| 碳纤维/环氧树脂复合材料L型接头拉伸失效机制 |
| |
| 引用本文： | 张琪,蔡登安,余章杰,戴征征,吴大可,周光明.碳纤维/环氧树脂复合材料L型接头拉伸失效机制[J].复合材料学报,2023,40(1):542-552. |
| |
| 作者姓名： | 张琪 蔡登安 余章杰 戴征征 吴大可 周光明 |
| |
| 作者单位： | 南京航空航天大学 机械结构力学及控制国家重点实验室，南京 210016 |
| |
| 基金项目： | 国家自然科学基金(52005256)；江苏省基础研究计划(自然科学基金)资助项目(BK20190394)；江苏省博士后科研资助计划项目(2020Z437)；中央高校基本科研业务费专项资金资助(NS2019001)；江苏高校优势学科建设工程资助项目(PAPD) |
| |
| 摘 要： | 设计了单L型(LS)及双L型(LD)两种重量相近的L型接头。采用试验与数值模拟相结合的方式对两种接头的拉伸失效机制进行了研究。通过自行设计的试验夹具在伺服液压试验机上将两种L型接头准静态加载至破坏，分析其破坏机制及应变分布。研究发现，两种L型接头存在不同的失效机制，在破坏阶段单L型接头表现出更好的延展性。单L型接头加载至峰值载荷时，在靠近加载侧的内侧螺栓孔附近首先出现破坏，随后损伤向外侧螺栓孔附近扩展，直至完全失效。双L型接头加载至峰值载荷的50%左右时，L型框体和L型片之间的胶膜首先发生破坏，随后载荷继续增加至峰值载荷时，L型框螺栓孔附近发生破坏，损伤向框体边缘扩展，载荷大幅下降。此外，两种接头的应变随载荷的增加存在不同的变化趋势。采用一种新型复合材料初始失效准则及刚度折减方法，编写用户自定义子程序(UMAT)，结合内聚区模型建立复合材料L型接头的渐进损伤模型。基于ABAQUS软件进行计算，得到接头的预测失效载荷及破坏形式。结果表明：有限元分析所得复合材料L型接头的损伤位置及失效模式与试验吻合，预测载荷与试验值相差较小，证明了有限元模型的适用性。
|
| 关 键 词： | 复合材料 L型接头 失效机制 有限元分析 内聚区模型 |
| 收稿时间： | 2021-12-31 |
Tensile failure mechanism of carbon fiber/epoxy composite L-joints |
| |
| Affiliation: | State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China |
| |
| Abstract: | Single-L and double-L composite joints were designed with similar weights. A combination of experiment and numerical simulation was used to study the tensile failure mechanism of the two joints. Two kinds of L-joints were quasi-statically loaded to failure on the servo hydraulic testing machine through a self-designed test fixture, and the failure mechanism and strain distribution were analyzed. It’s found that the two L-joints have different failure mechanisms, and the single L-joint exhibits better ductility in the failure stage. When the single L-joints are loaded to the peak load, the damage first occurs near the inner bolt hole in the loading side, and then the damage spreads to the outer bolt hole until failing completely. When the double L-joints are loaded to about 50% of the peak load, the adhesive film between the L-shaped frame and the L-shaped sheet is first damaged, and then when the load continues to increase to the peak load, damage occurs near the bolt holes of the L-shaped frame, extending to the edge of the frame, the load drops significantly. In addition, the strains of the two joints have different trends with the increase of load. Based on a new type of composite material initial failure criterion and stiffness reduction method, a user-defined material subroutine (UMAT) was written. Combined with the cohesive zone model, the progressive damage model of the composite material L-joint was established. Based on ABAQUS software for calculation, the predicted failure load and failure mode of composite single L-joint and double L-joint were obtained. The results show that the damage position and failure mode of the composite L-joint obtained by the finite element analysis are consistent with the test, and the predicted load is slightly different from the test value, which proves the applicability of the finite element model. |
| |
| Keywords: | |
|
| 点击此处可从《复合材料学报》浏览原始摘要信息 |
|
点击此处可从《复合材料学报》下载全文 |
|
