Acquiring pristine deep lunar regolith cores with appropriate drilling tools is crucial for deciphering the lunar geological history.Conventional thick-walled drill bits are inherently limited in obtaining deep lunar ...Acquiring pristine deep lunar regolith cores with appropriate drilling tools is crucial for deciphering the lunar geological history.Conventional thick-walled drill bits are inherently limited in obtaining deep lunar regolith samples,whereas thin-walled coring bits offer a promising solution for lunar deep drilling.To support future lunar deep exploration missions,this study systematically investigates the failure mechanisms of lunar regolith induced by thin-walled drilling tools.Firstly,five thin-walled bit configurations were designed and evaluated based on drilling load,coring efficiency,and disturbance minimization,with Bit D demonstrating optimal overall performance.And the interaction mechanisms between differently configured coring bits and large-particle lunar regolith were elucidated.Coring experiments under critical drilling parameters revealed an operational window for the feed-to-rotation ratio(FRR of 2.0–2.5),effectively balancing drilling load and core recovery rate.Furthermore,a novel theoretical framework was developed to characterize dynamic drilling load parameters,supported by experimental validation.Based on these findings,practical strategies are proposed to mitigate drilling-induced disturbances,including parameter optimization and bit structural improvements.This research could provide valuable insights for designing advanced lunar deep drilling tools and developing drilling procedures.展开更多
Ground anchor drilling is a promising technology for investigating the mechanical properties and environmental variability of lunar regolith in low-gravity environments,with minimal demands for reactive cutting.This s...Ground anchor drilling is a promising technology for investigating the mechanical properties and environmental variability of lunar regolith in low-gravity environments,with minimal demands for reactive cutting.This study explores the interaction behavior during ground anchor drilling of lunar regolith by employing a coupled approach that integrates the Material Point Method(MPM)and the ContinuouseDiscontinuous Element Method(CDEM),considering the interactions among numerous particles and blocks.The numerical parameters are calibrated based on experimental penetration resistance data of lunar regolith simulant.The numerical approach effectively captures key mechanical properties of the simulant,such as particle flow and scattering patterns,anchor penetration effects,and disturbance-related ultimate bearing characteristics.Additionally,this study examines the influence of inter-particle friction and compactness on penetration resistance.By combining the Golden Section Search Method(GSSM)with ground anchor drilling simulations,an inverse analysis model for penetration resistance is developed,allowing for the determination of mechanical parameters of the lunar regolith simulant.The feasibility of this parameter inversion method is verified,providing valuable insights for engineering applications in lunar exploration and construction.展开更多
In this study,a new GVS(Ground Volcanic Scoria)lunar regolith simulant was produced.The similarity between GVS and lunar soil was proved by comparison with Apollo lunar soil samples and other commercial lunar soil sim...In this study,a new GVS(Ground Volcanic Scoria)lunar regolith simulant was produced.The similarity between GVS and lunar soil was proved by comparison with Apollo lunar soil samples and other commercial lunar soil simulants.Then,GVS lunar regolith simulant was investigated as the source material for preparing geopolymer to produce building material for lunar colony construction.To study the possibility of preparing geopolymer from GVS lunar regolith simulant and the optimum activator formulation as well as the optimum curing conditions,alkaline activated GVS slurries with different mixing ratios based on an orthogonal test scheme were prepared.The geopolymer products based on GVS were characterized by flexural strength test,compressive strength test,X-ray fluorescence(XRF),X-ray diffraction(XRD),Fourier Transform Infrared Spectroscopy(FTIR),Scanning Electron Microscope coupled with Energy Dispersive Spectroscopy(SEM-EDS),29Si magic angle spinning-nuclear magnetic resonance(29Si MAS-NMR),and 27Al MAS-NMR.The experimental results indicate that changes in the mass ratio of sodium hydroxide and GVS and curing temperature have the most significant influence on the flexural strength and compressive strength,respectively.The GVS-based geopolymer can obtain the highest 28-day compressive strength and 28-day flexural strength up to 75.6 MPa and 6.3 MPa.Microstructural results imply that the changes of Si occurring in a variety of environments that explaining preliminarily about the reaction mechanism of GVS-based geopolymer.This study approves the feasibility of making a geopolymer derived from the GVS lunar regolith simulant and the potential utilization of geopolymer based on lunar regolith for construction of the lunar colony in future space exploration.展开更多
Establishing a base on the Moon is one of the new goals of human lunar exploration in recent years.Sintered lunar regolith is one of the most potential building materials for lunar bases.The physical,mechanical and th...Establishing a base on the Moon is one of the new goals of human lunar exploration in recent years.Sintered lunar regolith is one of the most potential building materials for lunar bases.The physical,mechanical and thermal properties of sintered lunar regolith are vital performance indices for the structural design of a lunar base and analysis of many critical mechanical and thermal issues.In this study,the HUST-1 lunar regolith simulant(HLRS)was sintered at 1030,1040,1050,1060,1070,and 1080℃.The effect of sintering temperature on the compressive strength was investigated,and the exact value of the optimum vacuum sintering temperature was determined between 1040 and 1060℃.Then,the microstructure and material composition of vacuum sintered HLRS at different temperatures were characterized.It was found that the sintering temperature has no significant effect on the mineral composition in the temperature range of 1030-1080℃.Besides,the heat capacity,thermal conductivity,and coefficient of thermal expansion(CTE)of vacuum sintered HLRS at different temperatures were investigated.Specific heat capacity of sintered samples increases with the increase of test temperature within the temperature range from-75 to 145℃.Besides,the thermal conductivity of the sintered sample is proportional to density.Finally,the two temperatures of 1040 and 1050℃were selected for a more detailed study of mechanical properties.The results showed that compressive strength of sintered sample is much higher than tensile strength.This study reveals the effects of sintering temperature on the physical,mechanical and thermal properties of vacuum sintered HLRS,and these material parameters will provide support for the construction of future lunar bases.展开更多
The dielectric constant of the lunar regolith can directly influence the reflection coefficient and the trans-mission coefficient of the Moon′s surface, and plays an important role in the Moon research. In order to s...The dielectric constant of the lunar regolith can directly influence the reflection coefficient and the trans-mission coefficient of the Moon′s surface, and plays an important role in the Moon research. In order to study the di-electric properties of the lunar regolith, the lunar regolith simulant was made according to the making procedure of the CAS-1 simulant made by Chinese Academy of Sciences. Then the dielectric constants of the lunar regolith simulant were measured with 85070E Aiglent Microwave Network Analyzer in the frequency ranging from 0.2 GHz to 20.0 GHz and at temperature of 25.1℃, 17.7℃, 13.1℃, 11.5℃, 9.6℃, 8.0℃, 4.1℃, -0.3℃, -4.7℃, -9.5℃, -18.7℃, -27.7℃, and -32.6℃, respectively. The Odelevsky model was employed to remove the influence of water in the air on the final effective dielectric constants. The results indicate that frequency and temperature have apparent influences on the dielectric constants of the lunar regolith simulant. The real parts of the dielectric constants increase fast over the range of 0.2 GHz to 3.0 GHz, but decrease slowly over the range of 4.0 GHz to 20.0 GHz. The opposite phenomenon occurs in the imaginary parts. The influences of the frequency and temperature on the brightness temperature were also estimated based on the radiative transfer equation. The result shows that the variation of the frequency and temperature results in great changes of the microwave brightness temperature emitting from the lunar regolith.展开更多
Drilling and coring, as effective ways to obtain lunar regolith along the longitudinal direction, are widely applied in the lunar sampling field. Conventionally, modeling of drill-soil interaction was divided into soi...Drilling and coring, as effective ways to obtain lunar regolith along the longitudinal direction, are widely applied in the lunar sampling field. Conventionally, modeling of drill-soil interaction was divided into soil cutting and screw conveyance processes, ignoring the differences in soil mechanical properties between them. To improve the modeling accuracy, a hypothesis that divides the drill-soil interaction into four parts: cuttings screw conveyance, cuttings extruding, cuttings bulldozing, and in situ simulant cutting, is proposed to establish a novel model based on the passive earth pressure theory. An iterative numerical calculation method is developed to predict the drilling loads. A drilling and coring testbed is developed to conduct experimental tests. Drilling experiments indicate that the drilling loads calculated by the proposed model match well the experimental results. The proposed research provides the instructions to adopt a suitable drilling strategy to match the rotary and penetrating motions, to increase the safety and reliability of drilling control in lunar sampling missions.展开更多
The authors apologize for the erroneous transcription of the average chemical composition data of Apollo lunar soil samples in Table 4.The difference in chemical composition between lunar regolith simulants and actual...The authors apologize for the erroneous transcription of the average chemical composition data of Apollo lunar soil samples in Table 4.The difference in chemical composition between lunar regolith simulants and actual lunar samples is an important indicator for evaluating their similarity.For comparison,Table 4 lists the chemical compositions of Apollo 12,Apollo 14,Apollo 15,Apollo 16,and other classic lunar regolith simulants.However,the Apollo lunar soil data in the original Table 4 contained errors,which have been corrected in this corrigendum.展开更多
Dense building components can be fabricated using lunar regolith simulants prepared via microwave sintering.In this study,the microstructure and properties of such simulants containing high(14.72%),medium(6.71%),and l...Dense building components can be fabricated using lunar regolith simulants prepared via microwave sintering.In this study,the microstructure and properties of such simulants containing high(14.72%),medium(6.71%),and low(1.7%)TiO_(2)contents prepared via microwave sintering at different temperatures(1030℃-1070℃)were studied.The sample sintered at 1060℃ with 14.72%TiO_(2)content exhibited the highest compressive strength of(125.2±22)MPa.This was because high TiO_(2)content was more conducive to densification due to microwave sintering.The influence of TiO_(2)content and sintering temperature on the strength of microwave-sintered samples was statistically analyzed,which revealed that sintering temperature was the main influencing factor(F value=187.3)and TiO_(2)content was the auxiliary influencing factor(F value=4.91).Using an enhanced multilayer perceptron model,a continuous surface diagram and prediction model were developed.These were then used to determine the influence of sintering temperature and TiO_(2)content on the compressive strength as well as to predict compressive strength with comparable accuracy.This study provides insights into microwave sintering of materials for future lunar construction.展开更多
Some type of penetration into a subsurface is required in planetary sampling. Drilling and coring, due to its efficient penetrating and cuttings removal characteristics, has been widely applied in previous sampling mi...Some type of penetration into a subsurface is required in planetary sampling. Drilling and coring, due to its efficient penetrating and cuttings removal characteristics, has been widely applied in previous sampling missions. Given the complicated mechanical properties of a planetary regolith, suitable drilling parameters should be matched with different drilling formations properly.Otherwise, drilling faults caused by overloads could easily happen. Hence, it is necessary to establish a drilling load model, which is able to reveal the relationships among drilling loads, an auger＇s structural parameters, soil＇s mechanical properties, and relevant drilling parameters. A concept for the filling rate of auger flute（FRAF） is proposed to describe drilling conditions. If the FRAF index under one group of drilling parameters is less than 1, this means that the auger flute currently removes cuttings smoothly. Otherwise, the auger will be choked with compressed cuttings. In drilling operations, the drilling loads on the auger mainly come from the conveyance action, while the drilling loads on the drill bit primarily come from the cutting action. Experiments in one typical lunar regolith simulant indicate that the estimated drilling loads based on the FRAF coincide with the test results quite well. Based on this drilling load model, drilling parameters have been optimized.展开更多
Low gravity fields have been simulated through magnetic acceleration to conduct experimental study on bearing capacity of circular footings on a type of crushable planetary regolith simulant,which has comparable densi...Low gravity fields have been simulated through magnetic acceleration to conduct experimental study on bearing capacity of circular footings on a type of crushable planetary regolith simulant,which has comparable density and particle size distribution of lunar soil.The loadesettlement responses of surface spread footings are obtained by investigating the relative density,footing size and gravity effects.Applying the hyperbolic asymptote method,normalised foundation stiffness and ultimate bearing capacity are obtained by curve fitting and predicted by power functions using multivariate nonlinear regression.The results show that the nonlinear gravity effect is not negligible,related to stress condition,soil dilatancy and mobilised friction angle.A cone penetration test(CPT)-based method for prediction of bearing capacity is proposed with correlations between ultimate bearing capacity of footings and shallow penetration stiffness of CPTs,avoiding the uncertainties of soil property estimations.Analyses of allowable bearing capacity and footing influence zone in consideration of footing size and gravity effects could therefore improve the design of shallow foundations on the Moon and Mars,and provide new understandings and potential implications to the bearing capacity of shallow foundations on crushable granular material in both terrestrial and extraterrestrial geotechnical engineering.展开更多
Over time,natural materials have evolved to be lightweight,high-strength,tough,and damage-tolerant due to their unique biological structures.Therefore,combining biological inspiration and structural design would provi...Over time,natural materials have evolved to be lightweight,high-strength,tough,and damage-tolerant due to their unique biological structures.Therefore,combining biological inspiration and structural design would provide traditional materials with a broader range of performance and applications.Here,the application of an ink-based three-dimensional(3D)printing strategy to the structural design of a Lunar regolith simulant-based geopolymer(HIT-LRS-1 GP)was first reported,and high-precision carbon fiber/quartz sand-reinforced biomimetic patterns inspired by the cellular sandwich structure of plant stems were fabricated.This study demonstrated how different cellular sandwich structures can balance the structure–property relationship and how to achieve unprecedented damage tolerance for a geopolymer composite.The results presented that components based on these biomimetic architectures exhibited stable non-catastrophic fracture characteristics regardless of the compression direction,and each structure possessed effective damage tolerance and anisotropy of mechanical properties.The results showed that the compressive strengths of honeycomb sandwich patterns,triangular sandwich patterns,wave sandwich patterns,and rectangular sandwich patterns in the Y-axis(Z-axis)direction were 15.6,17.9,11.3,and 20.1 MPa(46.7,26.5,23.8,and 34.4 MPa),respectively,and the maximum fracture strain corresponding to the above four structures could reach 10.2%,6.7%,5.8%,and 5.9%(12.1%,13.7%,13.6%,and 13.9%),respectively.展开更多
Using an in situ lunar regolith as a construction material in combination with 3D printing not only reduces the weight of materials carried from the Earth but also improves the automation of lunar infrastructure const...Using an in situ lunar regolith as a construction material in combination with 3D printing not only reduces the weight of materials carried from the Earth but also improves the automation of lunar infrastructure construction.This study aims to improve the printability of a geopolymer based on a BH-1 lunar regolith simulant,including the extrudability,open time,and buildability,by controlling the temperature and adding admixtures.Rheological parameters were used to represent printability with different water-to-binder ratios,printing temperatures,and contents of additives.The mechanical properties of the hardening geopolymer with different filling paths and loading directions were tested.The results show that heating the printed filaments with a water-to-binder ratio of 0.32 at 80°C can adjust the printability without adding any additive,which can reduce the construction cost of lunar infrastructure.The printability of the BH-1 geopolymer can also be improved by adding 0.3%Attagel-50 and 0.5%polypropylene fiber by mass at a temperature of 20℃to cope with the changeable environmental conditions on the Moon.After curing under a simulated lunar environment,the 72-h flexural and compressive strengths of the geopolymer specimens reach 4.1 and 48.1 MPa,respectively,which are promising considering that the acceleration of gravity on the Moon is 1/6 of that on the Earth.展开更多
One of the essential controls on the microwave thermal emissions(MTE) of the lunar regolith is the abundance of Fe O and TiO_2, known as the(Fe O+Ti O_2) abundance(FTA). In this paper, a radiative transfer simulation ...One of the essential controls on the microwave thermal emissions(MTE) of the lunar regolith is the abundance of Fe O and TiO_2, known as the(Fe O+Ti O_2) abundance(FTA). In this paper, a radiative transfer simulation is employed first to study the change in the brightness temperature(T_B) with FTA under a range of frequencies and surface temperatures. Then, we analyze the influence of FTA on the MTE of the lunar regolith using microwave sounder(CELMS) data from the Chang'E-2 lunar orbiter, Clementine UV-VIS data, and lunar samples recovered from the Apollo and Surveyor projects. We conclude that:(1) FTA strongly influences the MTE of the lunar regolith, but it is not the decisive control, and(2) FTA decreases slightly with depth. This research plays an essential role in appropriately inverting CELMS data to obtain lunar regolith parameters.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52225403,52434004,and 52404365)the National Key Research and Development Program of China(No.2023YFF0615404)the Scientific Instrument Developing Project of Shenzhen University.
文摘Acquiring pristine deep lunar regolith cores with appropriate drilling tools is crucial for deciphering the lunar geological history.Conventional thick-walled drill bits are inherently limited in obtaining deep lunar regolith samples,whereas thin-walled coring bits offer a promising solution for lunar deep drilling.To support future lunar deep exploration missions,this study systematically investigates the failure mechanisms of lunar regolith induced by thin-walled drilling tools.Firstly,five thin-walled bit configurations were designed and evaluated based on drilling load,coring efficiency,and disturbance minimization,with Bit D demonstrating optimal overall performance.And the interaction mechanisms between differently configured coring bits and large-particle lunar regolith were elucidated.Coring experiments under critical drilling parameters revealed an operational window for the feed-to-rotation ratio(FRR of 2.0–2.5),effectively balancing drilling load and core recovery rate.Furthermore,a novel theoretical framework was developed to characterize dynamic drilling load parameters,supported by experimental validation.Based on these findings,practical strategies are proposed to mitigate drilling-induced disturbances,including parameter optimization and bit structural improvements.This research could provide valuable insights for designing advanced lunar deep drilling tools and developing drilling procedures.
基金financial support from the National Natural Science Foundation of China(Grant Nos.52178324,12102059,and 12472207).
文摘Ground anchor drilling is a promising technology for investigating the mechanical properties and environmental variability of lunar regolith in low-gravity environments,with minimal demands for reactive cutting.This study explores the interaction behavior during ground anchor drilling of lunar regolith by employing a coupled approach that integrates the Material Point Method(MPM)and the ContinuouseDiscontinuous Element Method(CDEM),considering the interactions among numerous particles and blocks.The numerical parameters are calibrated based on experimental penetration resistance data of lunar regolith simulant.The numerical approach effectively captures key mechanical properties of the simulant,such as particle flow and scattering patterns,anchor penetration effects,and disturbance-related ultimate bearing characteristics.Additionally,this study examines the influence of inter-particle friction and compactness on penetration resistance.By combining the Golden Section Search Method(GSSM)with ground anchor drilling simulations,an inverse analysis model for penetration resistance is developed,allowing for the determination of mechanical parameters of the lunar regolith simulant.The feasibility of this parameter inversion method is verified,providing valuable insights for engineering applications in lunar exploration and construction.
基金supported by the National Natural Science Foundation of China(No.51978029,51622805)the Department of Transportation of Shandong Province of China(No.2018BZ4).
文摘In this study,a new GVS(Ground Volcanic Scoria)lunar regolith simulant was produced.The similarity between GVS and lunar soil was proved by comparison with Apollo lunar soil samples and other commercial lunar soil simulants.Then,GVS lunar regolith simulant was investigated as the source material for preparing geopolymer to produce building material for lunar colony construction.To study the possibility of preparing geopolymer from GVS lunar regolith simulant and the optimum activator formulation as well as the optimum curing conditions,alkaline activated GVS slurries with different mixing ratios based on an orthogonal test scheme were prepared.The geopolymer products based on GVS were characterized by flexural strength test,compressive strength test,X-ray fluorescence(XRF),X-ray diffraction(XRD),Fourier Transform Infrared Spectroscopy(FTIR),Scanning Electron Microscope coupled with Energy Dispersive Spectroscopy(SEM-EDS),29Si magic angle spinning-nuclear magnetic resonance(29Si MAS-NMR),and 27Al MAS-NMR.The experimental results indicate that changes in the mass ratio of sodium hydroxide and GVS and curing temperature have the most significant influence on the flexural strength and compressive strength,respectively.The GVS-based geopolymer can obtain the highest 28-day compressive strength and 28-day flexural strength up to 75.6 MPa and 6.3 MPa.Microstructural results imply that the changes of Si occurring in a variety of environments that explaining preliminarily about the reaction mechanism of GVS-based geopolymer.This study approves the feasibility of making a geopolymer derived from the GVS lunar regolith simulant and the potential utilization of geopolymer based on lunar regolith for construction of the lunar colony in future space exploration.
基金supported by the National Key Research and Development Program of China(Nos.2021YFF0500300 and 2023YFB3711300)the Strategic Research and Consulting Project of the Chinese Academy of Engineering(Nos.2023-XZ-90 and 2023-JB-09-10).
文摘Establishing a base on the Moon is one of the new goals of human lunar exploration in recent years.Sintered lunar regolith is one of the most potential building materials for lunar bases.The physical,mechanical and thermal properties of sintered lunar regolith are vital performance indices for the structural design of a lunar base and analysis of many critical mechanical and thermal issues.In this study,the HUST-1 lunar regolith simulant(HLRS)was sintered at 1030,1040,1050,1060,1070,and 1080℃.The effect of sintering temperature on the compressive strength was investigated,and the exact value of the optimum vacuum sintering temperature was determined between 1040 and 1060℃.Then,the microstructure and material composition of vacuum sintered HLRS at different temperatures were characterized.It was found that the sintering temperature has no significant effect on the mineral composition in the temperature range of 1030-1080℃.Besides,the heat capacity,thermal conductivity,and coefficient of thermal expansion(CTE)of vacuum sintered HLRS at different temperatures were investigated.Specific heat capacity of sintered samples increases with the increase of test temperature within the temperature range from-75 to 145℃.Besides,the thermal conductivity of the sintered sample is proportional to density.Finally,the two temperatures of 1040 and 1050℃were selected for a more detailed study of mechanical properties.The results showed that compressive strength of sintered sample is much higher than tensile strength.This study reveals the effects of sintering temperature on the physical,mechanical and thermal properties of vacuum sintered HLRS,and these material parameters will provide support for the construction of future lunar bases.
基金Under the auspices of National Natural Science Foundation of China (No. 40901159, 40901187)Doctoral Fund of Ministry of Education of China (No. 20090061120055)+1 种基金the Fundamental Research Funds for the Central Universities (No. 200903047)National High Technology Research and Development Program of China (No. 2010AA122203)
文摘The dielectric constant of the lunar regolith can directly influence the reflection coefficient and the trans-mission coefficient of the Moon′s surface, and plays an important role in the Moon research. In order to study the di-electric properties of the lunar regolith, the lunar regolith simulant was made according to the making procedure of the CAS-1 simulant made by Chinese Academy of Sciences. Then the dielectric constants of the lunar regolith simulant were measured with 85070E Aiglent Microwave Network Analyzer in the frequency ranging from 0.2 GHz to 20.0 GHz and at temperature of 25.1℃, 17.7℃, 13.1℃, 11.5℃, 9.6℃, 8.0℃, 4.1℃, -0.3℃, -4.7℃, -9.5℃, -18.7℃, -27.7℃, and -32.6℃, respectively. The Odelevsky model was employed to remove the influence of water in the air on the final effective dielectric constants. The results indicate that frequency and temperature have apparent influences on the dielectric constants of the lunar regolith simulant. The real parts of the dielectric constants increase fast over the range of 0.2 GHz to 3.0 GHz, but decrease slowly over the range of 4.0 GHz to 20.0 GHz. The opposite phenomenon occurs in the imaginary parts. The influences of the frequency and temperature on the brightness temperature were also estimated based on the radiative transfer equation. The result shows that the variation of the frequency and temperature results in great changes of the microwave brightness temperature emitting from the lunar regolith.
基金Supported by National Natural Science Foundation of China(Grant No.61403106)
文摘Drilling and coring, as effective ways to obtain lunar regolith along the longitudinal direction, are widely applied in the lunar sampling field. Conventionally, modeling of drill-soil interaction was divided into soil cutting and screw conveyance processes, ignoring the differences in soil mechanical properties between them. To improve the modeling accuracy, a hypothesis that divides the drill-soil interaction into four parts: cuttings screw conveyance, cuttings extruding, cuttings bulldozing, and in situ simulant cutting, is proposed to establish a novel model based on the passive earth pressure theory. An iterative numerical calculation method is developed to predict the drilling loads. A drilling and coring testbed is developed to conduct experimental tests. Drilling experiments indicate that the drilling loads calculated by the proposed model match well the experimental results. The proposed research provides the instructions to adopt a suitable drilling strategy to match the rotary and penetrating motions, to increase the safety and reliability of drilling control in lunar sampling missions.
文摘The authors apologize for the erroneous transcription of the average chemical composition data of Apollo lunar soil samples in Table 4.The difference in chemical composition between lunar regolith simulants and actual lunar samples is an important indicator for evaluating their similarity.For comparison,Table 4 lists the chemical compositions of Apollo 12,Apollo 14,Apollo 15,Apollo 16,and other classic lunar regolith simulants.However,the Apollo lunar soil data in the original Table 4 contained errors,which have been corrected in this corrigendum.
基金supported by the National Key Research and Development Program of China(Grant Nos.2023YFB3711300,2021YFF0500300)the Space Application System of China Manned Space Programthe Strategic Research and Consulting Project of the Chinese Academy of Engineering(Grant Nos.2023-XZ-90,2023-JB-09-10)。
文摘Dense building components can be fabricated using lunar regolith simulants prepared via microwave sintering.In this study,the microstructure and properties of such simulants containing high(14.72%),medium(6.71%),and low(1.7%)TiO_(2)contents prepared via microwave sintering at different temperatures(1030℃-1070℃)were studied.The sample sintered at 1060℃ with 14.72%TiO_(2)content exhibited the highest compressive strength of(125.2±22)MPa.This was because high TiO_(2)content was more conducive to densification due to microwave sintering.The influence of TiO_(2)content and sintering temperature on the strength of microwave-sintered samples was statistically analyzed,which revealed that sintering temperature was the main influencing factor(F value=187.3)and TiO_(2)content was the auxiliary influencing factor(F value=4.91).Using an enhanced multilayer perceptron model,a continuous surface diagram and prediction model were developed.These were then used to determine the influence of sintering temperature and TiO_(2)content on the compressive strength as well as to predict compressive strength with comparable accuracy.This study provides insights into microwave sintering of materials for future lunar construction.
基金supports by the National Natural Science Foundation of China (No. 61403106, No. 51575122)Program of Introducing Talents of Discipline to Universities (No. B07018) of ChinaFundamental Research Funds for the Central Universities (No. HIT.NSRIF.2014051) of China
文摘Some type of penetration into a subsurface is required in planetary sampling. Drilling and coring, due to its efficient penetrating and cuttings removal characteristics, has been widely applied in previous sampling missions. Given the complicated mechanical properties of a planetary regolith, suitable drilling parameters should be matched with different drilling formations properly.Otherwise, drilling faults caused by overloads could easily happen. Hence, it is necessary to establish a drilling load model, which is able to reveal the relationships among drilling loads, an auger＇s structural parameters, soil＇s mechanical properties, and relevant drilling parameters. A concept for the filling rate of auger flute（FRAF） is proposed to describe drilling conditions. If the FRAF index under one group of drilling parameters is less than 1, this means that the auger flute currently removes cuttings smoothly. Otherwise, the auger will be choked with compressed cuttings. In drilling operations, the drilling loads on the auger mainly come from the conveyance action, while the drilling loads on the drill bit primarily come from the cutting action. Experiments in one typical lunar regolith simulant indicate that the estimated drilling loads based on the FRAF coincide with the test results quite well. Based on this drilling load model, drilling parameters have been optimized.
基金The authors wish to thank the support from the‘Double Tops’Construction Independent Innovation Project of China University of Mining and Technology(Grant No.2018ZZCX04).
文摘Low gravity fields have been simulated through magnetic acceleration to conduct experimental study on bearing capacity of circular footings on a type of crushable planetary regolith simulant,which has comparable density and particle size distribution of lunar soil.The loadesettlement responses of surface spread footings are obtained by investigating the relative density,footing size and gravity effects.Applying the hyperbolic asymptote method,normalised foundation stiffness and ultimate bearing capacity are obtained by curve fitting and predicted by power functions using multivariate nonlinear regression.The results show that the nonlinear gravity effect is not negligible,related to stress condition,soil dilatancy and mobilised friction angle.A cone penetration test(CPT)-based method for prediction of bearing capacity is proposed with correlations between ultimate bearing capacity of footings and shallow penetration stiffness of CPTs,avoiding the uncertainties of soil property estimations.Analyses of allowable bearing capacity and footing influence zone in consideration of footing size and gravity effects could therefore improve the design of shallow foundations on the Moon and Mars,and provide new understandings and potential implications to the bearing capacity of shallow foundations on crushable granular material in both terrestrial and extraterrestrial geotechnical engineering.
基金support from the National Natural Science Foundation of China(Nos.52072090 and 51872063)the Heilongjiang Touyan Innovation Team Program and the Natural Science Foundation of Heilongjiang Province(No.YQ2019E002)the Advanced Talents Scientific Research Foundation of Shenzhen:Yu Zhou,and the Sichuan Provincial Science and Technology Program Project(No.21SYSX0170).
文摘Over time,natural materials have evolved to be lightweight,high-strength,tough,and damage-tolerant due to their unique biological structures.Therefore,combining biological inspiration and structural design would provide traditional materials with a broader range of performance and applications.Here,the application of an ink-based three-dimensional(3D)printing strategy to the structural design of a Lunar regolith simulant-based geopolymer(HIT-LRS-1 GP)was first reported,and high-precision carbon fiber/quartz sand-reinforced biomimetic patterns inspired by the cellular sandwich structure of plant stems were fabricated.This study demonstrated how different cellular sandwich structures can balance the structure–property relationship and how to achieve unprecedented damage tolerance for a geopolymer composite.The results presented that components based on these biomimetic architectures exhibited stable non-catastrophic fracture characteristics regardless of the compression direction,and each structure possessed effective damage tolerance and anisotropy of mechanical properties.The results showed that the compressive strengths of honeycomb sandwich patterns,triangular sandwich patterns,wave sandwich patterns,and rectangular sandwich patterns in the Y-axis(Z-axis)direction were 15.6,17.9,11.3,and 20.1 MPa(46.7,26.5,23.8,and 34.4 MPa),respectively,and the maximum fracture strain corresponding to the above four structures could reach 10.2%,6.7%,5.8%,and 5.9%(12.1%,13.7%,13.6%,and 13.9%),respectively.
基金supported by the National Natural Science Foundation of China(Grant Nos.42241128,51978029)Key Laboratory of Road and Traffic Engineering of the Ministry of Education,Tongji University(No.K202206)+1 种基金China Postdoctoral Science Foundation(No.2023M730174)Young Elite Scientist Sponsorship Program by Beijing Association for Science and Technology(No.BYESS2023418).
文摘Using an in situ lunar regolith as a construction material in combination with 3D printing not only reduces the weight of materials carried from the Earth but also improves the automation of lunar infrastructure construction.This study aims to improve the printability of a geopolymer based on a BH-1 lunar regolith simulant,including the extrudability,open time,and buildability,by controlling the temperature and adding admixtures.Rheological parameters were used to represent printability with different water-to-binder ratios,printing temperatures,and contents of additives.The mechanical properties of the hardening geopolymer with different filling paths and loading directions were tested.The results show that heating the printed filaments with a water-to-binder ratio of 0.32 at 80°C can adjust the printability without adding any additive,which can reduce the construction cost of lunar infrastructure.The printability of the BH-1 geopolymer can also be improved by adding 0.3%Attagel-50 and 0.5%polypropylene fiber by mass at a temperature of 20℃to cope with the changeable environmental conditions on the Moon.After curing under a simulated lunar environment,the 72-h flexural and compressive strengths of the geopolymer specimens reach 4.1 and 48.1 MPa,respectively,which are promising considering that the acceleration of gravity on the Moon is 1/6 of that on the Earth.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41371332 & 41590851)the Fundamental Research Funds for the Central Universities (Grant No. JCKY-QKJC23)the Science and Technology Development Fund of Macao (Grant No. 110/2014/A3)
文摘One of the essential controls on the microwave thermal emissions(MTE) of the lunar regolith is the abundance of Fe O and TiO_2, known as the(Fe O+Ti O_2) abundance(FTA). In this paper, a radiative transfer simulation is employed first to study the change in the brightness temperature(T_B) with FTA under a range of frequencies and surface temperatures. Then, we analyze the influence of FTA on the MTE of the lunar regolith using microwave sounder(CELMS) data from the Chang'E-2 lunar orbiter, Clementine UV-VIS data, and lunar samples recovered from the Apollo and Surveyor projects. We conclude that:(1) FTA strongly influences the MTE of the lunar regolith, but it is not the decisive control, and(2) FTA decreases slightly with depth. This research plays an essential role in appropriately inverting CELMS data to obtain lunar regolith parameters.
