应变隔离垫面外拉伸力学性能研究  

Study on the Out-of-Plane Tensile Mechanical Properties of Strain-Isolation-Pad

作　　者：陆毛须 吴振强[2] 李金铭 郝自清 刘刘 LU Maoxu;WU Zhenqiang;LI Jinming;HAO Ziqing;LIU Liu(School of Aerospace Engineering,Beijing Institute of Technology,Beijing 100081,China;Science and Technology on Reliability and Environmental Engineering Laboratory,Beijing Institute of Structure and Environment Engineering,Beijing 100076,China)

机构地区：[1]北京理工大学宇航学院力学系,北京100081 [2]北京强度环境研究所可靠性与环境工程技术重点实验室,北京100076

出　　处：《强度与环境》2023年第4期1-7,共7页Structure & Environment Engineering

基　　金：国家自然科学基金联合基金项目(U20B2002);重点实验室基金(6142004210202)。

摘　　要：应变隔离垫是重复使用飞行器刚性防热瓦热防护结构的重要组成部分,通过硅胶与冷结构和防热瓦进行粘接,应变隔离垫面外力学性能以及其与冷结构之间的粘接性能直接影响着飞行器使用安全,也是评估热防护系统可重复使用性能的基础性能参数。本文设计了应变隔离垫试验件,通过静载力学试验,获得了SIP在常温环境下(25℃)下拉伸应力-应变曲线及失效模式,应力-应变曲线表现出明显的大变形、非线性特征。建立了应变隔离垫的超弹性本构模型,结合有限元数值方法对SIP常温拉伸力学行为进行仿真分析,模拟结果和试验吻合较好。开展了100℃、120℃以及150℃高温环境下SIP面外拉伸试验,结果表明SIP的拉伸刚度和强度具有温度敏感性,与粘结工艺密切相关,拉伸强度较室温条件下分别下降了50.7%、70%、77%。上述研究成果能够为飞行器热防护系统的服役性能评估和工艺优化提供技术支撑。The strain isolation pad(SIP)is an important component of rigid insulation tile thermal protection system for reusable flight vehicles,which is bonded to the cold structure and thermal insulation tile by silica gel.The out-of-plane tensile mechanical properties of SIP and the bonding performance with the cold structure directly affect the safety of the flight vehicle,and are also important basic material properties for assessing the reusability of the thermal protection system.In this paper,a SIP specimen was designed and bonded to the cold structure by silicone,and the out-of-plane tensile stress-strain curve and failure mode of the SIP under room temperature(25℃)and elevated temperature were obtained by static test.The stress-strain curve exhibits large deformation and nonlinear characteristics.A hyperelastic constitutive model of the SIP was proposed.The tensile mechanical behavior of SIP at room temperature was predicted through the finite element numerical method,and the results were in good agreement with the test.The uniaxial tensile tests of SIP at 100°C,120°C and 150°C were conducted,and the results show that the tensile stiffness and strength of SIP are sensitive to temperature and closely related to the bonding process.The tensile strength decreases by 50.7%,70%and 77%respectively compared to that of room temperature.The results can provide technical support for the evaluation and process optimization of thermal protection systems.

关 键 词：刚性防热瓦 应变隔离垫 超弹性本构 高温力学性能 

分 类 号：V416.4[航空宇航科学与技术—航空宇航推进理论与工程]