【新文速递】2024年11月21日固体力学SCI期刊最新文章

 

今日更新：International Journal of Solids and Structures 4 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 4 篇

International Journal of Solids and Structures

Modeling the pull-off force of a mushroom-shaped fibrillar adhesive in dynamic detachment

Ru-Guo Ji, Yue-Yu Yuan, Xiao-Feng Liu, Xiao-Long Zhang, Guo-Ping Cai

doi:10.1016/j.ijsolstr.2024.113150

模拟蘑菇状纤维黏合剂在动态脱离时的拉脱力

Fibrillar adhesive, as a novel biomimetic controllable adhesive, holds broad application prospects in the fields of medical devices, aerospace, and robotics. Evaluating the critical detachment force (pull-off force) of such materials, that is, establishing a pull-off force model, is one of the key issues to be addressed in the application process. The experimental results show that preload, dwell time, and retraction velocity are key factors affecting critical detachment force. However, there is no model that can take into account the influence of these three factors. In order to accurately evaluate the adhesion performance of fibrillar adhesive, this study took mushroom-shaped fibrillar adhesive (MFSA) as the object and carried out theoretical and experimental research on the modeling problem of its pull-off force. First, we derived a new pull-off force model based on the Gent & Schultz hypothesis and linear elastic fracture theory. In this model, the relative contact area is introduced to quantify the impact of preload and dwell time on the pull-off force, and the rate-dependent properties of the effective adhesion work are used to describe the impact of retraction velocity on the pull-off force. Then, the validity of the model is experimentally investigated. The experimental results show that this paper’ s model can accurately predict the pull-off force of MFSA after parameter identification, thereby verifying the model’s effectiveness. Finally, we used the pull-off force model to study the effects of model parameters on pull-off force

纤维胶粘剂作为一种新型的仿生可控胶粘剂，在医疗器械、航空航天、机器人等领域有着广阔的应用前景。评估这类材料的临界剥离力（剥离力），即建立剥离力模型，是应用过程中需要解决的关键问题之一。实验结果表明，预紧力、停留时间和收放速度是影响临界分离力的关键因素。然而，目前还没有一个模型可以考虑到这三个因素的影响。为了准确评价纤维粘接剂的粘附性能，本研究以蘑菇形纤维粘接剂（MFSA）为研究对象，对其拔离力的建模问题进行了理论和实验研究。首先，我们基于根特&舒尔茨假设和线弹性断裂理论推导了一个新的拉脱力模型。在该模型中，引入了相对接触面积来量化预紧力和停留时间对拉拔力的影响，并使用有效粘附功的速率依赖特性来描述收放速度对拉拔力的影响。然后，对模型的有效性进行了实验验证。实验结果表明，本文模型经过参数辨识后能够准确预测MFSA的拉拔力，从而验证了模型的有效性。最后，利用拉拔力模型研究了模型参数对拉拔力的影响

Hyperelastic model for nonlinear elastic deformations of graphene-based polymer nanocomposites

Matteo Pelliciari, Stefano Sirotti, Angelo Aloisio, Angelo Marcello Tarantino

doi:10.1016/j.ijsolstr.2024.113144

石墨烯基聚合物纳米复合材料非线性弹性变形的超弹性模型

Graphene-based polymer nanocomposites (PNCs) are increasingly important in engineering applications involving large deformations. However, the nonlinear behavior of these materials has not been thoroughly studied. Current models do not address the specific nonlinear effects of graphene nanofillers under large strains, lack sufficient comparison with experimental data, and primarily focus on uniaxial behavior without exploring biaxial responses, which are relevant in technological applications. This study investigates PNCs composed of silicone elastomer and graphene nanoplatelets (GNPs). We present experimental tests conducted in both simple tension and biaxial inflation on circular membranes. A homogenized hyperelastic model is developed, incorporating distinct contributions from the matrix and the nanofiller. Specifically, we introduce a novel strain energy function for the nanofiller contribution, tailored to reproduce the observed experimental behavior. The model accurately predicts the nonlinear elastic response of the studied PNCs across varying contents of GNPs. The proposed strain energy function is implemented in MATLAB to obtain an exact numerical solution for the inflation of circular PNC membranes. Finally, to demonstrate its broader applicability, the hyperelastic model is applied to additional experimental data from other PNCs found in the literature. This model contributes to establishing a robust framework for the effective use of PNCs.

石墨烯基聚合物纳米复合材料（pnc）在涉及大变形的工程应用中越来越重要。然而，这些材料的非线性行为尚未得到深入的研究。目前的模型没有解决石墨烯纳米填料在大应变下的具体非线性效应，缺乏与实验数据的充分比较，并且主要关注单轴行为，而没有探索与技术应用相关的双轴响应。本研究研究了由有机硅弹性体和石墨烯纳米片（GNPs）组成的pnc。我们提出了在圆形膜上进行的简单张力和双轴膨胀的实验测试。建立了一个均质超弹性模型，结合了基质和纳米填料的不同贡献。具体来说，我们为纳米填料的贡献引入了一个新的应变能函数，以重现观察到的实验行为。该模型准确地预测了所研究的pnc在不同GNPs含量下的非线性弹性响应。在MATLAB中实现了所提出的应变能函数，得到了圆形PNC膜膨胀的精确数值解。最后，为了证明其更广泛的适用性，超弹性模型应用于文献中发现的其他pnc的附加实验数据。这一模式有助于为有效利用pnc建立一个强有力的框架。

Dispersive properties of metamaterial beams with rod-like resonators: A coupled axial-flexural analysis

Andrea Burlon

doi:10.1016/j.ijsolstr.2024.113145

具有棒状谐振腔的超材料光束的色散特性：耦合轴向弯曲分析

This paper addresses the propagation of coupled axial-flexural waves in metamaterial beams with rod-like resonators. Utilizing an exact frequency-dependent stiffness method, based on Euler–Bernoulli beam assumption for rods and host beam, and fully accounting for axial-flexural coupling phenomena, several adimensional parametric analyses are performed for investigating the dispersive properties of the metamaterial beams. The analyses reveal novel and relevant aspects unaddressed in previous studies. Firstly, they show that certain rod configurations lead to significant interference between flexural resonance and the band gaps opened by axial resonance, whereas other configurations enable flexural resonance to open substantial band gaps without interference from axial resonance. Results are complemented by 3D finite element analyses proving evidence of the findings and validating the method. Additional analyses demonstrate that adding a tip mass to the rods, while keeping the total mass of the resonator unchanged, can significantly reduce the opening frequency of the band gaps and can attenuate or remove the interference caused by flexural resonance within the band gaps opened by axial resonance; the rotational inertia of the tip mass can also play a significant role in removing flexural resonance interference. Notably, the paper also reveals that the attenuation phenomena for the coupled problem with a single set of rods are governed by the opening of weak band gaps, rather than by traditional band gaps; this aspect is elucidated by showing Bloch mode shapes of the infinite metamaterial beam and frequency response of the corresponding finite beam. Results and proposed design prove to be useful and promising for locally resonant beams featuring rod-like resonators, both as an alternative to traditional beam-like resonators and for their applicability in the 3D printing process of locally resonant structures, where rods serve as elastic elements in constructing the resonators.

本文研究了耦合轴向弯曲波在具有棒状谐振腔的超材料梁中的传播。利用精确的频率相关刚度方法，基于欧拉-伯努利梁对杆和主梁的假设，并充分考虑轴向弯曲耦合现象，进行了一些一维参数分析，以研究超材料梁的色散特性。这些分析揭示了以前研究中未涉及的新颖和相关方面。首先，他们表明，某些杆配置导致弯曲共振和轴向共振打开的带隙之间的显著干扰，而其他配置使弯曲共振打开大量带隙而不受轴向共振的干扰。结果由三维有限元分析补充，证明了研究结果的证据并验证了该方法。进一步分析表明，在保持谐振腔总质量不变的情况下，增加棒的尖端质量可以显著降低带隙的打开频率，并可以衰减或消除轴向共振打开的带隙内弯曲共振引起的干扰；尖端质量的转动惯量也可以在消除弯曲共振干扰方面发挥重要作用。值得注意的是，本文还揭示了单组棒耦合问题的衰减现象是由弱带隙的打开而不是传统带隙控制的；通过展示无限超材料梁的布洛赫振型和相应有限梁的频率响应来阐明这方面。结果和提出的设计被证明对于具有棒状谐振器的局部谐振梁是有用的和有前途的，既可以作为传统的棒状谐振器的替代品，也可以用于局部谐振结构的3D打印过程，其中棒状谐振器作为构造谐振器的弹性元件。

Liner wrinkling and buckling of a Bimaterial pipe under cyclic bending

Emile Naous, Stelios Kyriakides

doi:10.1016/j.ijsolstr.2024.113149

双材料管道在循环弯曲作用下的内衬起皱和屈曲

Carbon steel tubes and pipes used in offshore and other applications are often mechanically lined with a corrosion resistant alloy to protect them. It is well established that the extent to which lined pipe can be bent is limited by the liner separating from the carrier pipe, wrinkling and buckling. The instability is strongly influenced by geometric imperfections and by the contact pressure between the liner and the carrier. Contact can be maintained to a higher curvature by bending the pipe under a low level of internal pressure. The present study uses a finite element analysis to investigate how repeated bending to curvatures well below the critical value under monotonic bending leads to accumulation of wrinkling and, eventually, buckling of the liner. Cyclic bending requires the adoption of a nonlinear kinematic hardening constitutive model capable of reproducing the Bauschinger rounding of reverse loading. The model is calibrated to measured stress–strain responses of the liner and carrier tube materials. A small geometric imperfection is introduced to the composite structure to help initiate separation of the liner. It is found that cyclic bending causes progressive separation of the liner from the carrier that leads to crosswise wrinkles. The wrinkles grow with each additional cycle, initially at a slow rate, but when the separation reaches a critical value their rate of growth accelerates. Within a few additional cycles wrinkling reverts to the larger amplitude diamond-type buckling mode with which the liner fails under monotonic bending. The cycle at which the growth of liner separation accelerates is designated as the critical cycle number. The critical cycle number decreases as the amplitude of the curvature of the cycle increases. It also exhibits the same strong sensitivity to the amplitude of initial geometric imperfections as that under monotonic bending. Increasing the diameter of the composite pipe reduces the number of cycles required to reach criticality. For all parameter values considered, instability can be delayed by increasing the internal pressure by a few bar. An important observation that could simplify design is that the liner separation at the critical cycle is equivalent to the separation at the curvature corresponding to the limit moment under monotonic bending.

在海上和其他应用中使用的碳钢管和管道通常机械内衬耐腐蚀合金以保护它们。已经确定衬管的弯曲程度受到衬管与载体管分离、起皱和屈曲的限制。不稳定性受到几何缺陷和衬垫与载体之间的接触压力的强烈影响。通过在较低的内压下弯曲管道，可以使接触保持在较高的曲率上。本研究使用有限元分析来研究在单调弯曲下，反复弯曲到远低于临界值的曲率是如何导致起皱积累并最终导致衬垫屈曲的。循环弯曲需要采用一种非线性运动硬化本构模型，能够再现反向加载的包辛格舍入。该模型被校准为测量的衬垫和载体管材料的应力-应变响应。在复合材料结构中引入一个小的几何缺陷，以帮助衬里分离。研究发现，循环弯曲导致衬垫与载体的逐渐分离，从而导致横向起皱。皱纹随着每一个额外的循环而增长，最初以缓慢的速度增长，但当分离达到临界值时，它们的增长速度就会加快。在几个额外的循环内，起皱恢复到较大振幅的菱形屈曲模式，衬垫在单调弯曲下失效。将线性分离加速增长的周期称为临界循环数。临界循环数随着循环曲率幅值的增大而减小。它对初始几何缺陷的振幅也表现出与单调弯曲下相同的强敏感性。增加复合管径可以减少达到临界所需的循环次数。对于所考虑的所有参数值，可以通过增加几巴的内压来延缓不稳定。可以简化设计的一个重要观察结果是，临界循环处的衬里分离相当于单调弯曲下极限弯矩对应的曲率处的分离。

Journal of the Mechanics and Physics of Solids

Imperfection-insensitive flexible random network materials with horseshoe microstructures

Yue Xiao, Xiaonan Hu, Jun Wu, Zhangming Shen, Shuheng Wang, Shiwei Xu, Jianzhong Zhao, Jiahui Chang, Yihui Zhang

doi:10.1016/j.jmps.2024.105968

具有马蹄形微结构的不完美不敏感柔性随机网络材料

Flexible network materials with periodic constructions of bioinspired wavy microstructures are of focusing interest in recent years, because they combine outstanding mechanical performances of low elastic modulus, high stretchability, biomimetic stress-strain responses, and strain-limiting behavior. In practical applications (e.g., bio-integrated devices and tissue engineering), small holes are often strategically designed in flexible network materials to accommodate functional chips and other individual electronic components. The design of imperfection insensitive flexible network materials is therefore of pivotal importance. While random structural constructions are believed to play crucial roles in the excellent mechanical properties of many biological materials, the effect of randomness on mechanical performances of flexible network materials has not yet been explored. In this work, a class of two-dimensional (2D) flexible random network materials consisting of horseshoe microstructures is introduced. Their node distance distributions, which can be characterized by a parameter related to randomness, follow well the Weibull probability density function. Combined numerical and experimental studies were performed to elucidate the effect of randomness on nonlinear mechanical responses of flexible network materials. Simple analytical equations are obtained for their key mechanical properties (e.g., strength, stretchability, and initial modulus). Flexible random network materials (with randomness ≥ 0.4) were found to exhibit approximately isotropic J-shaped stress-strain responses, even in the high-strain regime. Finally, we study the reduction of stretchability and strength in random network materials induced by different types of imperfections (e.g., a missing filament, a missing node, or many missing filaments). In comparison to periodic network materials, random network materials (e.g., with randomness ≥ 0.6) show much smaller reductions of stretchability/strength when the imperfection appears, and are therefore more imperfection-insensitive. Such an imperfection-insensitive behavior can be mainly attributed to a relieved stress concentration around the imperfection of random network materials.

由于具有低弹性模量、高拉伸性、仿生应力-应变响应和应变极限行为等优异的力学性能，具有周期性生物波状微结构的柔性网络材料近年来备受关注。在实际应用中（例如，生物集成设备和组织工程），通常在灵活的网络材料中战略性地设计小孔，以容纳功能芯片和其他单个电子元件。因此，缺陷不敏感柔性网络材料的设计至关重要。虽然随机结构结构被认为在许多生物材料的优异力学性能中起着至关重要的作用，但随机性对柔性网络材料力学性能的影响尚未得到探讨。本文介绍了一类由马蹄形微结构组成的二维（2D）柔性随机网络材料。它们的节点距离分布很好地遵循威布尔概率密度函数，可以用一个与随机性相关的参数来表征。采用数值与实验相结合的研究方法，探讨了随机性对柔性网络材料非线性力学响应的影响。得到了其关键力学性能（如强度、拉伸性和初始模量）的简单解析方程。随机弹性网络材料（随机度≥0.4）即使在高应变状态下也表现出近似各向同性的j型应力应变响应。最后，我们研究了由不同类型的缺陷（例如，一个缺失的纤维，一个缺失的节点，或许多缺失的纤维）引起的随机网络材料的拉伸性和强度的降低。与周期性网络材料相比，随机网络材料（例如，随机性≥0.6）在缺陷出现时的拉伸性/强度降低幅度要小得多，因此对缺陷不敏感。这种对缺陷不敏感的行为主要是由于随机网络材料缺陷周围的应力集中得到了缓解。

Mechanics of Materials

An additive Mori–Tanaka scheme for elastic-viscoplastic composites based on a modified tangent linearization

K. Kowalczyk-Gajewska, S. Berbenni, S. Mercier

doi:10.1016/j.mechmat.2024.105191

基于改进切线化的弹粘塑性复合材料的加性Mori-Tanaka格式

Mean-field modelling based on the Eshelby inclusion problem poses some difficulties when the non-linear Maxwell-type constitutive law is used for elasto-viscoplasticity. One difficulty is that this behavior involves different orders of time differentiation, which leads a long-term memory effect. One of the possible solutions to this problem is the additive interaction law. Generally, mean field models solely use the mean values of stress and strain fields per phase, while variational approaches consider the second moments of stresses and strains. It is seen that the latter approach improves model predictions allowing to account for stress fluctuation within the phases. However, the complexity of the variational formulations still makes them difficult to apply in the large scale finite element calculations and for non-proportional loadings. Thus, there is a need to include the second moments within homogenization models based on the additive interaction law. In the present study, the incorporation of the second moments of stresses into the formulation of the additive Mori–Tanaka model of two-phase elastic-viscoplastic material is discussed. A modified tangent linearization of the viscoplastic law is proposed, while the Hill–Mandel’s lemma is used to track the evolution of second moments of stresses. To study the model performance and efficiency, the results are compared to the full-field numerical calculations and predictions of other models available in the literature. Very good performance of the modified tangent linearization is demonstrated from these benchmarks for both monotonic and non monotonic loading responses.

当弹粘塑性采用非线性maxwell型本构律时，基于Eshelby包含问题的平均场建模存在一些困难。一个困难是，这种行为涉及不同的时间分化顺序，这导致了长期记忆效应。这个问题的一个可能的解决方案是加性相互作用定律。一般而言，均场模型只使用每相应力场和应变场的平均值，而变分方法则考虑应力和应变的第二矩。可以看出，后一种方法改进了模型预测，允许考虑阶段内的应力波动。然而，变分公式的复杂性仍然使其难以应用于大规模有限元计算和非比例加载。因此，有必要在基于加性相互作用律的均匀化模型中加入二阶矩。本文讨论了在两相弹粘塑性材料的加性Mori-Tanaka模型中加入应力第二矩的问题。提出了粘塑性规律的修正切线化方法，并利用Hill-Mandel引理跟踪应力二阶矩的演化。为了研究模型的性能和效率，将结果与文献中其他模型的全场数值计算和预测结果进行了比较。从这些基准测试中可以看出，改进的切线化方法对单调和非单调加载响应都有很好的性能。

International Journal of Plasticity

Investigation of full-field strain evolution behavior of Cu/Ni clad foils by interpretable machine learning

Yuejie Hu, Chuanjie Wang, Haiyang Wang, Gang Chen, Xingrong Chu, Guannan Chu, Han Wang, Shihao Wu

doi:10.1016/j.ijplas.2024.104181

基于可解释机器学习的Cu/Ni包覆箔全场应变演化行为研究

Void characteristics are fundamentally correlated with the macroscopic deformation responses of materials, yet traditional modeling methods exhibit inherent limitations in data mining. In this study, a machine learning (ML) framework is proposed to predict the full-field strain evolution of Cu/Ni clad foils, and the impact of intrinsic voids is quantitatively assessed using interpretative analysis methods. The local strain and void data are extracted and integrated through digital image correlation and computed tomography. To accommodate the nature of the constructed dataset, a ML model is established with reference to the concept of time series forecasting. Subsequently, the influence of microstructural features such as volume fraction (VVF), area, and size of voids are investigated, alongside their role in driving local strain evolution. This approach successfully predicts strain localization, and accurately pinpoints the onset of plastic instability and the location of crack initiation. The VVF is identified as the most predominant factor, followed by void size along the tensile direction and grain size. The strongest association is observed between the VVF and grain size, which intensifies over extended time scales. Moreover, as void coalescence is almost completed, the promoting effect of the concentrated void distribution on macroscopic strain concentration will become increasingly pronounced. These findings provide novel perspectives for exploring the intricate relationship between deformation and damage.

孔隙特性与材料的宏观变形响应有着根本的联系，但传统的建模方法在数据挖掘中存在固有的局限性。在这项研究中，提出了一个机器学习（ML）框架来预测Cu/Ni覆层箔的全场应变演变，并使用解释分析方法定量评估了固有空洞的影响。通过数字图像相关和计算机断层扫描提取和整合局部应变和空洞数据。为了适应构建数据集的性质，参考时间序列预测的概念建立了ML模型。随后，研究了孔隙体积分数（VVF）、面积和尺寸等微观结构特征的影响，以及它们在驱动局部应变演化中的作用。该方法成功地预测了应变局部化，准确地确定了塑性失稳的开始和裂纹起裂的位置。VVF是最主要的影响因素，其次是沿拉伸方向的空洞尺寸和晶粒尺寸。在VVF和晶粒尺寸之间观察到最强的关联，这种关联随着时间的延长而增强。而且，随着孔洞聚并接近完成，孔洞集中分布对宏观应变浓度的促进作用将越来越明显。这些发现为探索变形与损伤之间的复杂关系提供了新的视角。

Thin-Walled Structures

Explosion resistance of self-balancing hyperboloid multilayered sandwich panels with hybrid cores

Wenyi Bao, Bei Zhang, Yongjun Wang, Zhenyu Qiu, Song Wang, Jun Lin, Yujun Cui, Hualin Fan

doi:10.1016/j.tws.2024.112710

混合芯层自平衡双曲面多层夹层板的防爆性能

This study introduces an innovative protective structure featuring a hyperbolic multilayered sandwich design with hybrid cores. The structure integrates orthogrid and fold-cores, which can be supplemented with polyethylene foams to enhance energy absorption. Experimental evaluations, including chemical explosions and simulated nuclear blasts, were conducted on these self-balancing hyperboloid folded-core sandwich panels (SHFSPs). The results indicate that the SHFSPs successfully resisted an impact of 0.7386 m/kg1/3 and a simulated nuclear explosion with a peak pressure of 0.75 MPa, showing no signs of damage. Additionally, after being filled with foam, the SHFSPs endured a chemical explosion of 0.5894 m/kg1/3 and a simulated nuclear blast with a peak pressure of 0.80 MPa, remaining undamaged. This study underscores the SHFSPs' potential as a robust blast-resistant solution, suitable for a variety of engineering applications.

本文介绍了一种具有混合芯的双曲线多层夹层结构的创新防护结构。该结构集成了正网格和折叠芯，可以补充聚乙烯泡沫，以增强能量吸收。对这些自平衡双曲面折叠芯夹芯板（shfsp）进行了化学爆炸和模拟核爆炸实验评价。结果表明，在0.7386 m/kg1/3的冲击和0.75 MPa峰值压力的模拟核爆炸作用下，shfsp成功抵抗了冲击，无损伤迹象；此外，泡沫填充后的shfsp经受了0.5894 m/kg1/3的化学爆炸和峰值压力为0.80 MPa的模拟核爆炸，均未受损。这项研究强调了shfsp作为一种强大的抗爆炸解决方案的潜力，适用于各种工程应用。

A review on the potential application of ultra-high performance concrete in offshore wind towers: insights into material properties, mechanisms, and models

Xuanchao Zhou, Feng Yu, Ashraf Ashour, Wen Yang, Yaoling Luo, Baoguo Han

doi:10.1016/j.tws.2024.112717

超高性能混凝土在海上风塔中的潜在应用综述：对材料特性、机理和模型的见解

Ultra-high performance concrete (UHPC), characterized by its high strength and toughness as well as durability, provides a promising solution for the construction of offshore wind towers (OWTs). This paper comprehensively reviews the durability and the dynamic mechanical properties of UHPC for OWTs under the impacts of the marine environment. Furthermore, the modifying effects of additives, including supplementary cementitious materials (SCMs) and reinforcing fibers, as well as nanofillers on UHPC are explored. Overall, UHPC possesses a dense microstructure that impedes the intrusion of harmful substances, and owing to the incorporation of additives, UHPC exhibits outstanding dynamic mechanical properties, making it an ideal material for applications in OWTs subjected to vibration fatigue and dynamic impact loads. Incorporating SCMs into UHPC can improve the durability and environmental benefits while maintaining similar dynamic mechanical properties concurrently. Nanofillers can serve as a beneficial supplement to steel fibers providing improved durability and dynamic mechanical properties by endowing UHPC dense microstructure and high system energy. Various models of marine environmental and loading actions on UHPC, examining ion transport, matrix degradation, and constitutive models, are concluded to gain insight into the underlying destructive mechanisms. These underlying mechanisms and the theoretical models further deepen the understanding of the service performance of UHPC in marine environments, thus providing the design guidance for the potential applications of UHPC in OWTs.

超高性能混凝土（UHPC）具有高强度、高韧性和耐久性的特点，为海上风电塔（OWTs）的建设提供了一种很有前途的解决方案。本文对海洋环境影响下水轮机用超高性能混凝土的耐久性和动态力学性能进行了综述。此外，还探讨了补充胶凝材料（SCMs）、增强纤维以及纳米填料等添加剂对UHPC的改性作用。总体而言，UHPC具有致密的微观结构，可以阻止有害物质的侵入，并且由于添加了添加剂，UHPC表现出出色的动态力学性能，使其成为振动疲劳和动态冲击载荷下wts应用的理想材料。在UHPC中加入scm可以提高耐久性和环境效益，同时保持相似的动态力学性能。纳米填料可以作为钢纤维的有益补充，通过赋予UHPC致密的微观结构和高的系统能量，提高其耐久性和动态力学性能。总结了各种海洋环境和负载作用于UHPC的模型，考察了离子传输、基质降解和本构模型，以深入了解潜在的破坏机制。这些潜在的机制和理论模型进一步加深了人们对海洋环境中超高压混凝土的使用性能的认识，从而为超高压混凝土在海上交通工具中的潜在应用提供了设计指导。

Machine learning-based multi-objective optimization of thermo-mechanical field of anisotropic plates

Sen Yang, Wen Yao, Richard-Kwok-Kit Yuen, Liao-Liang Ke

doi:10.1016/j.tws.2024.112718

基于机器学习的各向异性板热-力学场多目标优化

Designing plates is highly challenging due to the complex relationship between material layout and its properties. Traditional experimental, analytical, and computational methods suffer from problems such as long computation time and high cost, limiting their application in predicting and optimizing plates. In this paper, we propose an end-to-end prediction and multi-objective optimization framework integrating machine learning (ML) and non-dominated sorting genetic algorithm (NSGA-II). This framework can have high fidelity and simultaneously predict multiple thermo-mechanical fields of the anisotropic plate-heat source system. It can also perform multi-objective optimization for specific requirements by optimizing the distribution of materials and heat sources. To demonstrate the effectiveness of our approach, the maximum temperature and von Mises stress are considered as objectives, and the framework is applied to two different discrete multi-objective optimization problems, i.e., non-temperature constrained and temperature constrained optimization problem. By integrating ML and optimization algorithm, our framework offers a comprehensive solution for tackling complex optimization problems in the field of anisotropic plate-heat source system.

由于材料布局与其性能之间的复杂关系，设计板材极具挑战性。传统的实验、分析和计算方法存在计算时间长、成本高等问题，限制了它们在板的预测和优化中的应用。在本文中，我们提出了一个集成机器学习（ML）和非支配排序遗传算法（NSGA-II）的端到端预测和多目标优化框架。该框架具有较高的保真度，可同时预测各向异性板热源系统的多个热-力学场。它还可以通过优化材料和热源的分布，对特定的要求进行多目标优化。为了验证该方法的有效性，以最高温度和von Mises应力为目标，并将该框架应用于两个不同的离散多目标优化问题，即非温度约束和温度约束优化问题。该框架将机器学习与优化算法相结合，为解决各向异性板热源系统中的复杂优化问题提供了全面的解决方案。

Compressive mechanical properties of a novel three-dimensional auxetic structure based on additive manufacturing

Yunfei Deng, Yaoxiang Jin

doi:10.1016/j.tws.2024.112719

一种新型三维增材制造结构的压缩力学性能

Auxetic metamaterials are a class of functional materials with negative Poisson's ratio (NPR) properties achieved by artificially designing internal auxetic structures, which have broad application prospects in aerospace, shipbuilding, and other fields due to their excellent impact resistance, high specific stiffness, and unique mechanical behaviors. In this work, we propose a novel three-dimensional (3D) lattice asymmetrical re-entrant triangular (ART) structure (LART) based on two-dimensional (2D) ART, and the samples were manufactured by the liquid-crystal display (LCD) 3D printing technology. The crushing response of LART under quasi-static compression and the effects of structural parameters on the mechanical properties were investigated by a combination of experiments and finite element (FE) simulations. The results show that LART has an obvious NPR performance and the mechanical properties of LART can be tunable by changing the parameters. Additionally, the effects of wall thickness and cell numbers on LART were also studied using FE simulations. Finally, the LART was compared to the 2D-ART and 3D re-entrant lattice structure (3D-RE) to highlight the design advantages. The results show that LART has superior load-bearing capacity than the other two structures and the values of specific energy absorption (SEA) are 17 and 2.34 times higher than those of 2D-ART and 3D-RE, respectively. None of the LART configurations researched in this paper showed unstable deformation with unilateral buckling, which demonstrates its potential application in fields such as soft robotics and electronic devices.

增减超材料是一类通过人为设计内部增减结构而获得负泊松比（NPR）性能的功能材料，由于其优异的抗冲击性能、高比刚度和独特的力学性能，在航空航天、造船等领域有着广阔的应用前景。在这项工作中，我们提出了一种基于二维（2D） ART的新型三维（3D）晶格不对称重入三角形（ART）结构（LART），并通过液晶显示器（LCD） 3D打印技术制造样品。采用实验与有限元模拟相结合的方法，研究了LART在准静态压缩下的破碎响应以及结构参数对其力学性能的影响。结果表明，LART具有明显的NPR性能，其力学性能可以通过改变参数进行调节。此外，还利用有限元模拟研究了壁厚和细胞数对LART的影响。最后，将LART与2D-ART和3D重入点阵结构（3D- re）进行了比较，以突出其设计优势。结果表明，LART结构的承载能力优于其他两种结构，比能量吸收（SEA）值分别是2D-ART和3D-RE结构的17倍和2.34倍。本文所研究的LART结构均未出现单边屈曲的不稳定变形，显示了其在软机器人和电子设备等领域的潜在应用前景。