Effect of temperature on the mechanical and bonding properties of a carbon-reinforced bismaleimide

Abstract

For high temperature usage (200 °C and above) such as in certain supersonic aircraft structures, composites often used are either bismaleimides (BMI) or polyimides reinforced with carbon fibres. The composite used in this investigation was a carbon fabric 0/90° laminate of high-strength carbon fibres in a 2 × 2 twill weave impregnated with a BMI resin. To determine the mechanical behaviour of the BMI composite as a function of temperature, dynamic and static tests were preformed from −55 to +200 °C. The coefficient of thermal expansion (CTE) of the BMI composite was measured using strain gauges. Joint strength results are also presented to illustrate the importance of the through thickness strength of composites used in adhesive joints. The results show that the modulus and strength of the BMI composite suffer little variation from −55 to +200 °C and that it is important to take the CTE into account for the flexural modulus determination.