今日更新:Composite Structures 5 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Science and Technology 1 篇
A novel modeling and homogenization method of macro fiber composites considering inhomogeneous poling induced by interdigital electrodes
Hongli Ji, Yuemin Du, Chongcong Tao, Chao Zhang, Jinhao Qiu
doi: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 method
F. Rashidi, S.A.M. Ghannadpour, A. Farrokhabadi
doi: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 cell
Wenjie Li, Xiangxi Kong, Qi Xu, Ziyu Hao
doi: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 beams
Wen Wu, Yan Liu, Junbo Yan, Baichuan Wang, Fan Bai, Fenglei Huang
doi: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 plates
Y.S. Gao, C.S. Cai, C.Y. Huang, Q.H. Zhu, R. Schmidt, S.Q. Zhang
doi: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。
Rapid prediction for deflection history of CFRP beams during curing using LSTM network and its application to stacking sequence optimization with genetic algorithm
Yuncong Feng, Zhibin Han, Meiyu Liu, Weike Zheng, Biao Liang, Yifeng Xiong, Weizhao Zhang
doi: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。
Micro contact modeling of electrical current conduction behavior between carbon fiber yarns
Yousong Xue, Zhiyong Li, Shuwei Huang, Xin Xu, Jun Ding, Bohong Gu, Baozhong Sun
doi: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。