The relationship between paleogeographic pattern and sedimentary differentiation of evaporite-carbonate symbiotic system is examined based on logging,core and thin section data,by taking the sixth sub-member of fifth ...The relationship between paleogeographic pattern and sedimentary differentiation of evaporite-carbonate symbiotic system is examined based on logging,core and thin section data,by taking the sixth sub-member of fifth member of Ordovician Majiagou Formation(M56)in the central-eastern Ordos Basin as an example.(1)Seven sub-geomorphic units(Taolimiao west low,Taolimiao underwater high,Taolimiao east low,Hengshan high,East salt low,North slope and Southwest slope)developed in the study area.(2)The“three lows”from west to east developed dolomitic restricted lagoon,evaporite evaporative lagoon and salt evaporative lagoon sedimentary facies respectively,the"two highs"developed high-energy grain beach and microbial mound,and the north and south slopes developed dolomitic flats around land.(3)The paleogeographic pattern caused natural differentiation of replenishment seawater from the northwest Qilian sea,leading to the eccentric sedimentary differentiation of dolomite,evaporite and salt rock symbiotic system from west to east,which is different from the classic“bull's eye”and“tear drop”distribution patterns.(4)As the Middle Qilian block subducted and collided into the North China Plate,the far-end compression stress transferred,giving rise to the alternate highland and lowland in near north to south direction during the sedimentary period of M56 sub-member.(5)Taolimiao underwater high and Hengshan high developed favorable zones of microbial mounds and grain shoals in south to north strike in M56 sub-member,making them favorable exploration areas with great exploration potential in the future.展开更多
The interface has a significant influence on the macroscopic mechanical behaviors of composite materials,with interface cracking being a typical failure event.The ability to precisely describe the mechanical behavior ...The interface has a significant influence on the macroscopic mechanical behaviors of composite materials,with interface cracking being a typical failure event.The ability to precisely describe the mechanical behavior of the interface is critical for analyzing the failure of composite materials.Based on plasticity theory and damage mechanics,an elastic-plastic interface constitutive model is developed to simulate the irreversible plastic deformation at the interface under the cyclic loading condition.Furthermore,by incorporating a damage factor in scalar form,the model is able to simulate mixed loading forms(Modes I and II).The influence of interfacial strength and toughness on the overall mechanical properties of unidirectional fiber reinforced composites under transverse loading is studied with this model.The simulation results are consistent with the experimental data in the literature,demonstrating the model's effectiveness.The model can be used to simulate the mechanical behavior of composites with interfaces under cyclic loading,and it is helpful for understanding the plastic behavior and damage accumulation at the interfaces in the composites.展开更多
This paper presents an interval effective independence method for optimal sensor placement, which contains uncertain structural information. To overcome the lack of insufficient statistic description of uncertain para...This paper presents an interval effective independence method for optimal sensor placement, which contains uncertain structural information. To overcome the lack of insufficient statistic description of uncertain parameters, this paper treats uncertainties as non-probability intervals. Based on the iterative process of classical effective independence method, the proposed study considers the eliminating steps with uncertain cases. Therefore, this method with Fisher information matrix is extended to interval numbers, which could conform to actual engineering. As long as we know the bounds of uncertainties, the interval Fisher information matrix could be obtained conveniently by interval analysis technology. Moreover, due to the definition and calculation of the interval relationship, the possibilities of eliminating candidate sensors in each iterative process and the final layout of sensor placement are both presented in this paper. Finally, two numerical examples, including a five-storey shear structure and a truss structure are proposed respectively in this paper. Compared with Monte Carlo simulation, both of them can indicate the veracity of the interval effective independence method.展开更多
By using molecular dynamics simulations,we studied the ion irradiation induced damage in mechanically strained Cu nanowires and evaluated the effects of damage on the mechanical properties of nanowires.The stresses in...By using molecular dynamics simulations,we studied the ion irradiation induced damage in mechanically strained Cu nanowires and evaluated the effects of damage on the mechanical properties of nanowires.The stresses in the pre-strained nanowires can be released significantly by the dislocation emission from the cascade core when the strain is greater than 1%.In addition,comparison of the stress-strain relationships between the defect-free nanowire and the irradiated ones indicates that ion irradiation reduces the yield strength of the Cu nanowires,and both the yield stress and strain decrease with the increase of irradiation energy.The results are consistent with the microscopic mechanism of damage production by ion irradiation and provide quantitative information required for accessing the stability of nanomaterials subjected to mechanical loading and irradiation coupling effects.展开更多
基金Supported by the Fundamental Project of China National Petroleum Corporation(2021DJ0501).
文摘The relationship between paleogeographic pattern and sedimentary differentiation of evaporite-carbonate symbiotic system is examined based on logging,core and thin section data,by taking the sixth sub-member of fifth member of Ordovician Majiagou Formation(M56)in the central-eastern Ordos Basin as an example.(1)Seven sub-geomorphic units(Taolimiao west low,Taolimiao underwater high,Taolimiao east low,Hengshan high,East salt low,North slope and Southwest slope)developed in the study area.(2)The“three lows”from west to east developed dolomitic restricted lagoon,evaporite evaporative lagoon and salt evaporative lagoon sedimentary facies respectively,the"two highs"developed high-energy grain beach and microbial mound,and the north and south slopes developed dolomitic flats around land.(3)The paleogeographic pattern caused natural differentiation of replenishment seawater from the northwest Qilian sea,leading to the eccentric sedimentary differentiation of dolomite,evaporite and salt rock symbiotic system from west to east,which is different from the classic“bull's eye”and“tear drop”distribution patterns.(4)As the Middle Qilian block subducted and collided into the North China Plate,the far-end compression stress transferred,giving rise to the alternate highland and lowland in near north to south direction during the sedimentary period of M56 sub-member.(5)Taolimiao underwater high and Hengshan high developed favorable zones of microbial mounds and grain shoals in south to north strike in M56 sub-member,making them favorable exploration areas with great exploration potential in the future.
基金supported by the National Natural Science Foundation of China (Grant Nos.11972057,12272021,and 11972058)the National Science and Technology Major Project (Grant No.2017-VII-0003-0096)The support from Super Computing Center ScGrid/CNGrid of CAS。
文摘The interface has a significant influence on the macroscopic mechanical behaviors of composite materials,with interface cracking being a typical failure event.The ability to precisely describe the mechanical behavior of the interface is critical for analyzing the failure of composite materials.Based on plasticity theory and damage mechanics,an elastic-plastic interface constitutive model is developed to simulate the irreversible plastic deformation at the interface under the cyclic loading condition.Furthermore,by incorporating a damage factor in scalar form,the model is able to simulate mixed loading forms(Modes I and II).The influence of interfacial strength and toughness on the overall mechanical properties of unidirectional fiber reinforced composites under transverse loading is studied with this model.The simulation results are consistent with the experimental data in the literature,demonstrating the model's effectiveness.The model can be used to simulate the mechanical behavior of composites with interfaces under cyclic loading,and it is helpful for understanding the plastic behavior and damage accumulation at the interfaces in the composites.
基金supported by the National Natural Science Foundation of China(Grant No.11502278)
文摘This paper presents an interval effective independence method for optimal sensor placement, which contains uncertain structural information. To overcome the lack of insufficient statistic description of uncertain parameters, this paper treats uncertainties as non-probability intervals. Based on the iterative process of classical effective independence method, the proposed study considers the eliminating steps with uncertain cases. Therefore, this method with Fisher information matrix is extended to interval numbers, which could conform to actual engineering. As long as we know the bounds of uncertainties, the interval Fisher information matrix could be obtained conveniently by interval analysis technology. Moreover, due to the definition and calculation of the interval relationship, the possibilities of eliminating candidate sensors in each iterative process and the final layout of sensor placement are both presented in this paper. Finally, two numerical examples, including a five-storey shear structure and a truss structure are proposed respectively in this paper. Compared with Monte Carlo simulation, both of them can indicate the veracity of the interval effective independence method.
基金supported by the National Natural Sciences Foundation of China (Grant Nos. 11002011,10902111 and 10932001)Fundamental Research Funds for the Central Universities
文摘By using molecular dynamics simulations,we studied the ion irradiation induced damage in mechanically strained Cu nanowires and evaluated the effects of damage on the mechanical properties of nanowires.The stresses in the pre-strained nanowires can be released significantly by the dislocation emission from the cascade core when the strain is greater than 1%.In addition,comparison of the stress-strain relationships between the defect-free nanowire and the irradiated ones indicates that ion irradiation reduces the yield strength of the Cu nanowires,and both the yield stress and strain decrease with the increase of irradiation energy.The results are consistent with the microscopic mechanism of damage production by ion irradiation and provide quantitative information required for accessing the stability of nanomaterials subjected to mechanical loading and irradiation coupling effects.
