Thoracic reconstructions are essential surgical techniques used to replace severely damaged tissues and restore protection to internal organs.In recent years,advancements in additive manufacturing have enabled the pro...Thoracic reconstructions are essential surgical techniques used to replace severely damaged tissues and restore protection to internal organs.In recent years,advancements in additive manufacturing have enabled the production of thoracic implants with complex geometries,offering more versatile performance.In this study,we investigated a design based on a spring-like geometry manufactured by laser powder bed fusion(LPBF),as proposed in earlier research.The biomechanical behavior of this design was analyzed using various isolated semi-ring-rib models at different levels of the rib cage.This approach enabled a comprehensive examination,leading to the proposal of several implant configurations that were incorporated into a 3D rib cage model with chest wall defects,to simulate different chest wall reconstruction scenarios.The results revealed that the implant design was too rigid for the second rib level,which therefore was excluded from the proposed implant configurations.In chest wall reconstruction simulations,the maximum stresses observed in all prostheses did not exceed 38%of the implant material's yield stress in the most unfavorable case.Additionally,all the implants showed flexibility compatible with the physiological movements of the human thorax.展开更多
The vibration of underground or buried piping during construction and long-term operation causes secondary disasters,and becomes more complex when tubes are buried in cold regions.The interface between saturated froze...The vibration of underground or buried piping during construction and long-term operation causes secondary disasters,and becomes more complex when tubes are buried in cold regions.The interface between saturated frozen soil and lining is regarded as a thin spring-like layer whose thickness could be negligible.In this paper,the dynamic response of saturated frozen soil is studied in frequency domain by using the Helmholtz composition and Fourier transform to obtain analytical solutions of the radial and axial displacement,as well as expressions of the stiffness coefficient(Kr)and damping coefficient(Cr)of the spring-like interface.Numerical results indicate that Krand Crare related to physical properties of the lining and its surrounding soil,and the coefficients of the springlike model could be changed by adjusting lining parameters to improve structure stability under the same load conditions.Also,the viscoelastic contact surface of the spring-like model is considered to have less effect on the surrounding soil than that when the lining has complete contact with the soil under load.The degree of soil freezing significantly affects the axial and radial displacement of the soil when the interface between lining and unsaturated frozen soil is taken into consideration.展开更多
Heat dissipation is an important part of light-emitting diode(LED)filament research and has aroused constant concern.In this paper,we studied the thermal performance of flexible LED filament by numerical simulation an...Heat dissipation is an important part of light-emitting diode(LED)filament research and has aroused constant concern.In this paper,we studied the thermal performance of flexible LED filament by numerical simulation and through experiment.The heat dissipation characteristics of spring-like structure flexible LED filament were computed by finite volume method,and it was found that the chip junction temperature was closely related to the pitch and the bending radius.The effect of inclination angle of lighting LED filament was discussed because it is relevant to the spring-like structure flexible LED filament in geometry.The results demonstrated that the temperature of the filament increases as the inclination angle improves.展开更多
文摘Thoracic reconstructions are essential surgical techniques used to replace severely damaged tissues and restore protection to internal organs.In recent years,advancements in additive manufacturing have enabled the production of thoracic implants with complex geometries,offering more versatile performance.In this study,we investigated a design based on a spring-like geometry manufactured by laser powder bed fusion(LPBF),as proposed in earlier research.The biomechanical behavior of this design was analyzed using various isolated semi-ring-rib models at different levels of the rib cage.This approach enabled a comprehensive examination,leading to the proposal of several implant configurations that were incorporated into a 3D rib cage model with chest wall defects,to simulate different chest wall reconstruction scenarios.The results revealed that the implant design was too rigid for the second rib level,which therefore was excluded from the proposed implant configurations.In chest wall reconstruction simulations,the maximum stresses observed in all prostheses did not exceed 38%of the implant material's yield stress in the most unfavorable case.Additionally,all the implants showed flexibility compatible with the physiological movements of the human thorax.
基金supported by the National Natural Science Foundation of China(Grant No.51978039)the Fundamental Research Funds for the Central Universities(Grant No.2021YJS115)。
文摘The vibration of underground or buried piping during construction and long-term operation causes secondary disasters,and becomes more complex when tubes are buried in cold regions.The interface between saturated frozen soil and lining is regarded as a thin spring-like layer whose thickness could be negligible.In this paper,the dynamic response of saturated frozen soil is studied in frequency domain by using the Helmholtz composition and Fourier transform to obtain analytical solutions of the radial and axial displacement,as well as expressions of the stiffness coefficient(Kr)and damping coefficient(Cr)of the spring-like interface.Numerical results indicate that Krand Crare related to physical properties of the lining and its surrounding soil,and the coefficients of the springlike model could be changed by adjusting lining parameters to improve structure stability under the same load conditions.Also,the viscoelastic contact surface of the spring-like model is considered to have less effect on the surrounding soil than that when the lining has complete contact with the soil under load.The degree of soil freezing significantly affects the axial and radial displacement of the soil when the interface between lining and unsaturated frozen soil is taken into consideration.
基金Project supported by the National Natural Science Foundation of China(Grant No.51302171)Science and Technology Commission of Shanghai Municipality,China(Grant No.14500503300)+2 种基金Shanghai Municipal Alliance Program,China(Grant No.Lm201547)Shanghai Cooperative Project,China(Grant No.ShanghaiCXY-2013-61)Jiashan County Technology Program,China(Grant No.20141316)
文摘Heat dissipation is an important part of light-emitting diode(LED)filament research and has aroused constant concern.In this paper,we studied the thermal performance of flexible LED filament by numerical simulation and through experiment.The heat dissipation characteristics of spring-like structure flexible LED filament were computed by finite volume method,and it was found that the chip junction temperature was closely related to the pitch and the bending radius.The effect of inclination angle of lighting LED filament was discussed because it is relevant to the spring-like structure flexible LED filament in geometry.The results demonstrated that the temperature of the filament increases as the inclination angle improves.
