一种低重力落塔实验平台及方法

本发明公开一种低重力落塔实验平台及方法，属于航天领域，用于模拟月球、火星等近地星球表面的低重力（分数重力）环境，主要包括轴系系统、可移动龙门架、实验落舱、现场控制台等。平台利用微重力落塔的实验通道，让实验落舱在自身重力的作用下反向施加恒阻尼制动下落。同时设计制造一种可变加速度控制调节装置，对实验落舱下落的加速度进行实时调节和反馈控制，在实验落舱内达到低重力实验条件。本发明能够为相关领域的科学家及科研人员提供相应的低重力实验环境

一种落塔实验落舱的质心快速调整方法

本发明公开一种落塔实验落舱的质心快速调整方法，属于航天领域。本发明利用单丝悬吊旋转测距法和基准面定位法相结合，快速调整实验落舱的质心位置，最终实现实验落舱的重力线与其结构中心线重合。本发明让实验落舱在微重力实验的自由落体过程中的姿态保持理想的最小偏移和旋转，从而保证实验落舱内的试验载荷处于理想的微重力环境

反应烧结Si_3 N_4陶瓷断裂韧性的实验研究

本文对反应烧结氦化硅 Si_3N_4陶瓷的断裂韧性进行实验研究,用三种不同试件进行了测试,这三种试件是:山形切口双悬臂粱试件,山形切口三点弯曲梁试件和直穿透切口三点弯曲梁试件.用有限元方法分析了直穿透切口三点弯曲梁切口宽度对应力强度因子的影响,结合断裂载荷测定值估算了材料的断裂韧性值,指出直切口无预制裂纹试件的测定值必须用有限元法进行修正才能得到正确结果

北京落塔：探索微重力科学前沿

在地球上研究物质运动的规律，不可避免地要遇到地球引力的问题，特别是当物质出现上下方向的运动时。例如，热的空气比冷的空气轻，它就必然向上飘。此外，地球上演化出现生命的现象，也不能排除地球引力的影响。微重力科学是研究物质/物体在失重环境下的行为和相互作用的学科，是现代科学技术前沿的重要领域。由于完全失重，即真正的零重力很难达到，通常就以带有微小残余重力的实验条件进行研究

Drop tower tests of Taiji-1 inertial sensor substitute

Taiji-1, which is the first technical verification satellite of China's Space Gravitational Wave Detection Program, was successfully launched on August 31, 2019. The mission aimed to investigate the key technologies used in space gravitational wave detection. The inertial sensor, which was one of the main payloads, measured the residual acceleration of the satellite, and verified the drag-free control technology. Its performance was crucial to the success of the Taiji-1 mission. To ensure its performance in orbit, the inertial sensor was fully evaluated prior to launch. Owing to the gravitational acceleration on the ground, it is impossible to verify all the properties of the inertial sensor in a routine laboratory. A feasible method to conduct such tests is to use a drop tower. To guarantee the safety of the inertial sensor, a substitute was used with similar structure and circuit design. A total of 20 falls in three groups were completed, a set of research methods was established, and the importance of conducting simulations before the drop tests was verified. For the first time, the switch of different circuit gains in a drop tower test has been achieved and the National Microgravity Laboratory of China (NMLC) drop tower's residual accelerations in three dimensions were measured. The results demonstrated that the microgravity level of the drop tower can reach about 58 mu g(0) in the fall direction and 13 mu g(0) along the horizontal axes