【新文速递】2024年1月21日固体力学SCI期刊最新文章

 

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

International Journal of Solids and Structures

A unified pseudo-elastic model of continuous and discontinuous softening in the finite deformation of isotropic soft solids

Afshin Anssari-Benam, Mokarram Hossain

doi:10.1016/j.ijsolstr.2024.112670

各向同性软固体有限变形中连续和不连续软化的统一伪弹性模型

Building on a recently devised approach of hyperelasticity with intrinsic softening, a new framework for capturing both continuous and discontinuous softening in the finite deformation of isotropic incompressible elastomers is considered here. The continuous and discontinuous softening effects of interest pertain to the loading and unloading paths, respectively, and the model is developed within the theory of pseudo-elasticity. The performance of the model in capturing these effects is then compared with the deformation behaviour of a variety of elastomers, including a range of hydrogels from truly independent double-network (t-DN) to tough and nanocomposite hydrogels, dielectric elastomers and carbon-black filled rubber specimens, under uniaxial and multiaxial deformations. The model is demonstrated to show a favourable simulation and prediction of the extant experimental data. The application of the model is then extended to capturing the softening behaviour under rate-dependent loading, based on a prior work by the authors incorporating the rate effects directly into the pseudo-hyperelastic model, by assuming that the model parameters evolve with the deformation rate. The capability of the model to capture the rate-dependent effects accurately will be shown by considering the rate-dependent behaviour of two hydrogel specimens. Given the simplicity of the functional form of the model, akin to a standard pseudo-elastic model, the low(er) number of model parameters, the ability to capturing the softening behaviour in the deformation of a wide range of elastomeric materials, and the easy extension for incorporating additional features such as the rate-effects, the proposed model provides another step towards the unification of various complex deformation features into a single modelling framework, for a more universal application to the finite deformation of soft solids.

基于最近提出的一种具有内禀软化的超弹性方法，本文考虑了一种捕捉各向同性不可压缩弹性体有限变形中连续和不连续软化的新框架。所关注的连续软化效应和不连续软化效应分别属于加载路径和卸载路径，该模型是在拟弹性理论的基础上建立的。然后将模型在捕获这些效应方面的性能与各种弹性体的变形行为进行比较，包括一系列水凝胶，从真正独立的双网络(t-DN)到坚韧和纳米复合水凝胶，介电弹性体和碳黑填充橡胶样品，在单轴和多轴变形下。该模型对现有实验数据进行了较好的模拟和预测。然后，该模型的应用扩展到捕获速率相关加载下的软化行为，基于作者先前的工作，通过假设模型参数随变形率而变化，将速率效应直接纳入伪超弹性模型。通过考虑两个水凝胶样品的速率依赖行为，模型准确捕获速率依赖效应的能力将得到证明。考虑到模型功能形式的简单性，类似于标准的伪弹性模型，模型参数的低(er)数量，能够捕获各种弹性体材料变形中的软化行为，并且易于扩展以合并其他特征，例如速率效应，所提出的模型为将各种复杂变形特征统一到单个建模框架中提供了又一步。为了更普遍地应用于软固体的有限变形。

Numerical and experimental analysis of inelastic and rate-dependent buckling of thin injection-moulded high-density polyethylene structure

Martin Kroon, Eskil Andreasson, Viktor Pettersson, Elin Persson Jutemar

doi:10.1016/j.ijsolstr.2024.112673

高密度聚乙烯薄型注射成型结构非弹性及速率相关屈曲的数值与实验分析

Semi-crystalline polymers is an important group of materials that is used in a vast array of products. In this study, the rate-dependent properties of high-density polyethylene (HDPE) are investigated, both experimentally and theoretically. Experimental compression testing of a three-dimensional HDPE structure is performed and analysed numerically by use of the finite element method. In addition, an Eulerian constitutive material model for isotropic, semi-crystalline polymers is proposed. The model is able to account for such essential phenomena as strain-rate dependence, work hardening, pressure-dependence of inelastic deformations, and damage. The proposed material model was implemented in Abaqus as a VUMAT, which is an explicit implementation. The material model was calibrated by use of uniaxial tensile tests performed on HDPE dog-bone shaped samples, and the model was further explored by applying the VUMAT implementation to the compression tests of the HDPE structure. The simulation model was able to reproduce the experimental results well, both the uniaxial tests and the compression tests. In particular, the friction present in the compression tests seems to play an important role in determining the buckling mode of the structure.

半结晶聚合物是一种重要的材料，广泛应用于各种产品中。在本研究中，研究了高密度聚乙烯(HDPE)的速率依赖性质，实验和理论。对三维HDPE结构进行了压缩试验，并采用有限元法进行了数值分析。此外，提出了各向同性半结晶聚合物的欧拉本构材料模型。该模型能够解释诸如应变率依赖性、加工硬化、非弹性变形的压力依赖性和损伤等基本现象。提出的材料模型在Abaqus中作为VUMAT实现，这是一种显式实现。通过对HDPE狗骨样进行单轴拉伸试验，对材料模型进行校准，并将VUMAT实现应用于HDPE结构的压缩试验，对模型进行进一步探索。该模型能够较好地再现单轴试验和压缩试验的结果。特别是，在压缩试验中存在的摩擦似乎在确定结构的屈曲模式方面起着重要作用。

Mechanics of Materials

Shape transformers for crashworthiness of additively manufactured engineering resin lattice structures: Experimental and numerical investigations

Autumn R. Bernard, Muhammet Muaz Yalcin, Mostafa S.A. ElSayed

doi:10.1016/j.mechmat.2024.104925

增材制造工程树脂晶格结构的耐撞性形状变压器:实验和数值研究

Cellular materials have superior specific properties (e.g., specific strength, stiffness, and energy absorption) as compared to their monolithic material counterparts. With rapid advancements in additive manufacturing technology, the uniquely complex geometry of these materials – particularly periodic lattices – can be easily reproduced for additional experimental research, characterization, and potential industrial applications. This work utilizes the idea of shape transformers – previously employed to describe the structural efficiency of beams subjected to bending – to define new strut-based lattices, whose struts do not have the typical solid, circular cross-section shape. Both experimental and numerical model results have shown that this design parameter can be utilized to manipulate the crashworthiness efficiency of lattice materials. It is found that designing with a square or a rectangular cross-section could increase the plateau stress by up to 52% while increasing the mass normalized specific energy absorption by up to 32%.

与单片材料相比，蜂窝材料具有优越的特性(例如，比强度，刚度和能量吸收)。随着增材制造技术的快速发展，这些材料的独特复杂几何形状——尤其是周期性晶格——可以很容易地复 制，用于额外的实验研究、表征和潜在的工业应用。这项工作利用形状变压器的思想-以前用于描述弯曲梁的结构效率-来定义新的基于支柱的网格，其支柱不具有典型的实心圆形截面形状。实验和数值模型结果表明，该设计参数可用于控制晶格材料的耐撞效率。研究发现，采用方形或矩形截面设计可使平台应力提高52%，使质量归一化比能吸收提高32%。

Thin-Walled Structures

Dynamic stability of a lossy locally resonant metamaterial panel in supersonic flow

Pengtao Shi, Zhaolin Chen, Yanlong Xu, Yingsong Gu, Feng Liu, Zhichun Yang

doi:10.1016/j.tws.2024.111614

有耗局部谐振超材料板在超音速流动中的动态稳定性

In this paper, aimed at a lossy locally resonant metamaterial panel (LLRMP) in supersonic flow, the impact of changing bandgap and metadamping properties on dynamic stability considering the fluid-structure interaction (FSI) is studied for the first time. The analytical model for studying the transmission coefficient and dynamic stability is established by using the Galerkin method, while the complex energy band is obtained based on the Bloch theorem. The bandgap properties mainly affect the instability frequency, which is attributed to the change of coupling modes that dominate the dynamic instability. The metadamping properties play an important role in affecting the critical instability dynamic pressure, which can be increased/decreased by positive/negative metadamping. The mechanism of metadamping properties changing the critical instability dynamic pressure is that the influences of damping of the host panel and locally resonant unit on the root loci are different. Besides, the ability of LLRMP in changing the critical instability dynamic pressure is investigated, which demonstrates that the critical instability dynamic pressure can be increased by 16.13% even though the mass ratio is only 0.1. Our work broadens the potential applications of locally resonant metamaterials and provides a fresh perspective on anti-flutter design of panels in supersonic flow.

本文针对超声速流动中的有损局部共振超材料面板(LLRMP)，首次研究了考虑流固耦合(FSI)的带隙和元粘接特性变化对面板动力稳定性的影响。采用伽辽金方法建立了研究透射系数和动力稳定性的解析模型，并根据布洛赫定理得到了复能带。带隙特性主要影响失稳频率，这是由于耦合模式的变化主导了动态失稳。元粘接特性对临界失稳动压有重要影响，正/负元粘接可以增加/降低临界失稳动压。元固结特性改变临界失稳动压的机理是主面板和局部共振单元阻尼对根轨迹的影响不同。此外，研究了LLRMP对临界不稳定动压力的改变能力，结果表明，在质量比仅为0.1的情况下，LLRMP可使临界不稳定动压力提高16.13%。本研究拓宽了局部共振超材料的应用前景，为超声速流动中板的抗颤振设计提供了新的视角。

Crashworthiness study of aluminum foam-filled tubular lattice structures based on triply periodic minimal surface metamaterials under lateral crushing

Liang Wan, Dayong Hu, Hongbo Zhang

doi:10.1016/j.tws.2024.111616

基于三周期极小表面超材料的泡沫铝填充管状晶格结构横向破碎耐撞性研究

Owing to their superior energy absorption capabilities and lightweight characteristics, both aluminum foam and tubular lattice structures based on triply periodic minimal surfaces (named T-TLS) had attracted a lot of attention. However, they had never functioned together in combination. Accordingly, aluminum foam was filled into T-TLS to form foam-filled T-TLS with the aim of enhancing the energy absorption performance, and their mechanical properties under lateral crushing were experimentally and numerically studied. Quasi-static lateral crushing experiments were firstly performed on the empty T-TLS, cylindrical foam filler, and foam-filled T-TLS to obtain deformation modes, force–displacement responses, and crashworthiness parameters. The experimental results indicated that filling aluminum foam changed the deformation mode from a four-hinge mode to a six-hinge mode. Moreover, foam-filled T-TLS displayed significantly enhanced energy absorption performance attributed to the interaction between T-TLS and aluminum foam, as evidenced by higher energy absorption (EA) and specific energy absorption (SEA). Subsequently, validated finite element (FE) models of foam-filled T-TLS were developed to further reveal their crushing responses and crashworthiness performances. Numerical results revealed evident influences of relative densities of T-TLS and foam filler on the deformation mode and energy absorption performance. The competition in stiffness between T-TLS and foam filler led to three distinct deformation modes. Finally, a multi-objective optimization was carried out to derive optimized configurations for foam-filled T-TLS subjected to lateral crushing. In comparison with the baseline designs, the optimal results demonstrated enhanced crashworthiness, with the SEA value increasing by 40.6 to 97.3%.

泡沫铝和基于三重周期性极小表面的管状晶格结构（命名为 T-TLS）因其卓越的能量吸收能力和轻质特性而备受关注。然而，它们从未结合在一起发挥作用。因此，为了提高能量吸收性能，在 T-TLS 中填充了铝泡沫，形成了泡沫填充 T-TLS，并对其在横向挤压下的力学性能进行了实验和数值研究。首先对空 T-TLS、圆柱形泡沫填充物和泡沫填充 T-TLS 进行了准静态横向挤压实验，以获得变形模式、力位移响应和耐撞性参数。实验结果表明，填充铝泡沫使变形模式从四铰链模式变为六铰链模式。此外，由于 T-TLS 与铝泡沫之间的相互作用，泡沫填充 T-TLS 的能量吸收性能明显增强，这体现在更高的能量吸收（EA）和比能量吸收（SEA）上。随后，开发了经过验证的泡沫填充 T-TLS 有限元 (FE) 模型，以进一步揭示其挤压响应和防撞性能。数值结果显示，T-TLS 和泡沫填充物的相对密度对变形模式和能量吸收性能有明显影响。T-TLS 和泡沫填充物之间的刚度竞争导致了三种截然不同的变形模式。最后，通过多目标优化，得出了泡沫填充 T-TLS 受横向挤压的优化配置。与基线设计相比，优化结果显示出更强的耐撞性，SEA 值增加了 40.6% 至 97.3%。

Effects of section configurations on the dynamic responses of an integrated quasi-zero isolator

Haiping Liu, Shikun Zhou, Yan Wang, Qi Lv

doi:10.1016/j.tws.2024.111617

截面构型对积分准零隔离器动力响应的影响

In this research, a new passive-type integrated quasi-zero stiffness isolator with variable cross-section (IQZS-VCS) characteristic is proposed in order to extend the application fields. Compared with the integrated quasi-zero stiffness isolator with uniform cross-section (IQZS-UCS), the IQZS-VCS isolator has more adjustable structural parameters and can enhance vibration attenuation performance in lower-frequency region. Based on the developed static model, the nonlinear force and nonlinear stiffness characteristics of the IQZS-VCS isolator are evaluated using different design parameters. Furthermore, the effects of different factors on vibration reduction ability of the isolating system are addressed in terms of amplitude-frequency response and force transmissibility. Compared with a traditional linear, IQZS-UCS and conventional three-spring-type quasi-zero stiffness isolators, the proposed isolator exhibits better low-frequency and wide-band isolation performance. Quasi-static and electromagnetic exciting tests reveal that the developed theoretical models and related calculation results of the IQZS-VCS isolator are correct, providing an innovative solution and insight for broadband isolator.

本文提出了一种新型的无源型变截面集成准零刚度隔振器(IQZS-VCS)，以拓展其应用领域。与等截面一体化准零刚度隔振器(IQZS-UCS)相比，IQZS-VCS隔振器结构参数可调性更强，在低频区域的减振性能更好。在建立的静力模型的基础上，对不同设计参数下IQZS-VCS隔振器的非线性力和非线性刚度特性进行了评估。此外，从幅频响应和力传递率两方面分析了不同因素对隔振系统减振能力的影响。与传统的线性、IQZS-UCS和传统的三弹簧型准零刚度隔离器相比，该隔离器具有更好的低频和宽带隔离性能。准静态和电磁激励试验表明，所建立的IQZS-VCS隔离器的理论模型和相关计算结果是正确的，为宽带隔离器提供了一种创新的解决方案和见解。