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【新文速递】2023年11月6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,Journal of the Mechanics and Physics of Solids 1 篇,Mechanics of Materials 1 篇,International Journal of Plasticity 1 篇,Thin-Walled Structures 2 篇

International Journal of Solids and Structures

Numerical and Analytical Analyses of the formability and fracture of AA7075-O aluminum sheets in hemispherical punch tests

Shahzamanian M.M., Parsazadeh M., Wu P.D.

doi:10.1016/j.ijsolstr.2023.112558

在半球冲压试验中对 AA7075-O 铝板的成形性和断裂进行数值和分析

In this study, numerical simulations and experimental validations of the simulation of hemispherical punch tests for AA7075-O aluminum sheets with various sample widths are presented. It is convincingly believed in literature that a finite element (FE) based forming limit diagram (FLD) can be predicted very well using various time-dependent criteria. This matter has been investigated and securitized deeply and the FE-based FLD was predicted using three time-dependent criteria and compared with the experimental FLD. Results show that two of the three criteria could predict the relatively appropriate shape of the FLD while one of them has failed to match. Aside from using FE simulation to predict the FLD, an analytical method, namely, Marciniak-Kuczynski (M-K) was also used to make a better evaluation about the capability of the FEM to predict FLD. Among the FE-based FLDs, the one predicted using the Martinez-Donaire et al., 2014 (Martínez-Donaire et al., 2014) was found to be close to the one predicted using the M-K method. Although, the main objective of this paper is to investigate the capability of the FEM to predict an FLD for AA7075-O aluminum sheets, the fracture behavior for each case was predicted using a unified fracture model. Several computer runs were executed to perform the tests and reproduce the experimental results. The aim of this study was to discuss the simulation of hemispherical punch tests and analyze the numerical results and compare them with the experimental and analytical methods. It was observed that the experimental FLD can be reproduced using various time-dependent criteria in a relatively appropriate manner but with limitations especially at the equibiaxial stress state. These limitations were scrutinized and discussed in detail by comparing the results with experimental and analytical calculations.

本研究介绍了对不同试样宽度的 AA7075-O 铝板进行半球冲压试验模拟的数值模拟和实验验证。有文献令人信服地认为,基于有限元(FE)的成形极限图(FLD)可以利用各种随时间变化的准则进行很好的预测。我们对这一问题进行了深入研究和论证,并使用三种随时间变化的标准对基于有限元的 FLD 进行了预测,并与实验 FLD 进行了比较。结果表明,三个标准中的两个可以预测出相对合适的 FLD 形状,而其中一个则无法匹配。除了使用 FE 仿真预测 FLD 外,还使用了一种分析方法,即 Marciniak-Kuczynski (M-K),以更好地评估 FEM 预测 FLD 的能力。在基于有限元的 FLD 中,使用 Martinez-Donaire 等人,2014(Martínez-Donaire et al.虽然本文的主要目的是研究有限元预测 AA7075-O 铝板 FLD 的能力,但每种情况下的断裂行为都是使用统一的断裂模型预测的。为了进行测试并重现实验结果,执行了多次计算机运行。本研究旨在讨论半球冲压试验的模拟,分析数值结果,并将其与实验和分析方法进行比较。研究发现,使用各种随时间变化的标准可以以相对适当的方式再现实验的 FLD,但存在局限性,尤其是在等轴应力状态下。通过将结果与实验和分析计算结果进行比较,对这些局限性进行了详细的研究和讨论。


Journal of the Mechanics and Physics of Solids

Deformation and failure mechanisms in spider silk fibers

Olive Renata, Cohen Noy

doi:10.1016/j.jmps.2023.105480

蜘蛛丝纤维的变形和破坏机制

Spider silk fibers are protein materials that exhibit high strength and toughness thanks to a unique microstructure. In this work, a microscopically motivated model that sheds light on the underlying mechanisms behind the mechanical response of silk fibers is developed. The governing deformation mechanisms are as follows: initial stretching is enabled by the distortion of intermolecular hydrogen bonds that restrict the mobility of polypeptide chains. Once a sufficient force is applied, these bonds dissociate and the external load is transferred to the chains. Next, intramolecular β-sheets in the chains and/or the crystalline domains dissociate to provide additional chain length, thereby resulting in a macroscopic softening. Further deformation is enabled by the entropic elasticity of the chains, which stiffen with stretch. Based on the model, an algorithm to determine the overall constitutive response of silk fibers as a function of the initial distribution of chains and their composition is introduced. Experiments have shown that these two quantities can be controlled by supercontracting and dehydrating fibers under load. The model is validated through a comparison to various experimental findings at different alignment parameters. The merit of the model is three-fold: (1) it captures the microstructural evolution of the network as the fiber experiences stretch and reveals the role of key microstructural quantities such as chain-density, chain alignment, and chain composition, (2) it enables to compare between the microstructures of silk fibers produced by different spider species, and (3) it provides a platform for the microstructural design of biomimetic synthetic fibers with tunable properties.

蜘蛛丝纤维是一种蛋白质材料,由于其独特的微观结构而具有高强度和韧性。这项研究建立了一个微观模型,揭示了蛛丝纤维机械响应背后的基本机制。其变形机制如下:最初的拉伸是通过限制多肽链流动性的分子间氢键的变形实现的。一旦施加了足够的力,这些氢键就会解离,外部负载就会转移到多肽链上。接下来,分子内β-表层和/或结晶结构域解离,以提供额外的链长,从而导致宏观软化。链的熵弹性使其进一步变形,并随着拉伸而变硬。在该模型的基础上,引入了一种算法来确定丝纤维的整体构成响应,它是链的初始分布及其组成的函数。实验表明,这两个量可以通过纤维在负载下的超收缩和脱水来控制。通过与不同排列参数下的各种实验结果进行比较,验证了该模型。该模型有三方面的优点:(1)它捕捉到了纤维经历拉伸时网络的微观结构演变,并揭示了链密度、链排列和链组成等关键微观结构量的作用;(2)它能够比较不同种类蜘蛛生产的丝纤维的微观结构;(3)它为具有可调特性的仿生物合成纤维的微观结构设计提供了一个平台。


Mechanics of Materials

Modeling the thermo-responsive behaviors of polydomain and monodomain nematic liquid crystal elastomers

Chen Baihong, Liu Changyue, Xu Zengting, Wang Zhijian, Xiao Rui

doi:10.1016/j.mechmat.2023.104838

多域和单域向列液晶弹性体的热响应行为建模

Liquid crystal elastomers (LCEs) are polymeric materials that combine liquid crystal orientation and rubber elasticity. The mechanical responses of LCEs strongly depend on the nematic order and temperature. Developing a thermo-order-mechanical coupling model is important for the engineering applications of LCEs. In this work, we first synthesize both polydomain and monodomain LCEs. The shape change with temperature under a certain stress level is further characterized. In the theoretical part, the Landau-de Gennes model and neo-classical model is combined to construct the free energy density of LCEs. A linear term accounting for the effect of interior stress on nematic-isotropic transition is incorporated into the Landau-de Gennes free energy density, while a macro-order parameter is defined to describe the polydomain-monodomain transition for polydomain LCEs induced by the external force. Comparison between the model predictions and experimental results shows acceptably consistency for both polydomain and monodomain LCEs. Therefore, this work provides an efficient approach to predict the shape change of LCEs in various scenarios.

液晶弹性体(LCE)是一种结合了液晶取向和橡胶弹性的聚合物材料。液晶弹性体的机械响应在很大程度上取决于向列阶数和温度。开发一种热阶-机械耦合模型对于 LCE 的工程应用非常重要。在这项工作中,我们首先合成了多域和单域 LCE。并进一步研究了在一定应力水平下形状随温度变化的特征。在理论部分,我们结合朗道-德-吉尼斯模型和新古典模型构建了 LCE 的自由能密度。Landau-de Gennes 自由能密度中包含了一个线性项,用于解释内部应力对向列-各向同性转变的影响,同时定义了一个宏阶参数,用于描述外力诱导的多域 LCE 的多域-单域转变。模型预测与实验结果之间的比较显示,多域和单域 LCE 都具有可接受的一致性。因此,这项工作为预测 LCE 在各种情况下的形状变化提供了一种有效的方法。


International Journal of Plasticity

Microstructural insights into fatigue short crack propagation resistance and rate fluctuation in a Ni-based superalloy manufactured by Laser powder bed fusion

Li Jianghua, Huang Qinghui, Wang Zhiyang, Zhang Ningyu, Chen Gang, Qian Guian

doi:10.1016/j.ijplas.2023.103800

通过激光粉末床熔融技术制造的镍基超级合金抗疲劳短裂纹扩展能力和速率波动的微观结构启示

The microstructural sensitivity of fatigue short crack path and its propagation rate in a Ni-based superalloy GH4169 manufactured by laser powder bed fusion (LPBF) was investigated at room temperature. In-situ digital image correlation (DIC) observation and post-mortem microstructural analysis around the crack path were performed. The results show that the intragranular cracks developed in the shear cracking mode are closely aligned along the activated slip bands in the γ-matrix grains with the crystallographic characteristics of parallel to the γ-{111} slip planes. Multiple slip was also activated, causing the crack retardation or deflection. Low-angle grain boundaries and subgrain boundaries can affect intragranular cracking, while high-angle grain boundaries significantly arrest the short crack propagation. Moreover, the resistance of grain boundaries to short cracking was assessed using combined metrics including the crystallographic parameter of twist angle, the Schmid factor and the geometrical compatibility factor. These site-specific microstructural analyses around the crack path provide insights into the microstructural origins of resistance to the short crack propagation as well as an interpretation of the observed significant fluctuations in the crack propagation rate.

研究了室温下通过激光粉末床熔融(LPBF)制造的镍基超合金 GH4169 中疲劳短裂纹路径的微观结构敏感性及其传播速度。对裂纹路径周围进行了原位数字图像相关(DIC)观察和死后微观结构分析。结果表明,在剪切开裂模式下产生的粒内裂纹沿着γ基质晶粒中被激活的滑移带紧密排列,其晶体学特征是平行于γ-{111}滑移面。多重滑移也被激活,导致裂纹延缓或偏转。低角度晶界和亚晶界会影响晶内开裂,而高角度晶界则会显著阻止短裂纹的扩展。此外,晶界对短裂纹的阻力是通过包括扭转角晶体学参数、Schmid 因子和几何相容性因子在内的综合指标来评估的。这些围绕裂纹路径的特定部位微观结构分析有助于深入了解短裂纹扩展阻力的微观结构起源,并解释所观察到的裂纹扩展速率的显著波动。


Thin-Walled Structures

Experimental and analytical studies on a novel double-stage coupling damper

Sun Tongfei, Liu Ye, Dai Kaoshan, Camara Alfredo, Lu Yujie, Wang Lijie

doi:10.1016/j.tws.2023.111324

新型双级耦合阻尼器的实验和分析研究

A series of experimental and numerical studies on the novel double-stage coupling damper (DSCD) are presented in this paper. The effects of the damper configuration, friction-yield ratio (Rfy), and loading protocol on the hysteresis performance of the DSCD are investigated via quasi-static tests on seven specimens, and the variation in the failure mode, compression-strength adjustment factor, energy dissipation capacity, and equivalent viscous damping ratio of the DSCD is discussed. The test results demonstrate that the arrangement of ribs in the DSCD increased the average energy dissipation per loading cycle, compared to the device without these elements. The damper exhibits double-stage energy dissipation characteristics for several friction-yield ratios, however, relatively low values of this parameter (Rfy =0.5) leads to reduced energy dissipation capacity, due to significant variations in the friction force associated with creep, ploughing, and preload effect. Furthermore, a detailed finite element model of the DSCD is conducted based on the experimental data, focusing on exploring the effectiveness of the device. Numerical analysis revealed that the cumulative energy dissipation and peak force of the DSCD reduced with increasing the length of the friction mechanism (Lf). A large clearance between the yield segment and the restraining system (Cb) reduces the stability of the equivalent viscous damping ratio of the damper under compression, but Cb has no effect in the cumulation energy dissipation of the damper, which has important implications in the design of these devices for the seismic control of structures. Based on these results design recommendations for the DSCD are provided.

本文对新型双级耦合阻尼器(DSCD)进行了一系列实验和数值研究。通过对七个试样进行准静态试验,研究了阻尼器配置、摩擦屈服比(Rfy)和加载协议对 DSCD 滞后性能的影响,并讨论了 DSCD 失效模式、压缩强度调整系数、耗能能力和等效粘性阻尼比的变化。试验结果表明,与没有这些元件的装置相比,DSCD 中肋条的布置增加了每个加载周期的平均耗能。阻尼器在多个摩擦屈服比下表现出双级消能特性,然而,由于蠕变、犁地和预载效应导致摩擦力发生显著变化,该参数值相对较低(Rfy =0.5),导致消能能力降低。此外,还根据实验数据对 DSCD 进行了详细的有限元建模,重点探讨了该装置的有效性。数值分析表明,随着摩擦机构长度(Lf)的增加,DSCD 的累积能量耗散和峰值力减小。屈服段与约束系统之间的较大间隙(Cb)会降低阻尼器在压缩下的等效粘滞阻尼比的稳定性,但 Cb 对阻尼器的累积耗能没有影响,这对设计这些用于结构抗震控制的装置具有重要意义。基于这些结果,我们提出了 DSCD 的设计建议。


Improvement of Ni-CFRP Interfacial Properties using Compound Coupling Agent Treatment

Chen Yizhe, Xiang Wenfeng, Zhang Qingsong, Wang Hui, Hua Lin

doi:10.1016/j.tws.2023.111334

使用复合偶联剂处理改善 Ni-CFRP 的界面性能

When nickel and carbon fiber-reinforced plastics (CFRP) are combined, poor surface wettability of nickel makes it difficult to obtain ideal interfacial properties, which limits its extensive application in the aerospace field. In this paper, the surface of the nickel plate was modified by sandblasting, coupling agent treatment, and compound coupling agent treatment, the results showed that the bonding strength of CFRP/Ni joints was increased by 19.6%, 30.2%, and 49.7%, respectively, compared with the untreated joint. From the aspects of microstructure, surface wetting, and chemical bonding, the mechanism of strengthening nickel and CFRP bonding with the above surface modification methods were researched. Sandblasting treatment could form irregular pits on the surface of the nickel plate. These irregular pits effectively improved the surface roughness of nickel plate, but had little effect on the surface wettability. Coupling agent treatment has little effect on the surface roughness of the nickel plate, but greatly improvement on wettability with grafting the coupling agent molecule. Compound coupling agent treatment introduces -OH and -NH2 groups through plasma treatment to improve the grafting rate of coupling agent molecules on the surface of the nickel plate, achieving the purpose of strengthening the bonding of CFRP/Ni. This research is expected to provide research ideas for the connection of Ni and CFRP and other heterogeneous materials.

镍与碳纤维增强塑料(CFRP)结合时,镍的表面润湿性较差,难以获得理想的界面性能,限制了其在航空航天领域的广泛应用。本文通过喷砂、偶联剂处理和复合偶联剂处理对镍板表面进行了改性,结果表明,与未处理的接头相比,CFRP/镍接头的粘接强度分别提高了 19.6%、30.2% 和 49.7%。从微观结构、表面润湿和化学键合等方面,研究了上述表面改性方法强化镍与 CFRP 键合的机理。喷砂处理可在镍板表面形成不规则凹坑。这些不规则凹坑有效改善了镍板的表面粗糙度,但对表面润湿性影响不大。偶联剂处理对镍板的表面粗糙度影响不大,但接枝偶联剂分子后,润湿性会大大改善。复合偶联剂处理通过等离子处理引入 -OH 和 -NH2 基团,提高偶联剂分子在镍板表面的接枝率,达到增强 CFRP/Ni 粘接的目的。该研究有望为镍与 CFRP 及其他异质材料的连接提供研究思路。



来源:复合材料力学仿真Composites FEM
ACTMechanicalSystemMarcDeform疲劳断裂化学航空航天裂纹理论材料仿生控制试验
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首次发布时间:2024-11-03
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【新文速递】2023年11月8日固体力学SCI期刊最新文章

今日更新:International Journal of Solids and Structures 3 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 StructuresAn iterative plane stress integrated Transformation Field Analysis for Equivalent Homogeneous Medium characterization and localization — Application to structural holesLeconte Nicolas, Langrand Bertrand, Kruch Sergedoi:10.1016/j.ijsolstr.2023.112559 用于等效均质介质特征描述和定位的迭代平面应力综合变换场分析--应用于结构孔洞Full-scale structure models of high-energy situations exhibited insufficient localization when connector elements were employed to model the assemblies. An alternative approach using a super-element featuring a hole was proposed and successful in mechanical fields localization. However this approach was restrained to linear problems. An extension to materially non-linear problems was thus looked for, and in particular perforated plate materially non-linear fields.An iterative plane stress integrated TFA method is thus developed to relocate the micro-scale elastic–plastic mechanical fields of a plate containing an extremely soft medium / a strong discontinuity: a hole. To this end, a RVE is defined and discretized, the accuracy of the localization relation is assessed, and a radial return algorithm is set-up to integrate the constitutive equation of the micro-scale problem. The results of the proposed TFA approach are compared to an analytical solution and to non-linear FEA. The results show that the localization of elastic–plastic perforated plate mechanical fields is accurate, provided that the method is iterative and that the hole is discretized in the RVE. It is foreseen that both the sequential and integrated TFA approaches will be combined to evaluate criteria in full-scale structure computations.当采用连接器元件对装配体进行建模时,高能量情况下的全尺寸结构模型显示出定位不足。有人提出了另一种方法,即使用具有孔洞的超级元素,并在机械场定位方面取得了成功。然而,这种方法仅限于线性问题。因此,需要将其扩展到材料非线性问题,特别是穿孔板材料非线性场。因此,我们开发了一种迭代平面应力集成 TFA 方法,用于重新定位含有极软介质/强不连续性(孔)的板的微尺度弹塑性机械场。为此,对 RVE 进行了定义和离散化,评估了定位关系的准确性,并建立了径向返回算法来整合微尺度问题的构成方程。将所提出的 TFA 方法的结果与分析解法和非线性有限元分析法进行了比较。结果表明,弹性塑性穿孔板机械场的定位是准确的,前提是该方法是迭代的,并且孔在 RVE 中被离散化。可以预见,在全尺寸结构计算中,将结合顺序和综合 TFA 方法来评估标准。Cage-shaped self-folding mechanical metamaterialsMeng Zhiqiang, Gao Xu, Yan Hujie, Liu Mingchao, Cao Huijie, Mei Tie, Qing Chen Changdoi:10.1016/j.ijsolstr.2023.112560 笼状自折叠机械超材料Self-folding is an effective design method for mechanical metamaterials with complex configurations and multiple material components. However, existing self-folding mechanical metamaterials are typically limited to a single transformation, limiting their potential for various deformation modes and diverse application scenarios. In this paper, we present the design of a cage-shaped, self-folding mechanical metamaterial. This metamaterial exhibits multiple deformation modes from an initial flat state upon heating to different temperatures and subsequently remains stable upon cooling. The constituent self-folding elements of the metamaterial comprise temperature-responsive materials to achieve different folding thresholds. Theoretical models have been developed to quantify the mechanical properties of the metamaterial, enabling programmable design of its mechanical performance. We also demonstrate that the cage-shaped mechanical metamaterial has tunable mechanical properties, multi-stage load-bearing, and decoupling of mechanical performance, providing the possibility of multifunctional applications in various fields.对于具有复杂结构和多种材料成分的机械超材料来说,自折叠是一种有效的设计方法。然而,现有的自折叠机械超材料通常局限于单一变形,限制了它们在各种变形模式和不同应用场景中的潜力。在本文中,我们介绍了一种笼形自折叠机械超材料的设计。这种超材料在加热到不同温度时,会从最初的平面状态表现出多种变形模式,并在冷却后保持稳定。超材料的自折叠元件由温度响应材料组成,以实现不同的折叠阈值。我们建立了理论模型来量化超材料的机械性能,从而实现了对其机械性能的可编程设计。我们还证明,笼形机械超材料具有可调的机械特性、多级承重和解耦机械性能,为其在各个领域的多功能应用提供了可能。Asymptotic analysis of thin linear elastic layers constrained by two rigid platesMovchan A.B., Movchan N.V., Rodin G.J.doi:10.1016/j.ijsolstr.2023.112561受两块刚性板约束的线性弹性薄层的渐近分析Two asymptotic solutions are presented for linear elastic thin, not necessarily circular, cylindrical layers fully constrained by two rigid plates. Other than being small, the plate displacements and rotations are not restricted, and therefore, in general, a constrained layer is subjected to combined stretching, bending, shearing, and twisting. The first solution is restricted to layers formed by compressible solids, whose Poisson’s ratio is not too close to one half. This solution is a superposition of a polynomial displacement field, valid in the bulk of the layer, and a corrective displacement field, which decays exponentially fast away from the cylindrical surface and becomes negligible at distances comparable to the layer thickness. The second solution is not restricted in terms Poisson’s ratio but it is correct only to a leading order. This solution unifies leading-order solutions for layers formed by compressible, nearly incompressible, and incompressible solids. The unification involves a parameter characterizing the competition between compressibility and thinness.本文提出了两个线性弹性薄圆柱层(不一定是圆形)的渐近解,这些薄层完全受到两块刚性板的约束。板的位移和旋转除了很小以外没有其他限制,因此一般来说,约束层会受到拉伸、弯曲、剪切和扭曲的综合作用。第一种解法仅限于由泊松比不太接近二分之一的可压缩固体形成的层。这种解法是多项式位移场和修正位移场的叠加,多项式位移场在层的主体上有效,修正位移场在远离圆柱表面的地方以指数速度衰减,在与层厚度相当的距离上可以忽略不计。第二种解法不受泊松比的限制,但其正确性仅限于前导阶。这种解法统一了由可压缩、几乎不可压缩和不可压缩固体形成的层的先导阶解法。这种统一涉及一个参数,该参数表征了可压缩性和薄度之间的竞争。Journal of the Mechanics and Physics of SolidsA treatment of particle-electrolyte sharp interface fracture in solid-state batteries with multi-field discontinuitiesZhang Xiaoxuan, Gupta Tryaksh, Wang Zhenlin, Trewartha Amalie, Anapolsky Abraham, Garikipati Krishnadoi:10.1016/j.jmps.2023.105490多场不连续固态电池中颗粒-电解质尖锐界面断裂的处理方法In this work, we present a computational framework for coupled electro-chemo-(nonlinear) mechanics at the particle scale for solid-state batteries. The framework accounts for interfacial fracture between the active particles and solid electrolyte due to intercalation stresses. We extend discontinuous finite element methods for a sharp interface treatment of discontinuities in concentrations, fluxes, electric fields and in displacements, the latter arising from active particle-solid electrolyte interface fracture. We model the degradation in the charge transfer process that results from the loss of contact due to fracture at the electrolyte-active particle interfaces. Additionally, we account for the stress-dependent kinetics that can influence the charge transfer reactions and solid state diffusion. The discontinuous finite element approach does not require a conformal mesh. This offers the flexibility to construct arbitrary particle shapes and geometries that are based on design, or are obtained from microscopy images. The finite element mesh, however, can remain Cartesian, and independent of the particle goemetries. We demonstrate this computational framework on micro-structures that are representative of solid-sate batteries with single and multiple anode and cathode particles.在这项研究中,我们为固态电池的粒子尺度提出了一个电化学(非线性)耦合力学计算框架。该框架考虑了活性颗粒与固体电解质之间因插层应力而产生的界面断裂。我们扩展了非连续有限元方法,对浓度、通量、电场和位移的不连续性进行了尖锐的界面处理,后者是由活性粒子-固体电解质界面断裂引起的。我们模拟了电解质-活性粒子界面断裂导致接触丧失而引起的电荷转移过程退化。此外,我们还考虑了可能影响电荷转移反应和固态扩散的应力相关动力学。非连续有限元方法不需要共形网格。这样就可以灵活地根据设计或显微镜图像构建任意的粒子形状和几何结构。不过,有限元网格可以保持笛卡尔式,与粒子的几何形状无关。我们在具有单个和多个阳极和阴极粒子的固态电池微结构上演示了这一计算框架。International Journal of PlasticityModeling and numerical simulation of liquid crystal elastomers with thermo-electro-mechanical couplingGuo Qiang, Zheng Yue, Cai Shengqiangdoi:10.1016/j.ijplas.2023.103799热-电-机耦合液晶弹性体的建模与数值模拟Liquid crystal elastomer (LCE), as a newly emerging soft material, has been extensively explored to construct diverse structures for a wide range of applications. Many unique yet complex properties of LCEs originate from the tight coupling between the alignment of liquid crystal mesogens and the deformation of polymer network. It makes the modeling and simulation of the deformation of LCEs caused by the actions of multiple external stimuli very challenging. In this work, we formulate a theoretical framework to model the intricate behaviors of LCEs with thermo-electro-mechanical coupling and derive analytical solutions for homogeneous deformation. To implement the model in finite element simulation, a numerical approach that employs a quasi-convexified free energy function and achieves a key transformation of reference configuration is proposed. The numerical approach is further developed into a user subroutine for the commercial software ABAQUS. Various simulations are conducted by using it to validate the effectiveness of the model and numerical approach, as well as to demonstrate their potential applications. We hope the current work, particularly the developed program, provides a useful tool for various researchers to study the complex phenomena of LCEs.液晶弹性体(LCE)作为一种新兴的软材料,已被广泛应用于构建各种结构。液晶弹性体的许多独特而复杂的特性源于液晶介质的排列与聚合物网络的变形之间的紧密耦合。因此,对液晶介质在多种外部刺 激作用下的变形进行建模和模拟极具挑战性。在这项工作中,我们建立了一个理论框架,为具有热-电-机械耦合的 LCE 的复杂行为建模,并推导出均匀变形的解析解。为了在有限元模拟中实现该模型,我们提出了一种采用准凸自由能函数的数值方法,并实现了参考构型的关键转换。该数值方法被进一步开发成商业软件 ABAQUS 的用户子程序。我们利用它进行了各种模拟,以验证模型和数值方法的有效性,并展示其潜在应用。我们希望当前的工作,尤其是开发的程序,能为各类研究人员研究 LCE 的复杂现象提供有用的工具。Thin-Walled StructuresDynamic responses of kerosene-filled riveted tanks subjected to hydrodynamic ram caused by ballistic impactsRen Kerong, Yuan Wenhao, Hua Qing, Peng Yong, xu Wentao, Jia Haobo, li Xiangyu, Lu Fangyundoi:10.1016/j.tws.2023.111337煤油填充铆接储罐在弹道撞击造成的流体冲压下的动态响应The hydrodynamic ram (HRAM) is a hydrodynamic pressure phenomenon that occurs when high-speed projectiles impact a liquid-filled tank. During combat missions, aircraft are prone to HRAMs caused by projectile impacts, which can damage the structural integrity of riveted tanks, posing a threat to flight safety. In this study, kerosene-filled riveted tanks were chosen as the research object. The dynamic response histories of the rear panel were observed using the three-dimensional digital image correlation (3D-DIC) technique. Additionally, numerical simulations of the projectile's impact on the tank were performed using the fluid–structure interaction finite element method. The simulation results had a good fit with the experimental results. The spatial and temporal distribution of the HRAM and the effect of the projectile impact velocity on the deformation of the tank structure were further analyzed. The impulse exerted by the drag wave on the rear panel was greater than that of the pioneer wave. However, the drag wave's region was limited to a radius of 6 cm around the exit point with the impact velocity range of the projectile of 955 m·s−1–1607 m·s−1 in both the experiments and simulations. When the impact velocity of the projectile reached 955 m·s−1, radial plastic hinge lines appeared on the rear panel along the diagonal direction. When the impact velocity increased to 1607 m·s−1, radial plastic hinge lines along the diagonal direction, and traveling plastic hinges at the root of the central cross-shaped cracks appeared on the rear panel, accompanied by a petal-shaped hole. Based on the spatial distribution of the impulse on the rear panel, a dimensional relationship was established between the hole size and the impulse on the rear panel. The petal model for describing petal-shaped cracks was proposed based on the law of conservation of energy, which could predict the hole size in the case of projectile impact at high velocity. The research results are of great significance for the study of the damage of riveted tanks with HRAMs and provide support for the vulnerability analysis of aircraft tanks.流体动力冲压(HRAM)是一种流体动力压力现象,当高速射弹撞击充满液体的油箱时就会发生。在执行作战任务时,飞机很容易受到弹丸撞击而产生 HRAM,从而破坏铆接油箱的结构完整性,对飞行安全构成威胁。本研究选择煤油填充铆接油箱作为研究对象。使用三维数字图像相关(3D-DIC)技术观察了后面板的动态响应历史。此外,还使用流固耦合有限元法对弹丸对油箱的冲击进行了数值模拟。模拟结果与实验结果吻合良好。进一步分析了 HRAM 的时空分布以及弹丸撞击速度对坦克结构变形的影响。阻力波对后面板产生的冲力大于先驱波。然而,在实验和模拟中,当弹丸的冲击速度范围为 955 m-s-1-1607 m-s-1 时,阻力波的作用区域仅限于出口点周围 6 cm 的半径范围内。当弹丸的冲击速度达到 955 m-s-1 时,后面板上出现了沿对角线方向的径向塑性铰链线。当冲击速度增加到 1607 m-s-1 时,后面板上出现了沿对角线方向的径向塑性铰链线和位于中央十字形裂纹根部的游动塑性铰链,并伴有花瓣形孔。根据后面板上冲量的空间分布,建立了孔洞大小与后面板上冲量之间的尺寸关系。根据能量守恒定律,提出了描述花瓣形裂纹的花瓣模型,该模型可以预测高速弹丸冲击时的孔洞大小。该研究成果对研究带 HRAM 的铆接坦克的损伤具有重要意义,并为飞机坦克的脆弱性分析提供了支持。来源:复合材料力学仿真Composites FEM

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