【新文速递】2023年12月3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 1 篇，Thin-Walled Structures 5 篇

International Journal of Solids and Structures

Eulerian Finite Element Implementations of a Dislocation Density-based Continuum Model

Milovan Zecevic, M.J. Cawkwell, D.J. Luscher

doi:10.1016/j.ijsolstr.2023.112590

基于位错密度的连续模型的欧拉有限元实现

In Eulerian finite element simulations, the mesh moves relative to the material. After every change of position between the mesh and the material, the state variables are interpolated to the new mesh position, which is referred to as advection. Large strain crystal plasticity models are based on the multiplicative decomposition of the total deformation gradient. The stress is evaluated as a function of the thermoelastic strain, temperature, and other state variables. Advection of tensor quantities, such as the strain, is coupled with possibly significant advection errors. In an effort to reduce the advection errors, we develop two rate forms of an established dislocation density-based continuum model. To that end, we replace the multiplicative decomposition of the deformation gradient with the additive decomposition of the velocity gradient, and define the stress rate instead of the total stress. The Eulerian implementation is compared with Lagrangian calculations, and two numerical examples with severe deformation levels are presented.

在欧拉有限元模拟中，网格相对于材料移动。网格和材料之间的位置每次改变后，状态变量都会插值到新的网格位置，这被称为平移。大应变晶体塑性模型基于总变形梯度的乘法分解。应力作为热弹性应变、温度和其他状态变量的函数进行评估。张量（如应变）的平移可能会产生显著的平移误差。为了减少平流误差，我们开发了基于位错密度的连续模型的两种速率形式。为此，我们用速度梯度的加法分解代替了变形梯度的乘法分解，并定义了应力率而不是总应力。我们将欧拉计算与拉格朗日计算进行了比较，并给出了两个具有严重变形水平的数值示例。

Mechanics of Materials

CrystalMind: A surrogate model for predicting 3D models with recrystallization in open-die hot forging including an optimization framework

Jan Petrik, Syed Irtiza Ali, Martin Feistle, Markus Bambach

doi:10.1016/j.mechmat.2023.104875

CrystalMind：用于预测开模热锻中再结晶三维模型的替代模型，包括优化框架

This work introduces CrystalMind, a surrogate model developed to accurately reconstruct 3D models along with recrystallization induced by the open-die hot forging process. CrystalMind employs two types of data inputs, a 3D Model depicting pre-stroke workpiece geometry, and a forging vector outlining the proposed forging strategy. This forging strategy consists of bite infeed, bite offset, number of offsets and initial position. Moreover, a machine learning architecture with two different units, MLP-based (Multi-Layer Perceptron) and PointNET++-based was implemented and compared, demonstrating similar performance in terms of recrystallization and deformation errors. However, MLP proved 36 times faster in computational time reaching an average computational time of 5ms pro run. Furthermore, CrystalMind adheres to the volume conservation condition and limits recrystallization error to less than 2% and deformation error to less than 0.1 mm or 0.9% for the test data. Finally, CrystalMind is employed in conjunction with an optimization algorithm, leading to remarkable enhancements in time efficiency. The optimization framework can effectively optimize a forging vector(s) for one, two, or three strokes. For instance, in the case of three strokes, CrystalMind enables the optimization process to be completed within an average of 7 min, a stark contrast to the approximately 2.3 years required when utilizing FEM simulation. Overall, CrystalMind provides fast and accurate predictions of deformed 3D models with corresponding recrystallization per point caused by a forging process, something not to be found in the state of the art so far.

这项工作介绍了 CrystalMind，它是一个代用模型，用于准确重建三维模型以及开模热锻工艺引起的再结晶。CrystalMind 采用两种类型的数据输入，一种是描述冲程前工件几何形状的三维模型，另一种是概述拟议锻造策略的锻造矢量。该锻造策略包括咬合进给、咬合偏移、偏移次数和初始位置。此外，基于 MLP（多层感知器）和 PointNET++ 的两种不同单元的机器学习架构也得到了实施和比较，在再结晶和变形误差方面表现出相似的性能。然而，MLP 的计算时间快了 36 倍，平均计算时间为 5 毫秒。此外，CrystalMind 遵循体积守恒条件，将测试数据的再结晶误差限制在 2% 以下，变形误差限制在 0.1 毫米或 0.9% 以下。最后，CrystalMind 与优化算法结合使用，显著提高了时间效率。优化框架可以有效优化一个、两个或三个冲程的锻造矢量。例如，在三个冲程的情况下，CrystalMind 使优化过程平均在 7 分钟内完成，与使用有限元模拟所需的约 2.3 年时间形成鲜明对比。总体而言，CrystalMind 能够快速准确地预测锻造过程中每点相应的再结晶所导致的变形三维模型，这是目前技术水平所无法实现的。

International Journal of Plasticity

Revealing the deformation mechanisms of <110> symmetric tilt grain boundaries in CoCrNi medium-entropy alloy

Dongpeng Hua, Qing Zhou, Yeran Shi, Shuo Li, Ke Hua, Haifeng Wang, Suzhi Li, Weimin Liu

doi:10.1016/j.ijplas.2023.103832

揭示钴铬镍中熵合金中 <110> 对称倾斜晶界的变形机制

The synergy of multiple deformation mechanisms responsible for the excellent mechanical properties attracts an increasing interest in CoCrNi medium entropy alloy (MEA). In this study, we employed molecular dynamics simulations to investigate the chemical properties of grain boundaries (GBs) and their influence on deformation mechanisms in CrCoNi MEA, with particular emphasis on role of lattice distortion and short-range order (SRO) in dislocation plasticity. After aging, we found Ni element segregate at GB through short-range diffusion driven by a more negative segregation enthalpy. The degree of SRO within the GB region is significantly correlated with the Ni concentration, and it markedly influences the structure and local stress distribution of the GB. Compared to the lattice distortion, SRO can effectively suppress the GB dislocations nucleation and slip, thereby increasing yield strength of the material. During the plastic stage, although the deformation microstructure is intimately linked to the active slip systems and grain orientation, the presence of SRO, as well as the resultant rugged dislocation pathways and increased slip resistance lowers the propensity for stacking faults and phase transformation. The current findings can enhance a fundamental comprehension of diverse deformation mechanisms in CoCrNi MEA and suggest that the chemical characteristics of GB could serve as a pivotal approach for modifying the mechanical properties of MEAs.

钴铬镍中熵合金（MEA）具有优异的机械性能，其多种变形机制的协同作用引起了越来越多的关注。在本研究中，我们采用分子动力学模拟研究了铬钴镍中熵合金晶界（GB）的化学性质及其对变形机制的影响，特别强调了晶格畸变和短程有序（SRO）在位错塑性中的作用。老化后，我们发现镍元素通过短程扩散在 GB 上发生偏析，偏析焓为负值。GB区域内的SRO程度与镍浓度显著相关，并明显影响GB的结构和局部应力分布。与晶格畸变相比，SRO 能有效抑制 GB 位错成核和滑移，从而提高材料的屈服强度。在塑性阶段，虽然变形微观结构与活跃的滑移系统和晶粒取向密切相关，但 SRO 的存在以及由此产生的崎岖位错通道和滑移阻力的增加降低了堆叠断层和相变的倾向。目前的研究结果可以从根本上加深对 CoCrNi MEA 中各种变形机制的理解，并表明 GB 的化学特性可以作为改变 MEA 机械性能的关键方法。

Thin-Walled Structures

Mechanical performance study of a novel modular gymnasium inner sleeve all-bolt cross connection joint – part Ⅰ: experiments and finite element modeling

Chang-jun Zhong, Farhad Aslani, Ruo-qiang Feng, Hu-yang Li, Yong-qi Huang

doi:10.1016/j.tws.2023.111422

新型组合式体育馆内套筒全螺栓交叉连接接头的机械性能研究 - 第Ⅰ部分：实验和有限元建模

The authors propose a novel movable modular gymnasium based on modular building technology to meet people's sports needs. However, the huge roof load puts higher requirements on the performance of modular units and their connecting joints. In light of this, the authors propose a novel connection joint using the inner sleeve and bolted connections, which connect the upper and lower columns of the modular unit to give it higher performance. In addition, it connects the upper and lower beams of the modular unit by bolts to improve its overall performance. The authors evaluated the mechanical properties of the connecting joints through experiments and simulations. The results indicate that the welding quality determines the beam-oriented bearing capacity of the connections, while has little impact on the column-oriented bearing capacity. It is difficult for the inner sleeve to enhance the initial stiffness and beam-oriented bearing capacity of the joints due to the initial gap between the inner sleeve and the modular column. The restraint effect of the stiffening ribs induces the deformation of the inner sleeve, and its bearing capacity increases up to 91%. The inner sleeve improves the column-ward bearing capacity and deformation capacity of the joints, and its bearing capacity rises to 135%.

作者提出了一种基于模块化建筑技术的新型可移动模块化体育馆，以满足人们的体育需求。然而，巨大的屋顶荷载对模块单元及其连接接头的性能提出了更高的要求。有鉴于此，作者提出了一种新型连接接头，采用内套筒和螺栓连接，将模块单元的上下柱连接起来，使其具有更高的性能。此外，它还通过螺栓连接模块单元的上下梁，以提高其整体性能。作者通过实验和模拟评估了连接接头的机械性能。结果表明，焊接质量决定了连接处面向梁的承载能力，而对面向柱的承载能力影响不大。由于内套筒与模块柱之间存在初始间隙，因此内套筒很难提高连接的初始刚度和面向梁的承载能力。加劲肋的约束作用诱导了内套筒的变形，使其承载能力提高了 91%。内套筒提高了接合处向柱方向的承载能力和变形能力，其承载能力提高了 135%。

Seismic performance of T-shaped CFST column to U-shaped steel composite beam joints

Shan Gao, Rui Chen, Jie Yang, Lanhui Guo, Laiming Deng

doi:10.1016/j.tws.2023.111443

T 型 CFST 柱与 U 型钢复合梁连接的抗震性能

U-shaped steel-concrete composite beams have the advantages of high bearing capacity, excellent fire resistance and quick construction, when it is used with special-shaped concrete-filled steel tube columns could achieve the architectural effect of no exposed beams and columns in the interior, showing great application potential in residential buildings. In this study, three full-scale T-shaped CFST column to U-shaped steel composite beam joints with different configurations were tested under cyclic loads. The damage modes, and hysteresis performance of the joint were discussed in detail. The test results indicated that the three joints with side plate connection all showed plastic hinge damage at the beam ends of which hysteresis curves show bowed shape, with excellent energy dissipation. The setting of truss reinforcement within the U-shaped steel beam could effectively improve the ductility of the member. Based on the validated finite element model, the effects of side plate configuration, the side plate position, and tube wall thickness on the seismic performance of the joints are investigated. The design methods for the bending capacity of the joints have also been proposed.

U 型钢-混凝土复合梁具有承载力高、耐火性能好、施工速度快等优点，与异型混凝土填充钢管柱配合使用，可实现室内无外露梁柱的建筑效果，在住宅建筑中具有很大的应用潜力。本研究在循环荷载下测试了三种不同构造的全尺寸 T 型 CFST 柱与 U 型钢复合梁连接。详细讨论了接头的破坏模式和滞后性能。试验结果表明，采用侧板连接的三个接头均在梁端出现塑性铰破坏，其滞后曲线呈弓形，具有良好的消能性能。在 U 型钢梁内部设置桁架加固可以有效提高构件的延性。基于已验证的有限元模型，研究了侧板配置、侧板位置和管壁厚度对接头抗震性能的影响。同时还提出了接头抗弯能力的设计方法。

Seismic performance of self-centring connections with two energy dissipation stages for reusable modular steel buildings

Jing He, Xuhong Zhou, Fei Xu, Yu Shi, Taichiro Okazaki

doi:10.1016/j.tws.2023.111442

可重复使用模块化钢结构建筑中带有两个消能阶段的自定心连接的抗震性能

This paper presented a feasibility study on a self-centring connection with two energy dissipation stages for use as a combined inter-module and intra-module connection in reusable modular steel buildings. The proposed connection was equipped with shape memory alloy (SMA) disc washers and friction dampers, the former for self-centring and the latter for energy-dissipation functions. The design concept of two energy dissipation stages was to achieve structural longevity and member reuse by 1) enabling rapid recovery after small and medium earthquakes, and 2) facilitating prompt repair if at all needed after large earthquakes. An analytical model was proposed, wherein each connection element was symbolised as a rotational spring. Based on the model, a design methodology to meet the two-stage performance goals was derived, where the critical story drift ratio between the two stages was expressed as a function of the properties of friction dampers and SMA disc washers. Detailed finite element simulations were used to validate the proposed design concept and the spring model and to assess the influence of the friction dampers and SMA disc washers on the hysteresis behaviour of the connection. The results demonstrated that the proposed connection would facilitate the design objectives when it could be designed based on the proposed spring model to ensure structural longevity, member reuse, and efficient recovery and repair after seismic events.

本文对可重复使用模块化钢结构建筑中作为模块间和模块内组合连接使用的具有两个消能阶段的自定心连接进行了可行性研究。拟议的连接件配备了形状记忆合金（SMA）圆盘垫圈和摩擦阻尼器，前者用于自定心，后者用于消能。两个消能阶段的设计理念是通过以下方式实现结构的使用寿命和构件的重复使用：1）在中小地震后能够快速恢复；2）在大地震后如有需要，便于及时修复。我们提出了一个分析模型，其中每个连接元件都被符号化为一个旋转弹簧。在该模型的基础上，推导出了满足两阶段性能目标的设计方法，其中两阶段之间的临界楼层漂移比表示为摩擦阻尼器和 SMA 碟形垫圈特性的函数。详细的有限元模拟用于验证所提出的设计概念和弹簧模型，并评估摩擦阻尼器和 SMA 碟形垫圈对连接滞后行为的影响。结果表明，如果能根据拟议的弹簧模型进行设计，确保结构的使用寿命、构件的重复使用以及地震事件后的有效恢复和修复，那么拟议的连接将有助于实现设计目标。

Seismic pushover analysis of unbraced adjustable pallet racks in the down-aisle direction. Need for multimode analysis

Oriol Bové, Vinod Kumar Golla, Elena Oliver-Saiz, Jordi Bonada, Francisco López-Almansa

doi:10.1016/j.tws.2023.111444

无支撑可调式托盘货架顺通道方向的地震推力分析。多模式分析的必要性

Modal Pushover Analysis has been proposed to account for the higher modes contribution in seismic analysis of slender structures, such as unbraced racks in the down-aisle direction. In these structures, only single-mode pushover analyses have been used so far. This paper investigates a suite of 96 unbraced representative prototype racks, and six of them are selected to be analyzed through modal pushover analysis. Results show that global damage significantly exceeds that derived from considering the first mode alone, thus proving that higher modes contribution is relevant for racks with low mass participation in the first mode (< 90%).

模态推移分析法的提出，是为了在对细长结构（如下走道方向的无支撑架）进行抗震分析时，考虑较高模态的影响。在这些结构中，迄今为止只使用过单模态推移分析。本文研究了一套 96 个无支撑的代表性原型货架，并选择其中 6 个进行模态推移分析。结果表明，全局破坏大大超过了仅考虑第一模态所得出的破坏，从而证明了对于第一模态质量参与度较低（< 90%）的机架来说，更高的模态贡献是相关的。

Experimental and numerical simulation study of mechanical properties of inner sleeve T-joint in modular gymnasia

Chang-jun Zhong, Yong-qi Huang, Hu-yang Li, Zi-wei Yang, Ruo-qiang Feng, Farhad Aslani

doi:10.1016/j.tws.2023.111446

组合式体育馆内套筒 T 型接头力学性能的实验和数值模拟研究

In response to the contradiction between the insufficient number and unreasonable distribution of stadiums in cities and the increasing demand of people for fitness, the authors propose movable modular gymnasiums. This gymnasium takes advantage of the modular building, which can be quickly built, dismantled, and reassembled to fully utilize the temporary empty land in the city to meet the fitness demand of the people. However, the box modules bear a huge roof load, which puts higher demands on the performance of the modular units and their connecting joints. This study proposes a novel joint node using an inner sleeve and bolted connections. The proposed connection uses an inner sleeve and bolts to connect the upper and lower columns of the modular unit to give it a higher bearing capacity. Bolts connect the lower unit's ceiling beam and the upper unit's floor beam to provide a better overall performance of the modular unit. The authors conducted experimental studies of 2 full-scale models and 24 finite-element parametric analyses. The results show that the welding quality determines the beam-ward bearing capacity of the joints, while it has little effect on the column-ward bearing capacity. In practical engineering, the authors suggest that the initial stiffness of the joints does not consider the contribution of the inner sleeve. The setting of stiffening ribs forces the inner sleeve to deform and force, improving the joints' mechanical properties, with the initial stiffness in the column direction increase of 25%, the initial stiffness in the beam direction increase of 31%, and a bearing capacity in the beam direction increase of 38%. The design thickness of the inner sleeve and stiffening ribs should be close to the wall thickness of the modular beam and column. The results of this paper contribute to the development of fitness for the whole population and the expansion of the application of modular buildings.

针对城市体育场馆数量不足、分布不合理与人民群众日益增长的健身需求之间的矛盾，作者提出了可移动的模块化体育馆。这种体育馆利用模块化建筑的优势，可以快速搭建、拆卸、重新组装，充分利用城市临时空地，满足人们的健身需求。然而，箱体模块承受着巨大的屋顶荷载，这对模块单元及其连接节点的性能提出了更高的要求。本研究提出了一种使用内套筒和螺栓连接的新型连接节点。拟议的连接采用内套筒和螺栓连接模块单元的上下柱，使其具有更高的承载能力。螺栓连接下部单元的顶梁和上部单元的地梁，使模块单元具有更好的整体性能。作者对 2 个全尺寸模型进行了实验研究，并进行了 24 次有限元参数分析。结果表明，焊接质量决定了接头的梁向承载能力，而对柱向承载能力影响不大。在实际工程中，作者建议接头的初始刚度不要考虑内套筒的作用。加劲肋的设置迫使内套筒变形受力，改善了接头的力学性能，柱向初始刚度提高了 25%，梁向初始刚度提高了 31%，梁向承载力提高了 38%。内套筒和加劲肋的设计厚度应接近模块化梁和柱的壁厚。本文的研究结果有助于全民健身运动的开展和模块化建筑应用范围的扩大。