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A systematic calibration and validating method for lunar soil DEM model
Advances in Space Research ( IF 2.8 ) Pub Date : 2021-07-03 , DOI: 10.1016/j.asr.2021.06.050
Tianxi Liu 1 , Jun Zhou 1 , Lei Liang 1 , Zhengfeng Bai 2 , Yang Zhao 1
Affiliation  

Calibration and validating are very important to DEM models especially for lunar soil. A review of present lunar soil models, evolutions, calibrations and verifications was executed. The result showed that most scholars used trial-and-error method to calibrate the parameters, but did not sum up a calibration law; in terms of validating, most scholars only focused on the internal friction angle and cohesion, but did not care about the elastic–plastic performance and adaptation. In this study, a systematic method was established instead of single-methods specifically for the calibration and validating of lunar soil DEM models. This is a multi-step method based on triaxial compression test. First, the alterable constitutive law previously proposed by the authors was used, and the influence law of each parameter on the peak stress difference and the position of failure point was analyzed and summed up for calibration. Second, the stress–strain curve was adjusted to coincide highly with Scott's test curve using loose real lunar soil. Third, the internal friction angle and cohesion under both loose and dense conditions were compared with the optimal estimated values to verify the shear strength. Fourth, the elastic–plastic behavior under dense condition was compared with Scott’s test result to verify the adaptation of density. Finally, two application simulations were executed to verify the practicability. By referring the systematic method, the purpose of parameter calibration is more explicit, and the validation is more comprehensive.



中文翻译:

一种月球土壤DEM模型的系统标定与验证方法

校准和验证对于 DEM 模型非常重要,尤其是对于月球土壤。对目前的月球土壤模型、演变、校准和验证进行了审查。结果表明,大多数学者采用试错法进行参数标定,但没有总结出标定规律;在验证方面,大多数学者只关注内摩擦角和内聚力,而没有关注弹塑性性能和适应性。在这项研究中,建立了一种系统的方法,而不是单一的方法,专门用于月球土壤 DEM 模型的校准和验证。这是一种基于三轴压缩试验的多步骤方法。首先,使用了作者先前提出的可变构成法,并对各参数对峰值应力差和失效点位置的影响规律进行了分析总结,以进行标定。其次,使用松散的真实月球土壤调整应力-应变曲线以与斯科特的测试曲线高度一致。第三,将松散和密实条件下的内摩擦角和内聚力与最佳估计值进行比较,以验证剪切强度。第四,将致密条件下的弹塑性行为与 Scott 的测试结果进行比较,以验证密度的适应性。最后,进行了两次应用仿真以验证其实用性。参照系统方法,参数标定的目的更加明确,验证更加全面。使用松散的真实月球土壤调整应力-应变曲线以与斯科特的测试曲线高度一致。第三,将松散和密实条件下的内摩擦角和内聚力与最佳估计值进行比较,以验证剪切强度。第四,将致密条件下的弹塑性行为与 Scott 的测试结果进行比较,以验证密度的适应性。最后,进行了两次应用仿真以验证其实用性。参照系统方法,参数标定的目的更加明确,验证更加全面。使用松散的真实月球土壤调整应力-应变曲线以与斯科特的测试曲线高度一致。第三,将松散和密实条件下的内摩擦角和内聚力与最佳估计值进行比较,以验证剪切强度。第四,将致密条件下的弹塑性行为与 Scott 的测试结果进行比较,以验证密度的适应性。最后,进行了两次应用仿真以验证其实用性。参照系统方法,参数标定的目的更加明确,验证更加全面。将松散和密实条件下的内摩擦角和内聚力与最佳估计值进行比较,以验证剪切强度。第四,将致密条件下的弹塑性行为与 Scott 的测试结果进行比较,以验证密度的适应性。最后,进行了两次应用仿真以验证其实用性。参照系统方法,参数标定的目的更加明确,验证更加全面。将松散和密实条件下的内摩擦角和内聚力与最佳估计值进行比较,以验证剪切强度。第四,将致密条件下的弹塑性行为与 Scott 的测试结果进行比较,以验证密度的适应性。最后,进行了两次应用仿真以验证其实用性。参照系统方法,参数标定的目的更加明确,验证更加全面。

更新日期:2021-07-03
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