【新文速递】2023年12月14日复合材料SCI期刊最新文章

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，International Journal of Plasticity 2 篇，Thin-Walled Structures 6 篇International Journal of Solids and StructuresMicrostructure generation algorithm and micromechanics of curved fiber composites with random wavinessAyan Kumar, Anirvan DasGupta, Atul Jaindoi:10.1016/j.ijsolstr.2023.112625随机波纹弯曲纤维复合材料微结构生成算法及细观力学During multiscale modeling and analysis of composite materials, accurately capturing the distinctive microstructural features of the material is essential. This is achieved by generating a representative volume element (RVE). Fiber reinforcements in composites can exhibit various shapes, including straight, slightly wavy, or complex shapes, depending on the inherent properties or the manufacturing process. Fibers are characterized based on their tortuosity, spread, and orientation distribution. It is crucial to account for these geometrical attributes during the microstructure generation and subsequent micromechanics modelling as they significantly influence the effective properties of the composite. The present work describes a novel algorithm capable of modeling a broad range of 3D periodic microstructures with fibers having random waviness. The effects of various parameters in the algorithm are studied to understand their influence on fiber shapes. This is followed by finite element analysis of the generated RVEs using the embedded element technique to quantify the microstructure- mechanical properties relationships. Finally, guidelines on the usage of the proposed model to generate fibers with desired microstructure is elucidated. A comprehensive framework for modeling and analyzing microstructures with complex fiber geometry is outlined.在复合材料的多尺度建模和分析中，准确捕捉材料独特的微观结构特征是必不可少的。这是通过生成一个代表性体积元素(RVE)来实现的。复合材料中的纤维增强材料可以呈现各种形状，包括直线型、微波浪形或复杂形状，这取决于其固有特性或制造工艺。纤维的特征是基于它们的弯曲度、扩散和取向分布。在微观结构生成和随后的微观力学建模过程中考虑这些几何属性是至关重要的，因为它们显著影响复合材料的有效性能。本工作描述了一种新的算法，能够模拟具有随机波纹的纤维的广泛的三维周期性微结构。研究了算法中各参数对纤维形状的影响。然后使用嵌入单元技术对生成的rve进行有限元分析，以量化微观结构与力学性能的关系。最后，阐明了使用所提出的模型生成具有所需微观结构的纤维的指导方针。概述了一种用于复杂纤维几何微结构建模和分析的综合框架。Journal of the Mechanics and Physics of SolidsMechanism of crack evolution and strength failure in chemo-mechanical induced fractureJiajing Yin, Quanzi Yuandoi:10.1016/j.jmps.2023.105525化学力学致断裂裂纹演化及强度破坏机制研究Chemo-mechanical coupled fracture is ubiquitous among various application fields. Understanding the mechanism of crack propagation is critical to the prediction and control of fracture behavior. In this paper, mechanical damage and chemical erosion have been investigated by a combination of experiments and theoretical analysis. We developed a theoretical model to analyze the interface evolution and the mechanical state of the crack tip in chemically active environments based on the transition-state theory. This model enables us to predict mechanical failure and chemical corrosion of materials exposed to external acid attack. Theoretical predictions of the corrosion rate and fracture strength have been validated by fracture experiments performed in different concentrations of corrosive solutions. In particular, we discovered a non-monotonic and non-linear relationship between the degree of corrosion and fracture strength, which demonstrates that corrosion-induced crack tip blunting and mass loss of materials together affect the cracking critical state. We further conducted the thermodynamic analysis of a quasi-static cracked body to investigate the effect of corrosion on energy stored in the crack tip. Our theory-experiment-combined study reveals the mechanism of coupling chemical and mechanical damage and provides significant insight into corrosion-induced fracture behavior in aggressive environments.化学-力学耦合断裂在各个应用领域中无处不在。了解裂纹扩展机制对断裂行为的预测和控制至关重要。本文采用实验和理论分析相结合的方法，对机械损伤和化学侵蚀进行了研究。基于过渡态理论，建立了分析化学活性环境中界面演化和裂纹尖端力学状态的理论模型。该模型使我们能够预测暴露于外部酸侵蚀的材料的机械失效和化学腐蚀。在不同浓度的腐蚀溶液中进行的断裂实验验证了腐蚀速率和断裂强度的理论预测。特别是，我们发现了腐蚀程度与断裂强度之间的非单调非线性关系，这表明腐蚀引起的裂纹尖端钝化和材料的质量损失共同影响裂纹临界状态。我们进一步进行了准静态裂纹体的热力学分析，以研究腐蚀对裂纹尖端储存能量的影响。我们的理论-实验相结合的研究揭示了化学和机械耦合损伤的机制，并为在腐蚀性环境中腐蚀引起的断裂行为提供了重要的见解。Mechanics of MaterialsSelf-similar hierarchical honeycombs in two different fractal layouts: A comparative study of the in-plane crushing behaviorsYu Chendoi:10.1016/j.mechmat.2023.104900两种不同分形布局下的自相似分层蜂窝:面内破碎行为的比较研究This paper provides a new avenue for the development of cellular structures. By mimicking the chemical structural formula of the TpPB-Fe coordination polymer, a new self-similar hierarchical honeycomb was proposed. With respect to the existing self-similar hierarchical honeycomb in the literature which was constructed by replacing every three-edge vertex of the regular hexagonal honeycomb with a smaller hexagon, the new one is created by setting the fractal position at the midpoint of the cell walls of the regular hexagonal honeycomb. What I am really curious about is the difference in mechanical properties between the two self-similar hierarchical honeycombs. Finite element (FE) model was first built and validated by comparing against the existing theoretical data. Subsequently, the in-plane crushing behaviors of the honeycombs under different impact velocities were fully investigated by FE simulations. The deformation modes, plateau stress as well as the energy absorption capability of the honeycombs were studied. Different macroscopic and microscopic deformation patterns between the two hierarchical honeycombs were observed. The plateau stress of the new hierarchical honeycomb is higher than that of both the existing counterpart and the basic regular hexagonal one. Under low- and medium-velocity impact loading, the new honeycomb with low fractal ratio (α) has superior energy absorption capability with respect to the existing counterpart and the basic regular hexagonal one. However, the new honeycomb will lose its advantage in energy absorption when the fractal ratio or the impact velocity is large.这为细胞结构的发展提供了一条新的途径。通过模拟TpPB-Fe配位聚合物的化学结构式，提出了一种新的自相似分层蜂窝结构。文献中已有的自相似分层蜂窝是用较小的六边形代替正六边形蜂窝的每一个三边顶点来构造的，本文将分形位置设置在正六边形蜂窝细胞壁的中点处来构造新的自相似分层蜂窝。我真正好奇的是这两种自相似的等级蜂巢在机械性能上的差异。首先建立了有限元模型，并与已有的理论数据进行了对比验证。在此基础上，通过有限元模拟全面研究了不同冲击速度下蜂窝的面内破碎行为。研究了蜂窝结构的变形模式、高原应力和吸能能力。观察到两种分层蜂窝的宏观和微观变形模式不同。新型分层蜂窝的高原应力高于现有的分层蜂窝和基本的正六边形蜂窝。在低、中速冲击载荷作用下，具有低分形比(α)的新型蜂窝比现有蜂窝和基本正六边形蜂窝具有更强的吸能能力。然而，当分形比或冲击速度较大时，新型蜂窝在吸能方面的优势将会丧失。International Journal of PlasticityMicrostructural size effect on the notch fatigue behavior of a Ni-based superalloy using crystal plasticity modelling approachJin-Chao He, Shun-Peng Zhu, Jie-Wei Gao, Rui Liu, Wei Li, Qiang Liu, Yun He, Qingyuan Wangdoi:10.1016/j.ijplas.2023.103857显微组织尺寸对镍基高温合金缺口疲劳行为的影响Fatigue performances of critical structures are strongly affected by the microstructural (e.g. grain, defect, inclusion, etc.) size effect, and it is thus important to quantify their detrimental effect. In this work, a numerical procedure is constructed to quantify the influence of microstructure on the mechanical and fatigue behaviors of Ni-based superalloy GH4169. Specifically, by combining sub-modelling approach with crystal plasticity constitutive model, a dual-scale modelling approach is developed for studying grain-level mechanical behavior of Ni-based superalloy GH4169 notched components. In addition, the dislocation-based Tanaka-Mura-Wu model is applied for fatigue crack initiation life prediction. The Paris law is then utilized for fatigue crack propagation analysis based on the simulated short crack. To study the microstructural size effect on fatigue crack initiation and propagation behaviors, sub-models containing various grain orientation, grain size, defect size/shape are built and analysed. Finally, a series of fatigue tests on notched specimens of Ni-based superalloy GH4169 were carried out for method validation. Results indicate that the established dual-scale modelling approach and fatigue life prediction framework yields good agreement with experimental results.关键组织的疲劳性能受微观组织(如晶粒、缺陷、夹杂物等)尺寸效应的强烈影响，因此对其有害影响进行量化具有重要意义。本文建立了一种量化微观组织对ni基高温合金GH4169力学和疲劳行为影响的数值计算方法。具体而言，将子建模方法与晶体塑性本构模型相结合，建立了研究ni基高温合金GH4169缺口构件晶粒级力学行为的双尺度建模方法。此外，将基于位错的Tanaka-Mura-Wu模型应用于疲劳裂纹萌生寿命预测。在模拟短裂纹的基础上，利用Paris定律进行疲劳裂纹扩展分析。为了研究微观组织尺寸对疲劳裂纹萌生和扩展行为的影响，建立并分析了包含不同晶粒取向、晶粒尺寸、缺陷尺寸/形状的子模型。最后，对ni基高温合金GH4169的缺口试样进行了一系列疲劳试验，验证了方法的有效性。结果表明，所建立的双尺度建模方法和疲劳寿命预测框架与试验结果吻合较好。Short-range order-dependent dislocation mobilities in CrCoNi medium entropy alloy: atomistic simulations and modelingYu Tian, Fei Chendoi:10.1016/j.ijplas.2023.103859CrCoNi中熵合金中短距离有序化位错迁移率:原子模拟与建模Understanding dislocation behavior is considered an effective way to design high performance alloys, as it is closely associated with mechanical properties. The existence of short-range order (SRO) and its ability to improve the strength and ductility of high- and medium-entropy alloys (H/MEAs) have been experimentally documented. However, few researches focused on the mechanism of dislocation motion in H/MEAs with SRO. In this study, the correlation between the degree of SRO and edge dislocation mobility in CrCoNi MEA was studied by atomistic simulations. The results show that the dislocation mobility is strongly dependent on the degree of SRO. As the degree of SRO increased, the dislocation mobility decreased linearly due to the increased energy barrier. The dislocation mobility model coupling with the SRO effects was proposed, in which the parameters were determined by molecular dynamic (MD) simulations. The energy barriers varied with the SRO degree were obtained from the model and have been compared with the theoretical predictions. A good agreement between prediction of the model and theoretical values was achieved. Using the drag coefficients obtained from this fitting, a binary linear regression model of the drag coefficient as a function of SRO degree and temperature was constructed. The proposed dislocation mobility model might be important for the construction of mechanistic predictive theory of CrCoNi MEA systems with SRO, and can also provide more accurate and reliable inputs for higher length scale simulations.了解位错行为被认为是设计高性能合金的有效途径，因为它与力学性能密切相关。实验证明了短程有序(SRO)的存在及其提高高、中熵合金(H/MEAs)强度和延展性的能力。然而，对具有SRO的H/MEAs中位错运动机制的研究较少。本研究通过原子模拟研究了CrCoNi MEA中SRO程度与边缘位错迁移率之间的关系。结果表明，位错的迁移率与SRO的程度密切相关。随着SRO程度的增加，位错迁移率由于能垒的增加而线性降低。提出了考虑SRO效应的位错迁移率模型，并通过分子动力学模拟确定了模型参数。从模型中得到了随SRO程度变化的能垒，并与理论预测结果进行了比较。模型预测值与理论值吻合较好。利用拟合得到的阻力系数，构建了阻力系数随SRO程度和温度的二元线性回归模型。本文提出的位错迁移率模型对于构建含SRO的CrCoNi - MEA系统的力学预测理论具有重要意义，也可以为更高长度尺度的模拟提供更准确和可靠的输入。Thin-Walled StructuresSymmetric and asymmetric buckling of rotating eccentric annular plateYukang Yang, Jinming Fan, Youheng Dong, Yinghui Lidoi:10.1016/j.tws.2023.111489偏心旋转环形板的对称和非对称屈曲The thermo-induced buckling, including the symmetric and asymmetric buckling, of rotating eccentric annular plate is investigated. And the splitting phenomenon in buckling caused by structural eccentricity is at the core of the present paper. To overcome the computational difficulty resulted from the irregular physical field of the eccentric annular plate, the transformed differential quadrature method is adopted to solve the governing equations. The governing equations and boundary conditions are discretized directly in the physical domain by utilizing the conformal mapping. The combined effects of eccentricity, boundary conditions, geometric dimensions, and rotational motion on the buckling of annular plate are discussed through parameter studies. The eccentricity leads to the splitting of asymmetric buckling of eccentric annular plate. With the increase of eccentricity, this phenomenon becomes more obvious. Meanwhile, the variation tendency of critical buckling temperature rise is closely related to the number of pitch diameter in buckling mode. The sequence of symmetric and asymmetric buckling appears is affected by the boundary conditions. To a certain extent, the rotational motion inhibits the splitting phenomenon in buckling arised from the eccentricity.研究了偏心旋转环形板的热致屈曲，包括对称屈曲和非对称屈曲。而结构偏心引起的屈曲劈裂现象是本文研究的核心。为克服偏心环形板物理场不规则造成的计算困难，采用变换微分正交法求解控制方程。控制方程和边界条件通过保角映射直接在物理域中离散化。通过参数研究，讨论了偏心、边界条件、几何尺寸和旋转运动对环形板屈曲的综合影响。偏心导致偏心环形板的非对称屈曲开裂。随着偏心距的增大，这种现象更加明显。同时，临界屈曲温升的变化趋势与屈曲模式下的节径数密切相关。对称屈曲和非对称屈曲的发生顺序受边界条件的影响。旋转运动在一定程度上抑制了偏心引起的屈曲中的劈裂现象。Experimental study on the hysteretic behavior of aluminum alloy gusset joint with rectangular hollow sectionsMingze Wu, Shenggang Fan, Ziwei Zhao, Meijing Liu, Lizhi Hu, Tao Yudoi:10.1016/j.tws.2023.111500矩形空心截面铝合金扣板节点滞回特性试验研究Aluminum alloys were extensively applied in single-layer latticed shells owing to their exceptional mechanical properties, outstanding corrosion resistance, and aesthetic appeal. In traditional aluminum alloy grid shell structures, H-section components were widely utilized. However, the H-section components exhibited poor self-stability compared to rectangular hollow sections, whose limitation constrains the utilization of aluminum alloy single-layer latticed shells. To overcome this problem, a named ARH (Aluminum Rectangular Hollow) joint was developed using BOM bolts by some scholars, and the out-of-plane bending behavior was studied. This paper conducted out-of-plane hysteretic tests on four ARH joints with different bolt numbers and gusset thicknesses. Subsequently, a finite element model was developed to simulate the hysteretic behavior of the ARH joint. The simulation results were compared with the test results to verify the accuracy of the model. Then, a series of parameter analyses based on the developed finite element model were conducted. For the ARH joint, Analysis results showed that the decrease in bolt numbers and gusset thicknesses resulted in the weakening of the stiffness and bearing capacity, and the increase of bolt-hole diameters resulted in elevated slip deformation. Moreover, in gusset joints, joints with rectangular hollow sections have greater out-of-plane bending resistance compared to joints made from H-sections with the same section height and flange thickness.铝合金因其优异的力学性能、优异的耐腐蚀性和美观性，被广泛应用于单层网壳。在传统的铝合金网壳结构中，广泛采用h型钢构件。然而，与矩形空心截面构件相比，h截面构件的自稳定性较差，这限制了铝合金单层网壳的应用。为了解决这一问题，有学者采用BOM螺栓设计了一种ARH(铝矩形空心)连接，并对其面外弯曲行为进行了研究。本文对4种不同螺栓编号和扣板厚度的ARH节点进行了面外滞回试验。随后，建立了模拟ARH节点滞回特性的有限元模型。将仿真结果与试验结果进行对比，验证了模型的准确性。然后，基于所建立的有限元模型进行了一系列参数分析。对于ARH节点，分析结果表明，螺栓数量和扣板厚度的减少导致节点刚度和承载能力减弱，螺栓孔直径的增加导致滑移变形升高。此外，在扣板节点中，矩形空心截面的节点比相同截面高度和法兰厚度的h型截面的节点具有更大的面外抗弯能力。A tunable slit-plate absorber with multiparameter cooperative controlXiao Zhang, Fei Wu, Shanlin Yan, Dewen Zhang, Yi Qin, Jun Luo, Huayan Pu, Man Hu, Mingyuan Gaodoi:10.1016/j.tws.2023.111502一种多参数协同控制的可调缝板吸收器Tunable acoustic metamaterials have a more flexible operating spectrum while still controlling acoustic waves via subwavelength thickness, but their operating range and acoustic absorption performance are limited by a single-parameter tuning mechanism. In this study, we first propose a slit-plate absorber with reconstructed porosity, which has a dynamic continuous tuning capability and is easier to achieve low-frequency resonance. Then, in order to improve its acoustic absorption performance, we study the tuning laws of numerous structural factors as well as their cooperative interaction. Local parameter changes to achieve impedance compensation and isotropic control to enhance frequency shift are presented to greatly improve the tunable range and sound absorption level. A tunable absorber with multi-parameter cooperative control is constructed using this method. The results reveal that continuous tuning of 210-920Hz is possible at a total thickness of 25mm, and the sound absorption coefficient in the tuning range is more than 0.8, and the thickness of the structure at 210 Hz is 1/65 of the absorption wavelength. Our work demonstrates a new method for improving the performance of adjustable acoustic metamaterials and promotes the use of acoustic metamaterials in low frequency changing noise environments.可调谐声学超材料在通过亚波长厚度控制声波的同时具有更灵活的工作光谱，但其工作范围和吸声性能受到单参数调谐机制的限制。在本研究中，我们首先提出了一种具有重构孔隙度的缝板吸收体，它具有动态连续调谐能力，更容易实现低频共振。然后，为了提高其吸声性能，我们研究了多种结构因素的调谐规律及其协同相互作用。通过改变局部参数来实现阻抗补偿和各向同性控制来增强频移，大大提高了可调谐范围和吸声水平。利用该方法构造了一个多参数协同控制的可调谐吸收器。结果表明，在总厚度为25mm时，可以实现210 ~ 920hz的连续调谐，调谐范围内的吸声系数大于0.8,210 Hz处的结构厚度为吸收波长的1/65。我们的工作展示了一种改善可调声学超材料性能的新方法，并促进了声学超材料在低频变化噪声环境中的应用。Development of a Eurocode-based design method for local and distortional buckling for cold-formed C-sections encased in ultra-lightweight concrete under compressionAhmed Alabedi, Péter Hegyidoi:10.1016/j.tws.2023.111504基于欧洲规范的超轻混凝土冷弯c型钢受压局部屈曲和扭曲屈曲设计方法的发展An innovative direction in the field of light-gauge building systems has been presented in recent years when the cold formed steel (CFS) C-sections are encased in an ultra-lightweight material. The advantages of the two materials are integrated, resulting in a unique complex structure in which the encasing material provides heat insulation and fire protection. In addition, this material supports the CFS parts, which leads to an increase in their resistance to stability failures. This paper presents an innovative design procedure for encased CFS elements based on the specifications of Eurocode by applying the effective width method. The new design is based on analytical and numerical basis, incorporating the continuous bracing action of the encasing material by an elastic half-space-model, similar to sandwich beam theory. Close-form equations are derived to calculate the encased CFS's local and distortional critical stress. Furthermore, the applicability of the new design is demonstrated using a large set of experimental data of newly tested members and previously published ones. Results show that the trend of calculated and measured results matches well, making the proposed design method applicable in the investigated domain.近年来，在轻量化建筑系统领域提出了一个创新方向，即冷弯型钢(CFS)剖面图被超轻量化材料包裹。两种材料的优点融合在一起，形成了独特的复杂结构，其中包裹材料提供隔热和防火功能。此外，这种材料支持CFS部件，从而增加了它们对稳定性失效的抵抗力。本文在欧洲规范规范的基础上，采用有效宽度法，提出了一种新颖的包壳CFS构件设计方法。新的设计基于解析和数值基础，采用弹性半空间模型，类似于夹层梁理论，将包围材料的连续支撑作用纳入其中。推导了封闭CFS的局部临界应力和变形临界应力的近似方程。此外，利用大量新测试构件和先前发表的实验数据，证明了新设计的适用性。计算结果与实测结果吻合良好，表明所提出的设计方法适用于所研究的领域。Shear resistance of perforated QN1803 high-strength stainless steel plate girders through experimental testing and numerical analysisBoshan Chen, Yuanqing Wang, Jun Ye, James B.P. Lim, Letian Haidoi:10.1016/j.tws.2023.111505通过实验测试和数值分析对QN1803高强不锈钢穿孔板梁的抗剪性能进行了研究QN1803, a high-strength stainless steel, has been developed by steel industry recently. Its tensile yield strength can be approximately 40% (or more) higher than that of the commonly-used EN1.4301, while its cost is 20% lower due to its reduced nickel content. One obvious application for QN1803 is in plate girders, where web perforations are often required to accommodate building services. However, no research work has been reported in the literature that investigates the reduced shear buckling capacity of QN1803 plate girders as a result of web perforations. This issue is addressed herein. An experimental program comprising six plate girder tests is conducted in this study. Three different hole ratios were considered: 0.2, 0.4 and 0.6. The depths of web were selected as 700 mm and 500 mm, while the thickness of web was fixed as 4.0mm. The initial geometric imperfections were determined from three-dimensional (3D) scanning prior to the plate girder tests. Finite element (FE) models incorporating the material non-linearity and initial geometric imperfections were then developed and validated against the experimental results. A parametric analysis including 62 FE models was performed to examine the influences of the critical parameters on the shear buckling capacity of such perforated members. The results suggest that for those members with a hole diameter - web height ratio of 0.6, the shear buckling capacity was reduced by 56% on average due to the web perforation. The design rules for determining the shear buckling capacity of stainless steel plate girders as specified in Eurocodes (EN 1993-1-4+A1) (2015) and American Specification (ANSI/AISC 370-21) (2021) were evaluated. Upon comparison, it was demonstrated that both EN 1993-1-4+A1 (2015) and ANSI/AISC 370-21 (2021) cannot provide accurate and safe predictions for determining the shear buckling capacity of such members.QN1803是近年来钢铁工业开发的一种高强度不锈钢。其抗拉屈服强度可比常用的EN1.4301高约40%(或更多)，而由于镍含量降低，其成本降低了20%。QN1803的一个明显的应用是板梁，其中腹板穿孔通常需要容纳建筑服务。然而，没有研究工作的报道，在文献中调查降低剪切屈曲能力的QN1803板梁由于腹板穿孔。此问题在此解决。本文设计了一个由6个板梁试验组成的试验方案。考虑了三种不同的井眼比:0.2、0.4和0.6。腹板深度分别为700 mm和500 mm，腹板厚度固定为4.0mm。在板梁试验之前，通过三维扫描确定了初始几何缺陷。然后建立了包含材料非线性和初始几何缺陷的有限元模型，并根据实验结果进行了验证。采用62个有限元模型进行了参数分析，考察了关键参数对多孔构件抗剪屈曲能力的影响。结果表明，当孔直径与腹板高度之比为0.6时，腹板穿孔使构件的剪切屈曲能力平均降低56%;评估了欧洲规范(EN 1993-1-4+A1)(2015)和美国规范(ANSI/AISC 370-21)(2021)中规定的不锈钢板梁剪切屈曲能力的设计规则。通过比较，证明了EN 1993-1-4+A1(2015)和ANSI/AISC 370-21(2021)都不能为确定此类构件的剪切屈曲能力提供准确和安全的预测。Fatigue life prediction method of Q235 steel single lap thin-walled bolted connections under shear loadingLong Yang, Guangwu Yang, Han Zhao, Bing Yang, Lanxin Jiang, Shoune Xiaodoi:10.1016/j.tws.2023.111507 剪切作用下Q235钢单搭接薄壁螺栓连接疲劳寿命预测方法In this study, a large number of shear fatigue tests were conducted on Q235 steel single lap thin-walled bolted connections to investigate the influence of different geometric and load parameters on the dispersion of fitting data for load amplitude-life (Fa–N) curves. Due to the large dispersion of fitting data, the Fa–N curves were unable to meet engineering requirements. In order to standardize these Fa–N curves, an equivalent structural stress model for single lap thin-walled bolted connections was established based on a mechanical model with a strict physical definition. The shell equivalent model of the Q235 steel single lap thin-walled bolted connection was developed using the Rupp structural stress calculation method, and the equivalent structural stress was determined by considering the node loads coupled by the beam element. Subsequently, a normalized fatigue characteristic curve (Ss–N curve) was created to standardize the Fa–N curves. However, differences in external load, pre-tightening force, bolt diameter, and plate thickness resulted in a relatively low correlation across the entire Ss–N curve. To address this, four quasi-Newton optimization algorithms (C1–C4) were employed to optimize the equivalent structural stress model. This approach yielded the best optimization model for equivalent structural stress and an Ss–N curve with a higher correlation. These findings offer valuable insights for optimizing single lap thin-walled bolted connection parameters and predicting fatigue life.本研究对 Q235 钢单搭接薄壁螺栓连接进行了大量剪切疲劳试验，以研究不同几何参数和载荷参数对载荷振幅-寿命（Fa-N）曲线拟合数据离散度的影响。由于拟合数据离散性较大，Fa-N 曲线无法满足工程要求。为了使这些 Fa-N 曲线标准化，根据具有严格物理定义的力学模型，建立了单搭接薄壁螺栓连接的等效结构应力模型。采用 Rupp 结构应力计算方法建立了 Q235 钢单搭接薄壁螺栓连接的壳体等效模型，并通过考虑梁元素耦合的节点载荷确定了等效结构应力。随后，创建了归一化疲劳特性曲线（Ss-N 曲线），使 Fa-N 曲线标准化。然而，外部载荷、预紧力、螺栓直径和板厚的差异导致整个 Ss-N 曲线的相关性相对较低。为此，我们采用了四种准牛顿优化算法（C1-C4）来优化等效结构应力模型。这种方法产生了最佳的等效结构应力优化模型和相关性更高的 Ss-N 曲线。这些发现为优化单搭接薄壁螺栓连接参数和预测疲劳寿命提供了有价值的见解。来源：复合材料力学仿真Composites FEM