【新文速递】2023年12月31日固体力学SCI期刊最新文章

今日更新：International Journal of Solids and Structures 2 篇，Journal of the Mechanics and Physics of Solids 1 篇，Mechanics of Materials 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 6 篇International Journal of Solids and StructuresThe effect of friction coefficient on wrinkles of lined pipe under bendingYi-Fan Liang, Zhan-Feng Chen, Wen Wang, Chuan-Yong Wangdoi:10.1016/j.ijsolstr.2023.112615摩擦系数对弯曲下内衬管皱纹的影响Transporting corrosive hydrocarbons using lined pipe is an economical method and has been widely applied in inshore and offshore pipelines. However, when the lined pipe is subjected to bending, wrinkling behavior will occur. Wrinkle can pose a serious threat to the service life and structural integrity of the lined pipe. In this paper, the effect of the friction coefficient between the liner and carrier on the wrinkling behavior of liner under bending is studied. First, a finite element model of lined pipe is established. Second, the influence of friction coefficient on the starting time and amplitude of first type of wrinkles is studied. In the end, the influence of friction coefficient on the amplitude and shape of the second type of wrinkles is examined. The results show that the friction coefficient can affect both the first and the second type of wrinkles, but their effects are different. The friction coefficient can contribute to the first type of wrinkles. Friction coefficient will facilitate the appearance of the first type of wrinkles. While, the friction coefficient showed a strong inhibitory effect on the second type of wrinkles, which inhibited the maximum amplitude and shape of the wrinkles.使用内衬管道输送腐蚀性碳氢化合物是一种经济的方法，已广泛应用于近岸和海上管道。然而，当内衬管道受到弯曲时，就会出现起皱现象。褶皱会严重威胁内衬管道的使用寿命和结构完整性。本文研究了内衬和载体之间的摩擦系数对弯曲下内衬起皱行为的影响。首先，建立了内衬管道的有限元模型。其次，研究了摩擦系数对第一类皱纹起始时间和幅度的影响。最后，研究了摩擦系数对第二种皱纹的幅度和形状的影响。结果表明，摩擦系数对第一种和第二种皱纹都有影响，但影响程度不同。摩擦系数对第一类皱纹有促进作用。摩擦系数会促进第一类皱纹的出现。而摩擦系数对第二种皱纹有很强的抑制作用，会抑制皱纹的最大幅度和形状。Structural size effect in the mode I and mixed mode I/II fracture of strain-hardening cementitious composites (SHCC)Qingmin Wang, Qinghua Li, Xing Yin, Shilang Xudoi:10.1016/j.ijsolstr.2023.112628应变硬化水泥基复合材料（SHCC）在模式 I 和模式 I/II 混合断裂中的结构尺寸效应The size effect in the fracture of solids represents a highly critical issue with a prolonged history of research. The size effect of traditional quasi-brittle materials can already be well described through the size effect model. However, there is still a lack of research on the size effect of strain-hardening cementitious composites (SHCC), a special type of fibre-reinforced concrete with macro-scale strain-hardening behaviour after first cracking. Being distinct from traditional quasi-brittle materials with softening nature, SHCC is thus expected to behave differently in terms of size effect. In this research, the structural size effect problem of SHCC is comprehensively studied by experimental investigation and theoretical analysis. Geometrically similar notched three-point bending specimens were tested in mode I and mixed mode I/II fracture condition. The whole-process of failure and matrix cracking zone around the main crack was captured with high resolution by digital image correlation technology. Experimental results showed that apparent fracture energy, nominal strength, structural ductility and fracture resistance curve are all structural size-dependent. The apparent fracture energy was shown to arise with specimen size within the tested range. This is related to large-scale pseudo yielding, i.e. enlargement of matrix cracking zone (like the yielding zone in metals) with increasing structural size. It thus provides an indirect method for the estimation of cohesive fracture energy of single crack with constitutive nature. Due to the scaled matrix cracking zone, an intermediate asymptote exists in the size effect curve of nominal strength, in addition to the plastic and LEFM asymptotes in the Bažant original size effect law. This resembles the recent finding of intermediate asymptote in plastic-hardening metal(Dönmez et al. 2023). The size-dependence of R-curve was also examined. Though size-dependent, the equivalent LEFM-based R-curves are shown to have three common stages reflecting different cracking processes. Based on experimental results, the size effect of fracture energy and nominal strength are finally modelled theoretically in the Bažant’s framework of equivalence between energy release and fracture resistance.固体断裂中的尺寸效应是一个非常关键的问题，研究历史悠久。传统准脆性材料的尺寸效应已经可以通过尺寸效应模型得到很好的描述。然而，应变硬化水泥基复合材料（SHCC）是一种特殊的纤维增强混凝土，在首次开裂后具有宏观尺度的应变硬化行为，目前对其尺寸效应的研究仍显不足。应变硬化水泥基复合材料有别于传统的具有软化性质的准脆性材料，因此在尺寸效应方面会有不同的表现。本研究通过实验研究和理论分析，对 SHCC 的结构尺寸效应问题进行了全面研究。在模式 I 和模式 I/II 混合断裂条件下，对几何形状相似的缺口三点弯曲试样进行了测试。通过数字图像相关技术，高分辨率地捕捉了主裂纹周围的破坏全过程和基体开裂区。实验结果表明，表观断裂能、名义强度、结构延展性和抗断裂曲线都与结构尺寸有关。在测试范围内，表观断裂能随着试样尺寸的增大而增大。这与大尺度假屈服有关，即随着结构尺寸的增大，基体开裂区（类似于金属中的屈服区）也会增大。因此，它提供了一种间接方法，用于估算具有构成性质的单个裂缝的内聚断裂能。由于基体开裂区的缩放，除了 Bažant 原始尺寸效应定律中的塑性渐近线和 LEFM 渐近线外，名义强度的尺寸效应曲线中还存在一个中间渐近线。这与最近在塑性硬化金属中发现的中间渐近线相似（Dönmez 等人，2023 年）。我们还研究了 R 曲线的尺寸依赖性。虽然与尺寸有关，但基于 LEFM 的等效 R 曲线显示有三个共同阶段，反映了不同的开裂过程。根据实验结果，最终在 Bažant 的能量释放与断裂抗力等效框架内对断裂能和名义强度的尺寸效应进行了理论建模。Journal of the Mechanics and Physics of SolidsNon-slipping adhesive contact between dissimilar elastic solids under normal and tangential loadsLifeng Ma, Yifeng Chen, David A. Hillsdoi:10.1016/j.jmps.2023.105528不同弹性固体在法向和切向载荷作用下的无滑动粘合接触In this paper, a model of two-dimensional non-slipping adhesive contact between dissimilar elastic solids under normal and tangential loads is proposed, and the general analytical solution is derived. The interaction of adhesion and friction along the contacting interface is studied. Specifically, (i) the shear-off force of adhesive contact is proposed; (ii) the effect of tangential load on the puff-off force is presented; (iii) the influence of the normal load on the shear-off force is obtained; (iv) in the context of these results, the nominal static friction coefficient is defined and analyzed, and it is shown that the static friction coefficient is a function of external normal load, which can well explain some experimental results in the literature. The proposed model appears to be consistent with the available experimental data, which offers new insight into the interplay mechanism between friction and adhesion. These results provide the foundation for understanding and modelling some tribological phenomena at the macro-, micro- and nano- scales.本文提出了不同弹性固体在法向和切向载荷作用下的二维非滑动粘着接触模型，并推导了一般解析解。研究了接触界面上粘附力和摩擦力的相互作用。具体来说，(i) 提出了粘合剂接触的剪断力；(ii) 提出了切向载荷对剪断力的影响；(iii) 得到了法向载荷对剪断力的影响；(iv) 结合这些结果，定义并分析了标称静摩擦系数，结果表明静摩擦系数是外部法向载荷的函数，这可以很好地解释文献中的一些实验结果。所提出的模型似乎与现有的实验数据一致，这为我们了解摩擦与附着力之间的相互作用机制提供了新的视角。这些结果为理解和模拟一些宏观、微观和纳米尺度的摩擦学现象奠定了基础。Mechanics of MaterialsElastoplastic damage analysis and structural optimization of soluble bridge plug based on phase field methodZhaozhong Yang, Jianping Liu, Liangping Yi, Rongjie Yang, Xiaogang Lidoi:10.1016/j.mechmat.2023.104899 基于相场法的可溶性桥塞弹塑性损伤分析和结构优化Bridge plugs play a crucial role as a plugging tool for downhole staging in the staged fracturing process. In particular to the soluble bridge plug, which can be automatically dissolve in that backflow fluid after hydraulic fracture. In this paper, a single silp with small diameter soluble bridge plug is designed to take into account its passability in the casing deformation well. A three-dimensional phase field model of the elastoplastic anchoring mechanism was developed to investigate the maximum pressure-bearing of the designed soluble bridge plug during the fracturing and optimize its structure. The phase field model we use is suitable for linear isotropic hardening materials, in which the elastic energy is decomposed into compression and tension parts, and the plastic energy is decomposed into plastic free energy and plastic dissipation energy. The model is assumed to be quasi-static. Tensile experiments with two asymmetrically notched metal bars are used to verify the applicability of our model to materials with small plastic strains. The simulation shows that the designed bridge plug can adapt to the working pressure differential of 70 MPa, and the optimal number of slip teeth is 8 or 9.在分段压裂工艺中，桥塞作为井下分段的堵塞工具发挥着至关重要的作用。特别是可溶性桥塞，它可以在水力压裂后自动溶解在回流液中。本文设计了一种带小直径可溶性桥塞的单筒仓，以考虑其在套管变形井中的通过性。建立了弹塑性锚定机制的三维相场模型，以研究压裂过程中设计的可溶性桥塞的最大承压能力，并优化其结构。我们使用的相场模型适用于线性各向同性硬化材料，其中弹性能被分解为压缩和拉伸部分，塑性能被分解为塑性自由能和塑性耗散能。该模型假定为准静态模型。使用两根不对称缺口金属杆进行拉伸实验，以验证我们的模型是否适用于塑性应变较小的材料。模拟结果表明，所设计的桥塞可适应 70 兆帕的工作压差，最佳滑齿数量为 8 或 9 个。International Journal of PlasticityRole of and <c+a> dislocations on the room-temperature grain boundary migration in a deformed Mg alloyZijian Zhang, Lin Yuan, Jiaping Ma, Mingyi Zheng, Debin Shan, Bin Guodoi:10.1016/j.ijplas.2023.103862 和<c+a>位错对变形镁合金室温晶界迁移的作用During deformation, dislocation movements at grain boundaries (GBs) directly affect GB plastic behaviors, thus affecting the mechanical properties of metal materials. As common defects in deformed Mg alloys, the specific role of and <c+a> dislocations on room-temperature GB migration is still unclear. This work systematically investigates and answers this scientific question via experimental observations and atomic simulations. High-density serrated GBs of the AZ80 Mg alloy are achieved by multi-axial compression at room temperature. At the atomic scale, the overall slip of interfacial dislocations leads to GB migration, while the GB can remain flat. Different local migration rates caused by slip and interlock of adjacent and <c+a> dislocations result in GB steps, thus forming the serrated GB as the deformation proceeds. The basal-pyramidal lock at the GB prevents the continuous migration of the local GB. A new basal-pyramidal lock model at the GB is established to give a criterion for stable interlock of partial and <c+a> dislocations. The experimental results and the atomic simulations show good agreement at the atomic scale and atomic simulations can explain the GB structure changes observed in the experiments. This work contributes to understanding the GB migration mechanisms of Mg alloys, which helps design deformed Mg alloys through GB engineering.在变形过程中，晶界（GB）上的位错运动直接影响 GB 的塑性行为，从而影响金属材料的机械性能。作为变形镁合金中的常见缺陷，和<c+a>位错对室温下GB迁移的具体作用尚不清楚。这项工作通过实验观察和原子模拟，系统地研究并回答了这一科学问题。在室温下，通过多轴压缩实现了 AZ80 镁合金的高密度锯齿状 GB。在原子尺度上，界面 位错的整体滑移会导致 GB 迁移，而 GB 可以保持平坦。相邻 和 <c+a> 位错的滑移和互锁引起的不同局部迁移率导致了 GB 台阶，从而在变形过程中形成了锯齿状 GB。GB 上的基底金字塔锁阻止了局部 GB 的持续迁移。建立了一个新的基底金字塔锁定模型，给出了部分 和 <c+a> 位错稳定互锁的标准。实验结果和原子模拟在原子尺度上显示出良好的一致性，原子模拟可以解释实验中观察到的 GB 结构变化。这项工作有助于理解镁合金的 GB 迁移机制，从而有助于通过 GB 工程设计变形镁合金。Thin-Walled StructuresCouple-stress thermoelasticity of three-dimensional multilayered compositesA. Vattrédoi:10.1016/j.tws.2023.111503三维多层复合材料的耦合应力热弹性This work presents a comprehensive analysis of field solutions for three-dimensional multilayered composites within the framework of the couple-stress thermoelasticity. Using double Fourier series expansion solutions, the powerful and elegant mathematical Stroh formalism is extended to include the thermal coupling with the couple-stress elasticity theory to capture small-scale microstructural effects. The size-dependent layered approach leads to concise and general eigenrelations for each homogeneous orthotropic plate, while the unconditionally stable dual-variable technique is used to propagate the extended displacement/temperature fields and force-/tangential couple- tractions through the internal interfaces of the multilayered structures. Closed-form expressions are derived for the recursive layer-to-layer relations, as well as for the temperature, heat flux, displacement, stress and couple-stress field components, with respect to simply-supported structures subjected to combined thermal and mechanical loading. Application examples, including highly anisotropic fiber-reinforced composites, show significant deviations from the classical thermoelasticity, demonstrating the critical importance of considering the microstructural characteristics of interface-dominated materials. The results result come from a series of scenarios, covering mechanical and thermomechanical loading conditions, changes in aspect ratios and stacking sequences within multilayered systems, and the consequences of varying the number of sandwich plates.本研究在耦合应力热弹性框架内对三维多层复合材料的场解进行了全面分析。利用双傅里叶级数展开解法，扩展了强大而优雅的数学斯特罗形式主 义，将热耦合与耦合应力弹性理论纳入其中，以捕捉小尺度微结构效应。与尺寸相关的分层方法为每个均质正交板提供了简明而通用的特征关系，而无条件稳定的双变量技术则用于通过多层结构的内部界面传播扩展的位移/温度场和力/切向耦合牵引力。对于受热和机械综合载荷作用的简单支撑结构，推导出了层间递推关系以及温度、热通量、位移、应力和耦合应力场分量的闭式表达式。应用实例（包括高度各向异性的纤维增强复合材料）显示出与经典热弹性的显著偏差，表明考虑界面主导材料的微结构特性至关重要。研究结果来自一系列方案，包括机械和热机械加载条件、多层系统中长宽比和堆叠顺序的变化，以及改变夹层板数量的后果。Effects of functionally graded graphene reinforcements on nonlinear post-local buckling and axial stiffness of laminated channel section strutsS.F. Nikrad, A.H. Akbarzadeh, M. Hamidinejad, Z.T. Chendoi:10.1016/j.tws.2023.111517功能分级石墨烯增强材料对层状槽形截面支柱非线性局部后屈曲和轴向刚度的影响The role of local buckling on the behavior of slender members under compression has received considerable attention in structural engineering. For thin-walled sections, in particular, there is a noticeable decrease in the axial compressive stiffness, resulting in a substantial reduction in their load-bearing capacity due to the occurrence of local buckling. The principal purpose of this article is to explore the potential improvements in the postbuckling characteristics of polymeric composite channel section struts subjected to a progressive end-shortening by employing multi-layer graphene sheets reinforcements. The solution methodology incorporates the von Karman geometrical nonlinearity and is based on the layerwise third-order shear deformation theory (LW-TSDT). To verify the accuracy of the results obtained based on LW-TSDT and to evaluate its computational efficiency, a three-dimensional (3D) finite element model is also developed using ABAQUS for the comparative analysis. A thorough examination of nonlinear instability is conducted on composite laminated channel section struts, featuring distinctive graphene distribution patterns through the thickness directions of the flanges and webs to identify the most effective material distribution with the objective of a significant increase in critical end-shortening and axial compressive stiffness. The influence of the geometrical parameters on the critical end-shortening, postbuckling equilibrium paths, and load-bearing capacity of functionally graded graphene reinforced composite (FG-GRC) laminated channel section struts are elicited. The conducted parametric analyses emphasize that altering the distribution patterns of graphene reinforcement across the flanges and web can enhance the critical end-shortening and load-bearing capacity by 80% and 25%, respectively.在结构工程中，局部屈曲对细长构件受压行为的影响受到了广泛关注。特别是对于薄壁截面来说，由于局部屈曲的发生，轴向压缩刚度会明显下降，导致承载能力大幅降低。本文的主要目的是通过采用多层石墨烯片材加固，探讨如何改善承受渐进式端部缩短的聚合物复合材料槽形截面支柱的后屈曲特性。求解方法结合了 von Karman 几何非线性，并基于层向三阶剪切变形理论（LW-TSDT）。为了验证基于 LW-TSDT 得出的结果的准确性，并评估其计算效率，还使用 ABAQUS 开发了一个三维（3D）有限元模型进行对比分析。对复合材料层压槽形截面支柱的非线性不稳定性进行了深入研究，其特点是翼板和腹板的厚度方向均有独特的石墨烯分布模式，以确定最有效的材料分布，从而显著提高临界端面缩短和轴向压缩刚度。几何参数对功能分级石墨烯增强复合材料（FG-GRC）层叠槽形截面支柱的临界端部缩短、屈曲后平衡路径和承载能力的影响被激发出来。参数分析结果表明，改变石墨烯增强材料在翼缘板和腹板上的分布模式可将临界端面缩短率和承载能力分别提高 80% 和 25%。Thin-walled tapered conformable low-pressure tanks: Concept and principlesJoren Malfroy, Ben Van Bavel, Johan Steelant, Dirk Vandepittedoi:10.1016/j.tws.2023.111519薄壁锥形保形低压罐：概念和原理In pressure tank design, structural efficiency or the ratio of pressurized volume to structural mass is fundamental and implies a specific shape, such as a cylindrical or spherical layout. However, this axi-symmetric layout may be not conform to the enveloping shape. Previous investigations developed a conformable tank concept with a multi-bubble axi-symmetric layout, called a multi-lobe or multi-bubble tank, but structural design and analysis are limited to intersecting cylindrical, spherical or toroidal shells. The objective of this research is to increase the volumetric efficiency of multi-bubble tanks even further through the introduction of a conical shell. An integral analytical formulation of tank topology and explicit expression of equilibrium are provided in order to design a structurally efficient tapered multi-bubble tank under low differential pressure. The result is expressed in a geometric rule that is applicable for tapered multi-bubble tanks of any eligible shape.在压力容器的设计中，结构效率或受压容积与结构质量的比率是最基本的，这意味着要有特定的形状，如圆柱形或球形布局。然而，这种轴对称布局可能不符合包络形状。之前的研究提出了一种具有多气泡轴对称布局的保形水箱概念，称为多叶或多气泡水箱，但结构设计和分析仅限于相交的圆柱形、球形或环形壳体。本研究的目的是通过引入锥形壳进一步提高多气泡水箱的容积效率。为了设计低压差下结构高效的锥形多气泡水箱，提供了水箱拓扑结构的整体分析表述和平衡的明确表达。其结果以几何规则的形式表达，适用于任何合格形状的锥形多气泡水箱。Nonlinear in-plane buckling of fixed FGP-GPLRC arches subjected to a half-span distributed radial loadZixiang Zhang, Yuanyuan Liu, Lulu Liu, Airong Liu, Hanwen Lu, Weile Wangdoi:10.1016/j.tws.2023.111528承受半跨分布式径向荷载的固定 FGP-GPLRC 拱门的非线性平面内屈曲In this work, nonlinear in-plane buckling analysis of fixed functionally graded porous graphene nanoplatelet reinforced composite (FGP-GPLRC) shallow arches under a half-span distributed radial load is presented. Material properties of the arch with different porosity distribution modes are determined via a modified Halpin–Tsai micromechanical model. Neutral plane-based nonlinear governing equations of motion are established based on the principle of virtual work from which analytical solutions for the critical buckling load are derived and the complete equilibrium path is traced. Possible buckling modes of fixed FGP-GPLRC arches are determined by employing a perturbation technique. Key parameters controlling the buckling configuration switching are also proposed. FE analysis is then carried out to verify the accuracy of the presented solutions. Effects of porosity distributions, GPL weight fraction, and porosity coefficient on the buckling behaviors are comprehensively examined. It was found that under the action of a half-span distributed radial load, the fixed FGP-GPLRC shallow arches buckle in a limit point configuration only, and the equilibrium path especially the per-buckling branch is significantly affected by porosity coefficient.本文介绍了固定功能分级多孔石墨烯纳米片增强复合材料（FGP-GPLRC）浅拱在半跨分布式径向载荷作用下的非线性平面内屈曲分析。通过改进的 Halpin-Tsai 微机械模型确定了不同孔隙率分布模式下拱的材料特性。根据虚功原理，建立了基于中性平面的非线性运动控制方程，并据此推导出临界屈曲载荷的解析解和完整的平衡路径。采用扰动技术确定了固定 FGP-GPLRC 拱门的可能屈曲模式。还提出了控制屈曲配置切换的关键参数。然后进行了 FE 分析，以验证所提出解决方案 的准确性。全面研究了孔隙率分布、GPL 重量分数和孔隙率系数对屈曲行为的影响。研究发现，在半跨分布式径向荷载作用下，固定的 FGP-GPLRC 浅拱仅以极限点配置发生屈曲，且平衡路径尤其是每一屈曲分支受孔隙率系数的影响很大。Testing, numerical modelling and design of G550 high strength cold-formed steel built-up section columnsYao Cui, Jiahao Zhang, Chicheng Ma, Muchun Niu, Ke Jiang, Shuai Li, Andi Sudoi:10.1016/j.tws.2023.111529G550 高强度冷弯型钢内置型钢柱的测试、数值建模和设计This paper investigates the buckling behaviour and load-carrying capacity of G550 high strength cold-formed steel built-up section columns under axial compression through experiments and numerical simulations. Two types of built-up sectional profiles were formed, which were defined as built-up OI-section and built-up CB-section. Each built-up OI-section member is formed by connecting two cold-formed steel C-section members in a back-to-back manner using self-drilling screws, while each built-up CB-section member consists of a cold-formed steel C-section member and a cold-formed steel U-section member, which are connected in a face-to-face manner by self-drilling screws. The experimental programme included tensile coupon tests, initial geometric imperfection measurements and 20 pin-ended column compression tests. In the numerical modelling programme, finite element models were developed and validated against the experimental results, and then used for parametric analyses to generate a total of 250 numerical data with different cross-section dimensions and member lengths. Based on the experimental and numerical data, the accuracy of both the effective width method and the direct strength method for predicting the strengths of G550 high strength cold-formed steel built-up section columns, as set out in the American Specification, was evaluated. The evaluation results indicated that both the effective width method and direct strength method provided accurate and consistent failure load predictions for G550 high strength cold-formed steel built-up OI-section columns on average, but with some unsafe failure load predictions, while the predicted failure loads were inaccurate, scattered and conservative for G550 high strength cold-formed steel built-up CB-section columns. Moreover, the effective width method and direct strength method yielded a similar level of design consistency for G550 cold-formed steel built-up section columns, but the direct strength method resulted in more accurate and less conservative failure load predictions than the effective width method. The modifications to the codified DSM equations were proposed for G550 high strength cold-formed steel built-up section columns and shown to provide improved predictions of failure load over the design codes.本文通过实验和数值模拟研究了 G550 高强度冷弯型钢内置型钢柱在轴向压缩下的屈曲行为和承载能力。实验中形成了两种内置截面型材，分别为内置 OI 截面和内置 CB 截面。每个内置 OI 截面构件由两个冷弯钢 C 截面构件通过自钻螺钉背靠背连接而成，而每个内置 CB 截面构件由一个冷弯钢 C 截面构件和一个冷弯钢 U 截面构件组成，这两个构件通过自钻螺钉面对面连接。实验计划包括拉伸试样测试、初始几何缺陷测量和 20 个销端支柱压缩测试。在数值建模计划中，根据实验结果开发和验证了有限元模型，然后用于参数分析，生成了不同截面尺寸和构件长度的共 250 个数值数据。根据实验和数值数据，评估了有效宽度法和直接强度法预测美国规范中规定的 G550 高强度冷弯型钢内置截面柱强度的准确性。评估结果表明，有效宽度法和直接强度法对 G550 高强度冷弯型钢内置 OI 截面柱的平均破坏荷载预测准确且一致，但存在一些不安全的破坏荷载预测，而对 G550 高强度冷弯型钢内置 CB 截面柱的破坏荷载预测不准确、分散且保守。此外，有效宽度法和直接强度法对 G550 冷弯型钢内置截面柱的设计一致性水平相似，但直接强度法比有效宽度法预测的破坏荷载更准确，但不太保守。针对 G550 高强度冷弯型钢加固截面柱提出了对编纂 DSM 方程的修改建议，结果表明，与设计规范相比，对破坏荷载的预测有所改进。Axial strength prediction of seawater sea sand concrete-filled circular FRP tubes under alkaline environment based on ensemble learning modelsMaria D. C. Hernandez Obando, Mudassir Iqbal, Daxu Zhang, Pei-Fu Zhang, Qi Zhaodoi:10.1016/j.tws.2023.111530基于集 合学习模型的碱性环境下海水海砂混凝土填充圆形 FRP 管的轴向强度预测The rapid development of marine and urban infrastructure led to the extensive studies on seawater sea sand concrete (SWSSC) filled fiber reinforced polymer (FRP) / steel tubes. The material property of FRP is a function of fiber orientations, and the confinement of SWSSC by FRP tubes enhances its axial load carrying capacity. And therefore, its strength prediction is very challenging because of various FRP layouts, surrounding harsh environment and complicated failure modes. The existing empirical models do not consider effects of surrounding seawater environment under elevated temperature. Therefore, this study concentrates on evaluating the axial capacity of two types of physical models: (1) SWSSC filled circular FRP tubes immersed in seawater environment (Pu1), and (2) SWSSC filled FRP-steel-FRP circular tubes (Pu2), with the help of machine learning (ML) algorithms namely extreme gradient boosting (XGBoost), support vector machine (SVM) and artificial neural networks (ANN). The experimental results of 138 and 120 tested specimens were used for the training and testing of ML models. The models were trained with the best hyperparameters based on grid search and cross validation approach. The models were evaluated with number of statistical indices i.e., R2, MAE and RMSE accompanied with visual comparison of trend line between experimental and predicted values and predicted to experimental ratios. The ML models were graded on the basis of performance as XGBoost > ANN > SVM for the Pu1 model, whereas for the Pu2 model, the order was observed as ANN > XGBoost > SVM. Further, SHAP analysis was conducted based on XGBoost to see the influence of input attributes on ML models.海洋和城市基础设施的快速发展促使人们对海水海砂混凝土（SWSSC）填充纤维增强聚合物（FRP）/钢管进行了广泛研究。玻璃钢的材料特性是纤维取向的函数，玻璃钢管对海水海砂混凝土的约束增强了其轴向承载能力。因此，由于玻璃钢的布局、周围的恶劣环境和复杂的失效模式，其强度预测非常具有挑战性。现有的经验模型没有考虑高温下周围海水环境的影响。因此，本研究借助机器学习（ML）算法，即极端梯度提升（XGBoost）、支持向量机（SVM）和人工神经网络（ANN），集中评估了两种物理模型的轴向承载力：（1）浸入海水环境中的 SWSSC 填充玻璃钢圆管（Pu1）和（2）SWSSC 填充玻璃钢-钢-玻璃钢圆管（Pu2）。138 个和 120 个测试样本的实验结果被用于训练和测试 ML 模型。根据网格搜索和交叉验证方法，使用最佳超参数对模型进行了训练。模型通过一些统计指标（即 R2、MAE 和 RMSE）进行评估，并对实验值与预测值之间的趋势线以及预测值与实验值之间的比率进行直观比较。在 Pu1 模型中，ML 模型的性能分级为 XGBoost > ANN > SVM，而在 Pu2 模型中，顺序为 ANN > XGBoost > SVM。此外，还基于 XGBoost 进行了 SHAP 分析，以了解输入属性对 ML 模型的影响。来源：复合材料力学仿真Composites FEM