融合纤维数据的复合材料筒体结构持久寿命评估方法

Method on rupture life evaluation for composite cylinder based on data fusion of carbon fiber

对于由T700碳纤维浸胶丝束缠绕铝合金筒壁构成的复合材料筒体结构,通过提高筒体转速增加纤维拉应力的加速寿命试验仍无法获得充分的失效数据,试验结果多表现为高应力大删失比与低应力无失效混合的寿命数据类型,且采用现行方法进行持久寿命评估的结果存在置信度偏低的问题。针对这一问题,首先对纤维和筒体的加速等同性与失效机制一致性进行分析,进而通过对加速模型参数估计量的部分协方差矩阵进行统计检验与信息融合,建立了一种可融合纤维数据的筒体结构持久寿命评估方法。该方法通过综合利用碳纤维的相似性信息,从而提高筒体结构持久寿命评估的精度。采用实例验证了文中方法的有效性,使筒体结构持久寿命的评估精度提高了35%。

A composite cylinder structure consists of aluminum alloy cylinder structure wall winded by T700 carbon fiber composite. The failure data still cannot he obtained sufficiently by the accelerated life test due to the time limitation in engineering, and the most of the data is a mixture of high censored ratio data in high stress level and zero-failure data in low stress level. To the problem of low confidence level for rupture life evaluation by the current method, the equivalency of acceleration and consistency of failure mechanism for carbon fiber and cylinder were analyzed firstly, and then the statistical test was made and the information was fused for the part covariance matrix of accelerated model parameters. At last, a rupture life evaluation method was established for the cylinder with fusion the carbon fiber data. It can improve the evaluation accuracy of the cylinder by using the similar information. The proposed method is proved e~{eetively by the test data, and it makes the evaluation accuracy of the cylinder increase 35 %.