Large-scale solar sails can provide power to spacecraft for deep space exploration.A new type of telescopic tubular mast(TTM)driven by a bistable carbon fiber-reinforced polymer tube was designed in this study to solv...Large-scale solar sails can provide power to spacecraft for deep space exploration.A new type of telescopic tubular mast(TTM)driven by a bistable carbon fiber-reinforced polymer tube was designed in this study to solve the problem of contact between the sail membrane and the spacecraft under light pressure.Compared with the traditional TTM,it has a small size,light weight,high extension ratio,and simple structure.The anti-blossoming and self-unlocking structure of the proposed TTM was described.We aimed to simplify the TTM with a complex structure into a beam model with equal linear mass density,and the simulation results showed good consistency.The dynamic equation was derived based on the equivalent model,and the effects of different factors on the vibration characteristics of the TTM were analyzed.The performance parameters were optimized based on a multiobjective genetic algorithm,and prototype production and load experiments were conducted.The results show that the advantages of the new TTM can complete the deployment of large-scale solar sails,which is valuable for future deep space exploration.展开更多
This research paper presents a comprehensive conceptual design approach for the development of a telescopic machine system, which is portable and will provide a safe method of harvesting palm fruits. For this machine ...This research paper presents a comprehensive conceptual design approach for the development of a telescopic machine system, which is portable and will provide a safe method of harvesting palm fruits. For this machine system development, the material for each component of the machine system was first selected, the boom length, maximum boom angle, force and stroke length of each hydraulic cylinder, the hydraulic pump pressure, base weight, permissible weight of the cutting system and power required were then calculated in the design analysis. Furthermore, from the calculated parameters, the model of the system was created using SolidWorks engineering software, the model was developed and tested. The result shows that the cutting time of the system for one bunch of palm fruit was longer when compared to conventional systems. It was concluded that though the machine is maintenance friendly and portable, further improvements in its design are necessary so as to develop a system that will give desirable economic output at a shorter time.展开更多
根据选定的升降桅杆整体结构形式和碳管的铺层方案,通过有限元计算,对18 m CFRP升降桅杆进行了抗风模拟分析。模拟计算结果显示,对碳纤管组装成的18 m CFRP升降桅杆,在28 m/s风载荷情况下,级杆铺层为0/90/+45/-45的桅杆,其整体应力、局...根据选定的升降桅杆整体结构形式和碳管的铺层方案,通过有限元计算,对18 m CFRP升降桅杆进行了抗风模拟分析。模拟计算结果显示,对碳纤管组装成的18 m CFRP升降桅杆,在28 m/s风载荷情况下,级杆铺层为0/90/+45/-45的桅杆,其整体应力、局部应力和整体变形均小于级杆铺层为0/90的桅杆;通过对18 m CFRP升降桅杆两种方案在0°方向最大应力、90°方向最大应力、剪切最大应力、最大变形和级杆蔡-希尔强度校核值的分析和比较,证明了级杆铺层为0/90/+45/-45桅杆的合理性。展开更多
基金Supported by National Key R&D Program of China (Grant No.2018YFB1304600)National Natural Science Foundation of China (Grant No.51905527)+1 种基金CAS Interdisciplinary Innovation Team of China (Grant No.JCTD-2018-11)State Key Laboratory of Robotics Foundation of China (Grant No.Y91Z0303)。
文摘Large-scale solar sails can provide power to spacecraft for deep space exploration.A new type of telescopic tubular mast(TTM)driven by a bistable carbon fiber-reinforced polymer tube was designed in this study to solve the problem of contact between the sail membrane and the spacecraft under light pressure.Compared with the traditional TTM,it has a small size,light weight,high extension ratio,and simple structure.The anti-blossoming and self-unlocking structure of the proposed TTM was described.We aimed to simplify the TTM with a complex structure into a beam model with equal linear mass density,and the simulation results showed good consistency.The dynamic equation was derived based on the equivalent model,and the effects of different factors on the vibration characteristics of the TTM were analyzed.The performance parameters were optimized based on a multiobjective genetic algorithm,and prototype production and load experiments were conducted.The results show that the advantages of the new TTM can complete the deployment of large-scale solar sails,which is valuable for future deep space exploration.
文摘This research paper presents a comprehensive conceptual design approach for the development of a telescopic machine system, which is portable and will provide a safe method of harvesting palm fruits. For this machine system development, the material for each component of the machine system was first selected, the boom length, maximum boom angle, force and stroke length of each hydraulic cylinder, the hydraulic pump pressure, base weight, permissible weight of the cutting system and power required were then calculated in the design analysis. Furthermore, from the calculated parameters, the model of the system was created using SolidWorks engineering software, the model was developed and tested. The result shows that the cutting time of the system for one bunch of palm fruit was longer when compared to conventional systems. It was concluded that though the machine is maintenance friendly and portable, further improvements in its design are necessary so as to develop a system that will give desirable economic output at a shorter time.
文摘根据选定的升降桅杆整体结构形式和碳管的铺层方案,通过有限元计算,对18 m CFRP升降桅杆进行了抗风模拟分析。模拟计算结果显示,对碳纤管组装成的18 m CFRP升降桅杆,在28 m/s风载荷情况下,级杆铺层为0/90/+45/-45的桅杆,其整体应力、局部应力和整体变形均小于级杆铺层为0/90的桅杆;通过对18 m CFRP升降桅杆两种方案在0°方向最大应力、90°方向最大应力、剪切最大应力、最大变形和级杆蔡-希尔强度校核值的分析和比较,证明了级杆铺层为0/90/+45/-45桅杆的合理性。
