Study on mechanical properties of aeronautical composite material interference-fit structures in hygrothermal service

Abstract

Currently，the study on the influence of hygrothermal environment on composite material is more inclined to the material composition structure，rather than the composite connection. A numerical simulation model of composite interference-fit structure is established based on the mechanical ontological relationship and continuous damage model of composites under the hygrothermal environment with the object of composite interference-fit structure. The model is utilized to analyze the static strength and damage failure of interference-fit structures in the hygrothermal cycle of 0 days，30 days，60 days，90 days and 120 days respectively，and is validated with the hygrothermal aging experiment. The results show that the ultimate load of the composite interference-fit structure decreases by 3.33%，5.63%，8.83% and 10.81% respectively，as the hygrothermal cycling period increases from 0 days to 120 days；the hygrothermal environment causes the aging reaction within the matrix of composite opening，results in a rapid deterioration of the matrix performance，while has little effect on the fiber damage.

Keywords

• composite material
• interference-fit structure
• hygrothermal aging
• damage
• failure