复合材料蜂窝板积水的脉冲热像检测的研究

 用数值模拟和实验研究了飞机蜂窝板积水的脉冲热像检测的规律。提出了蜂窝板积水检测的新型三维传热模型;用有限元法分析了近水检测、远水检测和立放检测3种检测模式下信息参数与积水量的关系;用脉冲热像实验验证了近水检测的基本规律。结果表明:在这3种检测模式下,最大温差和最大对比度与积水高度均呈非线性关系,随着积水高度的增加而增大。近水检测灵敏度最高,其次是蜂窝板立放检测,远水检测灵敏度最低。积水和富胶对表面温度的影响趋势一致,利用温差曲线或最大温差信息无法区分积水和富胶状态。根据可检信息参数与积水高度的关系曲线可以反向估计积水高度。这些研究结果为飞机蜂窝板积水的脉冲热像检测及评估提供了技术支持。

Study on Pulsed Thermography for Water Ingress Detection in Composite Honeycomb Panels

The mechanism of pulsed thermography(PT) for water detection in aviation composite honeycomb panels is studied by numerical simulation and experiment.A new 3-D heat conduction model of water detection in honeycomb panels is presented;the relationships between information parameters and water are analyzed for three testing modes,i.e.detecting from the near-water side,detecting from the far-water side and detecting as the honeycomb panel is vertically laid.The basic laws of water detection from the near-water side are verified by a PT experiment.The results indicate that,in the three testing modes,both the maximum temperature difference and maximum contrast are non-linear functions of water height,and will increase as the increment of the water height.The detection sensitivity is the highest from the near-water side,followed by the vertically laid honeycomb panel,and the far-water side is the lowest.Both water ingress and glue have similar influence on the surface temperature.Therefore,they cannot be distinguished by the temperature difference curve or the maximum temperature difference information.The water height can be evaluated inversely by the curves of the information parameters vs water height.The results obtained can provide technical support for water detection and evaluation of aviation honeycomb structures by PT.