含填充孔复合材料层压板极限压缩强度分析与预测

基于复合材料层压板与填充螺栓之间的载荷分配情况,提出一种估算含填充孔复合材料层压板压缩极限强度的方法。利用MSC.Patran/Nastran有限元分析软件,建立考虑界面接触的有限元模型。分析了层压板刚度和螺栓刚度对载荷分配系数的影响规律,界面单元应力表明层压板与螺栓之间接触力分布为余弦函数形式。同时,开展了三种铺层T700/LT—03A碳纤维复合材料层压板开孔和填充孔极限压缩强度试验。试验结果表明,含填充孔层压板压缩强度较开孔压缩极限强度提高约30%左右。与试验结果相比,方法的预测值较为保守,且预测误差小于5%。此外,对文献中的T800/3900—2层压板试验数据进行分析,预测误差小于5%,说明该方法能较好地预测含填充孔复合材料层压板压缩极限强度,具有一定的工程应用意义。

ANALYSIS AND PREDICTION OF COMPOSITE LAMINATE COMPRESSIVE STRENGTH WITH FILLED HOLE

A predictive method was proposed to estimate the filled hole compressive(FHC) strength of composite laminates based on the load distribution between composite plate and bolt filled in the plate. A MSC.Patran/Nastran based finite element model, which considered surface contact effect, was developed to verify the influence of stacking sequence and bolt stiffness on load distribute factor near the hole. The stress analysis results of surface elements showed that the distribution of contact force between plate and bolt appeared to be cosine over half the hole. With T700/LT-03A carbon fiber composite laminates, experiments concerning three different stacking sequences were taken to derive the open hole and FHC strength. Test results showed that the FHC strength was 30% higher than the open hole compressive strength. The predicted results complied with the experiment results with error less than 5%. Comparison was also applied between the results from the very method and the experiment results of T800/3900-2 shown in other works. The proposed method could well predict the FHC strength with accuracy, and has certain significance in engineering.