Following the theory of linear piezoelectricity,we consider the electro-elastic prob- lems of a finite crack in a functionally gradient piezoelectric ceramic strip.By the use of Fourier transforms we reduce the proble...Following the theory of linear piezoelectricity,we consider the electro-elastic prob- lems of a finite crack in a functionally gradient piezoelectric ceramic strip.By the use of Fourier transforms we reduce the problem to solving two pairs of dual integral equations.The solution to the dual integral equations is then expressed in terms of a Fredholm integral equation of the second kind.Numerical calculations are carried out for piezoelectric ceramics.The electric field intensity factors and the energy release rate are shown graphically,and the electroelastic interactions are illustrated.展开更多
Dielectric elastomers(DE),renowned for their lightweight,rapid response,high energy density,and efficient conversion,have garnered significant attention in the realm of avian flight bionics.However,a lack of understan...Dielectric elastomers(DE),renowned for their lightweight,rapid response,high energy density,and efficient conversion,have garnered significant attention in the realm of avian flight bionics.However,a lack of understanding of the mechanical principles underlying flapping wing biomimetics has hindered accurate simulations of actual bird flight postures.To address this,a stiffness-variable DE-based wing(DEW)has been designed,inspired by the characteristics of seagulls,to mimic the wing deformations across different bird flight phases.The evolution of the DEW’s deformation is modeled based on the differential equation describing the bending curve of a DE cantilever beam.By applying different voltage cycles,three continuous avian flight postures have been replicated:takeoff,cruising,and hovering.The simulation results demonstrate that the stiffness-variable DEW effectively mimics the wing deformations observed in birds during different flight postures,closely resembling real-world flight conditions.This study has the potential to serve as an important reference for exploring changes in bird flight behavior,thereby advancing the application of DE materials in the field of soft robotics.展开更多
基金Project supported by the National Excellent Young Scholar Fund of China(Nos.10072041 and 10125209) the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of MOE of China.
文摘Following the theory of linear piezoelectricity,we consider the electro-elastic prob- lems of a finite crack in a functionally gradient piezoelectric ceramic strip.By the use of Fourier transforms we reduce the problem to solving two pairs of dual integral equations.The solution to the dual integral equations is then expressed in terms of a Fredholm integral equation of the second kind.Numerical calculations are carried out for piezoelectric ceramics.The electric field intensity factors and the energy release rate are shown graphically,and the electroelastic interactions are illustrated.
基金the financial support of the National Natural Science Foundation of China(Nos.12172206 and 11972218).
文摘Dielectric elastomers(DE),renowned for their lightweight,rapid response,high energy density,and efficient conversion,have garnered significant attention in the realm of avian flight bionics.However,a lack of understanding of the mechanical principles underlying flapping wing biomimetics has hindered accurate simulations of actual bird flight postures.To address this,a stiffness-variable DE-based wing(DEW)has been designed,inspired by the characteristics of seagulls,to mimic the wing deformations across different bird flight phases.The evolution of the DEW’s deformation is modeled based on the differential equation describing the bending curve of a DE cantilever beam.By applying different voltage cycles,three continuous avian flight postures have been replicated:takeoff,cruising,and hovering.The simulation results demonstrate that the stiffness-variable DEW effectively mimics the wing deformations observed in birds during different flight postures,closely resembling real-world flight conditions.This study has the potential to serve as an important reference for exploring changes in bird flight behavior,thereby advancing the application of DE materials in the field of soft robotics.
