Coupled effects of hygrothermal degradation and fatigue damage of sheet molding compound (SMC) composite

• Published in: European journal of mechanics, A, Solids Vol. 109; p. 105480
• Main Authors: Abdessalem, Abir, Tamboura, Sahbi, Shirinbayan, Mohammadali, Laribi, Mohamed Amine, Ben Daly, Hachmi, Fitoussi, Joseph
• Format: Journal Article
• Language: English
• Published: Elsevier Masson SAS 01-01-2025
• Subjects: Aging; Damage; Fatigue life prediction; Hydrothermal degradation; SMC composite; Aging; Hydrothermal degradation; SMC composite; Damage; Fatigue life prediction
• ISSN: 0997-7538
• DOI: 10.1016/j.euromechsol.2024.105480

Industrial sheet molding compound (SMC) composite structures are susceptible to environmental degradation, primarily from moisture and temperature. Furthermore, these materials are subjected to fatigue loading. It is therefore necessary to generate Wohler curves for a range of service conditions, taking into account exposure time and temperature. Given the time-consuming nature of these preliminary characterizations, this paper presents an innovative approach to rapid fatigue life prediction using both monotonic and fatigue tests. The core concept of the proposed model is to establish an equation of state that correlates first-cycle macroscopic damage to fatigue life. By coupling this relationship with micromechanical modelling of quasi-static damage, we can rapidly determine SN curves for any considered aged state. The methodology also integrates the microstructure as an input, significantly reducing the need for extensive experimental characterization. A comparison between experimental and simulated Wöhler curves shows excellent agreement over different ageing conditions for SMC composites.
•This study introduces a novel approach to predict fatigue life of industrial SMC composites under environmental degradation.•This innovative model establishes an equation of state linking first-cycle macroscopic damage to fatigue life, combined with micromechanical modeling to rapidly determine S-N curves for various aged states.•This approach minimizes extensive experimental requirements by integrating microstructural data, showing strong alignment between experimental and simulated S-N curves across various aging conditions.