Predicting interlaminar damage behaviour of fibre-metal laminates containing adhesive joints under bending loads
Predicting interlaminar damage behaviour of fibre-metal laminates containing adhesive joints under bending loads
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DOI：
10.1177/07316844211051706
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发表时间：
2021-11
影响因子：
3.1
通讯作者：
A. Al-Azzawi;L. Kawashita;C. Featherston
中科院分区：
文献类型：
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作者：
A. Al-Azzawi;L. Kawashita;C. Featherston
本文研究了含粘结接头的金属纤维层压结构在静弯曲荷载作用下的实验和数值研究。实验测试是在内部制造的眩光®4B样品上进行的，其中包含双倍关节特征。利用Abaqus软件对玻璃纤维增强聚合物层的损伤、树脂袋（FM94环氧树脂）的韧性损伤和金属层的塑性损伤进行了数值分析。建立了贯穿厚度压应力作用下的摩擦与界面剪切耦合的黏结区模型，以模拟受弯荷载作用下金属/纤维界面层裂的发生和发展。该模型是通过Abaqus/Explicit软件中的用户自定义VUMAT子程序实现的，包括两种主要方法，首先，结合摩擦和界面剪切应力在金属纤维层压板的层间层中产生的通过厚度应力；采用基于梯形规律的粘聚区模型（比常用的双线性粘聚区模型更能准确地模拟增韧环氧基的弹塑性损伤行为）。数值结果与四点弯曲试验的实验数据进行了验证，并且在裂纹萌生和演化方面观察到良好的相关性。正如预期的那样，分层和剪切破坏是弯曲应力下的主要破坏模式。这是由于在弯曲过程中引入了更高的ii型应力，导致与轴向应力不同的损伤演化行为。有限元结果表明，在这种荷载作用下，由全厚度压缩应力产生的摩擦强度和剪切强度参数对预测金属纤维层合结构的损伤有显著的影响。
This study includes experimental and numerical investigations on fibre-metal laminate structures containing adhesive joints under static bending loads. Experimental tests were carried out on Glare® 4B specimens manufactured in-house and containing doubler joint features. Numerical analyses were performed using Abaqus software including damage in the glass fibre reinforced polymer layers, ductile damage in the resin pockets (FM94 epoxy) and plasticity in the metal layers. A new cohesive zone model coupling friction and interfacial shear under through-thickness compressive stress has been developed to simulate delamination initiation and growth at the metal/fibre interfaces with the adhesive joint under flexural loading. This model is implemented through a user-defined VUMAT subroutine in the Abaqus/Explicit software and includes two main approaches, firstly, combining friction and interfacial shear stresses created in the interlaminar layers of the fibre-metal laminate as a result of through-thickness stresses and secondly, considering elastic-plastic damage behaviour using a new cohesive zone model based on the trapezoidal law (which provides more accurate results for the simulation of toughened epoxy matrices than the commonly used bilinear cohesive zone model). Numerical results have been validated against experimental data from 4-point bending tests and a good correlation observed with respect to both crack initiation and evolution. Delamination and shear failure were noted to be the predominant failure modes under bending stresses as expected. This is due to the higher mode-II stresses introduced during bending which cause different damage evolution behaviour to that seen for axial stresses. Finite element results revealed that both friction and shear strength parameters generated from through-thickness compression stresses have a significant effect in predicting damage in fibre-metal laminate structures under this type of loading.