Hygrothermal aging of polyimide matrix composite laminates

Hygrothermal Aging of Polyimide Matrix Composite Laminates

Two polyimide-matrix systems were subjected to a series of hygrothermal aging experiments at various temperatures and relative humidities. For each aging condition, we measured the microcracking fracture toughness as a function of aging time. The toughness decreased with time. The rate of decrease increased with temperature and relative humidity. All experimental results could be fit to a simpl...

The Effect of Hygrothermal Aging on the Microcracking Properties of of Some Carbon Fiber/Polyimide Laminates

When dry, quasi-isotropic, Avimid R © K polymer laminates were immersed in water at temperatures ranging from 35◦C to 95◦C, the water uptake initially had Fickian behavior, but later, after apparently reaching an equilibrium level of water saturation, showed a non-Fickian jump in uptake rate. Microscopy results showed that the secondary uptake process was caused by spontaneous formation of matr...

Environmental Effects on Mechanical Properties of Glass/Epoxy and Fiber Metal Laminates, Part I: Hygrothermal Aging

In this article, the effect of hygrothermal aging on mechanical properties of fiber metal laminates (FMLs) and E-glass/epoxy (GE) composites is investigated. First, FML and GE specimens were built using wet lay-up technique under vacuum pressure. Hygrothermal aging simulation was then carried out on both specimen types in distilled water at a constant temperature of 90 °C for 5 weeks. The resul...

Modeling of Hygrothermal Damage of Composite Materials

Composite materials have been used extensively in various applications, such as mechanical engineering, aerospace engineering, and aviation thanks to their interesting mechanical properties. However, a substantial drawback in the use of such composite materials is that they absorb a significant amount of moisture when exposed to severe hygrothermal conditions. This factor dramatically affects t...

Novel Thermoplastic Polyimide Composite Materials