【新文速递】2024年11月29日固体力学SCI期刊最新文章

 

今日更新：Journal of the Mechanics and Physics of Solids 2 篇，Mechanics of Materials 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 3 篇

Journal of the Mechanics and Physics of Solids

Rate dependency and fragmentation response of phase field models with micro inertia and micro viscosity terms

Giang D. Huynh, Reza Abedi

doi:10.1016/j.jmps.2024.105971

含微惯性和微粘度项的相场模型的速率依赖性和破碎响应

We present elliptic, parabolic, and hyperbolic phase field (PF) equations, referred to as EPF, PPF, and HPF, for cohesive zone model (CZM) and Linear Elastic Fracture Mechanics (LEFM) PF models. The micro viscosity and micro inertia terms result in PPF and HPF, that can be solved explicitly in time. The additional advantage of the HPF is implying a finite damage propagation speed and a more favorable time advance limit. The desired micro-viscosity for the HPF is shown to correspond to a damping factor of one. The appropriate length and time scales, nondimensional equations, and (asymptotic) strain-stress solutions are provided for each differential equation. Two sources of rate sensitivity are discussed. First, when the fields are spatially uniform (0D solution) the rate effect arises from the form of differential equation. Asymptotic solutions show that at high loading rates, the energy dissipation has the rates of 2/3 and 1 for the PPF and HPF, respectively, with the former matching the Grady’s rate-sensitivity. The dynamic strength and failure strain show half of this rate. The analysis is extended to damage models with stress-based and bounded driving forces. Second, the rate effect arises from the deviation of 1D from 0D solutions as the damage exceeds a critical value and fragments form. Since this critical value tends to zero for quasi-static loading, this rate-effect is mainly present for low loading rates. This results in lower- and upper-shelf energy limits for the EPF at low and high loading rates, resembling some experimentally observed sigmoidal rate models for energy dissipation.

我们提出了椭圆，抛物线和双曲相场（PF）方程，即EPF， PPF和HPF，用于内聚区模型（CZM）和线性弹性断裂力学（LEFM） PF模型。微粘度项和微惯性项导致了可及时显式求解的PPF和HPF。HPF的另一个优点是意味着有限的损伤传播速度和更有利的时间提前限制。HPF所需的微粘度对应于阻尼系数为1。为每个微分方程提供了适当的长度和时间尺度、无量纲方程和（渐近）应变-应力解。讨论了速率敏感性的两个来源。首先，当场是空间均匀的（0D解）时，速率效应由微分方程的形式产生。渐近解表明，在高加载速率下，PPF和HPF的能量耗散率分别为2/3和1，前者符合Grady的速率敏感性。动强度和破坏应变为该速率的一半。将分析扩展到基于应力和有界驱动力的损伤模型。其次，当损伤超过临界值并形成碎片时，由于1D与0D溶液的偏差而产生速率效应。由于该临界值在准静态加载时趋于零，因此这种速率效应主要出现在低加载速率下。这导致EPF在低和高加载速率下的下架和上架能量限制，类似于一些实验观察到的能量耗散的s型速率模型。

Thermomechanical coupling during large strain deformation of polycarbonate: Experimental study

Peihao Song, David Chapman, Aaron Graham, Akash Trivedi, Clive Siviour

doi:10.1016/j.jmps.2024.105976

聚碳酸酯大应变变形时的热-机耦合实验研究

Polycarbonate is a widely used ductile glassy polymer that can undergo large strain deformation before failure. During the plastic deformation process, some mechanical energy is converted to heat, which, if the specimen is loaded at rates sufficient that the heat cannot conduct out of the material, can result in significant temperature rises that affect the mechanical response. Typically, this is expected to result in a reduction in stress at large strain, compared to the behaviour under isothermal conditions; however, compared to other glassy polymers, it has been observed that less softening than expected is experienced in polycarbonate at high strain rates. The current paper describes a thorough investigation of temperature rises in polycarbonate. Compression experiments are performed using a screw-driven machine, a hydraulic machine, and a long split Hopkinson bar, all instrumented with a high-speed infrared camera to measure temperature rises at strain rates between 0.01 and 2600 s-1 at a starting temperature around 20°C. Further, temperature rises in compression experiments at 0.5 s-1 and starting temperatures between -80 to 150°C are measured using embedded thermocouples. These span the range of the secondary- to glass-transitions of polycarbonate, allowing investigation of the effect of these transitions. These experiments are supported by finite element simulations, which use a phenomenological viscoplastic model, to ensure the thermal boundary conditions are adiabatic. Temperature rises are observed in both temperature and rate-dependent tests: experiments at higher strain rates and lower temperatures experience a greater temperature rise because of the higher yield stress; however, there are differences in the conversion ratio between plastic work and heat (Taylor Quinney coefficient), which is both temperature and rate dependent, and strongly affected by both the secondary and glass transitions.

聚碳酸酯是一种广泛使用的延展性玻璃状聚合物，在破坏前可以承受较大的应变变形。在塑性变形过程中，一些机械能被转化为热量，如果试样的加载速度足以使热量不能从材料中传导出去，则会导致显著的温度升高，从而影响机械响应。通常，与等温条件下的行为相比，这有望导致大应变下应力的降低；然而，与其他玻璃状聚合物相比，已经观察到聚碳酸酯在高应变速率下的软化比预期的要少。本文对聚碳酸酯的温升进行了深入的研究。压缩实验采用螺杆机、液压机和长裂霍普金森杆进行，均配有高速红外摄像机，测量了在20℃左右的起始温度下，应变速率在0.01 ~ 2600 s-1之间的温升。此外，使用嵌入式热电偶测量了0.5 s-1压缩实验中的温升和-80至150°C之间的起始温度。这些跨越了聚碳酸酯的二级到玻璃转变的范围，允许研究这些转变的影响。为了确保热边界条件是绝热的，这些实验得到了有限元模拟的支持，该模拟使用了现象学粘塑性模型。在温度和速率相关的试验中都观察到温升：由于屈服应力较高，在较高应变率和较低温度下的实验经历了较大的温升；然而，塑料功与热之间的转换率（泰勒昆尼系数）存在差异，这既取决于温度也取决于速率，并且受到二次和玻璃化转变的强烈影响。

Mechanics of Materials

Enhancing strength-ductility synergy of multilayer metals by periodic necking: experiments and simulations

Jianfeng Zhao, Baoxi Liu, Wenxing Yu, Zengmeng Lin, Xiaochong Lu, Xu Zhang, Hui Chen

doi:10.1016/j.mechmat.2024.105210

利用周期性颈缩增强多层金属的强度-延性协同效应：实验与模拟

Multilayer metals are typical heterostructured materials where superior strength-ductility synergy is sought by combining materials with significant mismatches in mechanical properties. Strain delocalization has been identified as a pivotal mechanism for improving their ductility. However, the strategy for achieving this enhancement through manipulating the critical geometrical and mechanical factors pertaining to multilayer materials remains unclear. In this study, the uniaxial tensile behavior of multilayer TWIP/maraging steels is investigated through experiments, which unveil periodic necking-assisted plasticity regulated by the properties of constituent materials, rendering the multilayer steel both strong and ductile (Ultimate strength∼1.5GPa, fracture strain∼15%). To explore optimized strategies for enhancing this advantage, detailed finite element simulations are performed on the tensile deformation of multilayer TWIP/maraging steels with varying geometrical and mechanical parameters. The formation of periodic necks observed in experiments is successfully reproduced by employing a ductile damage model for the constituent material and a cohesive zone model for the interface. Comprehensive simulation results revealed that within the parameter range studied in this work, the layer thickness ratio is the most relevant factor dominating the strength-ductility synergy, while the layer thickness, interface strength, interface thickness, and strain hardening ability of the TWIP steel mainly affect the ductility rather than strength. This research contributes to our understanding of ductility mediated by strain delocalization and provides valuable insights for the design of multilayer metals.

多层金属是典型的异质结构材料，通过将力学性能显著不匹配的材料组合在一起，寻求优异的强度-延性协同效应。应变离域已被确定为提高其延性的关键机制。然而，通过操纵与多层材料有关的关键几何和机械因素来实现这种增强的策略仍不清楚。在本研究中，通过实验研究了多层TWIP/马氏体时效钢的单轴拉伸行为，揭示了由组成材料性能调节的周期性颈状辅助塑性，使多层钢具有强韧性（极限强度~ 1.5GPa，断裂应变~ 15%）。为了探索增强这一优势的优化策略，对不同几何和力学参数的多层TWIP/马氏体时效钢的拉伸变形进行了详细的有限元模拟。利用组成材料的延性损伤模型和界面的内聚区模型成功地再现了实验中观察到的周期性颈部的形成。综合模拟结果表明，在本文研究的参数范围内，层厚比是主导强度-延性协同效应的最相关因素，而TWIP钢的层厚、界面强度、界面厚度和应变硬化能力主要影响延性而非强度。该研究有助于我们对应变离域介导的延性的理解，并为多层金属的设计提供了有价值的见解。

International Journal of Plasticity

A parallelised algorithm to identify arbitrary yield surfaces in multiscale analyses

Jakob Platen, Johannes Storm, Michael Kaliske

doi:10.1016/j.ijplas.2024.104183

多尺度分析中任意屈服面识别的并行算法

Plasticity is a common phenomenon in many materials. Furthermore, it is also commonly applied in multiscale analyses. Plasticity is mainly characterised by the yield function. This function distinguishes between the elastic and the plastic material domain. The transition surface is denoted as the yield surface, and characterises the material behaviour significantly. In the contribution at hand, an algorithm is proposed, which can identify arbitrary yield surfaces. No assumptions regarding the geometry, kinematics, or material model need to be incorporated. The algorithm can identify yield surfaces as long as a function can be formulated, which measures the distance of any point in the principal stress space to the yield surface, and an indicator exists, which characterises the behaviour of the material to be elastic or plastic. Hence, a very general algorithm is achieved, which can also be applied to crystal plasticity. The property of star-convexity of yield surfaces is exploited. This algorithm is also well suited for the application in high performance computing environments. Furthermore, the proposed algorithm can be applied to the identification of initial damage surfaces as well. The proposed algorithm is validated on one macroscopically formulated yield function. Subsequently, it is applied to multiscale frameworks to highlight the benefits of the proposed approach. Furthermore, the capabilities of the algorithm to also identify yield surfaces after hardening are presented. Important properties of such yield surfaces are highlighted. The good scalability within distributed memory systems is shown, and the applicability for anisotropic yield surfaces is demonstrated.

塑性是许多材料普遍存在的现象。此外，它也常用于多尺度分析。塑性主要表现为屈服函数。该函数区分了弹性材料域和塑性材料域。过渡面表示为屈服面，并显著表征材料的性能。在现有的贡献中，提出了一种可以识别任意屈服曲面的算法。没有关于几何，运动学或材料模型的假设需要纳入。该算法可以识别屈服面，只要可以制定一个函数，测量主应力空间中任何一点到屈服面的距离，并存在一个指标，表征材料的弹性或塑性行为。因此，获得了一个非常通用的算法，也可以应用于晶体塑性。利用屈服曲面的星形凸性。该算法也非常适合在高性能计算环境下的应用。此外，该算法还可用于初始损伤面的识别。该算法在一个宏观表述的屈服函数上得到了验证。随后，将其应用于多尺度框架，以突出所提出方法的优点。此外，该算法还可以识别硬化后的屈服面。这类屈服面的重要性质被强调。在分布式存储系统中显示了良好的可扩展性，并证明了各向异性屈服面的适用性。

Thin-Walled Structures

Experimental and numerical simulation of explosion resistance of composite structure of shallow-buried box steel structure and polyurethane elastomer supports under the action of ground explosion

Hang Xu, Youquan Qin, Weifeng Zhang, Yingxiang Wu, Tainian Chen, Yunke Lu, Xiangyu Xu

doi:10.1016/j.tws.2024.112751

浅埋箱钢结构与聚氨酯弹性体支架复合结构在地面爆炸作用下的抗爆性能试验与数值模拟

The light weight of thin-walled steel structures and their ease of transport and installation have great advantages for protection works that need to be constructed quickly. With the improvement of weapon accuracy and destructive effects, there is an urgent need to improve the resistance of shallow buried steel protection works. However, according to the design concept of traditional protection structures relying on the strength of materials and structural rigidity to resist explosive load, the size of structural components will also increase, and the advantage of rapid construction is seriously reduced. In this study, a composite structure (hereinafter referred to as a composite structure) consisting of a polyurethane elastomer (PUE) set as supports underneath a box steel structure consisting of sandwich plates is proposed to improve the blast resistance of shallow buried box steel structures from ground explosions without increasing the size of the components. Explosive tests and numerical simulations were used to study the blast resistance of the composite structure and its blast resistance mechanism. Other factors affecting the blast resistance of the composite structure, such as the PUE stress-strain relationship and thickness and arrangement of the PUE supports, were also analyzed. The results show that the composite structure is able to generate overall motion and convert part of the explosive energy into kinetic energy of the overall motion of the structure, which is absorbed by the PUE support, thus reducing the structural load and internal force while decreasing deformation and improving the blast resistance performance. While the PUE stress-strain relationship and arrangement of the composite structure have a significant impact on the enhancement of blast resistance, the influence of the thickness of the PUE support is small.

薄壁钢结构重量轻，便于运输和安装，对于需要快速施工的防护工程具有很大的优势。随着武器精度和杀伤效果的提高，迫切需要提高浅埋钢防护工程的抗冲击能力。但是，按照传统的依靠材料强度和结构刚度来抵抗爆炸载荷的防护结构的设计理念，结构构件的尺寸也会增大，快速施工的优势严重降低。为了在不增加构件尺寸的情况下提高浅埋箱钢结构的抗地面爆炸能力，本研究提出在夹芯板箱钢结构下部设置聚氨酯弹性体（PUE）作为支撑的复合结构（以下简称复合结构）。通过爆炸试验和数值模拟研究了复合材料结构的抗爆性能及其抗爆机理。分析了影响复合材料结构抗爆性能的其他因素，如PUE应力-应变关系、PUE支架的厚度和布置。结果表明，复合结构能够产生整体运动，并将部分爆炸能量转化为结构整体运动的动能，被PUE支架吸收，从而在减小结构载荷和内力的同时减小变形，提高抗爆性能。PUE的应力-应变关系和复合结构的布置对增强抗爆性能有显著影响，而PUE支架厚度的影响较小。

Ballistic performance of additive manufacturing metal lattice structures

XIE Zhihao, FU Xinqiang, ZHANG Qin, LIU Lulu, ZHU Xinying, REN Yi, CHEN Wei

doi:10.1016/j.tws.2024.112763

增材制造金属晶格结构的弹道性能

For the purpose of elucidating the destruction and energy absorption mechanisms of lattice structures during ballistic impacts, this study explored the behavior of two additively manufactured metal lattice structures (BCC and BCCZ) under quasi-static/dynamic compression and ballistic impact through experiments and numerical simulations. Both structures exhibited typical stress-strain behaviors during quasi-static compression, with stress plateauing after reaching yield strength and then sharply declining upon failure. The vertical struts in the BCCZ structure resulted in higher yield strength but lower normalized failure strain compared to the BCC structure, especially at higher strain rates. The ballistic limit of the BCC lattice sandwich target plate at 199 m/s and that of the BCCZ lattice sandwich target plate at 195 m/s. At an impact velocity of 207 m/s, the energy absorbed by the BCC lattice structure itself (498 J) was marginally lower than that absorbed by the BCCZ structure (505 J). The BCC structure, characterized by lower stiffness and yield strength but a larger failure strain, absorbed energy primarily through greater deformation during impact. In contrast, the BCCZ structure, with a smaller failure strain, depended on its higher stiffness and yield strength for energy absorption.

为了阐明点阵结构在弹道冲击中的破坏和能量吸收机理，本研究通过实验和数值模拟研究了两种增材制造金属点阵结构（BCC和BCCZ）在准静态/动态压缩和弹道冲击下的行为。两种结构在准静态压缩过程中均表现出典型的应力-应变行为，在达到屈服强度后应力趋于稳定，破坏后应力急剧下降。与BCC结构相比，BCCZ结构中的垂直支板具有更高的屈服强度和更低的归一化破坏应变，特别是在高应变率下。BCC晶格夹层靶板的弹道极限为199 m/s， BCCZ晶格夹层靶板的弹道极限为195 m/s。在207 m/s的冲击速度下，BCC晶格结构自身吸收的能量（498 J）略低于BCCZ结构吸收的能量（505 J）， BCC结构刚度和屈服强度较低，但破坏应变较大，主要通过较大的冲击变形吸收能量。相比之下，BCCZ结构具有较小的破坏应变，依赖于其较高的刚度和屈服强度来吸收能量。

Experimental and numerical multiscale testing of CFRP bonded stepped repairs

Jean-Baptiste Orsatelli, Eric Paroissien, Frédéric Lachaud, Sébastien Schwartz, Nathalie Barrière

doi:10.1016/j.tws.2024.112764

CFRP粘结阶梯式修复的多尺度试验与数值分析

Bonded stepped repairs to aircraft composite structures offer many advantages, such as a smooth aerodynamic surface, high strength, and low mass addition. However, their design remains challenging due to the varying stiffness along the bondline in a thin laminate. This study investigates, numerically and experimentally, to what extent an “equivalent” stepped joint can be used to design a stepped repaired panel. In the proposed case, failure is driven by laminate fracture instead of patch disbonding. Tension tests on stepped repairs at the scale of coupons and panels were carried out in 11 different configurations. Specimens were obtained by hot-bonding as it would be done to perform in-situ repairs. Finite element modelling was performed with cohesive zone modelling to account for disbonding and delamination, and continuum damage mechanics to simulate composite failure. This multiscale experimental study showed that stepped repaired coupons have a similar behaviour to repaired panels in terms of damage mechanisms, failure onset location, and tensile strength. It supports the idea to use coupons instead of whole panels to carry out experimental testing of stepped repairs. A good agreement with 2D and 3D numerical simulations was also found. They predicted accurately the strength of the repairs and highlighted a failure location compatible with the experimental results. As a conclusion, an equivalent stepped joint can be representative for the strength of a stepped repaired panel, including when failure occurs inside the laminates.

飞机复合材料结构的粘合阶梯式修复具有许多优点，如光滑的气动表面、高强度和低质量附加。然而，它们的设计仍然具有挑战性，因为在薄层压板中沿结合线的刚度变化。本文从数值和实验两方面探讨了“等效”阶梯节点在多大程度上可以用于设计阶梯修复板。在这种情况下，破坏是由层压断裂而不是贴片剥离驱动的。在11种不同的配置下，按票板和面板的比例对阶梯式修复进行了张力试验。试样是通过热粘接获得的，因为它将进行原位修复。有限元建模采用内聚区建模来考虑剥离和分层，连续损伤力学来模拟复合材料的破坏。该多尺度实验研究表明，阶梯修复板在损伤机制、破坏发生位置和抗拉强度方面与修复板具有相似的行为。它支持使用优惠券而不是整个面板来进行阶梯式修复的实验测试的想法。与二维和三维数值模拟结果吻合较好。他们准确地预测了修复的强度，并突出了与实验结果相符的故障位置。因此，等效阶梯节点可以代表阶梯修复板的强度，包括层板内部发生破坏时的强度。