A practical fatigue strain prediction model for normal and high-strength concrete under compression

Abstract

• A practical fatigue strain prediction model is presented. • The model depictes the strain development of concrete under compressive fatigue loading. • The model is based on a fatigue strain equation, a stress-strain model and a Wöhler curve. • The proposed model is accurate for normal and high-strength concrete. Fatigue-induced deterioration has played an important role in governing the reliability of modern concrete structures, such as wind turbines, highway pavements, and high-speed railway bridges. Although the fatigue of concrete gains increasing attention, a thorough understanding of its mechanism is still lacking, and an accurate model for the prediction of strain development under fatigue loading is required. This paper presents a practical model that is accurate in fatigue strain prediction for normal and high-strength concrete. In the proposed model, a visco-elastic–plastic fatigue strain equation is correlated to a well-established monotonic stress–strain model via assumed strain equivalences between concrete fatigue strain development and monotonic stress–strain behavior. The model has explicit closed-form equations and depends on four practical inputs [i.e., the cylinder compressive strength of concrete ( f cm ), the maximum stress level ( S max ), the minimum stress level ( S min ), and the frequency of fatigue loading ( f p )]. The performance of the proposed model is evaluated by comparing its predictions for normal and high-strength concrete with those made by seven existing models. The comparisons show that the proposed model has the lowest Mean Absolute Percentage Error ( MAPE ) and the highest Integral Absolute Error ( IAE ) among all models for both normal and high-strength concrete, suggesting high accuracy in fatigue strain prediction.