The footpad structure of a deep space exploration lander is a critical system that makes the initial contact with the ground,and thereby plays a crucial role in determining the stability and energy absorption characte...The footpad structure of a deep space exploration lander is a critical system that makes the initial contact with the ground,and thereby plays a crucial role in determining the stability and energy absorption characteristics during the impact process.The conventional footpad is typically designed with an aluminum honeycomb structure that dissipates energy through plastic deformation.Nevertheless,its effectiveness in providing cushioning and energy absorption becomes significantly compromised when the structure is crushed,rendering it unusable for reusable landers in the future.This study presents a methodology for designing and evaluating structural energy absorption systems incorporating recoverable strain constraints of shape memory alloys(SMA).The topological configuration of the energy absorbing structure is derived using an equivalent static load method(ESL),and three lightweight footpad designs featuring honeycomb-like Ni-Ti shape memory alloys structures and having variable stiffness skins are proposed.To verify the accuracy of the numerical modelling,a honeycomb-like structure subjected to compression load is modeled and then compared with experimental results.Moreover,the influence of the configurations and thickness distribution of the proposed structures on their energy absorption performance is comprehensively evaluated using finite element simulations.The results demonstrate that the proposed design approach effectively regulates the strain threshold to maintain the SMA within the constraint of maximum recoverable strain,resulting in a structural energy absorption capacity of 362 J/kg with a crushing force efficiency greater than 63%.展开更多
Three kinds of possible structures of legged lander including monocoqe, semi-monocoqe and space frame are compared, and the lightest space frame structure is selected as the lander's structure. Then, a new lander ...Three kinds of possible structures of legged lander including monocoqe, semi-monocoqe and space frame are compared, and the lightest space frame structure is selected as the lander's structure. Then, a new lander with four-legged truss structure is proposed. In the premise of ensuring that the main and assistant structures of landing legs are not changed, six possible lander body structures of the new lander are put forward. Taking the section size of each component of lander as design variables, and taking the total mass of the structure as the objective function, the six structures are analyzed by using the software Altair. OptiStruct and the results show that the mass of the basic structure is the lightest, and it is selected as the final design scheme of lander due to its simple structure and convenient manufacture. The optimization on the selected lander structure is conducted, and the detailed results are presented.展开更多
采用TJ-1模拟月壤作为试验材料,通过静力触探、静载荷试验的对比分析,探讨适合月壤承载力计算的经验公式,以期为未来载人登月时宇航员和着陆器登陆可能涉及到有关月面承载能力的问题提供必要的参考。首先,使用近255 t TJ-1模拟月壤人工...采用TJ-1模拟月壤作为试验材料,通过静力触探、静载荷试验的对比分析,探讨适合月壤承载力计算的经验公式,以期为未来载人登月时宇航员和着陆器登陆可能涉及到有关月面承载能力的问题提供必要的参考。首先,使用近255 t TJ-1模拟月壤人工制备出13 m×12 m×1.2 m试验用地基,后在试验地基均匀布置6个静力触探测点和2个静载荷试验测点进行测试。针对太沙基承载力计算半经验公式以及规范和国内外学者提出的12个适合中密实砂土静力触探承载力计算的经验公式,对试验结果进行探讨。发现直接运用太沙基提出的半经验公式计算月壤承载力结果明显偏小,而由联合试验小组提出的经验公式s[R]36 P 76.6能够用来近似计算月壤地基承载力。计算结果表明,该经验公式在计算承载力时能够与静载荷试验值较好的吻合。展开更多
基金Supported by Fundamental Research Funds for the Central Universities of China(Grant No.2021JBM021)National Natural Science Foundation of China(Grant Nos.52202431,52172353).
文摘The footpad structure of a deep space exploration lander is a critical system that makes the initial contact with the ground,and thereby plays a crucial role in determining the stability and energy absorption characteristics during the impact process.The conventional footpad is typically designed with an aluminum honeycomb structure that dissipates energy through plastic deformation.Nevertheless,its effectiveness in providing cushioning and energy absorption becomes significantly compromised when the structure is crushed,rendering it unusable for reusable landers in the future.This study presents a methodology for designing and evaluating structural energy absorption systems incorporating recoverable strain constraints of shape memory alloys(SMA).The topological configuration of the energy absorbing structure is derived using an equivalent static load method(ESL),and three lightweight footpad designs featuring honeycomb-like Ni-Ti shape memory alloys structures and having variable stiffness skins are proposed.To verify the accuracy of the numerical modelling,a honeycomb-like structure subjected to compression load is modeled and then compared with experimental results.Moreover,the influence of the configurations and thickness distribution of the proposed structures on their energy absorption performance is comprehensively evaluated using finite element simulations.The results demonstrate that the proposed design approach effectively regulates the strain threshold to maintain the SMA within the constraint of maximum recoverable strain,resulting in a structural energy absorption capacity of 362 J/kg with a crushing force efficiency greater than 63%.
基金Sponsored by the Project on Absorption of Intellects by Institutions of Higher Education for Academic Disciplinary Innovations(Grant No. B07018)
文摘Three kinds of possible structures of legged lander including monocoqe, semi-monocoqe and space frame are compared, and the lightest space frame structure is selected as the lander's structure. Then, a new lander with four-legged truss structure is proposed. In the premise of ensuring that the main and assistant structures of landing legs are not changed, six possible lander body structures of the new lander are put forward. Taking the section size of each component of lander as design variables, and taking the total mass of the structure as the objective function, the six structures are analyzed by using the software Altair. OptiStruct and the results show that the mass of the basic structure is the lightest, and it is selected as the final design scheme of lander due to its simple structure and convenient manufacture. The optimization on the selected lander structure is conducted, and the detailed results are presented.
文摘采用TJ-1模拟月壤作为试验材料,通过静力触探、静载荷试验的对比分析,探讨适合月壤承载力计算的经验公式,以期为未来载人登月时宇航员和着陆器登陆可能涉及到有关月面承载能力的问题提供必要的参考。首先,使用近255 t TJ-1模拟月壤人工制备出13 m×12 m×1.2 m试验用地基,后在试验地基均匀布置6个静力触探测点和2个静载荷试验测点进行测试。针对太沙基承载力计算半经验公式以及规范和国内外学者提出的12个适合中密实砂土静力触探承载力计算的经验公式,对试验结果进行探讨。发现直接运用太沙基提出的半经验公式计算月壤承载力结果明显偏小,而由联合试验小组提出的经验公式s[R]36 P 76.6能够用来近似计算月壤地基承载力。计算结果表明,该经验公式在计算承载力时能够与静载荷试验值较好的吻合。
