Study on the Compressive Strength of Carbon Fiber Reinforced Polymer Composites – A Lesson Learned from Composite Structure Design for Large Commercial Aircraft

Over the past 50 years, advanced Carbon Fiber Reinforced Polymer (CFRP) composites have become central to large commercial aircraft structures. The Boeing 787 and Airbus A350 are the first to feature composite wings and fuselages, marking significant milestones. However, recent developments in the Boeing 777-9 program suggest a shift away from this trend, partly due to CFRP's cost. Although high-performance CFRP composites are up to 30% lighter than aluminum alloys in tensile strength comparisons, their compressive strength limitations have hindered their overall structural performance. This paper reviews compressive strength based on the latest data and results from Toray and provides a comprehensive theoretical investigation into predicting CFRP compressive performance, with a focus on kinking band formation mechanisms. The study compares upper bound solutions from various theories with published data. The findings highlight that the compressive strength of high-performance CFRP composites is primarily determined by the stiffness and toughness of the resin assuming the elimination of bonding defects and fiber misalignments. To advance CFRP materials, enhancing the resin's nonlinear shear modulus should be prioritized. This is especially significant for China's C919 and C929 projects, which aim to replace imported CFRP with domestically sourced materials, advancing self-reliance in aerospace manufacturing.