with the theoretical models and verified parameters, the one-dimensional finite element method (1-D FEM) was used to perform mechanical modelings of spallation under shock loadings. The calculated results, including the time evolutions of stress, free surface velocity, and the density distribution of the damage region, agree with the MD data. We believe that this study could shed light on the studies of spall damage under conditions of ultra-high strain rates.

采用分子动力学和力学模拟方法研究了单晶铝在冲击载荷作用下的动态断裂机制和损伤演化过程。对冲击剥落过程进行了MD模拟，研究了应变速率对剥落过程的影响。结果表明，随着应变速率的增大，损伤激活临界应力、损伤发展速率和破片强度增大，而损伤区宽度减小；利用MD模拟得到的孔隙体积分数随时间的变化规律，确定了几种理论模型的参数，包括成核生长（NAG）模型和Kanel模型。结合理论模型和验证参数，采用一维有限元法（1-D FEM）对冲击载荷下的开裂进行力学建模。计算结果包括应力的时间演变、自由表面速度和损伤区域的密度分布，与MD数据一致。本研究为超高应变速率条件下的碎片损伤研究提供了新的思路。

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引用次数: 0

Ratcheting behavior of pressurized 316L austenitic stainless steel pipe tee under cyclic bending using DIC method 加压316L奥氏体不锈钢三通管在DIC循环弯曲下的棘轮行为

IF 3.5 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Forces in mechanics

Pub Date : 2025-08-01 DOI: 10.1016/j.finmec.2025.100325

Ali Shahrjerdi, Faezeh Nazari

In this study, the ratcheting behavior of a 316 L Austenitic Stainless Steel pipe tee under cyclic bending and constant internal pressure was investigated experimentally and numerically using the digital image correlation (DIC) method. First, the material of the tee was verified with chemical analyses. During the experimental tests, bending load was applied using an INSTRON 8503 machine, a compressed air capsule was used to apply the constant internal pressure and Strain was measured using the digital image correlation (DIC) method. In the experimental tests, tee samples were tested at controlled force and room temperature (25 °C). It was observed that increasing the average force, amplitude force, and internal pressure resulted in an increased accumulation of ratcheting strain. Finally, the ratcheting behavior of the tee samples was simulated using ANSYS software and the finite element method based on a nonlinear kinematic/isotropic hardening model. The FE simulation results were compared with experimental data, and it was found that the numerical data are in good agreement with experimental data.

采用数字图像相关（DIC）方法，对316l奥氏体不锈钢三通管在循环弯曲和恒内压作用下的棘轮行为进行了实验和数值研究。首先，用化学分析验证了三通的材料。实验过程中，采用INSTRON 8503试验机施加弯曲载荷，采用压缩空气胶囊施加恒定内压，采用数字图像相关（DIC）方法测量应变。在实验测试中，三通样品在受控力和室温（25°C）下进行测试。观察到，增加平均力、振幅力和内压导致棘轮应变积累增加。最后，采用ANSYS软件和基于非线性运动/各向同性硬化模型的有限元方法对三通试件的棘轮行为进行了模拟。将有限元模拟结果与实验数据进行了比较，发现数值数据与实验数据吻合较好。

引用次数: 0