Rudder is an important part for the glider aircraft. In order to satisfy the long-time high-velocity for the near-space vehicle in the atmosphere, the light- weight, high-stiffness and high-strength all-composites rud...Rudder is an important part for the glider aircraft. In order to satisfy the long-time high-velocity for the near-space vehicle in the atmosphere, the light- weight, high-stiffness and high-strength all-composites rudderpost is required urgently to be prepared. The all-composites rudderpost can keep high rudder efficiency in the high temperature environment. Based on the technique require-ment of high-performance composites rudder, a 3D C/SiC rudderpost was manufactured by the CVI-CMC-SiC [1] processes. It was found during rudderpost testing that the high-temperature mechanical properties decreased and had large discretization. The analysis of the failure mechanisms was conducted by FTA method to recognize the failure modes and main reasons for rudderpost abnormal fracture and to reproduce the fracture phenomenon, which could guide production company to modify their preparation process control. Then the modified processes were proved to be validated. And the stability and reliability of the production performances were improved.展开更多
Two dimensions (2D) C/SiC laminated composites is the material with isotropic properties in laminated sheets, which is considered as a promising thermal skin for aircrafts. There are intense thermal flux and thermal i...Two dimensions (2D) C/SiC laminated composites is the material with isotropic properties in laminated sheets, which is considered as a promising thermal skin for aircrafts. There are intense thermal flux and thermal impact at the local interference region during the flight of the aircrafts. Therefore, mastering ablation and mechanical properties of 2D C/SiC laminated composite under extreme environments become the guild lines for the designs of the flight corridor and the aircraft security. This paper presents the experimental results of the ablation and thermal impact of C/SiC composites under different thermal environments (thermal flux ~5 MW/m2), which were carried out with the equipments of free-jets and conduct pipes. The effects on the ablation and mechanical properties of the C/SiC composites are studied, including gas pressure, thermal temperature, and the rates of temperature increasing and decreasing. The results show that the active oxidation and ablation behaviors of 2D C/SiC laminated composites under the thermal flux 5 MW/m2 consist with that of theoretical simulations. The critical failure conditions of 2D C/SiC laminated composite is also provided for the enveloping designs of the whole composites lightweight aircrafts.展开更多
文摘Rudder is an important part for the glider aircraft. In order to satisfy the long-time high-velocity for the near-space vehicle in the atmosphere, the light- weight, high-stiffness and high-strength all-composites rudderpost is required urgently to be prepared. The all-composites rudderpost can keep high rudder efficiency in the high temperature environment. Based on the technique require-ment of high-performance composites rudder, a 3D C/SiC rudderpost was manufactured by the CVI-CMC-SiC [1] processes. It was found during rudderpost testing that the high-temperature mechanical properties decreased and had large discretization. The analysis of the failure mechanisms was conducted by FTA method to recognize the failure modes and main reasons for rudderpost abnormal fracture and to reproduce the fracture phenomenon, which could guide production company to modify their preparation process control. Then the modified processes were proved to be validated. And the stability and reliability of the production performances were improved.
文摘Two dimensions (2D) C/SiC laminated composites is the material with isotropic properties in laminated sheets, which is considered as a promising thermal skin for aircrafts. There are intense thermal flux and thermal impact at the local interference region during the flight of the aircrafts. Therefore, mastering ablation and mechanical properties of 2D C/SiC laminated composite under extreme environments become the guild lines for the designs of the flight corridor and the aircraft security. This paper presents the experimental results of the ablation and thermal impact of C/SiC composites under different thermal environments (thermal flux ~5 MW/m2), which were carried out with the equipments of free-jets and conduct pipes. The effects on the ablation and mechanical properties of the C/SiC composites are studied, including gas pressure, thermal temperature, and the rates of temperature increasing and decreasing. The results show that the active oxidation and ablation behaviors of 2D C/SiC laminated composites under the thermal flux 5 MW/m2 consist with that of theoretical simulations. The critical failure conditions of 2D C/SiC laminated composite is also provided for the enveloping designs of the whole composites lightweight aircrafts.
