In this paper, the theorem of structure continual variation of truss structure in the analysis of structure reliability is derived, and it is used to generate limit state function automatically. We can avoid repeated ...In this paper, the theorem of structure continual variation of truss structure in the analysis of structure reliability is derived, and it is used to generate limit state function automatically. We can avoid repeated assembly of global stiffness matrix and repeated inverse operations of the matrix caused by constant changes of structure topology. A new criterion of degenerate of the structure into mechanism is introduced. The calculation examples are satisfactory.展开更多
Hinged booms are widely used in astrophysics missions;however,the trajectory and deployment velocity are difficult to control because they are usually driven by springs,which limits their application in narrow spaces....Hinged booms are widely used in astrophysics missions;however,the trajectory and deployment velocity are difficult to control because they are usually driven by springs,which limits their application in narrow spaces.Thus,a novel hinged boom is highly required to achieve motion controllability.Through an equivalent substitution between the cable drive loop and the binary link in topology,a type synthesis method for the cable-driven single-degree-of-freedom chain is proposed based on the single-open-chain(SOC)adding method.According to the configuration design,a novel cable-driven hinged boom is proposed,aiming to achieve boom synchronism.Then,to preload easily,a method that preload is applied and measured at the cable ends is adopted and the relationship between the initial preload and the target preload is deduced.By analyzing the distribution of cable tension,a new stiffness model is proposed thus a stiffness equation is obtained.Finally,the dynamic simulation analysis and zero-gravity deployment experiment of the hinged boom is carried out to verify its reliability.This research provides a new way for the type synthesis of cable-driven single-degree-of-freedom chain and a new model for analyzing cable-driven stiffness.Moreover,the novel cable-driven hinged boom obtained in this study can be well-applied in the field of aerospace.展开更多
Achievements are presented for truss models of RC structures developed in previous years: 1. Two constitutive models, biaxial and triaxial, are based on regular trusses, with bars obeying nonlinear uniaxial σ-ε laws...Achievements are presented for truss models of RC structures developed in previous years: 1. Two constitutive models, biaxial and triaxial, are based on regular trusses, with bars obeying nonlinear uniaxial σ-ε laws of material under simulation;both models have been compared with test results and show a dependence of Poisson ratio on curvature of σ-ε law. 2. A truss finite element has been used in the nonlinear static and dynamic analysis of plane RC frames;it has been compared with test results and describes, in a simple way, the formation of plastic hinges. 3. Thanks to the very simple geometry of a truss, the equilibrium equations can be easily written and the stiffness matrix can be easily updated, both with respect to the deformed truss, within each step of a static incremental loading or within each time step of a dynamic analysis, so that to take into account geometric nonlinearities. So the confinement of a RC column is interpreted as a structural stability effect of concrete. And a significant role of the transverse reinforcement is revealed, that of preventing, by its close spacing and sufficient amount, the buckling of inner longitudinal concrete struts, which would lead to a global instability of the RC column. 4. The proposed truss model is statically indeterminate, so it exhibits some features, which are not met by the “strut-and-tie” model.展开更多
The recycling of spent lithium-ion batteries in a scientific and efficient manner is expected to address resource scarcity and reduce environmental pollution.Currently,conventional direct regeneration methods are diff...The recycling of spent lithium-ion batteries in a scientific and efficient manner is expected to address resource scarcity and reduce environmental pollution.Currently,conventional direct regeneration methods are difficult to simultaneously repair the particles,crystal structure,and interface of spent Lithium cobalt oxide(LCO)in three dimensions.This work adopts a"disintegrate-mend"reshaping approach to construct a localized heterogeneous hinge structure,grain boundary gradient crystal phases,and uniform polycrystalline particles,thereby achieving a unique structure for regenerated LCO materials.This design overcomes the limitations of uneven degradation in spent LCO,enhances the three-dimensional electron shuttle behaviour of the regenerated material,suppresses the redox activity of lattice oxygen,and optimizes spin-orbital coupling effects.Consequently,the regenerated LCO material demonstrates exceptionally high discharge capacity,with an initial discharge specific capacity of 228.94 mAh g^(-1).Moreover,the soft-packed batteries demonstrate outstanding cycle stability,with capacity retentions of 95.94%after 500 cycles.展开更多
Based on the elastic foundation beam theory and the multi-floating-module hydrodynamic theory,a novel method is proposed to estimate the dynamic responses of VLFS(Very Large Floating Structure).In still water,a VLFS c...Based on the elastic foundation beam theory and the multi-floating-module hydrodynamic theory,a novel method is proposed to estimate the dynamic responses of VLFS(Very Large Floating Structure).In still water,a VLFS can be simplified as an elastic foundation beam model or a multi-floating-module model connected by elastic hinges.According to equivalent displacement of the two models in static analysis,the problem of rotation stiffness of elastic hinges can be solved.Then,based on the potential flow theory,the dynamic responding analysis of multi-floatingmodule model under wave loads can be computed in ANSYS-AQWA software.By assembling the time domain analysis results of each module,the dynamic responses of the VLFS can be obtained.Validation of the method is conducted through a series of comparison calculations,which mainly includes a continuous structure and a three-part structure connected by hinges in regular waves.The results of this paper method show a satisfactory agreement with the experiment and calculation data given in relative references.展开更多
Acute intermittent porphyria (AIP), an inherited disease of heme biosynthesis, is one of the most common type of the porphyrias. Reduced activity of the enzyme
文摘In this paper, the theorem of structure continual variation of truss structure in the analysis of structure reliability is derived, and it is used to generate limit state function automatically. We can avoid repeated assembly of global stiffness matrix and repeated inverse operations of the matrix caused by constant changes of structure topology. A new criterion of degenerate of the structure into mechanism is introduced. The calculation examples are satisfactory.
基金co-supported by the National Natural Science Foundation of China(No51775052)Beijing Natural Science Foundation(No.21C10109)+1 种基金Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment&Technology(No.FMZ202022)Beijing Municipal Key Laboratory of Space-ground Interconnection and Convergence of China。
文摘Hinged booms are widely used in astrophysics missions;however,the trajectory and deployment velocity are difficult to control because they are usually driven by springs,which limits their application in narrow spaces.Thus,a novel hinged boom is highly required to achieve motion controllability.Through an equivalent substitution between the cable drive loop and the binary link in topology,a type synthesis method for the cable-driven single-degree-of-freedom chain is proposed based on the single-open-chain(SOC)adding method.According to the configuration design,a novel cable-driven hinged boom is proposed,aiming to achieve boom synchronism.Then,to preload easily,a method that preload is applied and measured at the cable ends is adopted and the relationship between the initial preload and the target preload is deduced.By analyzing the distribution of cable tension,a new stiffness model is proposed thus a stiffness equation is obtained.Finally,the dynamic simulation analysis and zero-gravity deployment experiment of the hinged boom is carried out to verify its reliability.This research provides a new way for the type synthesis of cable-driven single-degree-of-freedom chain and a new model for analyzing cable-driven stiffness.Moreover,the novel cable-driven hinged boom obtained in this study can be well-applied in the field of aerospace.
文摘Achievements are presented for truss models of RC structures developed in previous years: 1. Two constitutive models, biaxial and triaxial, are based on regular trusses, with bars obeying nonlinear uniaxial σ-ε laws of material under simulation;both models have been compared with test results and show a dependence of Poisson ratio on curvature of σ-ε law. 2. A truss finite element has been used in the nonlinear static and dynamic analysis of plane RC frames;it has been compared with test results and describes, in a simple way, the formation of plastic hinges. 3. Thanks to the very simple geometry of a truss, the equilibrium equations can be easily written and the stiffness matrix can be easily updated, both with respect to the deformed truss, within each step of a static incremental loading or within each time step of a dynamic analysis, so that to take into account geometric nonlinearities. So the confinement of a RC column is interpreted as a structural stability effect of concrete. And a significant role of the transverse reinforcement is revealed, that of preventing, by its close spacing and sufficient amount, the buckling of inner longitudinal concrete struts, which would lead to a global instability of the RC column. 4. The proposed truss model is statically indeterminate, so it exhibits some features, which are not met by the “strut-and-tie” model.
基金The Yunnan Fundamental Research Projects(202501AW070007)the Yunnan Province Xingdian Talent Support Program(XDYC-QNRC2023-0092)the High-level Talent Introduction Scientific Research Start Project of KUST(20190015)are gratefully acknowledged-。
文摘The recycling of spent lithium-ion batteries in a scientific and efficient manner is expected to address resource scarcity and reduce environmental pollution.Currently,conventional direct regeneration methods are difficult to simultaneously repair the particles,crystal structure,and interface of spent Lithium cobalt oxide(LCO)in three dimensions.This work adopts a"disintegrate-mend"reshaping approach to construct a localized heterogeneous hinge structure,grain boundary gradient crystal phases,and uniform polycrystalline particles,thereby achieving a unique structure for regenerated LCO materials.This design overcomes the limitations of uneven degradation in spent LCO,enhances the three-dimensional electron shuttle behaviour of the regenerated material,suppresses the redox activity of lattice oxygen,and optimizes spin-orbital coupling effects.Consequently,the regenerated LCO material demonstrates exceptionally high discharge capacity,with an initial discharge specific capacity of 228.94 mAh g^(-1).Moreover,the soft-packed batteries demonstrate outstanding cycle stability,with capacity retentions of 95.94%after 500 cycles.
基金financially supported by the High-Tech Ship Research Projects sponsored by the Ministry of Industry and Information Technology of China(Grant No.[2019]357)China Postdoctoral Science Foundation(Grant No.2020M683755)。
文摘Based on the elastic foundation beam theory and the multi-floating-module hydrodynamic theory,a novel method is proposed to estimate the dynamic responses of VLFS(Very Large Floating Structure).In still water,a VLFS can be simplified as an elastic foundation beam model or a multi-floating-module model connected by elastic hinges.According to equivalent displacement of the two models in static analysis,the problem of rotation stiffness of elastic hinges can be solved.Then,based on the potential flow theory,the dynamic responding analysis of multi-floatingmodule model under wave loads can be computed in ANSYS-AQWA software.By assembling the time domain analysis results of each module,the dynamic responses of the VLFS can be obtained.Validation of the method is conducted through a series of comparison calculations,which mainly includes a continuous structure and a three-part structure connected by hinges in regular waves.The results of this paper method show a satisfactory agreement with the experiment and calculation data given in relative references.
文摘Acute intermittent porphyria (AIP), an inherited disease of heme biosynthesis, is one of the most common type of the porphyrias. Reduced activity of the enzyme
