热冲击会导致飞机蒙皮表面冰层局部碎裂和脱粘,针对目前无法有效测量冰层脱粘程度的问题,提出采用非接触超声脉冲回波技术对冰层脱粘程度进行评估.首先,采用PZFlex软件建立了包含超声传感器、飞机蒙皮与冰层的二维模型,研究了冰层内部裂缝及冰/蒙皮界面脱粘区域尺寸对冰层超声脉冲回波信号影响规律,初步获得了冰层局部脱粘超声评估方法;其次,基于LabVIEW软件搭建了由加热控制模块、温度采集模块、超声信号发生及采集模块组成的地面冷环境实验平台,通过电加热膜产生热冲击造成冰层局部区域脱粘,验证了提出的冰层局部脱粘超声评估方法的可行性.在电加热功率密度为1.6 W/cm2的作用下,铝板-冰层界面温度由-24℃升至-4℃时,探测区域内脱粘面积达到62.8%以上.结果表明,采用非接触式超声脉冲回波技术可以有效评估探测区域内冰层局部脱粘程度.该方法可用于评估飞机除冰系统工作时冰层脱粘面积,为除冰控制系统提供可靠状态信息.
Thermal shock will lead to local fragmentation and delamination of ice on the surface of aircraft.In view of the problem that it is unavailable to acquire the information of delamination of ice at present,a non-contact detection using ultrasonic pulse-echo technology is proposed to evaluate the degree of debonding of ice.Firstly,a two-dimensional model including ultrasonic sensor,aluminum surface and ice layer is established by PZFlex software.Based on the model,the relationship between the delamination parameters and the received echo signals is analyzed.Then the evaluation method of local icing delamination is preliminarily proposed.In or-der to verify the feasibility of the proposed evaluation method,an experiment is performed on the experimental platform based on LabVIEW software.When the aluminum plate ice interface temperature rised from-24 ℃ to-4 ℃ under 1.6 W/cm2,the delamination area within the detection area reach more than 62.8%.The results show that the non-contact ultrasonic pulse-echo detection can effectively evaluate the local delamination degree of ice within the detecting range,which can provide the accurate information of ice on the swings to the deicing system.