【新文速递】2024年7月22日复合材料SCI期刊最新文章

   

今日更新：Composite Structures 6 篇，Composites Part A: Applied Science and Manufacturing 1 篇，Composites Part B: Engineering 1 篇，Composites Science and Technology 4 篇

Composite Structures

Thermal buckling of variable stiffness composite laminates using high order plate finite elements

F. Bracaglia, R. Masia, A. Pagani, E. Zappino, E. Carrera

doi:10.1016/j.compstruct.2024.118393

用高阶板有限元分析变刚度复合材料层合板的热屈曲

This paper proposes a study on the thermal buckling of Variable Angle Tow (VAT) composite plates using high-order theories. Here, the governing equations are derived via the principle of virtual work. Under the assumption of linear pre-buckling, the stability problem is reduced to a linear eigenvalue analysis considering proportional geometric stiffness. In contrast, a constant thermal load is assumed to be known along the plate thickness, and the uncoupled thermo-mechanical formulation is used, where the thermal effects are described as external loads. The plate is discretized using the Finite Element Method (FEM) and high-order theories are developed using the Carrera Unified Formulation (CUF). Using the CUF, the equations are expressed as an invariant of the plate theory approximation order. Therefore, Equivalent Single Layer (ESL) and Layer-Wise (LW) models can be easily implemented. Several geometries and lamination cases are considered for verification purposes, including different side-to-thickness ratios and fiber orientations, which result in various anisotropy effects. In addition, the effect of changing constraints and materials is evaluated. Particular attention is paid to the effect of the structural theory approximation on the evaluation of the thermal buckling load. It is shown that the correct evaluation is highly dependent on the edge-to-thickness ratio and on the anisotropy given by both the fiber orientation and the material properties. As a final remark, sensitivity analysis and best fibre angle solutions are discussed to highlight the importance of the LW modelling approach.

本文采用高阶理论对变角Tow复合材料板的热屈曲进行了研究。本文利用虚功原理推导了控制方程。线性的假设下前挠曲,稳定性问题是减少到一个线性特征值分析考虑几何刚度成比例。相反，假设沿板厚已知恒定的热负荷，并使用不耦合的热-机械公式，其中热效应被描述为外部负荷。采用有限元法对板进行离散化，采用Carrera统一公式建立了高阶理论。利用CUF，将方程表示为板理论近似阶的不变量。因此，等效单层(ESL)和分层(LW)模型可以很容易地实现。为了验证目的，考虑了几种几何形状和层压情况，包括不同的边厚比和纤维取向，这些都会导致不同的各向异性效应。此外，还评估了约束条件和材料变化的影响。特别注意了结构理论近似对热屈曲载荷评估的影响。结果表明，正确的评价高度依赖于边厚比和纤维取向和材料性能所给出的各向异性。最后，讨论了灵敏度分析和最佳纤维角解，以突出LW建模方法的重要性。

Topological design of soft substrate acoustic metamaterial for mechanical tuning of sound propagation

Yan Li, Xiaopeng Zhang, Qiming Tian, Yangjun Luo

doi:10.1016/j.compstruct.2024.118399

用于声音传播机械调谐的软基声学超材料拓扑设计

The design of tunable acoustic waves is crucial in phononic crystals (PnCs), as acoustic waves exhibit continuous variation across diverse frequency ranges in practical applications. While there have been research efforts on tunable PnCs, existing design strategies predominantly rely on predetermined topology and scatterer shapes based on empirical experience. This reliance poses challenges in ensuring customized and reversible tuning of the bandgap. In this work, we present a customized tunable PnC design model and solution strategy based on soft substrates, which enables reversible tuning of a specific frequency/order bandgap. The designed structure consists of a soft substrate and crystalline columns dispersed in the soft substrate and air. The relative positions of the scatterers in the air are changed by stretching the substrate, thereby realizing the modulation of sound propagation. Since soft materials have both material nonlinearities and complex geometrical variations that are difficult to obtain design sensitivity information, the material-field series expansion topology optimization approach is employed to achieve custom tunable design of the bandgap. The paper presents simulation-based analyses and experimental verification of the customized bandgap opening and closing. The results demonstrate a close alignment between theoretical predictions of propagation curves and experimental findings. This concurrence serves as evidence that the soft-substrate PnC, derived through topology optimization, effectively facilitates the adjustment of bandgaps of arbitrary orders and enables switching between various acoustic functions.

可调谐声波的设计在声子晶体(pnc)中是至关重要的，因为声波在实际应用中在不同的频率范围内表现出连续的变化。虽然对可调谐pnc进行了研究，但现有的设计策略主要依赖于基于经验经验的预定拓扑和散射体形状。这种依赖在确保定制和可逆调谐带隙方面提出了挑战。在这项工作中，我们提出了一种基于软基板的定制可调谐PnC设计模型和解决策略，它可以对特定频率/阶带隙进行可逆调谐。所设计的结构由软基板和分散在软基板和空气中的结晶柱组成。通过拉伸基片来改变散射体在空气中的相对位置，从而实现声音传播的调制。针对软质材料具有材料非线性和复杂几何变化难以获得设计灵敏度信息的特点，采用材料场串联展开拓扑优化方法实现带隙的自定义可调设计。本文对自定义的带隙开闭进行了仿真分析和实验验证。结果表明，理论预测的传播曲线与实验结果非常吻合。这种一致性证明，通过拓扑优化得到的软基板PnC有效地促进了任意阶带隙的调整，并实现了各种声学功能之间的切换。

Theoretical study on the bond performance of CFRP-to-steel single-lap shear tests with multiple debonding defects

Hugo C. Biscaia, Pedro Coelho, Fábio Conde, Tommaso D’Antino

doi:10.1016/j.compstruct.2024.118406

含多剥离缺陷的cfrp -钢单搭接剪切试验粘结性能的理论研究

The amount of research on the external bonding of Carbon Fiber Reinforced Polymers (CFRP) to degraded structures has increased recently. The adhesive is the weakest element of the joint and the bonding of the adherends is critical for the efficiency of the joint. Therefore, the influence of multiple debonding defects on CFRP-to-steel joints has still not been correctly quantified nor fully understood. For this reason, the current work proposes a new numerical strategy that allows for studying the influence of multiple debonding defects when a brittle and ductile adhesive is used. A new nonlinear bond-slip relationship is used and four different ratios between the debonded and the bonded area (η) are assumed: 0%, 25%, 50%, and 75%. The proposed model is based on the Finite Difference Method (FDM) and validation is carried out with a commercial Finite Element Method (FEM) package. The load-slip curves allowed for observing that the proposed FDM and the FEM are consistent and both revealed degradation of the load capacity of the joints with the increase of η. Moreover, by adopting a displacement control at the CFRP-free end, a snap-through and snap-back phenomenon are observed in the specimens with a localized debonding defect.

近年来，对碳纤维增强聚合物(CFRP)与降解结构外键合的研究越来越多。胶粘剂是接头最薄弱的环节，胶粘剂的粘结对接头的工作效率至关重要。因此，多重脱粘缺陷对cfrp -钢连接的影响还没有得到正确的量化和充分的认识。因此，目前的工作提出了一种新的数值策略，允许研究脆性和延性粘合剂使用时多重脱粘缺陷的影响。采用一种新的非线性粘结-滑移关系，并假设脱粘与粘结面积(η)的比值为0%、25%、50%和75%。所提出的模型基于有限差分法(FDM)，并使用商业有限元方法(FEM)软件包进行了验证。从载荷-滑移曲线可以看出，所提出的FDM和FEM是一致的，都显示了节点的承载能力随着η的增加而退化。此外，通过在无cfrp端进行位移控制，在具有局部脱粘缺陷的试件中观察到弹穿和弹回现象。

Comparative study on the impact behaviors of CFWST columns reinforced with steel spiral and tube

Xia Yang, Jiu-Yuan Wang, Yu Chen, Geng-chen Wu

doi:10.1016/j.compstruct.2024.118408

钢管与螺旋钢加固CFWST柱冲击性能对比研究

To obtain superior corrosion resistance and impact resistance, as well as good economic benefits, two new types of composite structure called as steel tube internally-reinforced concrete-filled weathering steel tube (STRCFWST) and steel spiral internally-reinforced concrete-filled weathering steel (SSRCFWST) columns are proposed and compared in terms of their impact resistance in this paper. Eleven impact tests were conducted and three parameters comprising steel spiral diameter, wall thicknesses of outer and inner steel tube were considered to evaluate their influences on the lateral impact behaviors. Results show the presence of inner steel tube and reinforcement cage significantly enhances the impact resistance while slightly decreases the energy absorption capacity. Increasing inner steel tube wall thickness helps to improve the impact resistance, however the contribution is not so good as that produced by increasing the outer steel tube wall thickness, whilst varying steel spiral diameter almost has no impact. Numerical models were developed by ABAQUS/Explicit and verified via the test, based on which the full-range behaviors of STRCFWST, SSRCFWST and unreinforced concrete-filled weathering steel tube (CFWST) columns under impact loading were compared and discussed. It is demonstrated that steel tube and reinforcement cage provide little confinement on concrete infill under impact. With the same internal steel ratio, inner steel tube makes a greater contribution to sectional bending moment resistance and energy absorption as compared to the reinforcement cage.

为了获得优异的耐腐蚀和抗冲击性能以及良好的经济效益，本文提出了钢管内筋混凝土填充耐候钢(STRCFWST)和钢螺旋内筋混凝土填充耐候钢(SSRCFWST)两种新型组合结构，并对其抗冲击性能进行了比较。进行了11次冲击试验，考虑了钢螺旋直径、外、内钢管壁厚3个参数对横向冲击行为的影响。结果表明，内钢管和钢筋笼的存在显著提高了结构的抗冲击能力，但对结构的吸能能力略有降低。增加内管壁厚度有助于提高抗冲击能力，但贡献不如增加外管壁厚度，而改变钢螺旋直径几乎没有影响。采用ABAQUS/Explicit软件建立数值模型并进行试验验证，在此基础上对STRCFWST、SSRCFWST和无筋耐候钢钢管混凝土柱在冲击荷载作用下的全工况性能进行了比较和讨论。结果表明，钢管和钢筋笼对混凝土充填体在冲击作用下的约束作用较小。在相同的内钢比下，内钢管对截面抗弯矩和吸能的贡献大于钢筋笼。

Influence of rate effects on delamination: From Crack Leap Shear tests to low-velocity impacts

Maxime Pouliquen, Olivier Allix, Roland Ortiz, Juan Pedro Berro Ramirez

doi:10.1016/j.compstruct.2024.118409

速率效应对分层的影响:从裂纹跳跃剪切试验到低速冲击

This paper is devoted to the study of different aspects of rate effects in the case of delamination. Two rate dependent cohesive zone models are compared for which the shear rate dependency is identified using Crack Leap Shear experiments. For both models, the key factor appears to be the evolution of the critical energy release rate as function of the crack opening. Moreover, if for very low velocity (1 m/s) rate effects can be neglected, it is not the case for quite low velocity (10 m/s). In the case of a 16 plies quasi-isotropic plate for the size and the shape of the delamination are significantly influenced by the rate effects.

本文致力于研究分层情况下速率效应的不同方面。比较了两种速率相关的黏聚带模型，并利用裂缝跃进剪切实验识别出剪切速率相关。对于这两种模型，关键因素似乎是临界能量释放率随裂纹开度的变化。此外，如果对于非常低的速度(1m /s)速率效应可以忽略不计，那么对于非常低的速度(10m /s)就不是这样了。在16层准各向同性板的情况下，分层的大小和形状受到速率效应的显著影响。

An explicit finite element discrete crack analysis of open hole tension failure in composites

K. Tian, J. Zhi, V.B.C. Tan, T.E. Tay

doi:10.1016/j.compstruct.2024.118411

复合材料开孔拉伸破坏的显式有限元离散裂纹分析

Developing efficient, robust methods for predicting the progressive failure of carbon fiber composites under tension is essential for optimal design, balancing weight reduction, damage tolerance, and service life. Implicit finite element (FE) methods struggle with the complex interplay of failure mechanisms, leading to a heavy reliance on costly, time-consuming experimental testing. This study introduces a novel explicit algorithm designed for laminate-level mesh models, capable of simulating cohesive cracks without predefined paths. Utilizing an explicit finite element software approach, our method effectively addresses convergence issues associated with the non-linear and unstable nature of composite failures during quasi-static loading. Contrasting with implicit FE method, this mesh-independent approach is both practical and numerically robust. The algorithm’s performance, tested on carbon-fiber reinforced composites with varying ply configurations [45_2 /-45_2]s, [45n/90n/-45n/0n]s and [45/90/-45/0]ns (n=1/2/4/8), demonstrates improved simulation accuracy and efficiency over implicit FE methods, aligning well with prior experimental and simulation data. This advancement offers a promising solution for accurately simulating and understanding the complex failure behavior of these composites.

开发高效、可靠的方法来预测碳纤维复合材料在拉力作用下的渐进失效，对于优化设计、平衡减重、损伤容限和使用寿命至关重要。隐式有限元 (FE) 方法难以应对复杂的失效机制相互作用，导致严重依赖昂贵、耗时的实验测试。本研究介绍了一种专为层状网格模型设计的新型显式算法，能够模拟无预定路径的内聚裂纹。利用显式有限元软件方法，我们的方法能有效解决与准静态加载期间复合材料失效的非线性和不稳定性相关的收敛问题。与隐式有限元方法相比，这种与网格无关的方法既实用又具有数值稳定性。该算法在不同层配置 [45_2/-45_2]s、[45n/90n/-45n/0n]s 和 [45/90/-45/0]ns（n=1/2/4/8）的碳纤维增强复合材料上进行了性能测试，结果表明，与隐式 FE 方法相比，该算法提高了模拟精度和效率，与之前的实验和模拟数据非常吻合。这一进步为准确模拟和理解这些复合材料的复杂失效行为提供了一种有前途的解决方案。

Composites Part A: Applied Science and Manufacturing

A new modified direct method for determining the mode I delamination traction-separation law

A.B. de Morais

doi:10.1016/j.compositesa.2024.108365

一种新的改进的直接法确定I型分层牵引分离规律

A new equation was developed for the crack-tip separation in the double cantilever beam (DCB) specimen, which has been standardised for mode I delamination of composites. The very simple closed-form equation is based on a pseudo-elastic beam model and on the effective crack concept. Moreover, it only requires the common load–displacement data up to crack initiation and easy to obtain elastic moduli. Strain-energy release rate versus crack-tip separation curves can then be differentiated for obtaining the tractions, as in the classical direct method. Numerical results for piecewise linear traction-separation laws (TSL) showed good accuracy of strain-energy release rate versus crack-tip separation curves predicted. Application to two carbon/epoxy materials gave very promising TSL results, including cohesive strengths similar to transverse tensile strengths and post-peak steep traction decreases.

建立了双悬臂梁(DCB)试样裂纹尖端分离的新方程，并对该方程进行了标准化处理。非常简单的封闭形式方程是基于伪弹性梁模型和有效裂缝的概念。该方法只需要裂纹起裂前的常用荷载-位移数据，且弹性模量易于获得。然后，与经典的直接法一样，可以区分应变-能量释放率与裂纹尖端分离曲线，以获得牵引力。分段线性牵引分离律(TSL)的数值结果表明，所预测的应变能释放率与裂纹尖端分离曲线具有较好的准确性。应用于两种碳/环氧树脂材料的TSL结果非常有希望，包括与横向拉伸强度相似的内聚强度和峰后陡峭牵引力下降。

Composites Part B: Engineering

Design optimization of advanced tow-steered composites with manufacturing constraints

Chuan Luo, Federico Ferrari, James K. Guest

doi:10.1016/j.compositesb.2024.111739

具有制造约束的先进牵引复合材料的设计优化

Tow steering technologies, such as automated fiber placement, enable the fabrication of composite laminates with curvilinear fiber, tow, or tape paths. Designers may therefore tailor tow orientations locally according to the expected local stress state within a structure, such that strong and stiff orientations of the tow are (for example) optimized to provide maximal mechanical benefit. Tow path optimization can be an effective tool in automating this design process, yet has a tendency to create complex designs that may be challenging to manufacture. In the context of tow steering, these complexities can manifest in defects such as tow wrinkling, gaps, overlaps. In this work, we implement manufacturing constraints within the tow path optimization formulation to restrict the minimum tow turning radius and the maximum density of gaps between and overlaps of tows. This is achieved by bounding the local value of the curl and divergence of the vector field associated with the tow orientations. The resulting local constraints are effectively enforced in the optimization framework through the Augmented Lagrangian method. The resulting optimization methodology is demonstrated by designing 2D and 3D structures with optimized tow orientation paths that maximize stiffness (minimize compliance) considering various levels of manufacturing restrictions. The optimized tow paths are shown to be structurally efficient and to respect imposed manufacturing constraints. As expected, the more geometrical complexity that can be achieved by the feedstock tow and placement technology, the higher the stiffness of the resulting optimized design.

拖曳导向技术，如自动纤维放置，可以制造具有曲线纤维、拖曳或胶带路径的复合材料层压板。因此，设计人员可以根据结构中预期的局部应力状态在局部定制拖缆方向，例如，拖缆的强和硬方向被优化以提供最大的机械效益。拖径优化是实现设计过程自动化的一种有效工具，但它往往会产生复杂的设计，这可能对制造构成挑战。在拖曳转向的情况下，这些复杂性可以表现在缺陷，如拖曳起皱，缝隙，重叠。在这项工作中，我们在牵引路径优化公式中实施制造约束，以限制最小牵引转弯半径和最大牵引间隙和重叠密度。这是通过约束与两个方向相关的向量场的旋度和散度的局部值来实现的。通过增广拉格朗日方法在优化框架中有效地实现了局部约束。通过设计具有优化的两种方向路径的2D和3D结构，从而在考虑各种制造限制的情况下最大化刚度(最小化顺应性)，从而证明了所得到的优化方法。优化后的两条路径在结构上是有效的，并且尊重强加的制造约束。正如预期的那样，原料束和放置技术可以实现的几何复杂性越高，优化设计的刚度就越高。

Composites Science and Technology

Characterization on fibre kinking fracture of laminated composites under combined compression and shear at high loading rate

Rui He, Longfei Cheng, Yidi Gao, Hao Cui, Yulong Li, Jianhu Liu

doi:10.1016/j.compscitech.2024.110770

 

高加载速率下压剪复合材料纤维扭结断裂特性研究

This paper presented a novel method to characterize the fracture toughness and cohesive law of laminated composites under combined compression and shear at high loading rate. Compact compression specimens with off-axis fibres which introduce the in-plane shear stresses were conducted on the uniaxial bidirectional electromagnetic Hopkinson bar system and the displacement field and strain field were recorded by the high-speed camera for the digital image correlation analysis and J-integral calculation. The results reveal that the in-plane shear stresses bring the increase of fracture toughness at crack initiation and propagation and advance the damage initiation of the specimens. The fracture surfaces indicate that the shear stresses cause the fibre bundles' shear failure during the formation of the kink band, accompanied by more energy dissipation with the increase of off-axis angle.

提出了一种表征高加载速率下压剪复合层合材料断裂韧性和粘聚规律的新方法。在单轴双向电磁霍普金森杆体系上进行了带离轴纤维且引入面内剪应力的致密压缩实验，利用高速摄像机记录了位移场和应变场，进行了数字图像相关分析和j积分计算。结果表明:面内剪应力增加了裂纹萌生和扩展时的断裂韧性，促进了试样的损伤萌生;断裂面表明，在扭结带形成过程中，剪切应力导致纤维束发生剪切破坏，随离轴角的增大，能量耗散增大。

Investigation on Thermal Conductivities of Plain-woven Carbon/Phenolic and Silica/Phenolic Composites at High Temperature: Theoretical Prediction and Experiment

Yifan Wang, Qiuyu Wang, Shuangyu Lv, Bowen Zuo, Lei Chen, Taofeng Cao, Chen Chen, Wen-Quan Tao

doi:10.1016/j.compscitech.2024.110771

 

炭/酚醛和硅/酚醛复合材料高温热导率研究:理论预测与实验

Phenolic resin-based ablation materials have found widespread applications in the aerospace industry. The prediction of their thermal conductivity is of paramount importance for the optimization and evaluation for thermal protection systems. However, there is rarely reported thermal conductivity performance of phenolic composites during ablation processes. Therefore, this investigation theoretically predicts the dynamic response of thermal conductivity at high temperatures for plain-woven carbon/phenolic and high silica/phenolic composites. By combining the progressive cubic ablation model with existing composite material property formulas, a multiscale prediction model for effective thermal conductivity is developed. The thermal performance of the resin matrix, reinforcing fibers, yarns, and overall fabric composites is calculated. Additionally, mesoscale representative volume elements are implemented to investigate the overall heat transfer characteristics of carbon/phenolic and high-silica/phenolic composites, including temperature and heat flux distributions. Moreover, both composites thermal conductivities are measured in the range from 298 K to 473 K. The proposed prediction model demonstrates good reliability, with average deviations of 3.76% and 7.36% compared to finite element analysis results and experimental data, respectively.

酚醛树脂基烧蚀材料在航空航天工业中有着广泛的应用。其导热系数的预测对于热防护系统的优化和评价具有至关重要的意义。然而，在烧蚀过程中，酚醛复合材料的导热性能却鲜有报道。因此，本研究从理论上预测了普通编织碳/酚醛和高硅/酚醛复合材料在高温下导热系数的动态响应。将渐进立方烧蚀模型与现有的复合材料性能公式相结合，建立了复合材料有效导热系数的多尺度预测模型。计算了树脂基体、增强纤维、纱线和整体织物复合材料的热性能。此外，采用中尺度代表性体积元来研究碳/酚醛和高硅/酚醛复合材料的整体传热特性，包括温度和热流密度分布。此外，两种复合材料的热导率在298 ~ 473 K范围内进行了测量。该预测模型具有良好的可靠性，与有限元分析结果和实验数据相比，平均偏差分别为3.76%和7.36%。

Fully 3D printed functional PDMS composites with designable structures and performances

Yi An, Wenhao Wang, Renyi Cheng, Chenglin Li, Jiaming Liu, Hong Xu, Xiaoli Wang, Daming Wu, Jingyao Sun

doi:10.1016/j.compscitech.2024.110773

 

全3D打印功能PDMS复合材料具有可设计的结构和性能

Three-dimensional (3D) printing, as a layer-to-layer additive manufacturing technology, has received widespread attention for excellent designability. However, as for direct ink writing (DIW), current printing level is difficult to achieve high-precision printing of thermoset composites of different compositions. Therefore, fully 3D printing based on thermoset composites with high designability is proposed. The intralayer and interlayer of structure and materials prepared by this method are designable, and layer thicknesses as well as inter-layer patterns are adjustable. In this work, alumina (Al2O3) and short carbon fiber (SCF) are used as thermally conductive fillers, polydimethylsiloxane (PDMS) is conducted as thermoset matrix. Benefit from the high designability of our method, a series of Al2O3/SCF/Al2O3 (ASA) and SCF/Al2O3/SCF (SAS) composite samples with sandwich structures are fabricated and compared. The different materials and structural designs of these composite samples give them completely different properties in terms of thermal, electromagnetic shielding, and mechanical properties, making it possible to create customized designs for different scenarios. Taking thermal management materials (TMMs) as an example, we use this method to prepare ASA and SAS composites with sandwich structure, thermal conductivity of A40S30A40 and S30A40S30 reached 1.00 W/(m·K) and 1.55 W/(m·K) respectively. In all, customized and multifunctional applications make PDMS composites have a widespread prospect.

三维打印作为一种层对层增材制造技术，因其优异的可设计性而受到广泛关注。然而，对于直墨书写(DIW)，目前的印刷水平很难实现不同成分热固性复合材料的高精度印刷。因此，提出了基于高可设计性热固性复合材料的全3D打印技术。用该方法制备的结构和材料的层内和层间是可设计的，层厚度和层间图案是可调节的。本文采用氧化铝(Al2O3)和短碳纤维(SCF)作为导热填料，聚二甲基硅氧烷(PDMS)作为热固性基体。利用该方法的高可设计性，制备了一系列具有夹层结构的Al2O3/SCF/Al2O3 (ASA)和SCF/Al2O3/SCF (SAS)复合样品并进行了比较。这些复合材料样品的不同材料和结构设计使其在热、电磁屏蔽和机械性能方面具有完全不同的性能，从而可以针对不同的场景创建定制设计。以热管理材料(TMMs)为例，利用该方法制备了具有夹层结构的ASA和SAS复合材料，A40S30A40和S30A40S30的导热系数分别达到1.00 W/(m·K)和1.55 W/(m·K)。总之，定制化和多功能的应用使得PDMS复合材料具有广泛的应用前景。

Microscopic damage behavior in CFRP cross-ply laminates at cryogenic temperature

Kazuyoshi FUJISHIRO, Toshio OGASAWARA, Koki MIZUTANI, Hisashi KUMAZAWA, Takahira AOKI

doi:10.1016/j.compscitech.2024.110774

 

低温下CFRP交叉层合板的微观损伤行为

For the practical use of cryogenic propellant tanks made of CFRP laminates, experimental elucidation of the laminates’ microstructural damage propagation behavior at cryogenic temperatures is important. This paper presents a newly developed tensile test rig that enables in-situ observation of microscopic damage using an optical microscope at cryogenic temperatures using a Gifford–McMahon refrigerator. In-situ observations of microscopic damage under uniaxial tensile loading were done at room temperature (290 K, 17 °C) and at 30 K (-243 °C) on cross-ply thin-layer CFRP specimens of three kinds with different 90° layer thicknesses. The results demonstrated that the crack propagation behavior is independent of temperature, that the matrix crack density is higher, and that the onset of matrix crack initiation strain is lower at 30 K than at 290 K. Furthermore, the thermal strain within 90° layer at 30 K and 290 K was estimated using finite element analyses (FEA). The FEA results suggest that the decrease in onset strain of matrix crack initiation at 30 K is mainly attributed to the increase in the thermal strains within the 90° layer.

为了实际应用碳纤维复合材料制成的低温推进剂储罐，对复合材料在低温下的微结构损伤扩展行为进行实验研究具有重要意义。本文介绍了一种新开发的拉伸试验台，该试验台使用Gifford-McMahon冰箱在低温下使用光学显微镜对微观损伤进行原位观察。在室温(290 K, 17°C)和30 K(-243°C)条件下，对三种不同90°层厚的交叉铺层CFRP薄层试样进行了单轴拉伸加载下的微观损伤现场观察。结果表明:裂纹扩展行为与温度无关，基体裂纹密度较高，30k时基体裂纹起裂应变小于290k;此外，利用有限元分析(FEA)估算了30 K和290 K时90°层内的热应变。有限元分析结果表明，30k时基体裂纹起裂应变的减小主要是由于90°层内热应变的增大。