Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent...Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent properties of natural layered rock masses.In this paper,soft-hard interbedded rock masses with different dip angles were prepared based on 3D printing(3DP)sand core technology.Uniaxial compression creep tests were conducted to investigate its anisotropic creep behavior based on digital imaging correlation(DIC)technology.The results show that the anisotropic creep behavior of the 3DP soft-hard interbedded rock mass is mainly affected by the dip angles of the weak interlayer when the stress is at low levels.As the stress level increases,the effect of creep stress on its creep anisotropy increases significantly,and the dip angle is no longer the main factor.The minimum value of the long-term strength and creep failure strength always appears in the weak interlayer within 30°–60°,which explains why the failure of the layered rock mass is controlled by the weak interlayer and generally emerges at 45°.The tests results are verified by comparing with theoretical and other published studies.The feasibility of the 3DP soft-hard interbedded rock mass provides broad prospects and application values for 3DP technology in future experimental research.展开更多
In this paper,the occurrence and development mechanism of strain on the cross-section during the wood drying is explored.Therefore,strain regularity on the cross-section of 50 mm thickness elm(Ulmus rubra)board at the...In this paper,the occurrence and development mechanism of strain on the cross-section during the wood drying is explored.Therefore,strain regularity on the cross-section of 50 mm thickness elm(Ulmus rubra)board at the temperature of 40℃and 80℃is detected via digital image correlation technology.Hence,the difference between tangential and radial strain at surface and core layers was denoted.The results showed that strain distribution in the width direction of the board is uneven.Moreover,a large drying shrinkage strain occurs at the near-core layer,while the maximum strain difference reaches 4.08%.Hence,the surface of the board is cracked along the thickness direction.The radial strain of the board is higher than the tangential strain in the early stage of drying,while these strains are reversed in the later stage of drying.The temperature is related to the difference between the tangential and radial strains of the elm board.These differences at the core layer are larger than those of the surface layer.The conducted research results provide a theoretical basis for process optimization.展开更多
基金the support of the National Natural Science Foundation of China(Grant Nos.42207199,52179113,42272333)Zhejiang Postdoctoral Scientific Research Project(Grant Nos.ZJ2022155,ZJ2022156)。
文摘Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent properties of natural layered rock masses.In this paper,soft-hard interbedded rock masses with different dip angles were prepared based on 3D printing(3DP)sand core technology.Uniaxial compression creep tests were conducted to investigate its anisotropic creep behavior based on digital imaging correlation(DIC)technology.The results show that the anisotropic creep behavior of the 3DP soft-hard interbedded rock mass is mainly affected by the dip angles of the weak interlayer when the stress is at low levels.As the stress level increases,the effect of creep stress on its creep anisotropy increases significantly,and the dip angle is no longer the main factor.The minimum value of the long-term strength and creep failure strength always appears in the weak interlayer within 30°–60°,which explains why the failure of the layered rock mass is controlled by the weak interlayer and generally emerges at 45°.The tests results are verified by comparing with theoretical and other published studies.The feasibility of the 3DP soft-hard interbedded rock mass provides broad prospects and application values for 3DP technology in future experimental research.
基金supported by the National Natural Science Foundation of China(No.31901242)Heilongjiang Science Foundation Project(No.LH2020C038)National Undergraduate Training Programs for Innovations(No.202110225074)。
文摘In this paper,the occurrence and development mechanism of strain on the cross-section during the wood drying is explored.Therefore,strain regularity on the cross-section of 50 mm thickness elm(Ulmus rubra)board at the temperature of 40℃and 80℃is detected via digital image correlation technology.Hence,the difference between tangential and radial strain at surface and core layers was denoted.The results showed that strain distribution in the width direction of the board is uneven.Moreover,a large drying shrinkage strain occurs at the near-core layer,while the maximum strain difference reaches 4.08%.Hence,the surface of the board is cracked along the thickness direction.The radial strain of the board is higher than the tangential strain in the early stage of drying,while these strains are reversed in the later stage of drying.The temperature is related to the difference between the tangential and radial strains of the elm board.These differences at the core layer are larger than those of the surface layer.The conducted research results provide a theoretical basis for process optimization.
