在微重力下缓慢侵入颗粒介质的机械行为
Taotao Hu1, Fan Guo1, He Zhang1
1Beijing Institute of Spacecraft System Engineering, China Academy of Space Technology (CAST), Beijing 100094, China. htt1926@163.com.
Soft matter
|October 13, 2025
概括
这项研究量化了小行星着陆器脚入侵微重力下的颗粒状土壤. 颗粒孔隙,滚动摩擦和弹性模量显著影响入侵阻力,为更安全的着陆器设计提供信息.
科学领域:
- 行星科学 行星科学
- 机器人工程 机器人工程 机器人工程
- 地质物理学 地质物理学
背景情况:
- 小行星着陆器任务需要可靠的脚和样本采集机制来进行表面操作.
- 了解微重力下颗粒物质的行为对于任务的成功至关重要.
- 之前的研究还没有完全量化颗粒性质对微重力中的抗入侵性能的影响.
研究的目的:
- 系统量化着陆器脚在微重力下进入颗粒床的恒定速度入侵行为.
- 识别和分析对入侵阻力的关键影响因素,特别是粒子物理参数.
- 开发一个理论框架来预测小行星着陆器设计的入侵阻力和边界效应.
主要方法:
- 使用离散元件方法 (DEM) 模拟来进行粒子物理参数的灵敏度分析.
- 在微重力条件下模拟了对颗粒床的恒定速度入侵测试.
- 建立了一个理论框架来预测入侵阻力,并定义边界效应的临界尺寸比.
主要成果:
- 粒子透度,滚动摩擦系数和弹性模量被确定为控制入侵阻力的主要因素.
- 降低孔隙性显著增加了入侵阻力,并诱导了剪带故障.
- 滚动摩擦的变化导致了实质性的力波动,而弹性模量增加加剧了阻力振荡.
结论:
- 该研究提供了关于在微重力下在颗粒状 regolith 中脚入侵的机制的关键见解.
- 已建立的理论框架和确定的关键参数使着陆器脚和采样机制的尺寸设计得以优化.
- 这些发现直接有助于减少小行星表面接触操作的任务风险.
相关概念视频
01:24Acceleration due to Gravity on Other Planets
4.9K
The gravitational acceleration of an object near the Earth's surface is called the acceleration due to gravity. It can be measured by conducting simple experiments on Earth. However, such an experiment is impossible to conduct on the surface of other planets.
Astronomical observations are thus used to measure the acceleration due to gravity on other planets. This can be determined by observing the effect of a planet's gravity on objects close to it. The crucial factor that helps in this...
Astronomical observations are thus used to measure the acceleration due to gravity on other planets. This can be determined by observing the effect of a planet's gravity on objects close to it. The crucial factor that helps in this...
4.9K
01:20Variation in Acceleration due to Gravity near the Earth's Surface
2.8K
An object's apparent weight is its weight measured by a spring balance at its location. It is different from its true weight, the force with which the Earth pulls it, because of the Earth's rotation. Mathematically, an object's apparent weight equals its true weight minus the centripetal force that keeps it in a circular motion along with the Earth's surface every 24 hours.
The difference between the true and apparent weights is proportional to the square of the Earth's...
The difference between the true and apparent weights is proportional to the square of the Earth's...
2.8K
01:03Rocket Propulsion in Gravitational Field - II
2.8K
A rocket's velocity in the presence of a gravitational field is decreased by the amount of force exerted by Earth's gravitational field, which opposes the motion of the rocket. If we consider thrust, that is, the force exerted on a rocket by the exhaust gases, then a rocket's thrust is greater in outer space than in the atmosphere or on a launch pad. In fact, gases are easier to expel in a vacuum.
A rocket's acceleration depends on three major factors, consistent with the...
A rocket's acceleration depends on three major factors, consistent with the...
2.8K
01:20Rocket Propulsion in Gravitational Field - I
3.3K
Rockets range in size from small fireworks that ordinary people use to the enormous Saturn V that once propelled massive payloads toward the Moon. The propulsion of all rockets, jet engines, deflating balloons, and even squids and octopuses are explained by the same physical principle: Newton's third law of motion. The matter is forcefully ejected from a system, producing an equal and opposite reaction on what remains.
The motion of a rocket in space changes its velocity (and hence its...
The motion of a rocket in space changes its velocity (and hence its...
3.3K
01:01Weightlessness
6.7K
When an object is dropped, it accelerates toward the center of the Earth. If the net external force on the object is its weight, it is said to be in free fall; that is, the only force acting on the object is gravity. Galileo was instrumental in showing that, in the absence of air resistance, all objects fall with the same acceleration g. However, when objects on the Earth fall downward, they are never truly in free fall, because there is always some upward resistance force from the air acting...
6.7K
01:17Frictional Forces on Screws
1.6K
Screws are characterized by a helical ridge known as a thread wrapped around a cylindrical shaft. They are commonly used as fasteners to hold objects together or to transmit power and motion in machines. One type of screw that is particularly useful for transmitting power is the square-threaded screw.
A jack with a square-threaded screw is a mechanical device used to lift heavy loads by applying a force at its handle. When the force is applied, the screw turns, raising the load. The screw can...
A jack with a square-threaded screw is a mechanical device used to lift heavy loads by applying a force at its handle. When the force is applied, the screw turns, raising the load. The screw can...
1.6K