Damage assessments in three dimensional (3D) textile composites subjected to mechanical loading can be performed by non-destructive and destructive techniques.This paper applies the two techniques to investigate the f...Damage assessments in three dimensional (3D) textile composites subjected to mechanical loading can be performed by non-destructive and destructive techniques.This paper applies the two techniques to investigate the fracture behavior of 3D tufted textile composites.X-ray computed tomography as a non-destructive evaluation method is appropriate to detect damage locations and identify their progression in 3D textile composites.Destructive methods such as sectioning toward observing damage provide valuable information about damage patterns.The results of this research could be utilized to evaluate the initial cause of rupture in 3D tufted composites used in aerospace structures and analyze fracture modes and damage progression.展开更多
We studied the characteristics of two-scale pore structure of preform in the deposition process and the mass transfer of reactant gas in dual-scale pores,and observed the physiochemical phenomenon associated with the ...We studied the characteristics of two-scale pore structure of preform in the deposition process and the mass transfer of reactant gas in dual-scale pores,and observed the physiochemical phenomenon associated with the reaction.Thereby,we established mathematical models on two scales,respectively,preform and reactor.These models were used for the numerical simulation of the process of ceramic matrix composites densified by isothermal chemical vapor infiltration (ICVI).The models were used to carry out a systematic study on the influence of process conditions and the preform structure on the densification behaviors.The most important findings of our study are that the processing time could be reduced by about 50% without compromising the quality of the material,if the processing temperature is 950-1000℃ for the first 70 hours and then raised to 1100℃.展开更多
文摘Damage assessments in three dimensional (3D) textile composites subjected to mechanical loading can be performed by non-destructive and destructive techniques.This paper applies the two techniques to investigate the fracture behavior of 3D tufted textile composites.X-ray computed tomography as a non-destructive evaluation method is appropriate to detect damage locations and identify their progression in 3D textile composites.Destructive methods such as sectioning toward observing damage provide valuable information about damage patterns.The results of this research could be utilized to evaluate the initial cause of rupture in 3D tufted composites used in aerospace structures and analyze fracture modes and damage progression.
基金the National Natural Science Foundation of China (No.51472092).
文摘We studied the characteristics of two-scale pore structure of preform in the deposition process and the mass transfer of reactant gas in dual-scale pores,and observed the physiochemical phenomenon associated with the reaction.Thereby,we established mathematical models on two scales,respectively,preform and reactor.These models were used for the numerical simulation of the process of ceramic matrix composites densified by isothermal chemical vapor infiltration (ICVI).The models were used to carry out a systematic study on the influence of process conditions and the preform structure on the densification behaviors.The most important findings of our study are that the processing time could be reduced by about 50% without compromising the quality of the material,if the processing temperature is 950-1000℃ for the first 70 hours and then raised to 1100℃.