钢质蜂窝夹芯梁高温疲劳试验及寿命预测研究

Investigation on the fatigue behaviors and life prediction of steel honeycomb sandwich beams

针对实际工程中钢质蜂窝夹芯结构在热环境下的疲劳耐久性及寿命问题,开展了400℃下的三点弯曲疲劳试验研究,得到S-N曲线.基于刚度退化,提出一种用于该类材料在高温下的疲劳寿命预测模型和损伤演化模型.该方法允许预测不同载荷水平下的疲劳寿命,避免了大量重复性疲劳试验.应用于模型的参数与材料性质、高温等试验条件有关.借助简单模型,完成了钢质蜂窝梁高温寿命预测及损伤演化预测,预测值与试验值吻合较好.

In the industrial field,an investigation on how temperature can affect damage and fatigue life of a honeycomb sandwich structure is significant.The aim of this work is to investigate fatigue behaviors of the steel honeycomb sandwich beams at 400℃ by three-point bending fatigue experiments.An S-N curve was obtained.Based on stiffness degradation,life prediction and damage evolution models were developed.This approach allowed the prediction of fatigue life under different load levels while avoiding a large number of repetitive fatigue tests.Parameters used in the model depended on the material properties and high temperature test conditions among other things.The developed models were applied to analyze the fatigue life and damage evolution of steel honeycomb sandwich specimens under fatigue.The results show that experimental and prediction results were in good agreement.Thus the proposed method is feasible.