Mechanical characterization and fractographic study of the carbon/PEI composite under static and fatigue loading

Abstract

The fatigue life of carbon fiber reinforced thermoplastic matrix composites is of great interest for many engineering applications. This work evaluated the influence of poly(etherimide) (PEI) on the fatigue life of laminated thermoplastic composites reinforced with carbon fibers. The mechanical characterization of the carbon/PEI composites was performed by static loading (tensile test) and cyclic fatigue. Tensile strength obtained was used to calculate 5 stress levels for cyclic fatigue testing with R = 0.1 and 12 Hz for 85, 80, 70, 60, and 55%, being this last stress level found as the infinite life. These stress levels allowed plotting a well-described SN curve. Seeking to understand the fracture behavior of carbon/PEI composites, a fractographic study by scanning electron microscopy (SEM) was performed. SEM micrographs confirm the good quality of carbon/PEI laminate with good adhesion between fibers and matrix and also confirmed the nature of fatigue life showing in-plane fracture for high loads and explosive fracture for lower loads.

Keywords:

• Thermoplastic fatigue
• carbon/PEI composite
• fractography
• poly(etherimide)
• tensile test

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

The authors acknowledge the financial support received from the Brazilian Funding Institutions CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) (001), CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) (305123/2018-1; 307933/2021-0), and the Federal Government Program ‘Rota 2030’ linked to the “Development of Skills for Design and Manufacturing of Tooling for Composite Parts” n° 27194.03.03/2020.01-00 for the scholarship of G.F.M. Morgado. The authors also thank W. Kok and M. Koekenberg from Toray Innovation by Chemistry/Netherlands for providing the carbon/PEI laminates and Alltec Materiais Compostos/Brazil for supporting the preparation of specimens.