栅极系统电子返流是离子推力器寿命的主要失效模式之一。以20 cm Xe离子推力器地面运行测试数据为基础,结合离子推力器栅极系统电子返流失效机理,预测了离子推力器在地面测试环境中和空间飞行环境中栅极系统电子返流对寿命的影响。预测...栅极系统电子返流是离子推力器寿命的主要失效模式之一。以20 cm Xe离子推力器地面运行测试数据为基础,结合离子推力器栅极系统电子返流失效机理,预测了离子推力器在地面测试环境中和空间飞行环境中栅极系统电子返流对寿命的影响。预测结果表明:20 cm Xe离子推力器在地面试验环境中和空间飞行环境中的预期寿命分别为6 600 h和17 000 h。展开更多
In order to reveal the changing law of the mechanical response of asphalt pavements under the action of vehicle load and provide references for the design of durable pavements,three typical asphalt pavement structures...In order to reveal the changing law of the mechanical response of asphalt pavements under the action of vehicle load and provide references for the design of durable pavements,three typical asphalt pavement structures with flexible base(S1),combined base(S2),and semi-rigid base(S3)were selected to perform field strain tests under static and dynamic load using the fiber Bragg grating optical sensing technology.The changing characteristics of the strain field along the horizontal and depth directions of pavements were analyzed.The results indicate that the most unfavorable asphalt pavement layers were the upper-middle surface layer and the lower base layer.In addition,the most unfavorable loading positions on the surface layer and the base layer were the center of wheel load and the gap center between two wheels,respectively.The most unfavorable layer of the surface layers gradually moved from the lower layer to the upper layer with the increase of base layer modulus.The power function relationships between structural layer strain and vehicle speed were revealed.The semi-rigid base asphalt pavement was the most durable pavement type,since its strain value was lower compared to those of the other structures.展开更多
文摘栅极系统电子返流是离子推力器寿命的主要失效模式之一。以20 cm Xe离子推力器地面运行测试数据为基础,结合离子推力器栅极系统电子返流失效机理,预测了离子推力器在地面测试环境中和空间飞行环境中栅极系统电子返流对寿命的影响。预测结果表明:20 cm Xe离子推力器在地面试验环境中和空间飞行环境中的预期寿命分别为6 600 h和17 000 h。
基金Projects(51908071,51708071)supported by National Natural Science Foundation of ChinaProject(2020JJ5975)supported by the Natural Science Foundation of Hunan Province,China+1 种基金Project(18C0194)supported by the Scientific Research Project of Education Department of Hunan Province,ChinaProject(kfj190301)supported by Open Fund of Key Laboratory of Road Structure and Material of Ministry of Transport(Changsha University of Science&Technology),China。
文摘In order to reveal the changing law of the mechanical response of asphalt pavements under the action of vehicle load and provide references for the design of durable pavements,three typical asphalt pavement structures with flexible base(S1),combined base(S2),and semi-rigid base(S3)were selected to perform field strain tests under static and dynamic load using the fiber Bragg grating optical sensing technology.The changing characteristics of the strain field along the horizontal and depth directions of pavements were analyzed.The results indicate that the most unfavorable asphalt pavement layers were the upper-middle surface layer and the lower base layer.In addition,the most unfavorable loading positions on the surface layer and the base layer were the center of wheel load and the gap center between two wheels,respectively.The most unfavorable layer of the surface layers gradually moved from the lower layer to the upper layer with the increase of base layer modulus.The power function relationships between structural layer strain and vehicle speed were revealed.The semi-rigid base asphalt pavement was the most durable pavement type,since its strain value was lower compared to those of the other structures.
