首页/文章/ 详情

【新文速递】2024年4月3日固体力学SCI期刊最新文章

14天前浏览287

 

今日更新:Mechanics of Materials 1 篇,Thin-Walled Structures 5 篇

Mechanics of Materials

Failure mechanisms at the Li anode/solid electrolyte interface during Li stripping

S.S. Shishvan, N.A. Fleck, R.M. McMeeking, V.S. Deshpande

doi:10.1016/j.mechmat.2024.104990

锂剥离过程中锂离子阳极/固体电解质界面的失效机制

A precipitous increase in the resistance of the Li metal/solid electrolyte interface can occur during the stripping of Li from the electrode. This electrical failure has been typically attributed to the loss of contact associated with the growth of voids in the Li anode at the electrode/electrolyte interface. We first analyse the growth of voids at the electrode/electrolyte interface using a framework that couples the power-law creep deformation of the Li electrode and the flux of L i + through a single-ion conductor solid electrolyte. We show that a modified Butler-Volmer kinetics where the local interfacial resistance decreases due to dislocations within the creeping Li predicts that voids indeed grow around interfacial sub-micron impurity particles. Consistent with observations that the increase in resistance of interface occurs earlier for thinner electrodes, we predict that the propensity of void growth increases with decreasing electrode thickness, and this is associated with the mechanical constraint imposed by the current collector. However, in contrast to the observations and rather counterintuitively, this analysis predicts that the cell voltage decreases with void growth. Consequently, we investigate an alternative mechanism of contact loss due to the deposition of insulating solute atoms within the Li electrode onto the interface. Predictions of the rising cell voltage using this analysis are in broad agreement with measurements. This leads us to hypothesize that although void growth occurs at the interface it is not the primary mechanism leading to the increase in interface resistance during stripping.

在电极剥离锂的过程中,锂金属/固体电解质界面的电阻会急剧增加。这种电气失效通常归因于电极/电解质界面上锂阳极空隙的增长导致的接触损失。我们首先利用锂电极的幂律蠕变变形与通过单离子导体固体电解质的 L i + 通量的耦合框架来分析电极/电解质界面空隙的生长。我们的研究表明,根据修正的巴特勒-沃尔默动力学,蠕变锂电极内部的位错会导致局部界面电阻减小,因此可以预测界面亚微米杂质颗粒周围确实会出现空隙。与电极越薄界面电阻越早增加的观察结果一致,我们预测空隙生长的倾向会随着电极厚度的减小而增加,这与集流器施加的机械约束有关。然而,与观察结果相反的是,这一分析预测电池电压会随着空洞的增加而降低,这与直觉相反。因此,我们研究了由于锂电极内的绝缘溶质原子沉积到界面上而导致接触损失的另一种机制。利用这种分析方法对电池电压上升的预测与测量结果基本一致。由此我们推测,虽然界面上会出现空隙增长,但这并不是导致剥离过程中界面电阻增加的主要机制。


Thin-Walled Structures

Global buckling and resistances of austenitic stainless steel semi-oval hollow section beam-columns

Shuai Li, Tong Guo, Ou Zhao

doi:10.1016/j.tws.2024.111851

奥氏体不锈钢半椭圆空心截面梁柱的整体屈曲和抗力

As advanced manufacturing technologies become increasingly mature in civil engineering, novel tubular sections, characterised by appealing architectural appearance and prominent structural efficiency, can be fabricated, with an example being semi-oval hollow section. The present paper reports an experimental and numerical investigation into the global buckling behaviour and resistances of austenitic stainless steel semi-oval hollow section beam-columns under combined compression and bending. An experimental programme was firstly performed on ten austenitic stainless steel semi-oval hollow section beam-column specimens and included initial geometric imperfection measurements and eccentric compression tests. The obtained test failure loads, load–mid-height lateral deflection curves and failure modes were fully reported. Following the experimental programme, a numerical modelling programme was conducted, including validation studies to validate developed finite element models against the test results and parametric studies to generate additional numerical data. Given that the existing European code and American specification do not cover the design of stainless steel semi-oval hollow section components, the applicability of the codified design interaction curves for austenitic stainless steel circular hollow section beam-columns to their semi-oval hollow section counterparts was evaluated based on the obtained test and numerical data. The European code was found to result in relatively accurate and consistent resistance predictions for austenitic stainless steel semi-oval hollow section beam-columns with Class 1 and 2 cross-sections, but the resistance predictions for those with Class 3 cross-sections were conservative and scattered. The American specification was shown to offer overall accurate and consistent resistance predictions, but some resistance predictions were marginally unsafe.

随着先进制造技术在土木工程领域的日益成熟,可以制造出具有迷人建筑外观和突出结构效率的新型管状截面,半椭圆形空心截面就是一个例子。本文对奥氏体不锈钢半椭圆形空心截面梁柱在压缩和弯曲联合作用下的整体屈曲行为和阻力进行了实验和数值研究。首先对十个奥氏体不锈钢半椭圆空心截面梁柱试样进行了实验,包括初始几何缺陷测量和偏心压缩试验。试验中获得的失效载荷、载荷-中高侧向挠度曲线和失效模式得到了全面报告。实验计划结束后,进行了数值建模计划,包括根据测试结果验证开发的有限元模型的验证研究,以及生成更多数值数据的参数研究。鉴于现有的欧洲规范和美国规范并不涵盖不锈钢半椭圆形空心截面组件的设计,因此根据获得的测试和数值数据,对奥氏体不锈钢圆形空心截面梁柱的编纂设计交互曲线对其半椭圆形空心截面组件的适用性进行了评估。结果发现,欧洲规范对 1 级和 2 级截面的奥氏体不锈钢半椭圆形空心截面梁柱的阻力预测相对准确且一致,但对 3 级截面的梁柱的阻力预测则保守且分散。美国规范的阻力预测总体准确、一致,但某些阻力预测略显不安全。


Modeling and free vibration analysis of bolted composite flanged cylindrical-cylindrical shells under partial bolt loosening conditions

Honghao Liu, Wei Sun, Xiaofeng Liu, Hongwei Ma, Dongxu Du, Hui Li

doi:10.1016/j.tws.2024.111853

部分螺栓松动条件下螺栓连接复合法兰圆柱-圆柱壳体的建模和自由振动分析

The bolted composite coupled cylindrical shell is a common substructure in modern engineering, which may encounter the issue of local loosening conditions during service. Meanwhile, the influence of flanges on the structural vibration characteristics is often overlooked in dynamic numerical analysis. In this paper, a semi-analytical dynamic model for the bolted composite flanged cylindrical-cylindrical shell structure under arbitrary connection conditions is established, and the free vibration characteristics of locally loose structures are emphatically studied. In the model, the annular plate modeling method is developed to achieve the simulation of the flange part. To fully reflect the connection characteristics of the bolted joint, a spring surface model and the corresponding parameter determination method based on fractal contact theory are developed. The equations of motion of the structure are obtained utilizing the Lagrange equations. The accuracy of the model and its predictive ability for the vibration characteristics of the bolted composite flanged cylindrical-cylindrical shell under local loosening conditions are fully demonstrated through numerous comparisons with experimental results from other literature and modal test results obtained under various working conditions. Furthermore, the influence of the number and degree of loosening bolts on the free vibration characteristics of the structure and the coupling phenomenon between different modes are discussed. The research in this paper is expected to provide references for the design of bolted composite flanged cylindrical shell structures and the monitoring of bolt connection defects.

螺栓连接的复合耦合圆柱壳体是现代工程中常见的下部结构,在使用过程中可能会遇到局部松动的问题。同时,在动态数值分析中,法兰对结构振动特性的影响往往被忽视。本文建立了任意连接条件下螺栓复合法兰圆柱-圆柱壳体结构的半解析动力学模型,重点研究了局部松动结构的自由振动特性。在该模型中,开发了环形板建模方法来实现法兰部分的模拟。为充分反映螺栓连接的连接特性,建立了基于分形接触理论的弹簧面模型和相应的参数确定方法。利用拉格朗日方程获得了结构的运动方程。通过与其他文献中的实验结果和各种工况下的模态测试结果进行大量比较,充分证明了该模型的准确性及其对局部松动条件下螺栓复合法兰圆柱-圆柱壳体振动特性的预测能力。此外,还讨论了螺栓数量和松动程度对结构自由振动特性的影响以及不同模态之间的耦合现象。本文的研究有望为螺栓连接复合法兰圆柱壳结构的设计和螺栓连接缺陷的监测提供参考。


In-plane bidirectional dynamic crushing behaviors of a novel misplaced reinforced honeycomb

Junwei Pan, Qian Zhang, Meng Li, Jianguo Cai

doi:10.1016/j.tws.2024.111856

新型错位强化蜂窝材料的平面内双向动态挤压行为

Reinforced honeycomb exhibits exceptional energy dissipation capability. A misplaced design was introduced into reinforced honeycomb (RHC) in this paper, and a novel misplaced reinforced honeycomb structure was proposed (MRHC). The in-plane mechanical properties of MRHC was investigated experimentally, numerically and theoretically. MRHC possesses two plateau stresses in the two in-plane principle directions during low-velocity impact, while the RHC structure demonstrates this characteristic solely in one in-plane direction. The collapse modes and energy absorption performance of the MRHC structure under various impact velocities were investigated. The plateau stress behavior of the MRHC structure was investigated under various unit rotation angles. The two plateau stresses of the MRHC structure exhibit higher values when compared to the previously proposed structure with two plateau stresses. The structures exhibiting two-stage deformation characteristics can determine the extent of collision damage by analyzing the transformation of their structural configuration, establishing a foundation for the design of intelligent structures.

增强蜂窝具有卓越的消能能力。本文将错位设计引入增强蜂窝(RHC),并提出了一种新型错位增强蜂窝结构(MRHC)。实验、数值和理论研究了 MRHC 的平面力学性能。在低速冲击过程中,MRHC 在两个面内原理方向上具有两个高原应力,而 RHC 结构仅在一个面内方向上表现出这一特性。研究了 MRHC 结构在不同冲击速度下的坍塌模式和能量吸收性能。研究了不同单位旋转角度下 MRHC 结构的高原应力行为。与之前提出的具有两个高原应力的结构相比,MRHC 结构的两个高原应力值更高。表现出两阶段变形特征的结构可通过分析其结构配置的变化来确定碰撞损坏的程度,为智能结构的设计奠定了基础。


Theoretical modeling and vibration analysis of composite laminated wing-box structures of hydrogen-electric aircraft under hygrothermal environment

Xuyuan Song, Wenrui Zhao, Jian Zang, Zhen Zhang, Yewei Zhang

doi:10.1016/j.tws.2024.111854

湿热环境下氢电飞机复合材料层叠翼盒结构的理论建模与振动分析

For the sake of achieving the goal of ultra-low or even zero carbon emissions during flight, hydrogen-electric aircraft has been receiving increasing emphasis. Nevertheless, the hydrogen-electric aircraft owns an all-composite fuselage configuration and is subjected hygrothermal environment, which have a significant effect on the aircraft dynamics, especially for wing structure. In this study, an improved orthogonal polynomial solution based on the Rayleigh-Ritz method is developed for the dynamic analysis of composite laminated wing-box structures (CLWBSs) of hydrogen-electric aircraft with humid and hot environment and elastic boundary. In this solution approach, the potential energy, kinetic energy, elastic potential energy and hygrothermal potential energy of CLWBSs are derived from the framework of Kirchhoff thin plate hypothesis. A set of artificial springs is imported to the free edges of CLWBSs to simulate the elastic boundary and connection between two plates. The convergence, accuracy and computational efficiency of the proposed formulation are validated by experiment and finite element analysis. The effect of the coupling parameters and the elastic boundaries due to flexible composite fuselage in hygrothermal environment created by the hydrogen fuel cells are systematically investigated which have been confirmed by theoretical research, finite element analysis and experiment. The related findings indicate that the present approach provided an effective formulation for the vibration analysis and optimization of flexible composite wing-box structures. It can be applied in the field of aerospace and navigation industry at the same time.

为了实现飞行过程中超低甚至零碳排放的目标,氢电动飞机越来越受到重视。然而,由于氢电动飞机采用全复合材料机身结构,且受湿热环境影响较大,对飞机动力学,尤其是机翼结构影响较大。本研究针对氢电动飞机复合材料层压翼盒结构(CLWBS)在湿热环境和弹性边界下的动力学分析,提出了一种基于 Rayleigh-Ritz 方法的改进正交多项式求解方法。在这种求解方法中,CLWBS 的势能、动能、弹性势能和湿热势能都是从基尔霍夫薄板假说的框架中推导出来的。在 CLWBS 的自由边缘导入一组人工弹簧,以模拟两板之间的弹性边界和连接。实验和有限元分析验证了所提公式的收敛性、准确性和计算效率。通过理论研究、有限元分析和实验,系统地研究了氢燃料电池产生的湿热环境中柔性复合材料机身的耦合参数和弹性边界的影响。相关研究结果表明,本方法为柔性复合材料机翼箱体结构的振动分析和优化提供了有效的公式。该方法可同时应用于航空航天和航海工业领域。


Adjusting Dynamic and Damping Performance in Fiber-Reinforced Magnetorheological Elastomer Composite Conical Shells Subjected to Compressive Loads

Yunhe Zou, Shufeng Tang, Shijie Guo, Xiaodong He, Xianjuan Song, Xiaowen Song, Artin Hozuri

doi:10.1016/j.tws.2024.111855

调整承受压缩载荷的纤维增强磁流变弹性体复合锥形壳体的动态和阻尼性能

This study explores the dynamic behavior of axially loaded conical shells composed of magnetorheological elastomer composites (MRECs). The investigation focuses on analyzing the impact of compressive loads on the frequencies and loss factors of these composites. The MRECs consist of laminates reinforced with fibers, enabling tunable viscoelastic properties through the utilization of magnetic fields. The equivalent mechanical characteristics of the MREC are calculated using the modified Voigt and Halpin-Tsai micromechanical rules. By employing the first-order shear deformation theory and Sanders-based strains, the kinematics of the conical shell are accurately modeled. A semi-analytical analysis, combining trigonometric expansion and the generalized differential quadrature (GDQ) methods, is employed to solve the system's highly coupled partial differential equations. Two consecutive analyses are performed. Firstly, the critical buckling load of the MREC conical shell is obtained through a stability analysis. Subsequently, the frequencies and loss factors of the shell in the pre-buckling zone are computed. Parametric analyses are conducted to study the impact of key factors, including magnetic field strength, compressive load magnitude, composite properties, geometric parameters, and boundary conditions. The proposed methodology is rigorously validated through meticulous accuracy and convergence analysis. The outcomes provide valuable insights into the dynamic response of axially loaded magnetorheological elastomer composite conical shells, highlighting their potential in adjustable dynamic and damping systems.

本研究探讨了由磁流变弹性体复合材料(MREC)构成的轴向加载锥形壳体的动态行为。研究重点是分析压缩载荷对这些复合材料的频率和损耗因子的影响。磁流变弹性体复合材料由纤维增强的层压板组成,通过利用磁场实现可调的粘弹性能。MREC 的等效机械特性是利用改进的 Voigt 和 Halpin-Tsai 微机械规则计算得出的。通过采用一阶剪切变形理论和基于桑德斯的应变,对锥形外壳的运动学进行了精确建模。结合三角展开和广义微分正交(GDQ)方法的半解析分析被用来求解系统的高度耦合偏微分方程。连续进行了两次分析。首先,通过稳定性分析得出 MREC 锥壳的临界屈曲载荷。随后,计算壳体在预屈曲区的频率和损耗因子。通过参数分析,研究了磁场强度、压缩载荷大小、复合材料特性、几何参数和边界条件等关键因素的影响。通过细致的精度和收敛性分析,对所提出的方法进行了严格验证。研究结果为轴向加载磁流变弹性体复合锥形壳的动态响应提供了宝贵的见解,凸显了其在可调动态和阻尼系统中的潜力。



来源:复合材料力学仿真Composites FEM
ACTMechanicalSystemFluxMAGNET振动复合材料碰撞燃料电池航空航天建筑理论材料试验螺栓电气
著作权归作者所有,欢迎分享,未经许可,不得转载
首次发布时间:2024-11-13
最近编辑:14天前
Tansu
签名征集中
获赞 6粉丝 0文章 776课程 0
点赞
收藏
作者推荐

【新文速递】2024年4月7日复合材料SCI期刊最新文章

今日更新:Composite Structures 5 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Science and Technology 1 篇Composite StructuresA novel modeling and homogenization method of macro fiber composites considering inhomogeneous poling induced by interdigital electrodesHongli Ji, Yuemin Du, Chongcong Tao, Chao Zhang, Jinhao Qiudoi:10.1016/j.compstruct.2024.118082考虑数字间电极引起的不均匀极化现象的宏观纤维复合材料的新型建模和均质化方法Macro fiber composites (MFCs) are widely used in various fields due to their excellent piezoelectric performance. This paper presents a novel method that combines analytical and finite element analysis to accurately model MFCs. The method iteratively calculates the nonlinear poling field generated by interdigital electrodes (IDEs), leading to reliable estimates of the local orientation and properties of the piezoceramic. The local poling state is then incorporated into a 3D representative volume element (RVE) model to determine the strain response of the device under realistic loading conditions. The influence of the poling voltages, piezoceramic fiber thickness, and IDE geometries on the poling and actuating performance of the device is studied. Furthermore, considering the complexity of the modeling the entire MFC device, a simplified method is further presented that is much more efficient and maintains the same level of accuracy.宏观纤维复合材料(MFC)因其卓越的压电性能而被广泛应用于各个领域。本文介绍了一种结合分析和有限元分析的新方法,以精确建立 MFC 模型。该方法通过迭代计算数字间电极 (IDE) 产生的非线性极化场,从而对压电陶瓷的局部取向和特性做出可靠的估计。然后将局部极化状态纳入三维代表体积元素 (RVE) 模型,以确定器件在实际加载条件下的应变响应。研究了极化电压、压电陶瓷纤维厚度和 IDE 几何结构对装置极化和致动性能的影响。此外,考虑到整个 MFC 设备建模的复杂性,还进一步介绍了一种简化方法,该方法效率更高,且精度保持不变。Exploring the nonlinear response of cracked variable stiffness composite plates using plate decomposition methodF. Rashidi, S.A.M. Ghannadpour, A. Farrokhabadidoi:10.1016/j.compstruct.2024.118095利用板分解法探索开裂变刚度复合板的非线性响应This article examines the impact of crack characteristics such as length and position and also layup and boundary conditions on the nonlinear and post-buckling behavior of relatively thick variable stiffness composite plates. The Ritz method utilizes Legendre polynomials to approximate the displacements. The bending behavior of the plates is described using the first-order shear deformation theory of plates and von Karman assumptions. To model the crack, the entire plate domain is divided into six plate elements using the plate decomposition technique. Interface continuity between the plate elements is ensured using the penalty technique. The total potential energy of the plate is determined by summing the potential energies of the plate elements and the penalty value. To validate the results and assess convergence, ABAQUS software is utilized for all the findings presented in this article.本文研究了裂纹特征(如长度和位置)以及铺层和边界条件对相对较厚的变刚度复合板的非线性和屈曲后行为的影响。Ritz 方法利用 Legendre 多项式来近似位移。板材的弯曲行为采用板材一阶剪切变形理论和 von Karman 假设进行描述。为建立裂缝模型,使用板分解技术将整个板域划分为六个板元。使用惩罚技术确保板元素之间的界面连续性。板的总势能由板元素的势能和惩罚值相加确定。为了验证结果和评估收敛性,本文中介绍的所有结果都使用了 ABAQUS 软件。Vibration control and bandgap tuning of Layer-Gradient periodic pipes based on composite cellWenjie Li, Xiangxi Kong, Qi Xu, Ziyu Haodoi:10.1016/j.compstruct.2024.118109基于复合单元的层梯度周期管道的振动控制和带隙调整This paper presents a vibration control strategy that installs layer-gradient periodic pipes on general pipelines to suppress the transmission of bending vibration. Bandgap tuning can be achieved without changing the structural size. Initially, a composite cell is constructed based on the bandgap characteristics of ordinary periodic pipes, and a layer-gradient periodic pipe is innovatively designed. Secondly, the bending vibration model of the fluid-filled pipeline under external axial force is established using Hamilton's principle. Combining Bloch's theorem, the transfer matrix method is applied to derive the transfer formula for bending waves. The band structure of the layer-gradient periodic pipe is obtained by solving the eigenvalue equation. Subsequently, the frequency tuning advantages of the layer-gradient periodic pipes are demonstrated through a comparison with the conventional periodic pipes. The effectiveness of the proposed vibration control strategy is verified by finite element simulation. Finally, the effects of liquid filling, layer thickness ratio, number of layers, component ratio, and different material combinations on the bandgap characteristics are discussed. The results indicate that the layer-gradient periodic pipe can reduce the frequency of high-order bandgaps to a certain extent. This study can provide insights into the structural design, bandgap tuning, and engineering applications of periodic pipes in limited spaces.本文介绍了一种振动控制策略,即在一般管道上安装层梯度周期管道,以抑制弯曲振动的传播。带隙调整可以在不改变结构尺寸的情况下实现。首先,根据普通周期管道的带隙特性构建了复合单元,并创新性地设计了层梯度周期管道。其次,利用汉密尔顿原理建立了充满流体的管道在外力轴向作用下的弯曲振动模型。结合布洛赫定理,运用传递矩阵法推导出弯曲波的传递公式。通过求解特征值方程,得到了层梯度周期管道的带状结构。随后,通过与传统周期管道的比较,证明了层梯度周期管道的频率调谐优势。通过有限元模拟验证了所提出的振动控制策略的有效性。最后,讨论了液体填充、层厚比、层数、分量比和不同材料组合对带隙特性的影响。结果表明,层梯度周期性管道能在一定程度上降低高阶带隙的频率。这项研究可为有限空间内周期管道的结构设计、带隙调整和工程应用提供启示。Blast performance of polyurethane foam-filled auxetic honeycomb sandwich beamsWen Wu, Yan Liu, Junbo Yan, Baichuan Wang, Fan Bai, Fenglei Huangdoi:10.1016/j.compstruct.2024.118104聚氨酯泡沫填充辅助蜂窝夹层梁的抗爆性能This paper examines the impact of polyurethane foam (PUF) filling on the dynamic response of honeycomb sandwich beams (HSBs) through the blast testing. The HSBs are composed of steel face sheets and an aluminium alloy honeycomb core filled with PUF. A comparative analysis of damage modes is conducted between conventional hexagonal and auxetic HSBs, considering both foam-filled and unfilled configurations. The results reveal that the HSBs with foam filling demonstrate significantly enhanced blast performance compared to their counterparts without foam filling. This superiority is evident in both global deformation and local damage characteristics. Furthermore, a well-validated numerical model is developed to examine the damage mechanisms of PUF-filled HSBs under blast loading. The investigation reveals that appropriate PUF filling methods can effectively enhance bending resistance while minimizing the decline in the energy absorption efficiency. Finally, a multiobjective optimization was conducted using the back-propagation (BP) neural network and the SPEA2 algorithm to identify the optimal position for PUF. By utilizing a reduced foam filling approach as opposed to completely filling the structure, the two optimized configurations show a decrease in deformation of 5.38% with an equivalent specific energy absorption (SEA) or an increase in the SEA by 5.26% with an equivalent deformation.本文通过爆炸试验研究了聚氨酯泡沫(PUF)填充物对蜂窝夹层梁(HSB)动态响应的影响。蜂窝夹层梁由钢面板和填充聚氨酯泡沫的铝合金蜂窝芯组成。考虑到泡沫填充和未填充两种配置,对传统六边形和辅助蜂窝夹层梁的损坏模式进行了比较分析。结果表明,与未填充泡沫的同类产品相比,填充泡沫的 HSB 爆破性能明显提高。这种优越性在整体变形和局部损伤特征方面都很明显。此外,还开发了一个经过充分验证的数值模型,用于研究填充 PUF 的 HSB 在爆炸荷载下的损坏机制。研究表明,适当的 PUF 填充方法可以有效提高抗弯强度,同时最大限度地降低能量吸收效率。最后,利用反向传播(BP)神经网络和 SPEA2 算法进行了多目标优化,以确定 PUF 的最佳位置。通过采用减少泡沫填充而非完全填充结构的方法,两种优化配置显示,在同等比能量吸收(SEA)的情况下,变形减少了 5.38%;或在同等变形的情况下,SEA 增加了 5.26%。A compressible layerwise third-order shear deformation theory with transverse shear stress continuity for laminated sandwich platesY.S. Gao, C.S. Cai, C.Y. Huang, Q.H. Zhu, R. Schmidt, S.Q. Zhangdoi:10.1016/j.compstruct.2024.118108具有横向剪应力连续性的层状夹层板可压缩层向三阶剪切变形理论Sandwich structures with a soft core typically exhibit multiple deformation modes such as bending, twisting and compression when subjected to transverse loads. Compressive behavior of soft core significantly affects the structural response, which is usually neglected in conventional plate theories. Additionally, conventional plate theories do not take into account transverse shear stress continuity. In order to address this concern and precisely characterize the characteristics of arbitrary multilayer laminated structures, a novel electromechanical coupled finite element model is developed. This model is based on a compressible layerwise third-order shear deformation theory with a soft core. Notably, the proposed model theory requires only twelve degrees of freedom for each quadratic element node. The accuracy of the model is validated first. Afterwards, several numerical investigations are carried out for piezolaminated sandwich structures with different width-to-thickness ratios, reinforcement angle and skew angle. The results demonstrate the applicability of the current model in predicting the behavior of laminated sandwich plates.具有软核的三明治结构在承受横向载荷时通常会表现出多种变形模式,如弯曲、扭曲和压缩。软核的压缩行为会对结构响应产生重大影响,而传统的板理论通常会忽略这一点。此外,传统的板理论没有考虑横向剪应力的连续性。为了解决这一问题并精确描述任意多层叠层结构的特性,我们开发了一种新型机电耦合有限元模型。该模型基于具有软核的可压缩层向三阶剪切变形理论。值得注意的是,所提出的模型理论只需要每个二次元节点的十二个自由度。首先验证了模型的准确性。随后,对不同宽厚比、加强角和倾斜角的压层夹层结构进行了多次数值研究。结果表明,当前模型适用于预测层压夹层板的行为。Composites Part A: Applied Science and ManufacturingRapid prediction for deflection history of CFRP beams during curing using LSTM network and its application to stacking sequence optimization with genetic algorithmYuncong Feng, Zhibin Han, Meiyu Liu, Weike Zheng, Biao Liang, Yifeng Xiong, Weizhao Zhangdoi:10.1016/j.compositesa.2024.108195利用 LSTM 网络快速预测 CFRP 梁在固化过程中的挠度历史,并将其应用于利用遗传算法优化堆叠顺序Predicting process-induced deformation (PID) is crucial for part quality control. However, conventional numerical modeling is inefficient for this task as they require strict calculation for the entire parts. For improvement, a long-short term memory (LSTM) network was developed to rapidly predict PID of carbon fiber reinforced polymer (CFRP) beams throughout curing. The training database was generated using the finite element modeling (FEM) method with thermo-viscoelastic constitutive law. The principal component analysis, time standardization and logarithm operation were utilized in data pre-processing to enhance prediction accuracy. Afterwards, the LSTM model was integrated with the Genetic Algorithm to optimize stacking sequence of the CFRP beams for minimal PID, with the result experimentally validated to be less than 0.013 mm deviation in final PID of 7.5 cm long samples. Compared to FEM, the LSTM analysis saved 99.9 % of the running time, enabling fast product quality estimation and PID optimization in production lines.预测加工过程引起的变形(PID)对零件质量控制至关重要。然而,传统的数值建模需要对整个部件进行严格计算,因此效率低下。为了改进这一问题,我们开发了一种长短期记忆(LSTM)网络,用于快速预测碳纤维增强聚合物(CFRP)梁在整个固化过程中的 PID。训练数据库是利用有限元建模(FEM)方法和热-粘弹性构成法生成的。数据预处理采用了主成分分析、时间标准化和对数运算,以提高预测精度。随后,将 LSTM 模型与遗传算法相结合,优化 CFRP 梁的堆叠顺序,以获得最小的 PID,结果经实验验证,7.5 厘米长样品的最终 PID 偏差小于 0.013 毫米。与有限元分析相比,LSTM 分析节省了 99.9% 的运行时间,可在生产线上快速进行产品质量评估和 PID 优化。Composites Science and TechnologyMicro contact modeling of electrical current conduction behavior between carbon fiber yarnsYousong Xue, Zhiyong Li, Shuwei Huang, Xin Xu, Jun Ding, Bohong Gu, Baozhong Sundoi:10.1016/j.compscitech.2024.110587 碳纤维纱之间电流传导行为的微接触建模Electrical contact conduction between carbon fiber yarns is one of the important current conduction paths inside carbon fiber composites and is easily affected with fabric reinforcement structure and manufacturing process. Here we proposed a micro contact model to predict the contact resistance and to reveal the current conduction behavior between carbon fiber yarns. The model takes into account tunneling effect and yarn geometric structure. The fiber contact probability between yarns was determined based on the statistical characteristic of the fiber height on the yarn surface. The relationship between the yarn contact resistance in plain weave fabric and out-of-plane force was measured and the experimental results agree well with the model. We found that the current conduction between yarns depends on contact conduction between fibers and the contribution of tunneling conduction is negligible. The proposed micro contact model provides insight into the current conduction behavior between carbon fiber yarns and is meaningful for the electrical conductivity design of carbon fiber composites.碳纤维纱之间的电接触传导是碳纤维复合材料内部重要的电流传导路径之一,并且很容易受到织物增强结构和制造工艺的影响。在此,我们提出了一个微接触模型来预测接触电阻并揭示碳纤维纱之间的电流传导行为。该模型考虑了隧道效应和纱线几何结构。根据纱线表面纤维高度的统计特性,确定了纱线之间的纤维接触概率。测量了平纹织物中纱线接触电阻与平面外力之间的关系,实验结果与模型十分吻合。我们发现,纱线之间的电流传导取决于纤维之间的接触传导,而隧道传导的贡献可以忽略不计。所提出的微接触模型有助于深入了解碳纤维纱之间的电流传导行为,对碳纤维复合材料的导电性设计很有意义。来源:复合材料力学仿真Composites FEM

未登录
还没有评论
课程
培训
服务
行家
VIP会员 学习 福利任务 兑换礼品
下载APP
联系我们
帮助与反馈