【新文速递】2024年7月10日固体力学SCI期刊最新文章

今日更新：Composite Structures 2 篇，Composites Part A: Applied Science and Manufacturing 1 篇，Composites Part B: Engineering 3 篇Composite StructuresA piece-wise linear model for modelling the tension-stiffening effect in steel-reinforced UHPC compositesJunqing Xue, Angelo Aloisio, Alessandro Contento, Zhengxian Yang, Ni Hu, Bruno Briseghelladoi:10.1016/j.compstruct.2024.118373钢增强UHPC复合材料拉伸加劲效应的分段线性模型This study examines the tensile behaviour of Ultra-High Performance Concrete (UHPC) specimens reinforced with varying steel fibre content and rebar diameters. An experimental campaign involving 18 reinforced UHPC specimens was conducted, following individual tensile response characterizations of UHPC and reinforcing steel. These specimens were designed and fabricated with threaded welded steel cages to transfer loads to the central measurement area. Force–displacement curves were measured to derive stress–strain curves for the UHPC component, evaluating the impact of reinforcement rebar and steel fibre content on UHPC’s mechanical response. The analysis revealed that steel fibre volume content significantly influences the tensile response of UHPC reinforcement more than the steel bar diameter and yield strength. Comparing the strain in steel bars to the average strain in reinforced UHPC specimens indicated that post-cracking deformation concentrates at the crack. At the same time, the bond between reinforcement and UHPC remains intact in uncracked sections, allowing effective load transfer. UHPC specimens reinforced with 14 mm diameter steel bars displayed a significant horizontal segment in the descending phase of the stress–strain curve. In contrast, specimens with 18 mm or 22 mm diameter bars exhibit a progressive stress reduction at a nearly constant rate. Stress–strain curves of UHPC were fitted with a five-fold piecewise empirical model applicable to UHPC with a reinforcement ratio higher than 0.09%. The resulting model can be used to model the axial behaviour in UHPC, considering the effects of steel reinforcement.本研究考察了不同钢纤维含量和钢筋直径的超高性能混凝土(UHPC)试件的拉伸性能。一项涉及18个增强的UHPC试件的实验活动，在UHPC和钢筋的个体拉伸响应特性之后进行。这些试件是用螺纹焊接钢笼设计和制造的，以将载荷传递到中心测量区域。通过测量力-位移曲线，得出UHPC构件的应力-应变曲线，评估钢筋和钢纤维含量对UHPC力学响应的影响。分析表明，钢纤维体积含量对UHPC钢筋拉伸响应的影响大于钢筋直径和屈服强度。对比钢筋应变与加筋UHPC试件的平均应变，发现开裂后变形集中在裂缝处。与此同时，在未开裂的部分，钢筋和UHPC之间的结合保持完整，允许有效的荷载传递。直径为14mm钢筋的UHPC试件在应力-应变曲线下降阶段表现出明显的水平段。相比之下，直径为18 mm或22 mm的试件以几乎恒定的速率表现出渐进的应力减小。采用适用于配筋率大于0.09%的UHPC的五重分段经验模型拟合UHPC的应力应变曲线。所得到的模型可以用来模拟在考虑钢筋的影响下UHPC的轴向行为。Efficient equilibrium-based stress recovery for isogeometric laminated Euler–Bernoulli curved beamsAlessia Patton, Shirko Faroughi, Alessandro Realidoi:10.1016/j.compstruct.2024.118374等几何层合欧拉-伯努利曲线梁基于有效平衡的应力恢复Laminated curved composite parts, used, e.g., in the spar and ribs in aircraft and wind turbine blades, are typically subjected to high interlaminar stresses. This work focuses on a two-step procedure to study laminated Euler–Bernoulli curved beams discretized via Isogeometric Analysis (IGA). First, we solve a (planar) Euler–Bernoulli curved beam formulation in primal form to obtain the tangential and transverse displacements. This formulation features high-order PDEs, which we can straightforwardly approximate using either an IGA-Galerkin or an IGA-collocation approach. Starting from the obtained displacement solution, which accounts for bending-stretching coupling, we can directly compute the normal stress only, while we do not have information concerning the transverse shear stress state, typically responsible for delamination. However, by imposing equilibrium in strong form in a curvilinear framework which eases the post-processing, eliminating the need for coordinate changes, we can easily recover interlaminar transverse shear stresses at locations of interest. Such a posteriori step requires calculating the high-order displacement derivatives in the equilibrium equations and, therefore, demands once again higher-order regularity that can be easily fulfilled by exploiting the high-continuity properties of IGA. Extensive numerical tests prove the effectiveness of the proposed approach, which is also aided by the IGA’s superior geometric approximation.使用的层压弯曲复合材料部件，例如飞机和风力涡轮机叶片中的梁和肋，通常要承受高层间应力。本文主要研究了用等几何分析(IGA)离散化层合欧拉-伯努利曲线梁的两步法。首先，我们求解了(平面)欧拉-伯努利曲线梁的原始形式，得到了切向和横向位移。该公式具有高阶偏微分方程，我们可以使用IGA-Galerkin或iga -搭配方法直接近似。从得到的位移解出发，考虑了弯曲-拉伸耦合，我们可以直接计算正应力，而我们没有关于横向剪应力状态的信息，通常负责分层。然而，通过在曲线框架中施加强形式的平衡，简化了后处理，消除了坐标变化的需要，我们可以很容易地在感兴趣的位置恢复层间横向剪切应力。这种后检步骤需要计算平衡方程中的高阶位移导数，因此，再次需要高阶正则性，这可以通过利用IGA的高连续性特性轻松实现。大量的数值试验证明了所提出的方法的有效性，IGA的优越几何近似也有助于这种方法。Composites Part A: Applied Science and ManufacturingA hyperelastic approach for modeling the membrane behavior in finite element forming simulation of unidirectional non-crimp fabrics (UD-NCF)Bastian Schäfer, Dominik Dörr, Ruochen Zheng, Naim Naouar, Luise Kärgerdoi:10.1016/j.compositesa.2024.108359单向无卷曲织物(UD-NCF)有限元成形模拟中膜行为建模的超弹性方法Unidirectional non-crimp fabrics (UD-NCFs) are highly suitable for high-performance components due to their excellent lightweight potential. However, during forming they are prone to wrinkling and gapping compared to woven or biaxial textiles. Macroscopic simulation models can be used to efficiently predict these effects as well as the global forming behavior for complex geometries. Therefore, a new hyperelastic membrane model is proposed to describe the typical deformation of UD-NCFs based on superimposed shear, transverse tension and compression perpendicular to the fiber rovings. The model is parameterized using the forces and different ratios of superimposed strains obtained in experimental off-axis-tension-tests at bias angles of 30°, 45°and 60°. The resulting approach is validated by forming simulations of a hemisphere and tetrahedron geometry in different configurations and quantitative comparison to experimental tests. The model accurately predicts the forming behavior of UD-NCF with a good agreement of the global deformation behavior and local strains.单向无卷曲织物(ud - nfc)由于其优异的轻量化潜力，非常适合用于高性能部件。然而，在成型过程中，与机织或双轴纺织品相比，它们容易起皱和开裂。宏观模拟模型可以有效地预测这些影响以及复杂几何形状的整体成形行为。因此，提出了一种新的超弹性膜模型来描述ud - nfc的典型变形，该模型基于垂直于纤维粗纱的剪切、横向拉伸和压缩叠加。模型参数化采用离轴拉伸试验在30°、45°和60°偏置角下得到的力和不同的叠加应变比。通过不同形态的半面体和四面体的成形模拟以及与实验测试的定量比较，验证了该方法的有效性。该模型准确地预测了UD-NCF的成形行为，并能很好地反映整体变形行为和局部应变。Composites Part B: EngineeringAlkali-activated materials with organics: A critical reviewShengqian Ruan, Rongfeng Gao, Wenlin Tu, Dongming Yan, Mingzhong Zhangdoi:10.1016/j.compositesb.2024.111712有机碱活化材料:综述This paper represents a critical review on alkali-activated materials (AAM) containing organics with high homogeneity at nano-scale (<1 μm). Organics including organosilicons, surfactants, water-soluble polymers and epoxy resins can contribute to performance enhancement and tailorability of AAM based on their molecular characteristics. Hence, AAM with organics can generally possess improved characteristics between organic and inorganic components and may even exhibit emerging functional properties. According to the hybridisation modes between AAM and organics such as chemical bonding, physical adsorption, electrostatic attraction or phase crosslinking, these AAM with organics are categorised into four distinct types: organic-grafted, organic-adsorbed, phase-crosslinked and phase-separated AAM. In this paper, the hybridisation modes and reaction mechanisms of AAM with organics are summarised, for the first time, followed by a comprehensive discussion on the phase assemblage, microstructure, mechanical properties, durability and potential applications. Afterwards, the fundamental insights are gained and the remaining challenges for future research are identified and discussed.本文综述了在纳米尺度(<1 μm)上含有高均匀性有机物的碱活性材料(AAM)。有机硅、表面活性剂、水溶性聚合物和环氧树脂等有机物可以根据其分子特性提高AAM的性能和可定制性。因此，含有机物的AAM通常可以具有介于有机和无机组分之间的改进特性，甚至可能表现出新的功能特性。根据AAM与有机物的杂交方式，如化学键合、物理吸附、静电吸引或相交联，将AAM与有机物的杂交方式分为有机接枝、有机吸附、相交联和相分离四种不同的类型。本文首次综述了AAM与有机物的杂化方式和反应机理，并对其相组合、微观结构、力学性能、耐久性和潜在应用进行了全面讨论。之后，获得了基本见解，并确定和讨论了未来研究的剩余挑战。Hydrophilic Silsesquioxane Nanocages Toughened Extracellular Matrix Biomimetic Poly(γ-Glutamic Acid) Multidimensional Self-Polymerizable and Osteogenic Hybrid Hydrogel for Osteoporotic Bone RegenerationLingli Liu, Shiyuan Ma, Zhisheng Xiao, Jintao Li, Yue Wang, Zhihui Lu, Yitao Zhao, Jinshan Guodoi:10.1016/j.compositesb.2024.111713 纳米亲水性硅氧烷增韧细胞外基质仿生聚γ-谷氨酸多维自聚合成骨混合水凝胶用于骨质疏松性骨再生Rapid bone defect regeneration in osteoporotic conditions remains a significant challenge due to the fragile mechanical stability and pathological microenvironment. The absence of bone matrix is the primary characteristic of these defects, and advanced strategies for treating osteoporotic bone defects focus on remodeling the bone matrix’s spatial structure and regulating the microenvironment. While many hydrogels have been developed for bone regeneration, their use in repairing osteoporotic bone defects is constrained by deficiencies in shape-adaptivity, weak osteogenic bioactivity, and lack of physiological mechanical support. Herein, a novel bioactive hydrophilic semi-caged NH2-T4 silsesquioxane (NH2-T4-POSS) nanocage was developed, which was used to modify γ-polyglutamic acid (γ-PGA) together with dopamine, to give an organic/inorganic hybrid hydrogel PGA-DA&T4 for osteoporotic bone regeneration. The developed PGA-DA&T4 hydrogel possesses favorable injectability, shape-adaptivity, self-healability, and strong antioxidant ability. Benefited from organic/inorganic hybridation and multidimensional molecular interacting mechanism, PGA-DA&T4 exhibites enhanced thermal stability and longer degradation period, unique self-polymerizability, high elasticity, and considerable tissue adhesion ability. In vitro experiments proved that PGA-DA&T4 is biocompatible, and is able to promote cell migration and neovascularization, and possesses favorable immunoregulatory to promote macrophage polarization towards anti-inflammatory M2 phenotype. Furthermore, PGA-DA&T4 has been demonstrated to accelerate osteogenic differentiation and inhibit osteoclastogenesis, thereby promoting the repair of osteoporotic bone defects. Our research successfully developed a novel hybrid γ-PGA hydrogel with therapeutic effects and supplied a promising biomaterial with potential clinical application for repairing osteoporotic bone defects.由于脆弱的机械稳定性和病理微环境，骨质疏松症的骨缺损快速再生仍然是一个重大挑战。骨基质的缺失是这些缺陷的主要特征，治疗骨质疏松性骨缺陷的先进策略集中在骨基质空间结构的重塑和微环境的调节上。虽然许多用于骨再生的水凝胶已经被开发出来，但它们在修复骨质疏松性骨缺损方面的应用受到形状适应性不足、成骨生物活性弱和缺乏生理机械支持的限制。本研究制备了一种新型的具有生物活性的亲水半笼型NH2-T4硅氧烷(NH2-T4- poss)纳米笼，并将其与多巴胺一起修饰γ-聚谷氨酸(γ-PGA)，得到用于骨质疏松性骨再生的有机/无机杂化水凝胶PGA-DA&T4。制备的PGA-DA&T4水凝胶具有良好的可注射性、形状适应性、自愈性和较强的抗氧化能力。得益于有机/无机杂化和多维分子相互作用机制，PGA-DA&T4表现出更强的热稳定性和更长的降解期，独特的自聚合性，高弹性和可观的组织粘附能力。体外实验证明PGA-DA&T4具有生物相容性，能够促进细胞迁移和新生血管形成，并具有良好的免疫调节作用，促进巨噬细胞向抗炎M2表型极化。此外，PGA-DA&T4已被证明可以加速成骨分化，抑制破骨细胞的发生，从而促进骨质疏松性骨缺损的修复。本研究成功制备出具有良好治疗效果的新型γ-PGA杂化水凝胶，为修复骨质疏松性骨缺损提供了一种具有潜在临床应用前景的生物材料。The effect of gamma-ray irradiation on polymer-graphene nanocomposite interfacesSagar U. Patil, Josh Kemppainen, Trevor Wavrunek, Gregory M. Odegarddoi:10.1016/j.compositesb.2024.111715伽马射线辐照对聚合物-石墨烯纳米复合材料界面的影响CNT yarns are used in ultra-high strength composites for use in manned deep-space vehicles. It has been previously demonstrated through experiments that gamma-ray irradiation substantially improves the mechanical performance of these composites. It is unclear how the irradiation affects the mechanical response of the CNT yarn/polymer interface that ultimately leads to these panel-level performance improvements. Physical insight into this process could enable further improvements in the CNT yarn/polymer interface design in the future. The objective of this research is to use molecular dynamics simulation to provide physical insight into the effect of gamma-ray irradiation on the mechanical behavior (interfacial interaction energy, shear resistance, adhesive strength) of the CNT yarn/polymer interface for a range of high-performance polymer systems. The simulation results indicate that gamma-ray irradiation (simulated via inclusion of defects on the CNT surface) has a most significant effect on the shear deformation resistance of CNT yarn/polymer interfaces, which likely leads to the experimentally-observed improvements in panel-level CNT yarn composites irradiated with gamma rays. The results of this study also demonstrate the importance of computational modeling in providing physical insight into observed bulk-scale material behavior. Although the predictions cannot be validated directly via experiment, such insight can ultimately lead to efficient improvements in material design (e.g. mechanical performance) that lead to further increases in panel-level composite performance.碳纳米管纱线用于载人深空飞行器的超高强度复合材料。先前通过实验证明，伽马射线辐照大大提高了这些复合材料的机械性能。目前尚不清楚辐照如何影响CNT纱线/聚合物界面的机械响应，最终导致这些面板级性能的改善。对这一过程的物理洞察可以在未来进一步改进碳纳米管纱线/聚合物界面设计。本研究的目的是利用分子动力学模拟，为一系列高性能聚合物系统的碳纳米管纱线/聚合物界面的机械行为(界面相互作用能，剪切阻力，粘接强度)的影响提供物理见解。模拟结果表明，伽马射线辐照(通过碳纳米管表面的缺陷模拟)对碳纳米管纱线/聚合物界面的抗剪切变形能力有最显著的影响，这可能导致实验中观察到的经过伽马射线辐照的面板级碳纳米管纱线复合材料的改善。这项研究的结果也证明了计算建模在提供观察到的大块材料行为的物理洞察力方面的重要性。虽然预测不能通过实验直接验证，但这种见解最终可以导致材料设计(例如机械性能)的有效改进，从而进一步提高面板级复合材料的性能。来源：复合材料力学仿真Composites FEM