带胶应变隔离垫对防热瓦太赫兹无损检测的影响分析

Effect of Strain Isolation Pad with Adhesive on Terahertz Nondestructive Test of Thermal Protection System

重复使用飞行器是当前航天领域的研究热点之一。热防护系统的使用寿命和可重复使用性能直接影响飞行器的可重复使用,因此,热防护结构的无损检测评估对重复飞行至关重要。本文采用0.3THz的设备对预置缺陷的防热瓦结构进行检测,发现检测效果不理想。于是对组成防热瓦热防护系统的陶瓷瓦、应变隔离垫及硅橡胶3种材料试验件分别进行太赫兹检测,分析其与太赫兹波的作用。研究发现,太赫兹波对陶瓷瓦和应变隔离垫的穿透效果令人满意,对带有粘接胶的应变隔离垫穿透性较差。采用0.166THz的设备对其进行检测,发现较低频率的太赫兹波能获得对带胶隔离垫更好的穿透效果,同时不影响对陶瓷瓦和应变隔离垫的穿透性。在满足较好的穿透性后,0.166THz检测设备对防热瓦结构的检测效果较好。

Reusable aerospace craft is hot pot in aerospace industry research.The life of reusable aerospace craft is limited by the life and performance of thermal protection system(TPS).Therefore,the nondestructive testing technology for TPS is significant for reusable aerospace craft.In the paper,two defect-embedded TPS specimens are tested,and it is found that the test result is not ideal.Then the terahertz test on TPS contains such as ceramic tile,strain isolation pad(SIP)and silicon rubber are performed to analyze the interaction between materials and terahertz wave.The terahertz wave penetrates ceramic tiles and SIP well,but the penetration on SIP is not satisfied.Then the frequency of terahertz wave is changed and it is found that 0.166THz penetrates adhesive SIP better without losing penetration on ceramic tiles and SIP.With better penetration,the test result of 0.166THz terahertz wave on the defect-embedded TPS satisfies a lot.