On the effect of environmental temperature on fracture fatigue entropy

Fracture behavior of carbon steel 1018 operating in low-temperature environments is investigated. Specifically, fully-reversed bending experimental tests are performed to examine the efficacy of applying the concept of Fracture Fatigue Entropy (FFE) for predicting fatigue life at different environmental temperatures. A large cooling chamber was constructed that houses the entire bending test rig and maintains the environmental temperature at the desired value down to-10 degrees C. It is shown that under conditions tested, fatigue life improves at lower operating temperatures. Results also reveal that FFE remains nearly constant and can be used for reliable prediction of fatigue life. Illustrative examples are provided to show the utility of the approach for prediction purposes.