今日更新:International Journal of Solids and Structures 1 篇,Journal of the Mechanics and Physics of Solids 2 篇,Thin-Walled Structures 4 篇
Model for the onset of plasticity and hardness in bulk metallic glasses investigated by nanoindentation with a spherical indenter
Kai Tao, Xiao He, Hanwen Lu, Zhibo Zhang, Yong Yang, Eloi Pineda, Kaikai Song, Yiqiang He, Jichao Qiao
doi:10.1016/j.ijsolstr.2025.113238
球形压头纳米压痕法研究大块金属玻璃塑性和硬度的起始模型
Despite extensive research over the past three decades into how indentation depth affects the hardness (H) of both crystalline and non-crystalline materials, a mechanistic understanding of this phenomenon remains elusive. Here, we report that the depth dependence of H is also present in bulk metallic glasses. Importantly, indentation depth dependence is observed not only in hardness but also in the reduced elastic modulus Er. We observed that H initially increases with increasing indentation depth ht up to the yielding point. Beyond this point, however, it decreases with further increase of ht, indicating the presence of an indentation depth dependence in the plastic regions. The evolution of Er follows a similar trend. Based on our findings, firstly, we established the relationship between indentation hardness and the ratio of contact radius to indentation depth using classical Hertzian contact mechanics. Then, we developed a model based on the atomic-scale cooperative shear mechanism to interpret the indentation size effects in bulk metallic glasses. Furthermore, we observed that H correlates with the cube of the ratio of indentation elastic depth he to total depth ht, or alternatively, with the ratio of indentation elastic work to total work. Our findings gave a scaling law that uncovers an inherent relationship of hardness with the mean pressure at the onset of plasticity, flow hardness, and the ratio. The work underscores that the indentation depth effect stems from the interplay between elasticity and plasticity, rather than being solely influenced by factors like indentation depth, contact area, or indenter radius. This highlights its crucial role in comprehending and evaluating the plastic deformation of bulk metallic glasses at the submicron scale.
尽管过去三十年来对压痕深度如何影响晶体和非晶体材料的硬度(H)进行了广泛研究,但对其现象的机理理解仍不明确。在此,我们报告了在大块金属玻璃中也存在硬度(H)对压痕深度的依赖性。重要的是,这种压痕深度依赖性不仅在硬度上有所体现,在归一化弹性模量 Er 上也有观察到。我们发现,硬度 H 在压痕深度 ht 增加到屈服点之前会随其增加而增大,然而超过该点后,硬度 H 会随着 ht 的进一步增加而减小,这表明在塑性区域存在压痕深度依赖性。Er 的变化趋势也类似。基于我们的发现,首先,我们利用经典的赫兹接触力学建立了压痕硬度与接触半径与压痕深度比值之间的关系。然后,我们基于原子尺度的协同剪切机制开发了一个模型来解释大块金属玻璃中的压痕尺寸效应。此外,我们还观察到 H 与压痕弹性深度 he 与总深度 ht 的比值的立方相关,或者与压痕弹性功与总功的比值相关。我们的研究结果揭示了一种标度律,它揭示了硬度与塑性变形起始时的平均压力、流动硬度以及该比值之间的内在关系。这项工作强调了压痕深度效应源于弹性与塑性的相互作用,而非仅仅受压痕深度、接触面积或压头半径等因素的影响。这突显了其在理解及评估大块金属玻璃在亚微米尺度下的塑性变形中的关键作用。
The impacts of thermoelastic anisotropy and grain boundary misorientation on microcracking in ceramics
Andrew R. Ericks, Frank W. Zok, Daniel S. Gianola, Matthew R. Begley
doi:10.1016/j.jmps.2024.106024
热弹性各向异性和晶界取向偏差对陶瓷微裂纹的影响
This paper examines the role of thermoelastic anisotropy on grain boundary cracking in brittle materials using a highly efficient computational framework. Energy release rates (ERRs) are computed for 35 materials spanning all seven crystal systems. Two crack geometries are considered: short interface cracks in isolated bicrystals plates, and cracked grain boundaries in polycrystal plates comprising periodic hexagonal grains. Crack driving forces are computed for penetration through the plate thickness (for cracks of width equal to the length of a hexagonal grain boundary), extensions along bicrystal interfaces, transgranular cracks that emerge from triple junctions, and kinking into bulk materials and at grain triple junctions. The high throughput computational framework produces probably distributions for ERRs arising from randomly oriented grains; the distributions for cracks at grain edges in polycrystals are broader than those for short cracks along bicrystal interfaces. A broad study of different grain configurations also illustrates that only the first 5-6 rings of neighboring grains influence crack driving forces for a given interface. The implications for interpreting microcracking observations, quantifying the performance of textured ceramics, and designing two-phase ceramic composites are briefly discussed.
本文用一个高效的计算框架研究了热弹性各向异性在脆性材料晶界开裂中的作用。计算了7种晶体体系中35种材料的能量释放率(ERRs)。考虑了两种裂纹几何形状:孤立双晶板中的短界面裂纹和由周期性六角形晶粒组成的多晶板中的晶界裂纹。裂纹驱动力的计算包括:穿透板厚(宽度等于六角形晶界长度的裂纹)、沿双晶界面延伸、从三结处出现的穿晶裂纹、以及在晶粒三结处扭成块状材料。高通量计算框架产生随机取向颗粒产生的ERRs的概率分布;多晶边缘裂纹的分布比双晶界面短裂纹的分布更宽。对不同晶粒结构的广泛研究也表明,只有相邻晶粒的前5-6环影响给定界面的裂纹驱动力。简要讨论了微裂纹观测解释、织构陶瓷性能量化和两相陶瓷复合材料设计的意义。
Hydromechanical field theory of plant morphogenesis
Hadrien Oliveri, Ibrahim Cheddadi
doi:10.1016/j.jmps.2025.106035
植物形态发生的流体力学场理论
The growth of plants is a hydromechanical phenomenon in which cells enlarge by absorbing water, while their walls expand and remodel under turgor-induced tension. In multicellular tissues, where cells are mechanically interconnected, morphogenesis results from the combined effect of local cell growths, which reflects the action of heterogeneous mechanical, physical, and chemical fields, each exerting varying degrees of nonlocal influence within the tissue. To describe this process, we propose a physical field theory of plant growth. This theory treats the tissue as a poromorphoelastic body, namely a growing poroelastic medium, where growth arises from pressure-induced deformations and osmotically-driven imbibition of the tissue. From this perspective, growing regions correspond to hydraulic sinks, leading to the possibility of complex non-local regulations, such as water competition and growth-induced water potential gradients. More in general, this work aims to establish foundations for a mechanistic, mechanical field theory of morphogenesis in plants, where growth arises from the interplay of multiple physical fields, and where biochemical regulations are integrated through specific physical parameters.
植物的生长是一种流体力学现象,细胞通过吸收水分而扩大,而细胞壁在膨胀引起的张力作用下膨胀和重塑。在多细胞组织中,细胞在机械上相互联系,形态发生是局部细胞生长的综合作用的结果,这反映了异质的机械、物理和化学场的作用,每个场在组织内施加不同程度的非局部影响。为了描述这一过程,我们提出了植物生长的物理场理论。该理论将组织视为孔隙形态弹性体,即生长的孔隙弹性介质,其生长源于压力诱导的变形和组织的渗透驱动的吸吮。从这个角度来看,生长区对应于水力汇,从而导致复杂的非局部调节的可能性,例如水竞争和生长诱导的水势梯度。更一般地说,这项工作旨在为植物形态发生的机械,机械场理论奠定基础,其中生长源于多个物理场的相互作用,并且生化调节通过特定的物理参数集成。
Multi-patch isogeometric analysis for smart plates with distributed piezoelectric patches
Tao Liu, Xiangrong Sun, Jinde Zheng, Lu Wang, Qingyun Liu, Tinh Quoc Bui
doi:10.1016/j.tws.2025.112937
分布式压电贴片智能板的多贴片等几何分析
The previous isogeometric analysis (IGA) on piezoelectric smart structures mainly focused on plates and shells that were fully covered with piezoelectric materials. However, the piezoelectric materials in smart structures commonly exist in the form of patches that are locally attached to the substrate structures, in practical engineering applications. Thus, this paper aims to apply IGA to analyze the electro-mechanical coupled behaviors of distributed piezoelectric smart plates. The Nitsche-based non-conforming multi-patch technology is adopted to deal with the precision limitations associated with single-patch IGA for distributed piezoelectric smart plates. In accordance with first-order shear deformation theory (FSDT) and NURBS-based IGA, the non-conforming multi-patch governing equations for piezoelectric smart plates are then derived. In particular, the Nitsche’s method is adopted for addressing the non-conforming meshes and ensuring the continuity of the field variables on the coupling boundary between two adjacent patches. The developed methodology is further extended to analyze the fully-covered and distributed piezoelectric smart plates. Meanwhile, to enhance the general applicability of the method, the piezoelectric smart plates integrated with traditional piezoelectric ceramics and macro-fiber composite (MFC) materials are designed in numerical examples. Finally, comprehensive assessments for natural frequency and static response of piezoelectric smart plates are carried out and then compared with the existing reference solutions or the results calculated by ABAQUS software to demonstrate the effectiveness and accuracy of the developed method. These numerical examples validate that the proposed method is capable of addressing the limited accuracy of single-patch IGA in distributed piezoelectric smart structures.
以往对压电智能结构的等几何分析主要集中在被压电材料完全覆盖的板壳上。然而,在实际工程应用中,智能结构中的压电材料通常以贴片的形式存在,这些贴片局部附着在衬底结构上。因此,本文旨在应用IGA分析分布式压电智能板的机电耦合行为。采用基于nitsche的非一致性多贴片技术,解决了分布式压电智能板单贴片IGA的精度限制。根据一阶剪切变形理论(FSDT)和基于nurbs的IGA,推导了智能压电板的非协调多片控制方程。特别是采用Nitsche方法来处理不一致的网格,并保证相邻两个补丁之间耦合边界上场变量的连续性。将所开发的方法进一步扩展到分析全覆盖和分布式压电智能板。同时,为了提高方法的通用性,对传统压电陶瓷与宏纤维复合材料(MFC)相结合的压电智能板进行了数值算例设计。最后,对压电智能板的固有频率和静响应进行了综合评估,并与已有参考解或ABAQUS软件计算结果进行了比较,验证了所提方法的有效性和准确性。数值算例验证了该方法能够解决分布式压电智能结构中单片IGA精度有限的问题。
A machine learning-driven prediction of lower-bound buckling design load for cylindrical shells under localized axial compression
Xinyi Lin, Peng Jiao, Huangyang Xu, Xinshuang Li, Zhiping Chen
doi:10.1016/j.tws.2025.112960
局部轴压作用下圆柱壳下屈曲设计载荷的机器学习预测
Thin-walled cylindrical shells are extensively used across various fields because of their exceptional load-carrying efficiency. In practical applications, these structures are typically subjected to localized axial compression rather than the uniform axial compression considered in traditional research. A reliable and efficient buckling design method for cylindrical shells under such localized loads has not been developed to date. To address this challenge, a machine learning (ML) approach is proposed in this study for predicting the lower-bound buckling design load of cylindrical shells under localized axial compression. The artificial neural network (ANN) is selected as the ML model. Based on the modified energy barrier approach (MEBA), 500 samples are obtained by numerical simulations and their results are used to train the ANN model. The ANN model takes six geometric parameters, three material parameters, and one localized axial compression parameter as the inputs, while the lower-bound buckling load and the knockdown factor are the outputs. The feasibility and accuracy of the proposed ANN model are demonstrated by comparison with existing design codes and experimental results. The results suggest that this ML-based approach can fully exploit the load-carrying capacity of shells under localized axial compression, enabling more efficient and lightweight designs.
薄壁圆柱壳因其优异的承载效率而广泛应用于各个领域。在实际应用中,这些结构通常遭受局部轴压,而不是传统研究中认为的均匀轴压。目前还没有一种可靠而有效的圆柱壳在这种局部载荷作用下的屈曲设计方法。为了解决这一挑战,本研究提出了一种机器学习(ML)方法来预测局部轴向压缩下圆柱壳的下界屈曲设计载荷。选择人工神经网络(ANN)作为机器学习模型。基于修正能量势垒法(MEBA),对500个样本进行了数值模拟,并将模拟结果用于神经网络模型的训练。该模型以6个几何参数、3个材料参数和1个局部轴压参数为输入,以下界屈曲载荷和击倒因子为输出。通过与现有设计规范和实验结果的比较,验证了该模型的可行性和准确性。结果表明,这种基于ml的方法可以充分利用壳体在局部轴压下的承载能力,实现更高效、更轻量化的设计。
AM-FEMU: An optimization method for additive manufacturing simulation parameters based on finite element model updating, utilizing three-dimensional deformation and melt pool temperature fields
Ru Chen, Hanwen Xue, Qixian Zhong, Chenghao Zhang, Shiqing Li, Chuanqing Geng, Jiaye Zhao, Zhanwei Liu, Huimin Xie, Zhanfei Zhang
doi:10.1016/j.tws.2025.112962
AM-FEMU:一种基于有限元模型更新、利用三维变形和熔池温度场的增材制造仿真参数优化方法
Accurate model parameters are crucial for reliable metal additive manufacturing (AM) simulations, which are essential for understanding AM material formation mechanisms, designing AM components, and controlling manufacturing processes. This study addresses the discrepancy between AM simulations and experimental results by developing an Additive Manufacturing Finite Element Model Updating (AM-FEMU) method. The AM-FEMU method updates and optimizes the simulation parameters based on the temperature field of the melt pool and the deformation field of the substrate during the AM process. Online measurements of three-dimensional displacement and melt pool temperature were conducted using three-dimensional sampling moiré and multi-spectral colorimetric temperature measurement technologies. By comparing these measurements with finite element (FE) simulation, the heat source parameters and thermal expansion coefficient were updated successfully. Verification tests confirmed that the updated parameters significantly improved the accuracy of residual stress in AM simulations compared to the original parameters. This method promotes the application of FEMU in metal AM simulations, further providing a deeper understanding of the physical mechanism in metal AM process.
准确的模型参数对于可靠的金属增材制造(AM)模拟至关重要,这对于理解增材制造材料形成机制、设计增材制造部件和控制制造过程至关重要。本研究通过开发一种增材制造有限元模型更新(AM- femu)方法来解决增材制造仿真与实验结果之间的差异。AM- femu方法基于增材过程中熔池温度场和基材变形场对模拟参数进行更新和优化。采用三维采样仪和多光谱比色测温技术,实现了三维位移和熔池温度的在线测量。通过与有限元模拟结果的比较,成功地更新了热源参数和热膨胀系数。验证试验证实,与原始参数相比,更新后的参数显著提高了增材制造模拟中残余应力的准确性。该方法促进了FEMU在金属增材制造模拟中的应用,进一步加深了对金属增材制造过程物理机制的理解。
Impact angle-dependent residual burst strength of thin-walled composite pressure vessels under low-velocity impact
Honghao Liu, Lei Zu, Qian Zhang, Guiming Zhang, Jianhui Fu, Helin Pan, Qiaoguo Wu, Xiaolong Jia, Lichuan Zhou
doi:10.1016/j.tws.2025.112963
低速冲击下薄壁复合材料压力容器残余破裂强度与冲击角的关系
Thin-walled composite pressure vessels exhibit a promising potential for energy storage, but they are vulnerable to barely visible damage from random impacts. Yet, angle-dependent damage mechanisms remain unclear, challenging the structural design to resist impact loadings. Herein, this study elucidates the residual burst strength of composite vessels under low-velocity impacts, guiding impact-resistant design at varying impact angles. The impact damage model based on a segmented golden-section search algorithm enhances computational efficiency and accuracy. Results show that matrix damage intensifies within helical layers under small-angle oblique impacts, while fiber damage consistently concentrates in hoop layers, with delamination between the hoop and helical layers decreasing from the outer layers inward. Furthermore, impacts at different angles shift potential failure locations within the vessel, with small-angle oblique impacts resulting in a low peak impact force. Notably, increasing the proportion of the helical layer enhances resistance to oblique impacts, while thicker hoop layers improve resistance to vertical impacts; at high energies, both layers should be thickened regardless of impact angle. This work not only offers new insights into angle-dependent impact damage but also contributes to the design for impact-resistant enhancement of advanced composite pressure vessels.
薄壁复合材料压力容器在能量存储方面表现出很好的潜力,但它们很容易受到随机撞击造成的几乎看不见的损伤。然而,角度相关的损伤机制仍不清楚,这对结构设计抵抗冲击载荷提出了挑战。本文研究了复合材料容器在低速冲击下的残余爆裂强度,为不同冲击角度下的抗冲击设计提供指导。基于分段黄金分割搜索算法的冲击损伤模型提高了计算效率和精度。结果表明:在小角度斜冲击下,螺旋层内基体损伤加剧,而纤维损伤始终集中在环形层内,环形层与螺旋层之间的分层从外层向内逐渐减少;此外,不同角度的撞击会改变容器内潜在的失效位置,小角度的倾斜撞击会导致较低的峰值冲击力。值得注意的是,增加螺旋层的比例可以增强斜向冲击的阻力,而更厚的箍层可以提高垂直冲击的阻力;在高能量下,无论撞击角度如何,两层都应加厚。这项工作不仅为角度相关的冲击损伤提供了新的见解,而且有助于提高先进复合材料压力容器的抗冲击设计。