Accurate measurement of the interfacial shear strength between ice and solid surface has important reference significance for the design of anti-icing and de-icing functional surfaces.In this paper,a new method is pro...Accurate measurement of the interfacial shear strength between ice and solid surface has important reference significance for the design of anti-icing and de-icing functional surfaces.In this paper,a new method is proposed based on the shear lag model of a single fiber pulled out from matrix,in order to accurately determine the interfacial shear strength(ISS)between ice and metals.The maximum pull-out force at the initiation of interface debonding is well measured in the pull-out test of a metal fiber embedded in an ice matrix.A shear lag model similar to the pull-out test is established and a closed-form relation between the non-uniform interfacial shear stress and the pull-out force is achieved.When the pull-out force reaches its peak value,the ice/metal ISS can be consequently determined as the maximum interfacial shear stress.Such a method takes into account the stress concentration at the interface,which overcomes underestimation of ice/solid ISS based on the apparent strength in previous studies.The achieved ISS is proven to not only have good convergence,but also be independent of the size and embedded depth of metal fibers.Based on the present method,the enhancing effects of freezing temperature and surface roughness on the ice adhesion are further disclosed.The present research provides a simple and reliable approach to accurately calibrate the ice/solid ISS,which should be of important reference significance for the design and assessment of anti-icing functional surfaces.展开更多
Nanostructured electrodes with surface effect show a distinct advantage in prolonging the lifetime of lithium-ion(Li-ion)battery.In order to characterize the surface and chemical diffusion effects in a cylindrical nan...Nanostructured electrodes with surface effect show a distinct advantage in prolonging the lifetime of lithium-ion(Li-ion)battery.In order to characterize the surface and chemical diffusion effects in a cylindrical nanowire electrode,a new theoretical model is proposed based on a combination of the diffusion theory and a surface energy density-based elastic theory.With the reformulation of the stress boundary condition in terms of a surface-induced traction,the bulk surface energy density and surface relaxation parameter are introduced as two simple parameters characterizing the surface effect in nanowire electrodes,instead of the surface elastic constants always used in existing models.Closed-form solutions of the diffusion-induced elastic fields under potentiostatic operation are derived.It is found that the radial expansion and tensile stress in nanowire electrodes become smaller than the classical predictions without surface effect and decrease monotonically with a decreasing nanowire radius when the surface effect is considered.Such phenomena can be basically attributed to the action of surface-induced traction on the nanowire surface.These results demonstrate the convenience and effectiveness of the present model in predicting the chemo-mechanical behavior of nanowire electrodes,which should be of guidance value for the optimal design of durable electrodes.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12032004,12272043,12293000,and 12293002)。
文摘Accurate measurement of the interfacial shear strength between ice and solid surface has important reference significance for the design of anti-icing and de-icing functional surfaces.In this paper,a new method is proposed based on the shear lag model of a single fiber pulled out from matrix,in order to accurately determine the interfacial shear strength(ISS)between ice and metals.The maximum pull-out force at the initiation of interface debonding is well measured in the pull-out test of a metal fiber embedded in an ice matrix.A shear lag model similar to the pull-out test is established and a closed-form relation between the non-uniform interfacial shear stress and the pull-out force is achieved.When the pull-out force reaches its peak value,the ice/metal ISS can be consequently determined as the maximum interfacial shear stress.Such a method takes into account the stress concentration at the interface,which overcomes underestimation of ice/solid ISS based on the apparent strength in previous studies.The achieved ISS is proven to not only have good convergence,but also be independent of the size and embedded depth of metal fibers.Based on the present method,the enhancing effects of freezing temperature and surface roughness on the ice adhesion are further disclosed.The present research provides a simple and reliable approach to accurately calibrate the ice/solid ISS,which should be of important reference significance for the design and assessment of anti-icing functional surfaces.
基金This work was supported by the National Natural Science Foundation of China(Grants Nos.11532013,11872114,11772333)and the Project of State Key Laboratory of Explosion Science and Technology(Grants No.ZDKT17-02).
文摘Nanostructured electrodes with surface effect show a distinct advantage in prolonging the lifetime of lithium-ion(Li-ion)battery.In order to characterize the surface and chemical diffusion effects in a cylindrical nanowire electrode,a new theoretical model is proposed based on a combination of the diffusion theory and a surface energy density-based elastic theory.With the reformulation of the stress boundary condition in terms of a surface-induced traction,the bulk surface energy density and surface relaxation parameter are introduced as two simple parameters characterizing the surface effect in nanowire electrodes,instead of the surface elastic constants always used in existing models.Closed-form solutions of the diffusion-induced elastic fields under potentiostatic operation are derived.It is found that the radial expansion and tensile stress in nanowire electrodes become smaller than the classical predictions without surface effect and decrease monotonically with a decreasing nanowire radius when the surface effect is considered.Such phenomena can be basically attributed to the action of surface-induced traction on the nanowire surface.These results demonstrate the convenience and effectiveness of the present model in predicting the chemo-mechanical behavior of nanowire electrodes,which should be of guidance value for the optimal design of durable electrodes.
