【新文速递】2025年4月27日固体力学SCI期刊最新文章

 

今日更新：International Journal of Solids and Structures 1 篇，Mechanics of Materials 1 篇，International Journal of Plasticity 2 篇，Thin-Walled Structures 7 篇

International Journal of Solids and Structures

Surface curvature regulation of 3D kirigami soft gripper

Jian Wu, Bohan Yang, Zhe Li, Shixue He, Yingxuan Bu, Benlong Su, Youshan Wang

doi:10.1016/j.ijsolstr.2025.113410

三维kirigami软夹持器的表面曲率调节

Kirigami principles have been integrated into flexible grippers, exploiting the shape transforming advantages to improve the grippers’ performance and broaden the varieties upon which can be operated. However, few studies have adopted the 3D polygonal auxetic kirigami as the main structure of the gripper, due to its complex spatial design process, narrowed means of fabrication and multi-freedom actuation. Herein, gripper deformation based on auxetic kirigami under a simple actuation of 1-DoF is studied via an energy minimization framework. Firstly, a spring potential energy minimization problem of the 3D kirigami with geometric constraints is solved to obtain its deployment path and energy landscape. Then the deformed surface is analyzed using discrete Gauss-Bonnet theorem, proposing a method to regulate the shape morphing into the targets. Finite element analysis is used to verify the kirigami design framework and shape prediction. Finally, different types of kirigami grippers are fabricated and tested, achieving effective conformation and grasping of typical shaped objects, while exhibiting universal, easily actuated characteristics. These findings contribute to advancing the field of robotic handling and manipulation, particularly in applications requiring gentle and compliant interactions with diverse and specifically delicate objects.

将基里伽米原理融入到柔性夹持器中，利用其形状变换的优势，提高夹持器的性能，拓宽夹持器的操作品种。然而，由于其空间设计过程复杂、制造手段狭窄、多自由度驱动等特点，采用三维多边形异形基立ami作为夹持器主体结构的研究较少。在此基础上，通过能量最小化框架，研究了在简单的1自由度驱动下，基于惯性基利格米的夹持器变形。首先，求解几何约束下三维基里伽米弹簧势能最小化问题，得到其展开路径和能量格局；然后利用离散高斯-博内定理对变形曲面进行分析，提出了一种调节曲面形状向目标变形的方法。采用有限元分析对基里伽米设计框架和形状预测进行了验证。最后，制作和测试了不同类型的基利伽米夹持器，实现了典型形状物体的有效构象和抓取，同时表现出通用，易于驱动的特性。这些发现有助于推进机器人处理和操纵领域，特别是在需要与各种特别微妙的物体进行温和和顺从交互的应用中。

Mechanics of Materials

Permanent strains and post-peak tensile response of concrete by three-phase conceptual modeling

A.A. Basmaji, A. Fau, U. Nackenhorst, R. Desmorat

doi:10.1016/j.mechmat.2025.105359

基于三相概念模型的混凝土永久应变及峰后拉伸响应

Plain concrete exhibits pronounced stress softening and permanent strains in uniaxial cyclic tension. The permanent strains in concrete have been measured since the 1980s by repeated tensile loading-unloading sequences. Nevertheless, accurately modeling the permanent strains, as well as the post-peak response, is still a challenge. To overcome it, we propose a conceptual three-phase modeling of concrete discretized by finite elements, consisting of an elastic aggregate phase, a perfectly plastic Interfacial Transition Zone (ITZ), and an anisotropically damaging mortar phase. Damage in mortar is assumed to be anisotropic and governed by extensions. The corresponding anisotropic damage model is a nonlocal one. The positivity of the intrinsic dissipation is checked. Mesh independency is gained by nonlocal integral averaging of the Mazars equivalent strain acting in the damage criterion function. The permanent strain and post-peak response of Terrien (1980) and Gopalaratnam and Shah (1985) experimental tensile references are accurately reproduced.

素混凝土在单轴循环拉伸下表现出明显的应力软化和永久应变。自20世纪80年代以来，通过重复拉伸加载-卸载顺序测量了混凝土中的永久应变。然而，准确地模拟永久应变，以及峰后响应，仍然是一个挑战。为了克服这一问题，我们提出了一种由有限元离散化的混凝土概念三相模型，包括弹性骨料阶段、完全塑性界面过渡区（ITZ）和各向异性损伤砂浆阶段。假定砂浆的损伤是各向异性的，受扩展控制。相应的各向异性损伤模型是非局部损伤模型。对固有耗散的正性进行了检验。通过对损伤判据函数中的Mazars等效应变进行非局部积分平均，获得网格独立性。准确地再现了Terrien（1980）和Gopalaratnam和Shah（1985）实验拉伸参考文献的永久应变和峰后响应。

International Journal of Plasticity

Quantification of multi-stage recrystallization in low-alloy steel under varying deformation conditions using inhomogeneous-dislocation-density 3D cellular automaton

Jiawei Xu, Lifeng Lu, Xueze Jin, He Wu,  He, Daolei Yang, Jingchao Yao, Weiqiang Zhao, Shaoshun Bian, Bin Guo, Debin Shan, Wenchen Xu

doi:10.1016/j.ijplas.2025.104353

用非均匀位错-密度三维元胞自动机量化低合金钢在不同变形条件下的多阶段再结晶

In the thermoforming process, alloys experience severe plastic deformation under varying temperatures and strain rates, complicating dynamic recrystallization (DRX) behavior. Current DRX models developed under constant deformation conditions have limited accuracy in predicting complex stress and microstructure evolutions. This work develops a 3D cellular automaton (CA) model to precisely predict the DRX microstructure and flow stress of low-alloy steel under varying deformation conditions. The model incorporates dislocation density gradients and grain-boundary sliding to quantify dislocation density evolutions in matrix and multi-stage recrystallization grains during hot compression. Parameter variables related to dislocation accumulation and annihilation are derived from a new phenomenological constitutive model, in which the variation of the time for 50% DRX fraction and the residual softening induced by the first-stage recrystallization are considered. CA simulation results illustrate that the stress softening following peak stress after transiently increasing the Zener-Hollomon parameter ZP is attributed to the refinement of matrix and first-stage DRX grains (DRXGsI) resulting from dislocation differences. DRXGsI cannot be fully refined due to delayed nucleation of second-stage DRX grains (DRXGsII), resulting in a greater final grain size. After decreasing ZP, even if the DRX fraction increases to levels under constant conditions, some matrix still exhibits higher dislocation density due to an inhomogeneous-dislocation-density distribution. This accelerates DRXGsI growth to a size similar to that under the constant condition, producing a stress-decreasing rate that closely matches experimental findings. The proposed simulation framework not only contributes to visualizing multi-stage recrystallization but also aids in quantitative microstructure control during hot forging.

在热成型过程中，合金在不同的温度和应变速率下经历严重的塑性变形，这使得动态再结晶（DRX）行为变得复杂。目前在恒定变形条件下开发的 DRX 模型在预测复杂的应力和微观结构演变方面准确性有限。本研究开发了一种三维元胞自动机（CA）模型，以精确预测低合金钢在不同变形条件下的 DRX 微观结构和流动应力。该模型结合了位错密度梯度和晶界滑动，以量化热压缩过程中基体和多阶段再结晶晶粒中的位错密度演变。与位错积累和湮灭相关的参数变量是从一个新的经验本构模型中推导出来的，该模型考虑了 50% DRX 分数所需时间的变化以及第一阶段再结晶引起的残余软化。CA 模拟结果表明，在 Zener-Hollomon 参数 ZP 短暂增加后，峰值应力后的应力软化归因于由位错差异导致的基体和第一阶段动态再结晶晶粒（DRXGsI）的细化。由于第二阶段动态再结晶晶粒（DRXGsII）的成核延迟，DRXGsI 无法完全细化，从而导致最终晶粒尺寸更大。在 ZP 减小后，即使动态再结晶分数增加到恒定条件下的水平，由于位错密度分布不均匀，一些基体仍表现出较高的位错密度。这加速了 DRXGsI 的生长，使其尺寸接近恒定条件下的尺寸，从而产生与实验结果非常接近的应力下降率。所提出的模拟框架不仅有助于可视化多阶段再结晶，还有助于在热锻过程中实现微观结构的定量控制。

Zirconium δ-Hydrides: Strain Localisation, Ratcheting, and Fatigue Crack Propagation

Daniel J. Long, Thibaut Dessolier, T. Ben Britton, Stella Pedrazzini, Fionn P.E. Dunne

doi:10.1016/j.ijplas.2025.104344

锆δ-氢化物：应变局部化、棘轮和疲劳裂纹扩展

As many nations commit to achieving Net Zero, many low carbon scenarios indicate that civil nuclear power generation and the economics thereof are set to play a vital role. To maximise nuclear reactor operation lifetimes, it is essential to develop mechanistic understanding of failure and degradation mechanisms in safety-critical components for increasingly holistic reactor design codes and standards. In this paper, advanced micromechanical testing with in situ digital image correlation is used in combination with crystal plasticity modelling to study various aspects of damage associated with δ hydride precipitates in Zircaloy-4 for reactor fuel cladding applications. Measurements of static and cyclic hydride precipitation strains demonstrate a discernible strain field directionality (associated with intragranular precipitation) which was not previously reported, while cyclic thermomechanical loads are shown to promote the cyclic accumulation of strain due to repeated precipitation and dissolution of hydrides (hydride strain ratcheting) for up to five cycles, leading to the development of networks of geometrically necessary dislocations. Using crystal plasticity finite element modelling of the volumetric expansion associated with hydride precipitation, the strain directionality phenomenon is shown to be linked with hydride morphology. Comparisons with experimental strain fields also suggest that hydride plasticity is an important consideration for damage accumulation during precipitation. Experimental measurements of short fatigue crack propagation through Zircaloy-4 microstructures containing hydrides reveal new crack propagation mechanisms including decohesion, which on average, lead to accelerated rates of crack growth. Annealing twins and hydride precipitation therein are also implicated in even more damaging fatigue behaviour as fatigue cracks are provided a seemingly brittle and direct path for fracture, which was not previously reported in the literature.

随着许多国家致力于实现净零排放，许多低碳情景表明，民用核能发电及其经济性将发挥至关重要的作用。为了最大限度地延长核反应堆的运行寿命，为日益全面的反应堆设计规范和标准，发展对安全关键部件失效和退化机制的机械理解是至关重要的。在本文中，采用先进的微力学测试与原位数字图像相关，结合晶体塑性建模，研究了反应堆燃料包壳应用中锆合金-4中δ氢化物沉淀相关的各个方面的损伤。静态和循环氢化物析出应变的测量表明，应变场有明显的方向性（与颗粒内析出有关），这是以前没有报道过的，而循环热机械载荷显示，由于氢化物的反复析出和溶解（氢化物应变棘齿），可促进应变的循环积累，长达五个周期，导致几何上必要的位错网络的发展。通过对氢化物析出过程中体积膨胀的晶体塑性有限元模拟，表明应变方向性现象与氢化物形态有关。与试验应变场的比较也表明，氢化物塑性是影响沉淀过程中损伤积累的重要因素。通过含氢化物的锆合金-4微结构的短疲劳裂纹扩展实验测量揭示了新的裂纹扩展机制，包括脱黏，平均而言，这导致裂纹扩展速度加快。退火孪晶和其中的氢化物沉淀也涉及到更具破坏性的疲劳行为，因为疲劳裂纹提供了一个看似脆的直接断裂路径，这在以前的文献中没有报道过。

Thin-Walled Structures

On-orbit thermal-mechanical coupling performance analysis of a deployed hoop-column antenna

Wei Xu, Hao Zhu, Jiafeng Li

doi:10.1016/j.tws.2025.113312

展开环柱天线在轨热力耦合性能分析

Deployable hoop-column antennas have been employed extensively in communication satellites over the past few decades. The antenna may subject to significant deformation or even heat-induced vibration during on-orbit operation as a result of solar radiation shocks, which could potentially impact its normal functionality. In this paper, the finite element theory and Fourier thermal element method are combined to study the thermal-structural response of the antenna under solar thermal shock in a real space thermal environment. According to the antenna’s orbital position and orientation relative to the Sun and Earth’s, a noval spatial heat flux analysis model is first established to calculate the real solar heat radiation flux on local positions of the antenna considering the Earth’s shadow effect and reflector’s light shading effect. The coupled thermal-mechanical coupling analysis model which incorporates the cable pre-tension is then established and validated by comparison with the ground thermal radiation impact test. The on-orbit thermal-mechanical dynamic response of the antenna is examined during satellite operation in two types of orbits (geostationary orbit and general elliptical orbit). The findings indicate that the light-shadow effect intensifies the temperature gradient of the antenna and influences the thermal deformation of the antenna. However, due to the structural stability of the hoop-column antenna, minimal thermal vibration of the antenna is discerned.

在过去的几十年里，可展开环柱天线在通信卫星中得到了广泛的应用。由于太阳辐射冲击，天线在在轨运行期间可能会发生严重变形甚至热激振动，这可能会影响其正常功能。本文将有限元理论与傅里叶热单元法相结合，研究了真实空间热环境下太阳热冲击下天线的热结构响应。根据天线相对于太阳和地球的轨道位置和方向，首先建立了考虑地球阴影效应和反射器遮光效应的空间热流分析模型，计算了天线局部位置的真实太阳热辐射通量。建立了考虑锚索预张力的热力-力学耦合分析模型，并与地面热辐射冲击试验进行了对比验证。研究了卫星在静止轨道和普通椭圆轨道两种轨道上运行时天线的在轨热力动力响应。研究结果表明，光影效应加剧了天线的温度梯度，影响了天线的热变形。然而，由于环柱天线的结构稳定性，使得天线的热振动最小。

Hardening evolution and ductile fracture initiation properties in three orientations of S700MC ultra-high-strength structural steel

Mingxu Shang, Hua Yang

doi:10.1016/j.tws.2025.113375

S700MC超高强度结构钢三取向硬化演化及韧性起裂性能

Ultra-high-strength structural steels have gained more attention in the field of civil engineering due to their extremely high strength-to-weight ratio. Due to the practical need for assessing the cold bendability of S700MC ultra-high-strength structural steel by means of plasticity and ductile fracture model, a series of notched tensile specimens highly correlated with the stress states of uniaxial tension and plane strain was tested in this study. Additionally, in our pre-investigation, it was found that the hardening and ductile fracture properties of S700MC steel are highly sensitive to the orientation. Thus, three typical orientations, including rolling direction (0°), diagonal direction (45°) and transverse direction (90°), are incorporated in the testing programme considering the standard operation of actual processing. Based on the experimental flow curves along three orientations, an updated Hill48 plasticity model coupled with the effect of hardening evolution was introduced, calibrated, and subsequently applied to the three-point bending test and the tensile tests of stress-state-dependent notched specimens. With good agreement between experimental and simulated results, the loading paths, defined as a function of the equivalent plastic strain in terms of the stress triaxiality and the Lode angle parameter, are extracted from the finite element models along different orientations. Under the framework of the partially coupled ductile fracture model, three classic models including the Hosford-Coulomb model, the modified Mohr-Coulomb model, and the Lou-Huh model, were calibrated and validated in three orientations of the metallic material. Finally, aiming at assessing the cold bendability in three typical orientations of S700MC steel sheet, a parametric analysis, regarding the types of fracture locus and the ratio of punch radius to thickness, was conducted with the built-up constitutive models, providing a basis for the manufacturing of S700MC steel products.

超高强度结构钢由于具有极高的强度与重量比，在土木工程领域受到越来越多的关注。由于实际需要通过塑性和韧性断裂模型来评估S700MC超高强度结构钢的冷弯曲性能，本研究对一系列与单轴拉伸和平面应变应力状态高度相关的缺口拉伸试样进行了试验。此外，在我们的预研究中发现，S700MC钢的硬化和韧性断裂性能对取向高度敏感。因此，考虑到实际加工的标准操作，在测试程序中纳入了滚动方向（0°）、对角方向（45°）和横向方向（90°）三种典型方向。基于三个方向的试验流动曲线，引入并校正了考虑硬化演化效应的Hill48塑性模型，并将其应用于应力状态相关缺口试件的三点弯曲试验和拉伸试验。 在实验结果与模拟结果吻合良好的情况下，从有限元模型中提取了沿不同方向的加载路径，并将加载路径定义为应力三轴性与Lode角参数的等效塑性应变函数。在部分耦合韧性断裂模型的框架下，对霍斯福特-库仑模型、修正的莫尔-库仑模型和劳-哈模型3种经典模型在金属材料的3个方向上进行了标定和验证。最后，针对S700MC钢板在三种典型取向下的冷弯曲性能进行了评估，利用建立的本构模型对断裂轨迹类型和冲孔半径与厚度之比进行了参数化分析，为S700MC钢板产品的制造提供了依据。

Seismic performance of prefabricated connections for partially encased composite beam to CFST column

Yuexi He, Yan-Gang Zhao, Yu Bai, Siqi Lin

doi:10.1016/j.tws.2025.113378

部分包壳组合梁-钢管混凝土柱预制连接抗震性能研究

Partially encased composite (PEC) beam and concrete-filled steel tube (CFST) column may take advantages of both steel and concrete for high-rise and long-span applications. However, understanding on the seismic performance of such PEC beam-to-CFST column joints is still quite limited, leading to a lack of relevant moment resistance design methods. Two experimental scenarios and nine finite element (FE) models subjected to cyclic loading were developed in this study to understand their moment-rotation responses. The main results showed that the initial rotational stiffness, plastic moment, and ultimate moment generally decreased with the reduction in bolt diameter and end-plate thickness. The middle rows of bolts had a minimal impact on the initial rotational stiffness and bearing capacity of the connections, while the edge rows of bolts and the stiffeners presented more significant effects. Based on the experimental and FE results, a design method was developed to estimate the moment resistance of the PEC beam-to-CFST column joints. The resulting moment resistance was compared with the plastic moments from the experiments and FE analyses, with 97% in average and 0.06 in deviation.

部分包壳组合梁和钢管混凝土柱可以在高层和大跨度应用中充分利用钢和混凝土的优点。然而，对于此类PEC梁柱节点的抗震性能的认识仍然非常有限，导致缺乏相关的弯矩抗力设计方法。本研究建立了2个试验场景和9个循环荷载作用下的有限元模型，以了解其弯矩-旋转响应。结果表明：初始转动刚度、塑性弯矩和极限弯矩随锚杆直径和端板厚度的减小而减小；螺栓中间排对连接的初始转动刚度和承载力影响最小，而螺栓边缘排和加强筋的影响更为显著。在试验和有限元分析的基础上，提出了PEC梁柱节点弯矩抗力的设计方法。将所得的弯矩阻力与试验和有限元分析所得的塑性弯矩进行了比较，平均值为97%，偏差为0.06。

Shear strength of CFS shear walls with screw-rivet hybrid connections

Zhiqiang Xie, Ying Fan, Zengzhi Qian, Shi Zhang, Ye Bi, Hongwei Fang, Daxing Zhou, Xiyang Lei

doi:10.1016/j.tws.2025.113289

螺纹-铆钉混合连接CFS剪力墙抗剪强度研究

Numerous studies have demonstrated that the shear performance of cold-formed steel (CFS) shear walls is primarily influenced by the connection between the sheet sheathing and steel frame. The main connection type in CFS structures is self-drilling screws (SDS), which have high deformation capacity but low strength. Self-piercing rivets (SPR) have been found to improve the shear strength of CFS shear walls, but their deformation capacity is limited. Therefore, this paper presents a novel CFS shear wall with screw-rivet (SR) hybrid connections designed to enhance the shear performance of the wall by incorporating the properties and characteristics of both connection types. The influence of fastener arrangement on failure modes of the shear wall was studied and a hybrid connection type with better shear performance was proposed. Experimental investigation revealed that the shear strength of CFS shear walls with SR connections was primarily provided by the sheet sheathing through the diagonal tension field. However, the main failure mode was the failure of SR connections within the tension field. In view of this, the shear behaviour of SR connections was studied further. Shear tests were conducted on total of 42 specimens with two types of sheet combinations to assess the effects of fastener arrangement and number on shear performance and failure mechanisms. A calculation method based on the Group Effect was proposed for determining the shear strength of SR connections. Based on this, a calculation method for the shear strength of a CFS shear wall with SR connections combined with the effective strip method was proposed. The results indicated that the primary failure modes of SR connections were a combination of screw tilting and the rivet tail being pulled out from the lower sheet, and the bearing failure of the upper sheet. The sheet thickness combination was the main factor affecting the failure mode. Considering the Group Effect meant that the calculation method for the shear strength of SR connections was extremely accurate. Thus, SR connections can effectively improve the shear strength and deformation of a CFS shear wall compared to both a shear wall with SDS and a shear wall connected by SPR. The superior shear performance was observed in a shear wall in which screws were added continuously. The proposed calculation method for the shear strength of a CFS shear wall with SR connections was highly accurate, with an error of less than 5%. A design example is presented to illustrate this.

大量研究表明，冷弯型钢剪力墙的抗剪性能主要受薄板和钢框架连接的影响。CFS结构的主要连接方式是自钻螺钉（SDS），其变形能力大，但强度低。自穿铆钉（SPR）可以提高CFS剪力墙的抗剪强度，但其变形能力有限。因此，本文提出了一种新型的螺纹-铆钉（SR）混合连接的CFS剪力墙，旨在通过结合两种连接类型的特性和特点来提高墙体的抗剪性能。研究了扣件布置方式对剪力墙破坏模式的影响，提出了具有较好抗剪性能的混合连接方式。试验研究表明，钢筋混凝土连接的CFS剪力墙的抗剪强度主要由板壳通过斜向张力场提供。然而，主要的破坏方式是SR连接在张力场内的破坏。鉴于此，进一步研究了SR连接的剪切性能。通过对42个试件进行两种组合形式的剪切试验，评估紧固件布置方式和数量对试件抗剪性能和破坏机制的影响。提出了一种基于群效应的钢筋混凝土连接抗剪强度计算方法。在此基础上，提出了一种结合有效条法计算钢筋混凝土连接CFS剪力墙抗剪强度的方法。结果表明：SR连接的主要失效模式是螺杆倾斜和铆钉尾从下片拔出，以及上片的轴承失效。板料厚度组合是影响破坏模式的主要因素。考虑群效应意味着SR连接抗剪强度的计算方法是非常准确的。由此可见，与SDS连接剪力墙和SPR连接剪力墙相比，SR连接能有效提高CFS剪力墙的抗剪强度和变形。连续加螺杆的剪力墙抗剪性能较好。本文提出的钢筋混凝土连接CFS剪力墙抗剪强度计算方法精度高，误差小于5%。给出了一个设计实例来说明这一点。

Energy absorption behaviors of trapezoid origami boxes with curved-creases

Chenhao Teng, Zhichao Cai, Zhibo Song, Wenlong Lu, Jiayu Chen, Caihua Zhou, Peng Hao

doi:10.1016/j.tws.2025.113355

弯曲折痕梯形折纸盒的吸能特性

Compared with conventional square crash boxes, origami crash boxes demonstrate superior potential for widespread application because they can generate several times as many traveling plastic hinge lines (TPHL) as conventional ones, increase the plastic deformation area of the crash box, and greatly improve the energy absorption performance. However, for origami crash boxes, the increase in the number of TPHLs restricts their movement range. Consequently, it becomes difficult for ductile deformations with high energy absorption expressiveness to occur within the origami crash boxes, making it challenging to further enhance the energy absorption performance. Therefore, an innovative curved-crease design method is proposed in this paper. Due to the effect of the curved crease design, the curved crease can lead origami creases to change into TPHLs at the position of maximum curvature and produce a larger ductile deformation area. Through deformation mechanism analysis, compression experiments, numerical simulations, and theoretical analysis of trapezoidal origami crash boxes with curved-creases (TCB-ρ), it can be verified that the curved-crease design not only guides the crash box to generate multiple traveling plastic hinge lines but also further expands the in-plane ductile deformation. Moreover, multiple numerical simulation results indicate that the curved-crease design can decrease the Fmax , enhance the Fave , and ensure a stable energy absorption process in origami crash boxes. The curved-crease ρ and dihedral angle θ of the TCB-ρ have a significant effect on crashworthiness.

与传统的方形碰撞盒相比，折纸碰撞盒可以产生数倍于传统碰撞盒的移动塑性铰线（TPHL），增加碰撞盒的塑性变形面积，大大提高吸能性能，具有更大的推广应用潜力。然而，对于折纸碰撞盒，tphl数量的增加限制了它们的移动范围。因此，具有高能量吸收表现力的塑性变形难以在折纸碰撞盒内发生，进一步提高吸能性能是一项挑战。为此，本文提出了一种新颖的曲线折痕设计方法。由于弯曲折痕设计的影响，弯曲折痕可以使折纸折痕在曲率最大的位置转变为tphl，产生较大的延性变形面积。通过对带有弯曲折痕（TCB-ρ）的梯形折纸碰撞盒的变形机理分析、压缩实验、数值模拟和理论分析，验证了弯曲折痕设计不仅引导碰撞盒产生多条可移动的塑性铰线，而且进一步扩大了碰撞盒的面内延性变形。此外，多个数值模拟结果表明，弯曲折痕设计可以降低Fmax ，增强Fave ，并确保折纸碰撞盒稳定的能量吸收过程。TCB-ρ的弯曲折痕ρ和二面角θ对耐撞性有显著影响。

Mechanism of ultrasonic cutting aramid honeycomb using disc cutters with different blade shapes

Jialin Guo, Zhigang Dong, Mingye Wang, Heng Luo, Yidan Wang, Renke Kang, Jiansong Sun

doi:10.1016/j.tws.2025.113370

不同刀型圆盘刀超声切割芳纶蜂窝的机理

Aramid honeycomb (AH), as a thin-wall structural material, with its excellent properties is gaining popularity in sandwich structures in aerospace, etc. Ultrasonic cutting (UC) using disc cutters (DCs) is an innovative technology for processing honeycomb materials. Multi-tooth disc cutter (MTDC) is a novel cutter with revolutionary structure. However, the tool-material contact state is complicated by the introduction of ultrasonic vibration (UV) and variations of tool structure, and the cutting mechanism is not clarified. To address the issue, the finite element method (FEM) was adopted and multi-scale FE models were formulated, including a model of micro-region UC to investigate the mechanism of the cutting edge interacting with the cell wall, and a model of UC porous honeycomb to explore cutting forces and the machining quality with different blade shapes and UC parameters. Cutting simulations and experiments were performed. It was found that the cutting force of MTDC was significantly lower than that of the DC owing to the intermittent cutting effect of the teeth, and the stress concentration at the tool tip could reduce the deformation of the cell wall. The machined surface of MTDC was predominantly fiber pull-out, whereas the DC were predominantly burrs, but more refined. Ultrasonic amplitude (UA) was the most significant for machining quality, and good machining quality can be obtained when the UA is 20 µm. But the effects on machining quality of spindle speed and feed rate were not significant. Additionally, under different cutting parameters, the cutting force of MTDC in the feed direction and in the axial direction were reduced by an average 63.4 % and 76.9 % respectively compared to that of the DC. This provides theoretical guidance for the design of cutting processes for two different tools and the optimization of the structure of MTDC.

芳纶蜂窝材料作为一种薄壁结构材料，以其优异的性能在航空航天等领域的夹层结构中得到越来越广泛的应用。超声切割（UC）是一种利用圆盘刀具（DCs）加工蜂窝材料的创新技术。多齿盘式刀具是一种具有革命性结构的新型刀具。然而，由于超声振动的引入和刀具结构的变化，刀具与材料的接触状态变得复杂，切削机理不明确。为了解决这一问题，采用有限元方法，建立了多尺度有限元模型，包括研究切削刃与细胞壁相互作用机理的微区域UC模型，以及研究不同叶片形状和UC参数下切削力和加工质量的UC多孔蜂窝模型。进行了切削仿真和实验。研究发现，由于齿的间歇性切削作用，MTDC的切削力明显低于DC，刀尖处的应力集中可以减少细胞壁的变形。MTDC的加工表面以纤维拉出为主，而DC的加工表面以毛刺为主，但更为精细。超声振幅（UA）对加工质量影响最为显著，当UA为20µm时，加工质量较好。主轴转速和进给速度对加工质量的影响不显著。此外，在不同切削参数下，MTDC在进给方向和轴向方向的切削力比DC平均分别降低63.4%和76.9%。这为两种不同刀具的切削工艺设计和MTDC结构的优化提供了理论指导。

Numerical investigation and design of cold-formed steel elliptical hollow section X-joints under brace axial compression

Shichang Hu, Madhup Pandey, Man-Tai Chen, Ben Young

doi:10.1016/j.tws.2025.113374

支撑轴压作用下冷弯型钢椭圆空心截面x形接头的数值研究与设计

A comprehensive numerical investigation looking into the static structural behaviour and design of cold-formed steel elliptical hollow section X-joints (CFS-EHS-XJs) is reported. Detailed finite element (FE) models were developed for three distinct brace-chord configurations, incorporating cold-forming effects and heat-affected zones. The numerical models were validated against experimental results of 30 specimens through comparisons of load-deformation responses, joint resistance and failure mode. Parametric analyses encompassing 199 CFS-EHS-XJs were performed to examine the influence of key geometric parameters on joint static behaviour. The combined experimental and numerical dataset of 229 joints was used to evaluate the existing design provisions, including CIDECT and Eurocode 3 methods with equivalent circular and rectangular section approaches, and Wardenier’s EHS joint design method. These comparisons revealed significant scatter and inaccuracy in joint resistance predictions using the current design methods. A new design methodology based on the ring model theory has been proposed and calibrated against the developed dataset. The proposed approach demonstrates superior accuracy and consistency in predicting CFS-EHS-XJ resistances compared to existing design methods.

本文对冷弯型钢椭圆空心截面x形节点静力结构性能及设计进行了全面的数值研究。详细的有限元（FE）模型开发了三种不同的弦撑结构，包括冷成形效应和热影响区。通过对30个试件的荷载-变形响应、节点阻力和破坏模式的比较，对数值模型进行了验证。对199个cfs - ehs - xj节点进行了参数分析，考察了关键几何参数对节点静力性能的影响。利用229个节点的实验与数值相结合的数据集，对现有设计规定进行了评价，包括CIDECT和Eurocode 3的等效圆形和矩形截面方法，以及Wardenier的EHS节点设计方法。这些比较揭示了使用当前设计方法在联合阻力预测中的显著分散和不准确性。提出了一种新的基于环模型理论的设计方法，并针对开发的数据集进行了校准。与现有的设计方法相比，该方法在预测CFS-EHS-XJ电阻方面具有更高的准确性和一致性。