摘要
着落器月面软着陆时,着陆地月面岩土体特性和初始着陆速度是影响着陆成败的关键。模拟月壤是登月工程模型试验的重要材料,其性质直接影响着落器着落反应。为更好地实现安全着落,文章对着陆试验所用模拟月壤进行了系统的力学特性测试,由于月面不存在液态水、月面土层密度随深度变化很大,采用干燥试样进行了系列三轴试验,研究了不同相对密度、不同剪切速率条件下模拟月壤的抗剪强度,得到了不同密实程度的模拟月壤的应力应变关系曲线、弹性模量、峰值和残余段的粘聚力和摩擦角,通过不同应变速率的剪切速率测试,得到了模拟月壤的剪切速率与各力学强度参数的关系。结果表明:模拟月壤具有应变软化特性,剪切速率越大模拟月壤的弹性模量越小;峰值段摩擦角42.8~59°、残余段摩擦角16.8~22.4°,剪切速率越大模拟月壤的摩擦角越小。
The characteristics of simulant lunar have direct influence on the landing response.To make better calculation of the landing process,more detailed mechanical characteristics tests of the simulant lunar soil in use are conducted.Taking into account of the absence of liquid water on the moon surface,the great difference of soil density in depth and the variation of landing velocity,triaxial tests of dry sample are conducted in this paper.Shear strength of the simulant lunar soil is investigated under different density,shearing rate.The stress strain curves,elastic modulus,peak value and residual section of the soil in different degree of compaction were obtained.The relationship between the shear rate and the mechanical parameters of the soil was obtained by the test of the shear rate of different strain rate.The experimental results show that the elastic modulus of soil is smaller and the friction angle is smaller,the smaller the shear rate is,the smaller the elastic modulus of the lunar soil is simulated.The friction angle of the soil in the peak period is 42.8 ~ 59°,the friction angle of the residual section is 16.8 ~22.4° and the shear rate is smaller.
引文
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