CFRP复合材料螺栓连接失效载荷不确定性的评估方法

An evaluation method for uncertainty in failure load of CFRP composite bolted joints

螺栓连接是先进复合材料结构的薄弱环节。因此,螺栓连接力学性能显著的不确定性不仅阻碍了先进复合材料的高效应用,且给整体结构的安全性和可靠性带来威胁。为定量评估碳纤维增强树脂(CFRP)复合材料螺栓连接失效载荷的不确定性,将数值的渐进损伤模型和区间分析方法结合,提出了一种高效、准确的分析方法。采用该方法预测了典型T800碳纤维/X850环氧树脂复合材料螺栓连接失效载荷的不确定性,并与试验结果进行对比。预测结果与试验结果的误差不超过2%,证明本文所提出方法的有效性。采用本文所提方法预测的T800碳纤维/X850环氧树脂复合材料螺栓连接失效载荷的区间为[19.25 kN, 22.75 kN],与设计期望值的偏差为[-9.8%, 6.6%]。

Bolted joints are the weak points of composite structures. Therefore, the considerable uncertainty in mechanical properties of the bolted joints not only prevents advanced composites from efficient applications, but also threatens the safety and reliability of the structures. In order to quantitatively evaluate the uncertainty in failure load of carbon fiber reinforced polymer(CFRP) composite bolted joints, an efficient and accurate analysis method was proposed based on the numerical progressive damage model and interval analysis method. The proposed method was used to predict the uncertain failure load of T800 carbon fiber/X850 epoxy composite bolted joint. The predicted results were compared with the experimental outcome. The small error less than 2% between the predicted and experimental results validates the effectiveness of the proposed method. According to the predicted results, the interval of failure load of the T800 carbon fiber/X850 epoxy composite bolted joint is [19.25 kN,22.75 kN] with the deviations from the design expected values of [-9.8%, 6.6%].