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【新文速递】2024年2月28日固体力学SCI期刊最新文章

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今日更新:International Journal of Solids and Structures 1 篇,International Journal of Plasticity 1 篇,Thin-Walled Structures 1 篇

International Journal of Solids and Structures

Isotropic Elasticity of Dilatational Conical Inclusion.AN analytical APPROACH

Nguyen Van Tuyen, A.L Kolesnikova, A.E. Romanov

doi:10.1016/j.ijsolstr.2024.112735

扩张圆锥包容体的各向同性弹性--一种分析方法

In this article, the analytical solution for the isotropic elasticity problem for the cone-shaped inclusion with dilatational eigenstrain in an infinite medium is given. The conical inclusion is modeled by dilatational infinitesimally thin circular disks distributed continuously along the cone z-axis with the radii of the disks being proportional to z-coordinate. The displacements, strains, and stresses of the conical inclusion are given in spherical coordinates with the origin in the cone-apex in the form of the series with Legendre polynomials. The maps of the displacements and the stresses are presented. A comparison of the displacements of the conical inclusion with the displacements of the finite cylindrical and hemispherical inclusions is provided. It is also shown, as expected, that the energy of the dilatational inclusion does not depend on its shape. In Discussion section, the specific features of an “hourglass” dipole inclusion consisting of two conical inclusions with different sign eigenstrains are demonstrated.

本文给出了在无限介质中具有扩张特征应变的锥形包含体的各向同性弹性问题的解析解。锥形内含物由沿锥体 Z 轴连续分布的扩张性无限薄圆盘建模,圆盘半径与 Z 坐标成正比。锥形内含物的位移、应变和应力以球面坐标给出,原点位于锥顶,采用 Legendre 多项式的序列形式。并给出了位移和应力的分布图。将锥形内含物的位移与有限圆柱形和半球形内含物的位移进行了比较。结果还表明,正如预期的那样,膨胀夹杂物的能量并不取决于其形状。在讨论部分,演示了由两个具有不同符号特征应变的圆锥内含物组成的 "沙漏 "偶极内含物的具体特征。


International Journal of Plasticity

Deciphering non-elastic deformation in amorphous alloy: Simultaneous aging-induced ordering and rejuvenation-induced disordering

Q. Hao, G.J. Lyu, E. Pineda, J.M. Pelletier, Y.J. Wang, Y. Yang, J.C. Qiao

doi:10.1016/j.ijplas.2024.103926

解密非晶合金的非弹性变形:同时发生的老化诱导有序化和再生诱导无序化

The mechanical and physical properties of amorphous alloys depend on their time, temperature, and stress history. Due to their out-of-thermodynamic-equilibrium nature, describing the nonelastic deformation while considering the evolution of the structural state poses a significant challenge. We address this challenge by incorporating a parameter for structural state changes into a conventional deformation theory. This allows us to account for aging-induced ordering and deformation-induced disordering in the description of the mechanical deformation. In the apparent elastic regime (small strain), aging dominates while disorder caused by deformation can be disregarded. In this context, we have also made modifications to the widely used stretched exponential function, incorporating in situ aging during deformation. This modification successfully describes the stress relaxation behavior under small deformation conditions and provides insights into parameter evolution in this process. Under large deformation conditions, both aging and deformation induced rejuvenation effects on the structural state must be considered simultaneously. By analyzing the evolution of defect concentration during this process, we describe relevant experimental results within the framework of the free volume theory, effectively separating the contributions of aging and rejuvenation to the structural state during the deformation process.

非晶合金的机械和物理特性取决于其时间、温度和应力历史。由于非热力学平衡性质,在考虑结构状态演变的同时描述非弹性变形是一项重大挑战。为了应对这一挑战,我们在传统的变形理论中加入了结构状态变化参数。这使我们能够在描述机械变形时考虑老化诱导的有序化和变形诱导的无序化。在表观弹性体系(小应变)中,老化占主导地位,而变形引起的无序则可以忽略不计。在这种情况下,我们还对广泛使用的拉伸指数函数进行了修改,将变形过程中的原位老化纳入其中。这一修改成功地描述了小变形条件下的应力松弛行为,并为这一过程中的参数演变提供了深入的见解。在大变形条件下,必须同时考虑老化和变形对结构状态的再生效应。通过分析这一过程中缺陷浓度的演变,我们在自由体积理论的框架内描述了相关的实验结果,有效地分离了变形过程中老化和再生对结构状态的贡献。


Thin-Walled Structures

Topology Optimization Design of Recoverable Bistable Structures for Energy Absorption with Embedded Shape Memory Alloys

Kuan Liang, Shaojie Zhou, Yangjun Luo, Xiaopeng Zhang, Zhan Kang

doi:10.1016/j.tws.2024.111757

利用嵌入式形状记忆合金拓扑优化设计用于能量吸收的可恢复双稳态结构

In this work, multistable mechanical metamaterials with recoverable capabilities are designed for high energy absorption and resistance to repetitive impacts. Based on the known curved beam with energy dissipation characteristics, the shape memory alloys (SMAs) curved beam is added and optimized to achieve recoverability of the bi-layer beam structure. To simultaneously achieve bistable characteristics and recoverability in the designed metamaterial, the optimization model is formulated to maximize the energy absorption capacity of the structure while constraining the peak and valley forces. To solve this complex and highly nonlinear topological optimization problem with stringent constraints, the topological design of the SMAs layer is represented using a limited number of design variables along with the material-field series expansion strategy, and the optimization problem is subsequently solved using a non-gradient-based optimization algorithm. Finite element simulation results demonstrated that the optimized design possesses a substantial capacity for energy absorption. Additionally, the design structure can recover to its initial state from buckling induced by the initial load by regulating the external temperature. Different multistable metamaterials, including those designed to prevent repetitive impacts, have been further developed based on the designed recoverable high-energy-absorbing bistable unit cells, utilizing combinations of varying energy absorption capacities.

在这项工作中,设计了具有可恢复能力的多稳态机械超材料,用于吸收高能量和抵抗重复冲击。在已知具有能量耗散特性的弧形梁的基础上,增加并优化了形状记忆合金(SMAs)弧形梁,以实现双层梁结构的可恢复性。为了在设计的超材料中同时实现双稳态特性和可恢复性,制定了优化模型,以最大限度地提高结构的能量吸收能力,同时限制峰值和谷值力。为了解决这个具有严格约束条件的复杂且高度非线性的拓扑优化问题,SMA 层的拓扑设计采用了有限数量的设计变量和材料-场序列扩展策略,随后使用基于非梯度的优化算法解决了优化问题。有限元模拟结果表明,优化设计具有很强的能量吸收能力。此外,通过调节外部温度,设计结构还能从初始载荷引起的屈曲中恢复到初始状态。在所设计的可恢复高能量吸收双稳态单元单元的基础上,利用不同能量吸收能力的组合,进一步开发了不同的多稳态超材料,包括用于防止重复撞击的超材料。



来源:复合材料力学仿真Composites FEM
ACTMechanicalDeform非线性拓扑优化UM理论材料APEX
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首次发布时间:2024-11-06
最近编辑:18天前
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【新文速递】2024年3月4日固体力学SCI期刊最新文章

今日更新:International Journal of Solids and Structures 1 篇,Journal of the Mechanics and Physics of Solids 1 篇,International Journal of Plasticity 1 篇,Thin-Walled Structures 1 篇International Journal of Solids and StructuresLow velocity impact and compression after impact of thin and thick laminated carbon fiber composite panelsAndrew Seamone, Paul Davidson, Anthony M. Waas, Vipul Ranatungadoi:10.1016/j.ijsolstr.2024.112745薄层和厚层碳纤维复合板的低速冲击和冲击后的压缩情况This study explores the impact behavior of thin and thick composite panels, yielding insights into their behavior under increasing impact energies. Thin composite specimens demonstrated limited surface damage tolerance, while thicker panels remained visually intact but suffered internal damage, adversely affecting their compressive load capacity. The study shows a robust correlation between impact energy and key measurements, including dent depth, bottom surface matrix splitting, and internal delaminations. Moreover, the research identified a consistent pattern in damage initiation, showing that the onset of matrix splitting and delamination remained relatively constant regardless of increasing impact energy, emphasizing the predictability of damage initiation. Compression after impact study showed distinctive responses between thin and thick composites. Thin composites exhibited global buckling before final failure, with a gradual reduction in peak load-carrying capability as damage escalated. In contrast, thick composites suffered substantial damage and delamination at higher impact energies, leading to significant losses, up to 60%, in residual compressive load capacity. The study introduces a simplified quasi-static model to capture delamination effects on panel responses to low-velocity impacts. This study contributes significantly to understanding composite materials’ impact behavior, providing essential knowledge for practical applications and future research endeavors.本研究探讨了薄复合板和厚复合板的冲击行为,深入了解了它们在冲击能量增加时的行为。薄复合材料试样表现出有限的表面损伤耐受性,而较厚的板材虽然表面完好无损,但却遭受了内部损伤,对其抗压负载能力产生了不利影响。研究结果表明,冲击能量与凹痕深度、底面基质分裂和内部脱层等关键测量值之间存在紧密的相关性。此外,研究还发现了一种一致的损伤起始模式,表明无论冲击能量如何增加,基体开裂和分层的起始时间都保持相对稳定,强调了损伤起始的可预测性。冲击后的压缩研究表明,薄复合材料和厚复合材料的反应截然不同。薄复合材料在最终失效前表现出整体屈曲,随着损伤的加剧,峰值承载能力逐渐降低。与此相反,厚复合材料在冲击能量较高时遭受严重破坏和分层,导致剩余抗压承载能力大幅下降,最高达 60%。该研究引入了一个简化的准静态模型,以捕捉分层对面板对低速冲击响应的影响。这项研究极大地促进了对复合材料冲击行为的理解,为实际应用和未来研究工作提供了重要知识。Journal of the Mechanics and Physics of SolidsMapping deformation and dissipation during fracture of soft viscoelastic solidYuan Qi, Xueyu Li, Sairam Pamulaparthi Venkata, Xingwei Yang, Tao Lin Sun, Chung-Yuen Hui, Jian Ping Gong, Rong Longdoi:10.1016/j.jmps.2024.105595绘制软粘弹性固体断裂过程中的变形和耗散图Energy dissipation around a propagating crack is the primary mechanism for the enhanced fracture toughness in viscoelastic solids. Such dissipation is spatially non-uniform and is highly coupled to the crack propagation process due to the history-dependent nature of viscoelasticity. We present an experimental approach to map the dissipation field during crack propagation in soft viscoelastic solid. Specifically, we track randomly distributed tracer particles to measure the evolving deformation field. The measured deformation field is then put into a nonlinear constitutive model to determine the dissipation field. Our methodology was used to investigate the deformation and dissipation fields around a propagating crack in a Polyampholyte (PA) hydrogel. The deformation field measurements allowed us to assess whether the commonly assumed translational invariance in viscoelastic fracture theories holds true in practical experiments. Furthermore, by combining the obtained deformation fields with a nonlinear viscoelastic model, we captured the complete history of the dissipation field during crack propagation. We found that dissipation occurred even at material points that are a few millimeters away from the crack tip. The mapped dissipation field also enabled the separate determination of the intrinsic and dissipative components of fracture toughness for the viscoelastic hydrogel.传播裂纹周围的能量耗散是粘弹性固体断裂韧性增强的主要机制。由于粘弹性的历史依赖性,这种耗散在空间上是不均匀的,并且与裂纹扩展过程高度耦合。我们提出了一种绘制软粘弹性固体裂纹扩展过程中耗散场的实验方法。具体来说,我们通过追踪随机分布的示踪粒子来测量不断变化的变形场。然后将测量到的变形场放入非线性构成模型中,以确定耗散场。我们的方法被用于研究聚酰胺(PA)水凝胶中传播裂缝周围的变形场和耗散场。通过变形场测量,我们可以评估粘弹性断裂理论中通常假设的平移不变性在实际实验中是否成立。此外,通过将获得的变形场与非线性粘弹性模型相结合,我们捕捉到了裂纹扩展过程中耗散场的完整历史。我们发现,即使在距离裂纹尖端几毫米远的材料点也会发生耗散。通过绘制耗散场图,还能分别确定粘弹性水凝胶断裂韧性的内在和耗散成分。International Journal of PlasticityMulti-interface migration mechanism induced by carbide precipitation during the quenching-partitioning-tempering process in a high-carbon steelHongqing Zheng, Jiazhi Zhang, Xunwei Zuo, Yonghua Rong, Jianfeng Wan, Nailu Chendoi:10.1016/j.ijplas.2024.103928 高碳钢淬火-分区-回火过程中碳化物析出诱发的多界面迁移机制Phase-field finite element (PFFE) modeling of the quenching-partitioning-tempering (Q-P-T) process is proposed, and the two-dimensional PFFE-QPT model considering carbide precipitation and the interface migration between martensite and austenite is used to investigate microstructural evolution and the elastic/plastic strain distribution at quenching, partitioning and tempering stages in a high-carbon steel, respectively. The simulation results of the high carbon Q-P-T steel indicate that the precipitation strengthening of carbides occurs not only because they can block the movement of dislocations, but also because they can produce high internal stress. Meanwhile, the volume fractions of different phases (including primary martensite, retained austenite, secondary martensite, and carbide) and the carbon content in retained austenite predicted by the PFFE-QPT model are slightly better than those predicted by the novel one-dimensional QPT-LE (local equilibrium) model and much closer to experimental values. The PFFE-QPT model is also used to successfully predict the volume fractions of different phases in low-carbon and medium-carbon Q-P-T steels. More importantly, the microstructural morphologies closely related to mechanical properties can be demonstrated by the PFFE-QPT model and are comparable with the experimental observation. Therefore, the PFFE-QPT model will be a more powerful tool for guiding the process and microstructure design of Q-P-T steels compared with the QPT-LE model.提出了淬火-分区-回火(Q-P-T)过程的相场有限元(PFFE)模型,并使用考虑碳化物析出以及马氏体和奥氏体之间界面迁移的二维 PFFE-QPT 模型分别研究了高碳钢在淬火、分区和回火阶段的微观结构演变和弹性/塑性应变分布。高碳 Q-P-T 钢的模拟结果表明,碳化物的析出强化不仅是因为它们能阻止位错运动,还因为它们能产生高内应力。同时,PFFE-QPT 模型预测的不同相(包括原始马氏体、残余奥氏体、二次马氏体和碳化物)的体积分数和残余奥氏体中的碳含量略好于新型一维 QPT-LE(局部平衡)模型的预测值,且更接近实验值。PFFE-QPT 模型还可用于成功预测低碳和中碳 Q-P-T 钢中不同相的体积分数。更重要的是,PFFE-QPT 模型可以证明与力学性能密切相关的微观结构形态,并且与实验观察结果相当。因此,与 QPT-LE 模型相比,PFFE-QPT 模型将成为指导 Q-P-T 钢工艺和微观结构设计的更有力工具。Thin-Walled StructuresDynamic responses of steady-state transition structures under impact loadingWenxiao Li, Mohammed El Hoseny, Jianxun Madoi:10.1016/j.tws.2024.111761稳态过渡结构在冲击荷载下的动态响应Advancements in materials science and mechanical system have spurred widespread investigation into non-traditional structures. In particular, engineers have shown interest in steady-state transition structures with phase transition properties. In this paper, a three-dimensional steady-state transition structure was established using the genetic algorithm and three-dimensional expansion, on which the low-velocity impact tests were carried out. Force response and energy absorption of the steady-state transition structures under impact were studied. From the force response and energy absorption curves, it can be seen that the steady-state transition structures absorb and store portion of impact energy temporarily, gradually releasing it after impact peak. This unique energy behavior results in a steady state transition structure with a long impact response time and a low peak impact force under impact. In addition, investigation into energy transfer within these structures reveals that energy oscillations occur among multilayered bistable surfaces during steady-state transitions, further improving the energy dissipation. Further, the dynamic response and damage modes of the honeycomb structure and the steady state transition structure were compared, showing that the damage mode of the steady state transition structure under the impact is an overall damage, in contrast to the penetration damage of the honeycomb structure. Notably, the steady-state transition structures showcase a higher proportion of elastic strain energy during impacts, effectively delaying structural damage onset, and dispersing impact energy, thus enhancing impact resistance. In light of these findings, the demonstrated behavior of steady-state transition structures in absorbing and dissipating impact energy showcases their potential as promising avenues for the development of more effective impact protection strategies.材料科学和机械系统的进步推动了对非传统结构的广泛研究。特别是,工程师们对具有相变特性的稳态过渡结构表现出了浓厚的兴趣。本文利用遗传算法和三维展开建立了三维稳态过渡结构,并在此基础上进行了低速冲击试验。研究了稳态过渡结构在冲击下的力响应和能量吸收。从力响应和能量吸收曲线可以看出,稳态过渡结构暂时吸收并储存了部分冲击能量,并在冲击峰值后逐渐释放。这种独特的能量行为使得稳态过渡结构在冲击下具有较长的冲击响应时间和较低的冲击力峰值。此外,对这些结构内部能量传递的研究表明,在稳态转换过程中,多层双稳态表面之间会发生能量振荡,从而进一步提高了能量耗散效果。此外,还比较了蜂窝结构和稳态过渡结构的动态响应和破坏模式,结果表明稳态过渡结构在冲击下的破坏模式是整体破坏,与蜂窝结构的穿透破坏形成鲜明对比。值得注意的是,稳态过渡结构在冲击过程中显示出更高比例的弹性应变能,有效延缓了结构损伤的发生,分散了冲击能量,从而增强了抗冲击能力。鉴于这些发现,稳态过渡结构在吸收和消散冲击能量方面的表现展示了其作为开发更有效冲击防护策略的潜在途径的潜力。来源:复合材料力学仿真Composites FEM

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