This paper seeks to outline a novel three-layer model and a new birth-dteath element solution technique to evaluate static strength of notched metallic panel repaired with bonded com- posite patch and to optimize mate...This paper seeks to outline a novel three-layer model and a new birth-dteath element solution technique to evaluate static strength of notched metallic panel repaired with bonded com- posite patch and to optimize material parameters. The higher order 3D, 8-node isotropic solid ele- ment and 8-node anisotropic layered solid element with three degrees of freedom per node are respectively implemented to model substrate panel, adhesive layer and composite patch to establish three-layer model of repaired panel. The new solving technique based on birth-death element is developed to allow solution of the stress pattern of repaired panel for identifying failure mode. The new model and its solution are used to model failure mode and residual strength of repaired panel, and the obtained results have a good agreement with the experimental findings. Finally, the influences of material parameter of adhesive layer and composite patch on the residual strength of repaired panel are investigated for optimizing material properties to meet operational and envi- ronmental constraints.展开更多
Based on the finite element method, a numerical investigation into the bonded repair efficiency of cracked plates under in plane biaxial loadings is presented. The main considerations are: reduction in stress intensi...Based on the finite element method, a numerical investigation into the bonded repair efficiency of cracked plates under in plane biaxial loadings is presented. The main considerations are: reduction in stress intensity factor (SIF) at the crack tip, the maximum tensile stress in the composite patch and the maximum shear stress in the adhesive bond between the patch and the plate. Without the patch, a tensile or compressive stress parallel to the crack has no effect on the SIF at the crack tip. While with a composite patch, there exists coupling effect between the normal stress parallel to the crack and the SIF, and the coupling effect depends significantly on ply orientation of the patch and the biaxial stress ratio of the plate.展开更多
Developing the high biosafety,effective and wearable devices for fast wound healing is highly desired but remains a challenge.Here,we propose a“win–win co-operation”strategy to potentiate effective skin wound heali...Developing the high biosafety,effective and wearable devices for fast wound healing is highly desired but remains a challenge.Here,we propose a“win–win co-operation”strategy to potentiate effective skin wound healing at the wound site by constructing robust and ecofriendly composite patch under opto-electric stimulation.The wearable patch is composed of ionic gel doped with Ti3C2Tx(MXene),which possesses good photothermal response to kill the bacteria via effective inhibition of the expression of inflammatory factors,preventing wound infection.Importantly,the composite ionogel patch is capable of providing green and on-demand electrical stimulation for wound site,guiding cell migration and proliferation by improved bioenergy and expression up-regulation of growth factor.In mice wound models,the treatment group healed~31%more rapidly.Mechanistically,the wearable devices could enable visual and real-time supervising treatment effect due to their good transmittance.The proposed strategy would be promising for future clinical treatment of wound healing.展开更多
基金supported by the National Natural Science Foundation (No. 51075019)Aeronautical Science Foundation of China (No. 20095251024)
文摘This paper seeks to outline a novel three-layer model and a new birth-dteath element solution technique to evaluate static strength of notched metallic panel repaired with bonded com- posite patch and to optimize material parameters. The higher order 3D, 8-node isotropic solid ele- ment and 8-node anisotropic layered solid element with three degrees of freedom per node are respectively implemented to model substrate panel, adhesive layer and composite patch to establish three-layer model of repaired panel. The new solving technique based on birth-death element is developed to allow solution of the stress pattern of repaired panel for identifying failure mode. The new model and its solution are used to model failure mode and residual strength of repaired panel, and the obtained results have a good agreement with the experimental findings. Finally, the influences of material parameter of adhesive layer and composite patch on the residual strength of repaired panel are investigated for optimizing material properties to meet operational and envi- ronmental constraints.
文摘Based on the finite element method, a numerical investigation into the bonded repair efficiency of cracked plates under in plane biaxial loadings is presented. The main considerations are: reduction in stress intensity factor (SIF) at the crack tip, the maximum tensile stress in the composite patch and the maximum shear stress in the adhesive bond between the patch and the plate. Without the patch, a tensile or compressive stress parallel to the crack has no effect on the SIF at the crack tip. While with a composite patch, there exists coupling effect between the normal stress parallel to the crack and the SIF, and the coupling effect depends significantly on ply orientation of the patch and the biaxial stress ratio of the plate.
基金supported by the National Natural Science Foundation of China(grant No.22004117 and 21675146)Chinese Academy of Sciences for Special Research Assistant Grant.
文摘Developing the high biosafety,effective and wearable devices for fast wound healing is highly desired but remains a challenge.Here,we propose a“win–win co-operation”strategy to potentiate effective skin wound healing at the wound site by constructing robust and ecofriendly composite patch under opto-electric stimulation.The wearable patch is composed of ionic gel doped with Ti3C2Tx(MXene),which possesses good photothermal response to kill the bacteria via effective inhibition of the expression of inflammatory factors,preventing wound infection.Importantly,the composite ionogel patch is capable of providing green and on-demand electrical stimulation for wound site,guiding cell migration and proliferation by improved bioenergy and expression up-regulation of growth factor.In mice wound models,the treatment group healed~31%more rapidly.Mechanistically,the wearable devices could enable visual and real-time supervising treatment effect due to their good transmittance.The proposed strategy would be promising for future clinical treatment of wound healing.
