Hygrothermal effects on mode II interlaminar fracture toughness of co-bonded and secondary bonded composites joints

Autor(es)

Mendonca Sales, Rita de Cassia ^{[1, 2]} ; Gomes Brito, Camila Belo ^[1] ; Alves Silveira, Nubia Nale ^[1] ; de Souza Sena, Jhonathan Louis ^[1] ; Arbelo, Mariano Andres ^[1] ; Donadon, Mauricio Vicente ^[1]

Afiliação do(s) autor(es)

^[1] Aeronaut Inst Technol, Dept Aeronaut, Sao Paulo - Brazil

^[2] Fac Tecnol Sao Jose dos Campos Prof Jessen Vidal, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Polymer Composites; v. 40, n. 8, p. 3220-3232, AUG 2019.
• Citações Web of Science: 0

Resumo

Adhesive joints are being more extensively applied in the aeronautical industry, allowing for better integration between the structural parts and overall lower weight if compared with joints made with fasteners and rivets. However, a further evaluation of these new technologies is needed, once their critical fracture toughness under different environmental conditions is still unknown and this value is essential for design and certification of aircraft manufactured with these materials. Thus, this work focuses on the mode II fracture toughness characterization of carbon fiber composite laminates joined by co-bonded (CB) and secondarily bonded (SB) techniques, using EA 9695 epoxy adhesive aged at different environmental conditions (room temperature ambient-RTA and elevated temperature wet-ETW). Dynamic mechanical analysis (DMA) was used to understand the effect of moisture absorption on the glass transition of materials and on the decreasing of Mode II fracture toughness after aging. The DMA results showed a reduction of 11% in T-g values for the G(IIc) values of ETW samples in comparison with specimens tested at RTA condition. Reductions about 92 and 94% in Mode II fracture toughnesses were obtained for CB and SB aged specimens, respectively when compared with the toughness values obtained for specimens tested at RTA. Further inspection of the fracture surfaces using scanning electron microscope proved that light fiber-tear fracture occurred at both RTA and ETW conditions for CB joints, while fracture was mainly light-fiber-tear at RTA condition, becoming mostly cohesive after aging for SB joints. POLYM. COMPOS., 40:3220-3232, 2019. (c) 2018 Society of Plastics Engineers (AU)

• Processo FAPESP: 15/16733-2 - Modelagem de Junções Coladas para Aplicações em Estruturas Aeronáuticas de Materiais Compósitos
• Beneficiário: Mariano Andrés Arbelo
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado