【新文速递】2024年1月5日固体力学SCI期刊最新文章

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

International Journal of Solids and Structures

Analytical 3D model for coupled magneto-mechanical behaviors of ferromagnetic shape memory alloy

Qi Peng, Jiahui Chen, Ke Ni, Ze Liu, Long-Qing Chen, Zhengzhi Wang

doi:10.1016/j.ijsolstr.2023.112619

铁磁形状记忆合金耦合磁力学行为的三维分析模型

Ferromagnetic shape memory alloys (FSMA), a type of smart material, are promising for engineering applications due to their large, high-frequency, and reversible magnetic-field-induced-strain (MFIS). However, the magneto-mechanical behaviors of FSMA are still not well understood due to the intrinsically coupled and cross-scale magneto-mechanical responses, limiting the design and optimization of FSMA-based devices such as sensors and actuators. In this work, a fully-analytical 3D model containing only basic material parameters and incorporating all key mechanisms for the magneto-mechanical performances of FSMA is developed based on a new magneto-mechano-decoupled energy minimization approach. It is shown that the coupled magneto-mechanical responses of FSMA-based sensors (cyclic stress with constant magnetic field) and actuators (cyclic magnetic field with constant stress) predicted by the model are in excellent agreement with existing experimental measurements. Based on these analytical predictions, the optimal ranges for the constant field and demagnetization factor are determined to achieve simultaneous complete strain recovery and considerable magnetization change as required by the FSMA-based sensors. In addition, the dependences of switching and saturating fields of MFIS on the constant stress and demagnetization factor are quantified for the FSMA-based actuators. Finally, a phase diagram is constructed to quantitatively determine the critical magnetic fields and stresses for predicting the strain induction and recovery under various loading conditions. The analytical model provides a simple, reliable, and versatile tool to reveal the comprehensive mechanisms for the coupled magneto-mechanical behaviors of FSMA and to guide the design of FSMA-based sensors and actuators with customized and on-demand performances.

铁磁形状记忆合金（FSMA）是一种智能材料，由于其具有大尺寸、高频率和可逆磁场诱导应变（MFIS）的特点，因此在工程应用中大有可为。然而，由于其内在耦合和跨尺度磁力学响应，人们对 FSMA 的磁力学行为仍不甚了解，从而限制了基于 FSMA 的传感器和致动器等设备的设计和优化。在这项工作中，基于一种新的磁-机-解耦能量最小化方法，开发了一种仅包含基本材料参数的全分析三维模型，该模型包含了 FSMA 磁-机械性能的所有关键机制。结果表明，该模型预测的基于 FSMA 的传感器（恒定磁场的循环应力）和致动器（恒定应力的循环磁场）的耦合磁力学响应与现有的实验测量结果非常吻合。根据这些分析预测，确定了恒定磁场和退磁因子的最佳范围，以实现基于 FSMA 的传感器所需的完全应变恢复和显著磁化变化。此外，还量化了基于 FSMA 的致动器的 MFIS 开关场和饱和场对恒定应力和退磁因子的依赖关系。最后，构建了一个相图，以定量确定临界磁场和应力，从而预测各种加载条件下的应变感应和恢复。该分析模型提供了一种简单、可靠和通用的工具，可用于揭示 FSMA 磁力学耦合行为的综合机制，并指导设计具有定制和按需性能的基于 FSMA 的传感器和致动器。

Nonlocal interfaces accounting for progressive damage within continuum-kinematics-inspired peridynamics

Marie Laurien, Ali Javili, Paul Steinmann

doi:10.1016/j.ijsolstr.2023.112641

非局部界面在连续运动学启发的周动力学中解释渐进损伤

In this work, we present a modeling approach to nonlocal material interfaces in the framework of continuum-kinematics-inspired peridynamics. The nonlocal model accounts for progressive damage within a finite-thickness interface, as opposed to the more common practice of abrupt bond breakage across a zero-thickness interface. Our approach is based on an overlap of the constituents within the interface. Interfacial bonds between initially overlapping partner points are governed by a constitutive law reminiscent of a traction-separation-law. The governing equations for continuum-kinematics-inspired peridynamics in the presence of an interface are derived using a rate-variational principle. The damage formulation is established using the classical concept of internal variables. Following the notion of a standard dissipative material, thermodynamic consistency of the constitutive laws and the evolution of the internal variables is ensured. The latter results in a straightforward evaluation of a damage function. We give details about the computational implementation comprising a peridynamic discretization and a Newton–Raphson scheme. A sound approach to approximate the interface normal during deformation is presented, which allows to penalize material penetration across the interface. The proposed model is explored in a series of numerical examples, i.e., classical peeling and shearing tests, for a variety of damage functions. A key feature of our interface model are the nonlocal characteristics that are assumed to play a role especially at small scales. We, first, observe that an increasing thickness of the nonlocal interface leads to stronger interfacial bonding and less damage. Second, an increase in horizon size results in stiffer material behavior. When studying the wrinkling and delamination behavior of a compressed bilayer, it is found that an increase in interface stiffness leads to a smaller wrinkling wavelength. Moreover, delamination due to progressive damage of interfacial bonds in the post-wrinkling regime is observed, which, to the best of our knowledge, has not been studied in a nonlocal model before.

在这项工作中，我们在连续介质动力学启发的周动力学框架内提出了一种非局部材料界面建模方法。非局部模型考虑了有限厚度界面内的渐进式损坏，而不是更常见的零厚度界面上的突然断裂。我们的方法基于界面内成分的重叠。最初重叠的伙伴点之间的界面键受类似于牵引分离定律的构成定律支配。在存在界面的情况下，连续介质启发的周动力学控制方程是利用速率变异原理推导出来的。利用经典的内部变量概念建立了损伤公式。根据标准耗散材料的概念，确保了构成定律和内部变量演变的热力学一致性。后者可直接评估损伤函数。我们详细介绍了由周动态离散化和牛顿-拉斐森方案组成的计算实施。我们还介绍了在变形过程中近似界面法线的合理方法，该方法允许对跨界面的材料渗透进行惩罚。在一系列数值示例中，即经典的剥离和剪切试验中，针对各种损伤函数，对所提出的模型进行了探讨。我们的界面模型的一个主要特点是假定非局部特征在小尺度上发挥作用。首先，我们观察到非局部界面厚度的增加会导致更强的界面结合力和更小的损伤。其次，地平线尺寸的增加会导致材料更坚硬。在研究压缩双分子层的起皱和分层行为时，我们发现界面刚度的增加会导致起皱波长变小。此外，我们还观察到了由于界面键在起皱后逐渐损坏而导致的分层现象，据我们所知，这种现象以前从未在非局部模型中进行过研究。

Journal of the Mechanics and Physics of Solids

Morphomechanics of growing curled petals and leaves

Ting Wang, Chenbo Fu, Michel Potier-Ferry, Fan Xu

doi:10.1016/j.jmps.2023.105534

卷曲花瓣和叶片生长的形态力学

Petals and leaves are usually curled and exhibit intriguing morphology evolution upon growth, which contributes to their important biological functions. To understand the underlying morphoelastic mechanism and to determine the crucial factors that govern the growth-induced instability patterning in curved petals and leaves, we develop an active thin shell model that can describe variable curvatures and spontaneous growth, within the framework of general differential geometry based on curvilinear coordinates and hyperelastic deformation theory. Analytical solutions of distinguished growing shapes such as saddle surface and cylindrical mode are then derived. We reveal distinct morphological evolutions of doubly curved leaves/petals with different curvatures κx (along the main vein) and κy (perpendicular to the main vein) upon differential growth. Compared to the flat (zero curvature) configuration, leaves/petals with longitudinal curvature κx experiences a global bending deformation. With the increase of growth strain, the leaf/petal undergoes a coupling behavior of edge wrinkling and global bending deformation, associated with a pitchfork bifurcation. Conversely, the transverse curvature κy does not lead to significant bending behavior, but results in delayed critical buckling threshold and reduced wrinkling amplitude. Physical insights into curvature effects on morphology evolutions are further provided by the analysis of nonlinear competition between bending and membrane energies. Moreover, we explore the effect of vein constraint on pattern formation, showing that different from edge wrinkling observed in leaves with strong vein constraint, the ones with weak vein constraint are prone to grow into a saddle shape, which is consistent with analytical solutions. The results uncover the intricate interplay between configurational curvature and vein confinement on plant morphogenesis, providing fundamental insights into a variety of growing shapes of curled petals and leaves.

花瓣和叶片通常是卷曲的，在生长过程中会出现奇妙的形态演变，这有助于它们发挥重要的生物功能。为了了解其潜在的形态弹性机制，并确定支配弯曲花瓣和叶片生长诱导不稳定形态的关键因素，我们在基于曲线坐标和超弹性变形理论的一般微分几何框架内，建立了一个能描述可变曲率和自发生长的主动薄壳模型。然后推导出不同生长形状（如鞍面和圆柱模式）的解析解。我们揭示了双曲线叶片/花瓣在微分生长过程中不同曲率κx（沿主脉）和κy（垂直于主脉）的独特形态演变。与扁平（零曲率）结构相比，纵向曲率为 κx 的叶片/花瓣会出现整体弯曲变形。随着生长应变的增加，叶片/花瓣会出现边缘起皱和整体弯曲变形的耦合行为，这与干叉形分叉有关。相反，横向曲率 κy 不会导致明显的弯曲行为，但会导致临界屈曲阈值延迟和皱缩幅度减小。通过分析弯曲和膜能之间的非线性竞争，我们进一步了解了曲率对形态演变的物理影响。此外，我们还探讨了叶脉约束对形态形成的影响，结果表明，与在强叶脉约束下观察到的边缘起皱不同，弱叶脉约束下的叶片容易长成马鞍形，这与分析解一致。这些结果揭示了构型曲率和叶脉约束对植物形态发生的复杂相互作用，为研究各种卷曲花瓣和叶片的生长形状提供了基本见解。

Mechanics of Materials

A nonlinear continuum framework for constitutive modeling of active polymer gels

Priyanka Nemani, Ravi Sastri Ayyagari, Pratyush Dayal

doi:10.1016/j.mechmat.2023.104908

活性聚合物凝胶构成建模的非线性连续体框架

Chemo-mechanical transduction is one of the key mechanisms that has formed the basis for designing bio-inspired self-driven synthetic systems from soft materials. Polymer hydrogels that use Belousov–Zhabotinsky (BZ) reaction are a unique class of dynamical reaction–diffusion (RD) systems that can continuously transduce internal chemical energy, from the reaction, to produce sustained mechanical work. In particular, BZ gels represent a complex nonlinear chemo-mechanical system, wherein, the autocatalytic oscillatory BZ reaction drives the rhythmic mechanical deformations through polymer-solvent interdiffusion. The objective of our work is to develop a standardized finite element (FE) framework for chemically driven active hydrogels that captures nonlinear elastic deformations with limited chain extensibility. The distinguishing feature of our approach is that, unlike other approaches, it combines reaction kinetics, solvent transport, elastodynamics of the polymeric network, and polymer-solvent friction under a unified FE framework. Moreover, we adapt our approach to a specific case of BZ gels and capture its swelling-deswelling characteristics. We first implement our FE framework in MATLAB that subsequently, forms the basis for constructing a three-dimensional user element subroutine (3D-UEL) in ABAQUS. Ultimately, through our simulations, we are able to capture all the essential features of BZ gels that includes chemically driven mechanical deformations. In addition, we also demonstrate that our 3D-UEL efficiently captures the chemo-mechanical response of “stent-shaped” BZ gels–a non-standard 3D geometry. In essence, our FE approach not only allows us to simulate BZ gels but also provides a template for other active, dynamical, RD-based systems, driven by chemo-mechanical transduction, irrespective of internal or external mechanisms.

化学机械传导是一种关键机制，是利用软材料设计生物启发自驱动合成系统的基础。使用别洛乌索夫-扎博金斯基（Belousov-Zhabotinsky，BZ）反应的聚合物水凝胶是一类独特的动态反应-扩散（RD）系统，可持续地将反应产生的内部化学能转化为持续的机械功。特别是，BZ 凝胶代表了一种复杂的非线性化学机械系统，其中，自催化振荡 BZ 反应通过聚合物-溶剂相互扩散驱动有节奏的机械变形。我们的工作目标是为化学驱动的活性水凝胶开发一个标准化的有限元（FE）框架，以捕捉具有有限链伸展性的非线性弹性变形。与其他方法不同的是，我们的方法在统一的有限元框架下结合了反应动力学、溶剂传输、聚合物网络弹性动力学以及聚合物-溶剂摩擦。此外，我们还根据 BZ 凝胶的具体情况调整了我们的方法，并捕捉到了其溶胀-消肿特性。我们首先在 MATLAB 中实现了我们的 FE 框架，并在此基础上在 ABAQUS 中构建了三维用户元素子程序（3D-UEL）。最终，通过模拟，我们能够捕捉到 BZ 凝胶的所有基本特征，包括化学驱动的机械变形。此外，我们还证明了我们的 3D-UEL 能够有效捕捉 "支架状 "BZ 凝胶（非标准三维几何形状）的化学机械响应。从本质上讲，我们的 FE 方法不仅能模拟 BZ 凝胶，还能为其他基于 RD 的活性、动态系统提供模板，这些系统由化学机械传导驱动，不受内部或外部机制的影响。

Thin-Walled Structures

A Comprehensive Formulation for Determining Static Characteristics of Mosaic Multi-Stable Composite Laminates under Large Deformation and Large Rotation

M.S. Taki, R. Tikani, S. Ziaei-Rad

doi:10.1016/j.tws.2023.111545

确定大变形和大旋转下镶嵌式多稳复合层压板静态特性的综合公式

Multi-stable composite laminates are composite materials that exhibit multi-stable states, making them highly suitable for use in morphing structures. These materials are capable of maintaining each stable state without expending any energy. As a result, they are used extensively in numerous applications and garnered the interest of scholars and aerospace organizations. In the context of practical applications, such as morphing structures, it is insufficient for designers to rely solely on common bi-stable composite laminates that exhibit large deformations and medium rotations to achieve their desired objectives. Consequently, based on the objectives of the design, there are two potential resolutions to address this limitation. A designer may utilize mosaic multi-stable composite laminates to achieve a morphing structure that exhibits high flexibility, significant deformation, and substantial rotation. The utilization of a series connection between a bi-stable composite laminate and a symmetric composite laminate results in the formation of a mosaic bi-stable composite laminate with variable stiffness. Furthermore, the amalgamation of two asymmetric composite laminates with inverted orientations engenders a mosaic tri-stable composite laminate. The present research examines the static characteristics of mosaic bi-stable and tri-stable composite laminates. It also seeks to analyze the factors affecting the behavior of these types of laminates. A geometrically exact model was formulated for this objective. Apart from the geometrically exact model, a widely used and uncomplicated model relying on the conventional Classical Laminated-Plate Theory (CLPT) and Von-Karman nonlinear strains was employed. The proposed models were validated through finite element simulations. The system's static equations were derived using the virtual work principle and the Rayleigh-Ritz method. The present study examines and explores quasi-static snap-through behavior between stable states through the application of concentrated forces. The findings indicate a high level of concurrence between the outcomes derived from the geometrically exact model and the finite element analyses, particularly in composite laminates exhibiting significant deformations and rotations.

多稳定复合层压板是一种呈现多稳定状态的复合材料，因此非常适合用于变形结构。这些材料能够在不消耗任何能量的情况下保持每一种稳定状态。因此，它们被广泛应用于众多领域，并引起了学者和航空航天组织的兴趣。在变形结构等实际应用中，设计人员仅依靠表现出大变形和中等旋转的普通双稳态复合材料层压板来实现预期目标是不够的。因此，根据设计目标，有两种可能的解决方案来解决这一限制。设计者可以利用镶嵌式多稳定复合材料层压板来实现具有高柔性、大变形和大幅度旋转的变形结构。利用双稳态复合材料层压板与对称复合材料层压板之间的串联，可形成刚度可变的镶嵌式双稳态复合材料层压板。此外，将两个方向相反的非对称复合材料层压板组合在一起，还能产生一种镶嵌式三稳复合材料层压板。本研究探讨了马赛克双稳态和三稳态复合层压板的静态特性。研究还试图分析影响这些类型层压板行为的因素。为此，研究人员建立了一个几何精确模型。除几何精确模型外，还采用了一个广泛使用的简单模型，该模型依赖于传统的经典层压板理论（CLPT）和 Von-Karman 非线性应变。通过有限元模拟对所提出的模型进行了验证。系统的静态方程是利用虚功原理和 Rayleigh-Ritz 方法推导出来的。本研究通过施加集中力，检查并探索了稳定状态之间的准静态快速通过行为。研究结果表明，几何精确模型和有限元分析得出的结果高度一致，尤其是在复合材料层压板出现明显变形和旋转时。

Experimental investigation on residual capacity of steel-reinforced concrete-filled thin-walled steel tubular columns subjected to combined loading and temperature

Wen-Da Wang, Wen-Jing Mao, Kan Zhou

doi:10.1016/j.tws.2024.111557

钢筋混凝土填充薄壁钢管柱在荷载和温度共同作用下的残余承载力试验研究

Steel-reinforced concrete-filled thin-walled steel tube (SRCFST) is gaining popularity in construction, primarily due to its superior structural performance. However, there is still a scarcity of existing studies examining the residual capacity of SRCFST columns after exposure to fire. Comprehensive research was conducted in this, involving both experimental testing and numerical simulations, to investigate the residual capacity of SRCFST columns. Six SRCFST columns were tested under combined loading and temperature to achieve the temperature distribution, failure modes, residual strength, and structural response within the cross-section. The developed finite element (FE) model was used to validate the test results. Three different paths, including after exposure to fire and without initial load, full-rang fire, and the actual path in the current test, were considered to assess the influence of different time-load-temperature paths on the mechanical properties of SRCFST columns. Results reveal that the region comprised of profiled steel and surrounded concrete forms a composite constraint area, with little loss of strength and stiffness occurring in the core region. The initial load level and heating time ratio were found to have a significant negative influence on the residual load-carrying capacity and ductility of SRCFST columns. By contrast, circular SRCFST columns are more resistant to the effects of fire compared to square SRCFST columns. Finally, the existing design methods were used and extended to evaluate the residual load-carrying capacity of SRCFST columns subjected to a complete temperature-load-time process.

钢筋混凝土填充薄壁钢管（SRCFST）在建筑领域越来越受欢迎，这主要归功于其优越的结构性能。然而，目前仍很少有研究探讨 SRCFST 柱在遭受火灾后的剩余承载力。本研究通过实验测试和数值模拟，对 SRCFST 柱的剩余承载力进行了全面研究。对六根 SRCFST 柱进行了综合载荷和温度测试，以了解截面内的温度分布、破坏模式、剩余强度和结构响应。开发的有限元（FE）模型用于验证测试结果。考虑了三种不同的路径，包括暴露于火灾后且无初始荷载、全范围火灾以及本次试验中的实际路径，以评估不同时间-荷载-温度路径对 SRCFST 柱力学性能的影响。结果显示，由型钢和环绕混凝土组成的区域形成了一个复合约束区域，核心区域的强度和刚度损失很小。研究发现，初始荷载水平和加热时间比对 SRCFST 柱的剩余承载能力和延性有显著的负面影响。相比之下，圆形 SRCFST 柱比方形 SRCFST 柱更能抵抗火灾的影响。最后，使用并扩展了现有的设计方法，以评估 SRCFST 柱在完整的温度-荷载-时间过程中的剩余承载能力。