During the storage of composite propellants,the migration of plasticizers and other unbonded additives at the interfaces of liner adhesives has garnered significant attention in understanding liner failure mechanisms,...During the storage of composite propellants,the migration of plasticizers and other unbonded additives at the interfaces of liner adhesives has garnered significant attention in understanding liner failure mechanisms,aging processes,and safety performance.However,there is currently no non-destructive and quantitative detection method for migration of plasticizers in propellant liner.In this study,we developed a HTPB sensing liner by incorporating conductive fillers-namely carbon black(CB),carbon nanotubes(CNTs),and graphene nanoplatelets(GNP)-into the HTPB matrix.The synergistic interaction between CNTs and GNP facilitates the formation of a tunneling conductive network that imparts electrical conductivity to the HTPB liner.To elucidate the functional relationship between conductivity and nitroglycerin(NG)migration,we applied the HTPB sensing liner onto double base propellant surfaces and measured both the conductivity of the sensing layer and NG migration during a 71℃accelerated aging experiment.The results shows that when CNTs/GNP content reaches 3wt%,there is an exponential correlation between conductivity and NG migration with a fitting degree of 0.9652;the average response sensitivity of DR/R0 relative to NG migration is calculated as 41.69,with an average deviation of merely 5.67%between NG migrations derived from conductivity fittings compared to those obtained via TGA testing results.Overall,this sensing liner exhibits excellent capabilities for detecting NG migration nondestructively and quantitatively while offering a novel approach for assessing interfacial component migrations as well as debonding defects in propellantsda promising avenue for future self-monitoring strategies regarding propellant integrity.展开更多
传统的水下交流电磁场检测(alternating current filed measurement,ACFM)在仿真设计时未考虑外壳材料对检测信号和设备各个参数之间的影响。针对此问题,建立了ACFM仿真模型,对磁芯大小与形状进行了优化设计,缩减探头尺寸;分析了无损检...传统的水下交流电磁场检测(alternating current filed measurement,ACFM)在仿真设计时未考虑外壳材料对检测信号和设备各个参数之间的影响。针对此问题,建立了ACFM仿真模型,对磁芯大小与形状进行了优化设计,缩减探头尺寸;分析了无损检测探头的外壳材料的电导率和磁导率对检测信号的影响,并进行了仿真分析;分析出最适用于深水无损检测(nondestructive testing,NDT)的外壳材料为304不锈钢和最佳电流频率,并对无损检测探头的各参数进行了优化设计。结果表明:外壳材料的电导率达到10^(7) S/m时,磁性传感器检测到的特征信号会反向和电流的频率大于7 kHz会导致检测信号严重失真;外壳材料的磁导率对z方向的磁感应强度B_(z)、x方向的磁感应强度B_(x)的幅值衰减严重。研究成果有利于水下无损检测设备的研发设计。展开更多
基金funded by Zhijian Laboratory Open Fund,Rocket Force University of Engineering(Grant No.2023-ZJSYS-KF01-03).
文摘During the storage of composite propellants,the migration of plasticizers and other unbonded additives at the interfaces of liner adhesives has garnered significant attention in understanding liner failure mechanisms,aging processes,and safety performance.However,there is currently no non-destructive and quantitative detection method for migration of plasticizers in propellant liner.In this study,we developed a HTPB sensing liner by incorporating conductive fillers-namely carbon black(CB),carbon nanotubes(CNTs),and graphene nanoplatelets(GNP)-into the HTPB matrix.The synergistic interaction between CNTs and GNP facilitates the formation of a tunneling conductive network that imparts electrical conductivity to the HTPB liner.To elucidate the functional relationship between conductivity and nitroglycerin(NG)migration,we applied the HTPB sensing liner onto double base propellant surfaces and measured both the conductivity of the sensing layer and NG migration during a 71℃accelerated aging experiment.The results shows that when CNTs/GNP content reaches 3wt%,there is an exponential correlation between conductivity and NG migration with a fitting degree of 0.9652;the average response sensitivity of DR/R0 relative to NG migration is calculated as 41.69,with an average deviation of merely 5.67%between NG migrations derived from conductivity fittings compared to those obtained via TGA testing results.Overall,this sensing liner exhibits excellent capabilities for detecting NG migration nondestructively and quantitatively while offering a novel approach for assessing interfacial component migrations as well as debonding defects in propellantsda promising avenue for future self-monitoring strategies regarding propellant integrity.
