The dynamic model of a bistable laminated composite shell simply supported by four corners is further developed to investigate the resonance responses and chaotic behaviors.The existence of the 1:1 resonance relations...The dynamic model of a bistable laminated composite shell simply supported by four corners is further developed to investigate the resonance responses and chaotic behaviors.The existence of the 1:1 resonance relationship between two order vibration modes of the system is verified.The resonance response of this class of bistable structures in the dynamic snap-through mode is investigated,and the four-dimensional(4D)nonlinear modulation equations are derived based on the 1:1 internal resonance relationship by means of the multiple scales method.The Hopf bifurcation and instability interval of the amplitude frequency and force amplitude curves are analyzed.The discussion focuses on investigating the effects of key parameters,e.g.,excitation amplitude,damping coefficient,and detuning parameters,on the resonance responses.The numerical simulations show that the foundation excitation and the degree of coupling between the vibration modes exert a substantial effect on the chaotic dynamics of the system.Furthermore,the significant motions under particular excitation conditions are visualized by bifurcation diagrams,time histories,phase portraits,three-dimensional(3D)phase portraits,and Poincare maps.Finally,the vibration experiment is carried out to study the amplitude frequency responses and bifurcation characteristics for the bistable laminated composite shell,yielding results that are qualitatively consistent with the theoretical results.展开更多
Cavitation is a prevalent phenomenon within the domain of ship and ocean engineering,predominantly occurring in the tail flow fields of high-speed rotating propellers and on the surfaces of high-speed underwater vehic...Cavitation is a prevalent phenomenon within the domain of ship and ocean engineering,predominantly occurring in the tail flow fields of high-speed rotating propellers and on the surfaces of high-speed underwater vehicles.The re-entrant jet and compression wave resulting from the collapse of cavity vapour are pivotal factors contributing to cavity instability.Concurrently,these phenomena significantly modulate the evolution of cavitation flow.In this paper,numerical investigations into cloud cavitation over a Clark-Y hydrofoil were conducted,utilizing the Large Eddy Simulation(LES)turbulence model and the Volume of Fluid(VOF)method within the OpenFOAM framework.Comparative analysis of results obtained at different angles of attack is undertaken.A discernible augmentation in cavity thickness is observed concomitant with the escalation in attack angle,alongside a progressive intensification in pressure at the leading edge of the hydrofoil,contributing to the suction force.These results can serve as a fundamental point of reference for gaining a deeper comprehension of cloud cavitation dynamics.展开更多
Compared with teenage patients,adult patients generally show a slower rate of tooth movement and more pronounced alveolar bone loss during orthodontic treatment,indicating the maladaptation of alveolar bone homeostasi...Compared with teenage patients,adult patients generally show a slower rate of tooth movement and more pronounced alveolar bone loss during orthodontic treatment,indicating the maladaptation of alveolar bone homeostasis under orthodontic force.However,this phenomenon is not well-elucidated to date,leading to increased treatment difficulties and unsatisfactory treatment outcomes in adult orthodontics.Aiming to provide a comprehensive knowledge and further inspire insightful understanding towards this issue,this review summarizes the current evidence and underlying mechanisms.The age-related abatements in mechanosensing and mechanotransduction in adult cells and periodontal tissue may contribute to retarded and unbalanced bone metabolism,thus hindering alveolar bone reconstruction during orthodontic treatment.To this end,periodontal surgery,physical and chemical cues are being developed to reactivate or rejuvenate the aging periodontium and restore the dynamic equilibrium of orthodontic-mediated alveolar bone metabolism.We anticipate that this review will present a general overview of the role that aging plays in orthodontic alveolar bone metabolism and shed new light on the prospective ways out of the impasse.展开更多
In the present work,a state-based peridynamics with adaptive particle refinement is proposed to simulate water ice crater formation due to impact loads.A modified Drucker-Prager constitutive model was adopted to model...In the present work,a state-based peridynamics with adaptive particle refinement is proposed to simulate water ice crater formation due to impact loads.A modified Drucker-Prager constitutive model was adopted to model ice and was implemented in the state-based peridynamic equations to analyze the elastic-plastic deformation of ice.In simulations,we use the fracture toughness failure criterion in peridynamics to simulate the quasi-brittle failure of ice.An adaptive particle refinement method in peridynamics was proposed to improve computational efficiency.The results obtained using the peridynamic model were compared with the experiments in previous literatures.It was found that the peridynamic simulation results and the experiments matched well except for some minor differences discussed,and the state-based peridynamic model has shown the specific predictive capacity to capture the detailed crater features of the ice.展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.12293000,12293001,11988102,12172006,and 12202011)。
文摘The dynamic model of a bistable laminated composite shell simply supported by four corners is further developed to investigate the resonance responses and chaotic behaviors.The existence of the 1:1 resonance relationship between two order vibration modes of the system is verified.The resonance response of this class of bistable structures in the dynamic snap-through mode is investigated,and the four-dimensional(4D)nonlinear modulation equations are derived based on the 1:1 internal resonance relationship by means of the multiple scales method.The Hopf bifurcation and instability interval of the amplitude frequency and force amplitude curves are analyzed.The discussion focuses on investigating the effects of key parameters,e.g.,excitation amplitude,damping coefficient,and detuning parameters,on the resonance responses.The numerical simulations show that the foundation excitation and the degree of coupling between the vibration modes exert a substantial effect on the chaotic dynamics of the system.Furthermore,the significant motions under particular excitation conditions are visualized by bifurcation diagrams,time histories,phase portraits,three-dimensional(3D)phase portraits,and Poincare maps.Finally,the vibration experiment is carried out to study the amplitude frequency responses and bifurcation characteristics for the bistable laminated composite shell,yielding results that are qualitatively consistent with the theoretical results.
基金supported by the National Natural Science Foundation of China(Nos.12202011,12332014)China Postdoctoral Science Foundation(No.2022M710190).
文摘Cavitation is a prevalent phenomenon within the domain of ship and ocean engineering,predominantly occurring in the tail flow fields of high-speed rotating propellers and on the surfaces of high-speed underwater vehicles.The re-entrant jet and compression wave resulting from the collapse of cavity vapour are pivotal factors contributing to cavity instability.Concurrently,these phenomena significantly modulate the evolution of cavitation flow.In this paper,numerical investigations into cloud cavitation over a Clark-Y hydrofoil were conducted,utilizing the Large Eddy Simulation(LES)turbulence model and the Volume of Fluid(VOF)method within the OpenFOAM framework.Comparative analysis of results obtained at different angles of attack is undertaken.A discernible augmentation in cavity thickness is observed concomitant with the escalation in attack angle,alongside a progressive intensification in pressure at the leading edge of the hydrofoil,contributing to the suction force.These results can serve as a fundamental point of reference for gaining a deeper comprehension of cloud cavitation dynamics.
基金supported by grants from the National Key R&D Program of China(2021YFC2400403)the National Natural Science Foundation of China(82201017,51972005)+1 种基金the Young Elite Scientist Sponsorship Program by CAST(2022QNRC001)the China Postdoctoral Science Foundation(2022M710257).
文摘Compared with teenage patients,adult patients generally show a slower rate of tooth movement and more pronounced alveolar bone loss during orthodontic treatment,indicating the maladaptation of alveolar bone homeostasis under orthodontic force.However,this phenomenon is not well-elucidated to date,leading to increased treatment difficulties and unsatisfactory treatment outcomes in adult orthodontics.Aiming to provide a comprehensive knowledge and further inspire insightful understanding towards this issue,this review summarizes the current evidence and underlying mechanisms.The age-related abatements in mechanosensing and mechanotransduction in adult cells and periodontal tissue may contribute to retarded and unbalanced bone metabolism,thus hindering alveolar bone reconstruction during orthodontic treatment.To this end,periodontal surgery,physical and chemical cues are being developed to reactivate or rejuvenate the aging periodontium and restore the dynamic equilibrium of orthodontic-mediated alveolar bone metabolism.We anticipate that this review will present a general overview of the role that aging plays in orthodontic alveolar bone metabolism and shed new light on the prospective ways out of the impasse.
文摘In the present work,a state-based peridynamics with adaptive particle refinement is proposed to simulate water ice crater formation due to impact loads.A modified Drucker-Prager constitutive model was adopted to model ice and was implemented in the state-based peridynamic equations to analyze the elastic-plastic deformation of ice.In simulations,we use the fracture toughness failure criterion in peridynamics to simulate the quasi-brittle failure of ice.An adaptive particle refinement method in peridynamics was proposed to improve computational efficiency.The results obtained using the peridynamic model were compared with the experiments in previous literatures.It was found that the peridynamic simulation results and the experiments matched well except for some minor differences discussed,and the state-based peridynamic model has shown the specific predictive capacity to capture the detailed crater features of the ice.
