【新文速递】2025年4月18日固体力学SCI期刊最新文章

 

今日更新：International Journal of Solids and Structures 3 篇，Journal of the Mechanics and Physics of Solids 1 篇，Thin-Walled Structures 8 篇

International Journal of Solids and Structures

Elastic wave propagation in magneto-active fibre composites

Harold Berjamin, Stephan Rudykh

doi:10.1016/j.ijsolstr.2025.113373

磁活性纤维复合材料中的弹性波传播

Fibre-reinforced elastomers are lightweight and strong materials that can sustain large deformations. When filled with magnetic particles, their effective mechanical response can be modified by an external magnetic field. In the present study, we propose an effective theory of fibre-reinforced composite, based on a neo-Hookean elastic response and a linear magnetic law in each phase. The theory is shown suitable to describe the motion of composite cylinders. Furthermore, it is found appropriate for the modelling of fibre-reinforced composites subjected to a permanent magnetic field aligned with the fibres. To reach this result, we use the incremental theory (‘small on large’), in combination with homogenisation theory and the Bloch-Floquet method. This way, we show that wave directivity is sensitive to the application of a permanent magnetic field, whereas the frequency range in which wave propagation is forbidden is not modified by such a load (the band gaps are invariant). In passing, we describe a method to deduce the total stress in the material based on the measurement of two wave speeds. Furthermore, we propose an effective energy function for the description of nonlinear composites made of Yeoh-type generalised neo-Hookean fibres within a neo-Hookean matrix.

纤维增强弹性体是一种重量轻、强度高的材料，可以承受较大的变形。当充满磁性粒子时，它们的有效机械响应可以被外部磁场所改变。在本研究中，我们提出了一种有效的基于新胡克弹性响应和各相线性磁律的纤维增强复合材料理论。结果表明，该理论适用于描述复合材料圆柱体的运动。此外，它被发现适合于模拟纤维增强复合材料受到与纤维对齐的永久磁场。为了达到这个结果，我们使用增量理论（“小对大”），结合均质化理论和Bloch-Floquet方法。通过这种方式，我们证明了波的指向性对永久磁场的应用很敏感，而禁止波传播的频率范围不受这种负载的影响（带隙是不变的）。顺便，我们描述了一种基于测量两个波速来推断材料中总应力的方法。此外，我们提出了一个有效的能量函数来描述非线性复合材料的杨氏型广义新hookean纤维在一个新hookean矩阵。

Eulerian rates of elastic incompatibilities for crystal plasticity applied to size-dependent hardening in finite bending

Lorenzo Bardella, M.B. Rubin, Andrea Panteghini

doi:10.1016/j.ijsolstr.2025.113376

有限弯曲条件下晶体塑性的欧拉弹性不相容率应用于尺寸相关硬化

By following the work Rubin and Bardella (2024), this investigation develops measures of rates of elastic incompatibilities, denoted as R i j , for crystal plasticity. This relies on Eulerian constitutive equations for finite-deformation anisotropic elastoplasticity governed by the evolution of microstructural material vectors. The rates R i j depend on the crystallography as this enters the rate of plasticity L p and are obtained by evaluating the opposite of the current curl of L p relative to the microstructural vectors. Because of this, each component of R i j is invariant under superposed rigid body motions, such that it can be independently employed in the constitutive equations. In crystal plasticity, the adopted Eulerian framework allows for singling out in R i j the contributions due to rates of densities of geometrically necessary dislocations and to the elastic distortion of the crystal lattice. In this work, R i j are used to enhance the hardening, which is applied to the size-dependent material response of structurally thick circular sectors subjected to uniform large-deformation bending.

通过遵循Rubin和Bardella（2024）的工作，本研究开发了弹性不相容率的测量方法，表示为R i j，用于晶体塑性。这依赖于有限变形各向异性弹塑性的欧拉本构方程，该方程受微观结构材料矢量演化的支配。速率R i j取决于结晶学，因为它进入塑性速率L p，并通过评估相对于微观结构矢量的L p的当前旋度的相反方向获得。因此，R i j的每个分量在刚体叠加运动下是不变的，因此它可以独立地应用于本构方程中。在晶体塑性中，所采用的欧拉框架允许在R i j中挑出由于几何上必要的位错密度率和晶体晶格的弹性变形而产生的贡献。在这项工作中，使用R i j来增强硬化，这适用于受均匀大变形弯曲的结构厚圆形扇形的尺寸相关材料响应。

Elastic–plastic crack-tip-opening-displacement-based description for surface, corner and embedded cracks tip stress field

Jianqiang Zhang, Pengfei Cui, Wanlin Guo

doi:10.1016/j.ijsolstr.2025.113395

基于弹塑性裂纹尖端-开度-位移的表面、角部和嵌埋裂纹尖端应力场描述

Since part-through crack growth stages occupy most of crack growth life of engineering structures, it is essential to investigate the fracture parameters of part-through cracks. However, the complex three-dimensional (3D) stress states make it difficult to efficiently dominate the crack-tip fields. Here, the 3D elastic–plastic stress intensity factor Kδ-Tz is extended to dominate part-through cracks. Systematic 3D finite element (FE) analyses are conducted for typical part-through cracks (embedded, corner, and surface cracks) considering different elliptical ratios and hardening exponents. It is found that the predicted stress distributions by the δ-Tz solution agree well with 3D FE results. Additionally, the predictive performance of the δ-Tz solution improves with increasing hardening exponents. Across all experimental and numerical results, the variation of J-integral along the crack front line can reach 200%, while remaining within 21% for Kδ-Tz. These results demonstrate that Kδ-Tz can reduce geometric constraints effectively and be a more stable elastic–plastic fracture parameter for part-through cracks in engineering structures.

由于部分贯穿裂纹的扩展阶段占据了工程结构裂纹扩展寿命的大部分，因此研究部分贯穿裂纹的断裂参数至关重要。然而，复杂的三维应力状态使得难以有效地控制裂纹尖端场。在此，将三维弹塑性应力强度因子 Kδ-Tz 扩展用于控制部分贯穿裂纹。针对典型的部分贯穿裂纹（嵌入式、角部和表面裂纹），考虑不同的椭圆比和硬化指数，进行了系统的三维有限元（FE）分析。结果表明，δ-Tz 解法预测的应力分布与三维 FE 结果吻合良好。此外，δ-Tz 解法的预测性能随着硬化指数的增加而提高。在所有实验和数值结果中，J 积分沿裂纹前沿的变化可达 200%，而 Kδ-Tz 的变化则保持在 21%以内。这些结果表明，Kδ-Tz 能够有效降低几何约束，并成为工程结构中部分贯穿裂纹更稳定的弹塑性断裂参数。

Journal of the Mechanics and Physics of Solids

Cracking resistance of nanostructured freestanding tungsten films

S.E. Naceri, M. Rusinowicz, M. Coulombier, T. Pardoen

doi:10.1016/j.jmps.2025.106143

纳米结构独立钨膜的抗裂性能

The fracture toughness Kc of freestanding tungsten films is explored using a MEMS-based crack-on-chip method and multiscale finite element modelling, in the context of miniaturised testing of structural materials for nuclear fusion applications. The primary ambition is to determine to what extent testing thin nanostructured tungsten films can provide relevant data with respect to bulk tungsten fracture behavior, particularly in view of irradiation testing. The second objective is to enhance fundamental knowledge on the cracking behavior of thin metallic films with a quasi-brittle response. Tungsten films with 370 nm thickness are deposited by magnetron sputtering under different pressures and characterized using grazing incidence X-ray diffraction, surface curvature measurements, scanning electron microscopy and nano-indentation. Microstructure evolution, residual stresses, and tensile properties are analyzed to confirm the BCC α-phase. The fracture toughness of the tungsten films is determined on-chip using a crack arrest approach and finite element modelling to extract KIc. The analysis conducted on 90 successful test structures provides an average fracture toughness value of 3.2 ± 0.36 MPa √m. This value is typically, 50% lower than for bulk tungsten, despite the submicron thickness, while the same intergranular fracture mechanism is observed. The link with crack tip plasticity is further unravelled by extended finite element simulations relying on a cohesive zone model. Care is taken to properly resolve the mechanical behavior of the nanometer scale fracture process zone. The calibrated peak strength is equal 7.8 GPa, which is less than two times the large yield stress of the nanocrystalline film. With such a ratio, the impact of plasticity outside the fracture process zone is limited, corresponding to negligible R curve effect and extra dissipation upon crack growth in contrast with bulk specimens for which a ratio above four is expected.

本文在核聚变应用结构材料微型化测试的背景下，采用基于微机电系统的芯片裂纹法和多尺度有限元建模，对独立式钨薄膜的断裂韧性 Kc 进行了研究。主要目的是确定测试薄纳米结构钨薄膜在多大程度上能提供与块状钨断裂行为相关的数据，特别是考虑到辐照测试。第二个目标是增强对具有准脆性响应的薄金属薄膜开裂行为的基本认识。通过磁控溅射在不同压力下沉积 370 纳米厚的钨薄膜，并使用掠入射 X 射线衍射、表面曲率测量、扫描电子显微镜和纳米压痕对其进行表征。分析微观结构演变、残余应力和拉伸性能以确认体心立方α相。通过芯片上的裂纹止裂方法和有限元建模确定钨薄膜的断裂韧性 KIc。对 90 个成功测试结构进行的分析得出平均断裂韧性值为 3.2 ± 0.36 兆帕·米的平方根。尽管厚度在亚微米级，但该值通常比块状钨低 50%，同时观察到相同的晶间断裂机制。通过基于内聚区模型的扩展有限元模拟进一步揭示了与裂纹尖端塑性之间的联系。特别注意正确解析纳米级断裂过程区的力学行为。校准后的峰值强度为 7.8 吉帕，不到纳米晶薄膜大屈服应力的两倍。如此比例下，断裂过程区外塑性的影响有限，对应于可忽略的 R 曲线效应以及裂纹扩展时的额外耗散，这与块状试样预期的高于 4 的比例形成对比。

Thin-Walled Structures

Asymptotically correct non-linear analysis of multifunctional hyperelastic film-fabric laminate using Variational Asymptotic Method

Shravan Kumar Bhadoria, Ramesh Gupta Burela

doi:10.1016/j.tws.2025.113321

用变分渐近方法对多功能超弹性膜-织物层压板进行渐近正确非线性分析

The asymptotically correct dimensional reduction of a multifunctional film-fabric laminate from 3D to 2D is accomplished using the Variational Asymptotic Method (VAM). An asymptotically accurate 2D nonlinear (material and geometric nonlinear) constitutive law, that captures nonlinear effects and couplings, for a multifunctional hyperelastic film-fabric laminate has been derived analytically. The VAM divides the analysis into two parts: a 1D non-linear through-the-thickness analysis and a 2D non-linear reference surface analysis. The 1D analysis results in the derivation of asymptotically correct 3D warping functions and a 2D non-linear constitutive law. The 2D non-linear reference surface analysis employs the derived 2D nonlinear constitutive law to compute the 2D displacements and strains using 2D nonlinear FEA. The categorization of the 3D strain energy density into different orders is made feasible by introducing two inherent small parameters: 1) a geometric small parameter represented by the ratio of thickness to characteristic length (h/l<<1), and 2) a physical small parameter ensuring the largest component of 3D strain is limited to 20 percent, which is smaller than 1. The study leads to the analytical derivation of asymptotically correct 3D warping functions and a 2D non-linear constitutive law, which is then used to solve boundary value problems through the reference surface analysis. The computational efficiency of the current development stems from the dimensional reduction enabled by the VAM, while the accuracy is guaranteed by the asymptotic correctness of the derived 2D non-linear constitutive law.

利用变分渐近法（VAM）实现了多功能薄膜织物层合板从三维到二维的渐近精确尺寸缩减。通过解析推导，得到了一种渐近精确的二维非线性（材料和几何非线性）本构关系，该关系能够捕捉到多功能超弹性薄膜织物层合板中的非线性效应和耦合。VAM 将分析分为两部分：一维非线性厚度方向分析和二维非线性参考面分析。一维分析得出渐近精确的三维翘曲函数和二维非线性本构关系。二维非线性参考面分析采用推导出的二维非线性本构关系，通过二维非线性有限元分析计算二维位移和应变。通过引入两个固有的小参数，使得将三维应变能密度分类为不同阶次成为可能：1）几何小参数，由厚度与特征长度之比表示（h/l<<1）；2）物理小参数，确保三维应变的最大分量限制在 20% 以内，该值小于 1。该研究推导出了渐近正确的三维翘曲函数和二维非线性本构关系，然后通过参考面分析来解决边值问题。当前开发的计算效率得益于 VAM 实现的降维，而其精度则由所推导的二维非线性本构关系的渐近正确性来保证。

New free vibration solutions of arbitrarily constrained spherical-conical shell assemblies within a state-space-based piecewise solution framework

Yueqing Shi, Zhishan Chen, Dongqi An, Jie Xu, Zhenhuan Zhou, Tinh Quoc Bui, Rui Li

doi:10.1016/j.tws.2025.113322

基于状态空间的分段解框架下任意约束球锥壳组合自由振动新解

Spherical-conical shell assemblies have attracted continuing concerns due to their important utilizations in thin-walled engineering structures. Free vibration is one of the key mechanical behaviors of such structures. However, an accurate theoretical vibration analysis is challenging from the viewpoint of mathematical solution. In this study, a novel state-space-based piecewise solution framework is established for new free vibration solutions of arbitrarily constrained spherical-conical shell assemblies. Specifically, the free vibration equations of spherical and conical shells are first formulated in the state space. The transfer matrixes are then determined with a combination of the piecewise solution strategy and the precise integration method. Implementing the joining continuity and arbitrarily constrained conditions, the final solutions are obtained. The high accuracy and wide applicability of the developed solution framework are validated by extensive comparisons of the present numerical and graphical results with those from the literature and the finite element method. Leveraging the obtained solutions, quantitative parametric analyses are conducted. It is found that: the stiffnesses of the in-plane displacements have greater effects on the frequency parameter than those of radial and rotational displacements; stronger boundary stiffnesses lead to larger fundamental circumferential half-wave numbers; an unconstrained top spherical shell leads to a lower fundamental frequency; a shorter conical shell enhances the entire dynamic failure resistance of a spherical-conical shell assembly.

球锥壳组合由于其在薄壁工程结构中的重要应用而引起了人们的持续关注。自由振动是这类结构的关键力学行为之一。然而，从数学解的角度对振动进行精确的理论分析是一个挑战。本文建立了一种新的基于状态空间的球锥壳组合自由振动新解的分段解框架。具体而言，首先在状态空间中建立了球壳和圆锥壳的自由振动方程。然后采用分段求解和精确积分相结合的方法确定传递矩阵。采用连接连续性和任意约束条件，得到了最终解。通过与文献和有限元方法的数值和图形结果的广泛比较，验证了所开发的解框架的高精度和广泛适用性。利用得到的解，进行了定量参数分析。结果表明：面内位移刚度对频率参数的影响大于径向位移刚度和旋转位移刚度；边界刚度越大，基波周向半波数越大；无约束的顶球壳导致基频较低；较短的圆锥壳提高了球-圆锥壳组合的整体抗动力破坏能力。

Axial performance of locally corroded circular steel tubes strengthened with outer steel and sandwiched concrete jackets

Xinyu Chen, Dong Zhao, Zhenzhen Liu, Shan Li, Yiyan Lu

doi:10.1016/j.tws.2025.113330

外钢夹芯加固局部锈蚀圆钢管轴向性能研究

Hollow steel tubes (HSTs) are extensively utilized in bridge and building structures due to their excellent mechanical properties. However, prolonged service can result in localized corrosion, which compromises their load-bearing capacity. This study introduces a composite strengthening technique that employs outer steel tubes and concrete jackets (STSJC) and examines its reinforcement effect on locally corroded HST columns through experimental testing and finite element (FE) analysis. The findings indicate that this technique significantly enhances the load-bearing capacity and ductility of the specimens, with localized corrosion exerting a particularly pronounced effect on ductility. Furthermore, the FE analysis elucidates the stress concentration caused by localized corrosion, while also reinforcing the collaborative force mechanism between the inner and outer steel tubes and the concrete jackets, thereby augmenting the proportion of load supported by the concrete. Additionally, the study assesses existing load-bearing capacity calculation models, with Han's model exhibiting the highest applicability.

空心钢管以其优异的力学性能在桥梁和建筑结构中得到了广泛的应用。然而，长时间的使用可能导致局部腐蚀，从而影响其承载能力。本文介绍了一种采用外钢管和混凝土护套（STSJC）的复合加固技术，并通过试验试验和有限元分析，考察了其对局部腐蚀HST柱的加固效果。研究结果表明，该技术显著提高了试件的承载能力和延性，局部腐蚀对延性的影响尤为显著。此外，有限元分析阐明了局部腐蚀引起的应力集中，同时也强化了内外钢管与混凝土护套之间的协同受力机制，从而增加了混凝土支撑荷载的比例。此外，本研究还对现有的承载力计算模型进行了评估，其中Han的模型适用性最强。

Behaviour of screwed connections in cold-formed steel sheets at elevated temperatures

Liang Yin, Kang Liu, Wei Chen, Jihong Ye, Meng Zhang, Zhiyuan Fang, James B.P. Lim

doi:10.1016/j.tws.2025.113317

冷弯钢板螺纹连接在高温下的性能

This study conducts experiments on Q345 cold-formed steel (CFS) screw connections at ambient and elevated temperatures; investigates the effects of the number of screws, arrangement, and loading system on the mechanical properties; and investigates the load transfer and group effects in multiple screw connections. The results reveal that below 400°C, the main failure mode of multiple screw connections is screw tension‒shear failure, whereas above 400°C, it shifts to screw tilting accompanied by hole wall pressure failure. The arrangement of the screws and cyclic tensile actions had minimal effects on the ultimate load capacity of the multiple-screw connection. Under cyclic tensile action, both the unloading stiffness and the reloading stiffness increased with increasing number of screws but decreased with increasing temperature. With fewer than five screws, the group effect on the number of screw connections was insignificant, with the deviation between P (experimental value) and P2 (the limit load of a single-screw connection multiplied by the corresponding number of screws) remaining within 10%. However, as the number of screws exceeded five, the group effect became more pronounced, leading to an increase in the deviation between P and P1. This deviation reached a relative value of 38% with twelve screws. During the loading process, the central screws initially bore the primary load before being redistributed to the end screws. The load-carrying capacity of the end screws usually first increases. Prediction models for the ultimate load and load‒displacement curves of screw connections at ambient and elevated temperatures were developed.

本研究在常温和高温条件下对 Q345 冷弯型钢（CFS）螺杆连接进行了实验；研究了螺杆数量、排列方式和加载系统对力学性能的影响；还研究了多螺杆连接中的载荷传递和群体效应。结果表明，在 400°C 以下，多螺钉连接的主要失效模式是螺钉拉伸-剪切失效，而在 400°C 以上，则转变为螺钉倾斜并伴随孔壁压力失效。螺钉的排列和循环拉伸作用对多螺钉连接的极限承载能力影响很小。在循环拉伸作用下，卸载刚度和重新加载刚度都随着螺钉数量的增加而增加，但随着温度的升高而降低。当螺钉数量少于 5 个时，螺钉连接数量的群体效应并不明显，P（实验值）与 P2（单螺钉连接的极限载荷乘以相应的螺钉数量）之间的偏差保持在 10%以内。然而，当螺钉数量超过 5 个时，群体效应变得更加明显，导致 P 和 P1 之间的偏差增大。在使用 12 个螺钉时，这一偏差的相对值达到了 38%。在加载过程中，中心螺钉首先承担主要载荷，然后再重新分配给末端螺钉。末端螺钉的承载能力通常会首先增加。针对螺钉连接在常温和高温条件下的极限载荷和载荷-位移曲线建立了预测模型。

Prediction of fracture in metallic plates based on the phase-field approach

Hossein Ahmadian, Bahador Bahrami, Majid R. Ayatollahi, Mohammad Reza Khosravani

doi:10.1016/j.tws.2025.113323

基于相场法的金属板断裂预测

Studdying the failure of ductile materials is crucial for designing engineering structures. Ductile failure, associated with plastic deformation, makes failure analysis complex and computationally expensive. This study aims to analyze the fracture of cracked/notched ductile plates with different geometries and loading conditions (mode I, mixed mode I/II, and mode II), resulting in 41 analyses. First, it employs concepts that equate ductile materials with brittle ones. Then, these concepts are combined with the phase-field method (PFM) applied to brittle fracture to predict the fracture behavior of weakened metallic plates. Based on material properties, we couple the PFM with the equivalent material concept (EMC), the modified EMC (MEMC), and the fictitious material concept (FMC) to predict fracture load and initiation angle. The numerical results are validated with available experimental data, demonstrating that the proposed framework accurately predicts the fracture of ductile materials, with an accuracy of ±10%. Additionally, the proposed approach has demonstrated superiority over other methods for predicting the fracture load of ductile plates, including average strain energy density (ASED), mean stress (MS), and maximum tangential stress (MTS).

研究延性材料的破坏对工程结构设计具有重要意义。延性破坏与塑性变形相关联，使得破坏分析复杂且计算昂贵。本研究旨在分析裂纹/缺口韧性板在不同几何形状和加载条件下（I型、I/II混合型和II型）的断裂，共进行了41次分析。首先，它采用了将韧性材料与脆性材料等同起来的概念。然后，将这些概念与用于脆性断裂的相场法（PFM）相结合，对弱金属板的断裂行为进行预测。基于材料特性，将PFM与等效材料概念（EMC）、修正材料概念（MEMC）和虚拟材料概念（FMC）相结合，预测断裂载荷和起裂角。数值计算结果与已有的实验数据进行了验证，表明所提出的框架能够准确预测塑性材料的断裂，精度为±10%。此外，该方法在预测韧性板断裂载荷方面优于其他方法，包括平均应变能密度（ASED）、平均应力（MS）和最大切向应力（MTS）。

Experimental and theoretical investigations on reinforced concrete slabs subjected to low-velocity impact at various points by a drop hammer

Jiahe Zhong, Chunming Song, Zhongwei Zhang, Haotian Zhang, Feng Liu

doi:10.1016/j.tws.2025.113326

落锤对钢筋混凝土板各点低速冲击的试验与理论研究

Reinforced concrete slabs may experience impacts from weapons strikes or falling objects during service. The localized damage caused by initial impacts can affect the dynamic response of the structure to the subsequent effects at other locations. However, research concerning the effect of initial impact damage areas on subsequent impacts remains limited. This study first conducted experiments on the impact of a drop hammer at various points. The results showed that the initial impact damage caused by the hammer led to a decrease in the slab's bearing capacity and deformation resistance. Modal analysis was then performed on slabs with initial impact damage, confirming that the initial impact damage has a minimal effect on the low-order modes. Based on the experimental results, a various-point impact model for concrete slabs was proposed. Combined with the quasi-static contact force theory under low-velocity impact, the Lagrangian method was used to derive the theoretical method for the dynamic response of various point impacts on slabs considering the influence of the initial impact damage area. The results were compared and verified with the experimental results. The study focused on analyzing the influence of factors such as the equivalent stiffness (D1) and damage size (d1) of the initial impact damage region on the dynamic response of the structure. The results indicated that the equivalent stiffness and damage size of the localized damage area have a minor effect on the impact force but a significant effect on the displacement of the slab structure. The damage size has the greatest influence on the dynamic response of the slab, with the peak displacement increasing exponentially as the damage size increases.

钢筋混凝土板在使用过程中可能会受到武器打击或高空坠物的撞击。初始冲击造成的局部损坏会影响结构对其他位置后续影响的动态响应。然而，有关初始冲击破坏区域对后续冲击影响的研究仍然有限。本研究首先对落锤在不同位置的冲击进行了实验。结果表明，落锤造成的初始冲击破坏导致板的承载能力和抗变形能力下降。然后对有初始冲击损伤的楼板进行了模态分析，证实初始冲击损伤对低阶模态的影响很小。根据实验结果，提出了混凝土板的多点冲击模型。结合低速冲击下的准静态接触力理论，采用拉格朗日法推导出了考虑初始冲击损伤面积影响的板材各种点冲击动态响应的理论方法。研究结果与实验结果进行了比较和验证。研究重点分析了初始冲击损伤区域的等效刚度（D1）和损伤尺寸（d1）等因素对结构动态响应的影响。结果表明，局部损伤区域的等效刚度和损伤大小对冲击力的影响较小，但对板结构的位移影响很大。损伤尺寸对板结构动态响应的影响最大，随着损伤尺寸的增大，峰值位移呈指数增长。

ANALYSIS OF DEMOUNTABLE SHEAR CONNECTIONS IN COLD-FORMED STEEL-CONCRETE COMPOSITE BEAMS: A FINITE ELEMENT APPROACH VALIDATED WITH EXPERIMENTAL DATA

Vlaho Žuvelek, Ivan Ćurković, Ivan Lukačević, Andrea Rajić

doi:10.1016/j.tws.2025.113327

冷弯型钢-混凝土组合梁可拆卸剪切连接分析：一种经试验验证的有限元方法

The growing need for innovative solutions in the construction industry calls for continuous improvement of the value and usability of structural elements over their life cycle. The ongoing LWT-FLOOR project at the University of Zagreb, Faculty of Civil Engineering, Croatia, therefore presents an innovative solution for composite floor systems by investigating the performance of demountable shear connections within an innovative composite system comprised of a built-up cold-formed steel girder and a concrete slab. This configuration not only utilises the inherent advantages of cold-formed steel (CFS), but also highlights the efficiency of demountable shear connections compared to conventional solutions. Moreover, it emphasises compliance with sustainability principles. The configuration of analysed demountable shear connection specimens involves two different composite CFS-concrete systems: the BB and BCWB series. The BB series is comprised of the built-up sections in a back-to-back arrangement, where the webs of two C-shaped profiles are aligned and spot-welded with each other. In the BCWB series, a corrugated web is inserted between the webs of the CFS C profiles, further improving the section's stability. The behaviour of these demountable connections was investigated using a finite element approach, which was validated using experimental data and further analysed through a detailed parametric analysis. The finite element analysis revealed the complex behaviour of shear connections and the interaction of different failure modes affecting the overall resistance of the connection. Finally, the numerical results were compared with relevant standards to verify the predictions of shear resistance.

建筑行业对创新解决方案的需求不断增长，这就要求结构元件在其生命周期内不断提高其价值和可用性。因此，克罗地亚萨格勒布大学土木工程学院正在进行的LWT-FLOOR项目通过研究由冷弯钢梁和混凝土板组成的创新复合系统中的可拆卸剪切连接的性能，为复合地板系统提供了一种创新的解决方案。这种结构不仅利用了冷弯型钢（CFS）的固有优势，而且与传统解决方案相比，突出了可拆卸剪切连接的效率。此外，它强调遵守可持续性原则。分析的可拆卸剪切连接试件的结构涉及两种不同的复合碳纤维混凝土体系：BB和bbcb系列。BB系列是由一个背靠背的安排，其中两个c型型材的网对齐和点焊彼此组成的部分。在BCWB系列中，在CFS C型型材的腹板之间插入波纹腹板，进一步提高了截面的稳定性。使用有限元方法研究了这些可拆卸连接的行为，并通过实验数据进行了验证，并通过详细的参数分析进行了进一步分析。有限元分析揭示了剪切连接的复杂行为以及不同破坏模式对连接整体阻力的相互作用。最后，将数值计算结果与相关标准进行了比较，验证了预测结果的正确性。

Post-fire mechanical properties of corroded steel under different cooling methods

Chenrui Tian, Jian Jiang, Zongxing Zhang, Wenyu Cai, Wei Chen, Jihong Ye

doi:10.1016/j.tws.2025.113329

不同冷却方式下腐蚀钢火灾后的力学性能

Marine steel structures have greatly suffered from corrosion and fire, posing a prominent risk on structural safety. This combined effect is not well considered in evaluating post-fire behavior of steel, resulting in unsafe performance assessment. Experiments are conducted in this study to investigate the post-fire mechanical properties of corroded Q235 steel, considering different aging periods, exposure temperatures and cooling methods. Finite element models are developed based on three-dimensional surface morphology scanning, and the degradation rules of material properties are further explored. A calculation method is proposed to fully take into account the coupled effect of corrosions, temperatures and cooling methods. Experimental results show that the post-fire behavior of corroded steel is mainly dominated by corrosion under air cooling, and is governed by both corrosion and temperature for water cooling. For the steel experiencing temperatures higher than 700°C and water cooling, it exhibits brittle fracture behavior with a reduction of 90% in elongation, and its post-fire elastic modulus can decrease by 25%. It is numerically found that the reason behind these phenomena is due to the concentration of stress and strain at the corrosion pits, leading to premature failure. The water cooling method significantly reduces ductility of steel by intensifying stress concentration at corrosion pits. The calculation method can accurately and conservatively predict the post-fire behavior of corroded steel with errors within 10%, providing a reference for fast post-fire safety assessment of existing steel structures.

船用钢结构的腐蚀和火灾危害较大，对结构安全构成了突出的威胁。在评价钢的火灾后性能时，没有很好地考虑到这种综合效应，导致不安全的性能评价。在不同时效时间、暴露温度和冷却方式下，对Q235钢的火灾后力学性能进行了试验研究。建立了基于三维表面形貌扫描的有限元模型，进一步探讨了材料性能的退化规律。提出了一种充分考虑腐蚀、温度和冷却方式耦合效应的计算方法。试验结果表明，空冷条件下锈蚀钢的火后行为主要受锈蚀控制，水冷条件下锈蚀和温度共同控制。当温度高于700℃且水冷却时，钢表现出脆性断裂行为，伸长率降低90%，火灾后弹性模量降低25%。数值分析发现，造成这些现象的原因是由于腐蚀坑处应力和应变集中，导致过早破坏。水冷却方法通过强化腐蚀坑处的应力集中，显著降低了钢的延性。该计算方法能准确、保守地预测锈蚀钢的火灾后行为，误差在10%以内，为既有钢结构火灾后安全快速评估提供参考。