A new stiffness degradation model for fatigue life prediction of GFRPs under random loading

• Published in: International journal of fatigue Vol. 119; pp. 220 - 228
• Main Authors: Suzuki, Takuya, Mahfuz, Hassan, Takanashi, Masahiro
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.02.2019; Elsevier BV
• Subjects: Amplitudes; Composites; Damage accumulation; Degradation; Density; Failure modes; Fatigue failure; Fatigue life; Fatigue modelling; Fatigue tests; Glass fiber reinforced plastics; Life prediction; Materials fatigue; Mathematical models; Methods; Ocean current turbine; Ocean currents; Polymers; Predictions; Random loading; Reinforced plastics; Stiffness; Stress ratio; Life prediction; Fatigue modelling; Composites; Random loading; Ocean current turbine
• ISSN: 0142-1123; 1879-3452
• DOI: 10.1016/j.ijfatigue.2018.09.021

[Display omitted] •A new phenomenological fatigue model based on stiffness degradation is proposed.•The model considers failure mode shift and change in the damage accumulation rate.•The load sequence effect is implemented in the proposed model.•The fatigue life of GFRP coupons under random ocean current loadings was predicted.•The model predicted fatigue life more accurate than the conventional methods. A new phenomenological fatigue model based on stiffness degradation is proposed for life prediction of glass fiber reinforced plastics (GFRPs) under random ocean current loading. The model used Weibull cumulative density function to account for a shift in failure modes and corresponding changes in the rate of damage accumulation. The effects of stress ratio and stress amplitude on the model parameters were characterized using the results from constant amplitude tests. The fatigue life of GFRP coupons under random ocean current loadings was predicted both by the proposed model and by the conventional life prediction methodologies using Palmgren-Miner’s rule. The prediction was more accurate than the conventional methods.